Dr. Klarin is a fellowship-trained vascular surgeon.
For each patient, he develops a comprehensive, compassionate care plan customized to individual needs. His goal is to help each patient achieve the best possible health and quality of life.
Dr. Klarin performs the full spectrum of diagnostic and treatment procedures for cardiovascular conditions. He treats carotid disease, peripheral artery disease, abdominal aortic aneurysm, venous thromboembolism, and other vascular diseases.
To help advance his field, Dr. Klarin has conducted research. The American Heart Association, Howard Hughes Medical Institute, and other organizations have provided grants to support his studies. He also has co-patented advances in predicting and scoring risk factors for cardiovascular disease and other conditions.
He has published extensively and co-authored more than 50 articles on new techniques and technology for diagnosing and treating cardiovascular disorders. His work has appeared in the Journal of Vascular Surgery, Circulation, JAMA, Nature Medicine, and other peer-reviewed journals.
He also has made many invited presentations to his peers. He has spoken at the Vascular Research Initiatives Conference presented by the Society for Vascular Surgery, the American Heart Association Scientific Sessions, and the annual meeting of the American Society for Human Genetics. Topics include risk factors for peripheral artery disease, the benefits of ultrasound screening for abdominal aortic aneurysm, and the impact of genetic variations on cardiovascular disease.
He is a member of the Global Lipids Genetics Consortium. He is a founding member of the Abdominal Aortic Aneurysm Genetics Consortium and the Peripheral Artery Disease Genetics Consortium. He is also a candidate member of the Society for Vascular Surgery.
- Aortic Aneurysm
- Peripheral Artery Disease
- Vascular Surgery
- Venous Thromboembolism
Assistant Professor - University Medical Line, Surgery - Vascular Surgery
Board Certification: American Board of Surgery, Vascular Surgery (2022)
Fellowship, University of Florida College of Medicine, Gainesville, Vascular Surgery and Endovascular Therapy
Fellowship, Broad Institute of Harvard & MIT, Cambridge, Massachusetts, Research Fellow
Residency, Massachusetts General Hospital, Surgery
Medical Degree, David Geffen School of Medicine, University of California, Los Angeles
Graduate and Fellowship Programs
Vascular Surgery (Fellowship Program)
A GENOME-WIDE ASSOCIATION STUDY OF CHRONIC ALT-BASED NAFLD IN THE MILLION VETERAN PROGRAM WITH HISTOLOGICAL AND RADIOLOGICAL VALIDATION
WILEY. 2021: 6A-7A
View details for Web of Science ID 000707188000010
- A Missense Variant in the IL-6 Receptor and Protection from Peripheral Artery Disease. Circulation research 2021
Endothelial lipase mediates efficient lipolysis of triglyceride-rich lipoproteins.
2021; 17 (9): e1009802
Triglyceride-rich lipoproteins (TRLs) are circulating reservoirs of fatty acids used as vital energy sources for peripheral tissues. Lipoprotein lipase (LPL) is a predominant enzyme mediating triglyceride (TG) lipolysis and TRL clearance to provide fatty acids to tissues in animals. Physiological and human genetic evidence support a primary role for LPL in hydrolyzing TRL TGs. We hypothesized that endothelial lipase (EL), another extracellular lipase that primarily hydrolyzes lipoprotein phospholipids may also contribute to TRL metabolism. To explore this, we studied the impact of genetic EL loss-of-function on TRL metabolism in humans and mice. Humans carrying a loss-of-function missense variant in LIPG, p.Asn396Ser (rs77960347), demonstrated elevated plasma TGs and elevated phospholipids in TRLs, among other lipoprotein classes. Mice with germline EL deficiency challenged with excess dietary TG through refeeding or a high-fat diet exhibited elevated TGs, delayed dietary TRL clearance, and impaired TRL TG lipolysis in vivo that was rescued by EL reconstitution in the liver. Lipidomic analyses of postprandial plasma from high-fat fed Lipg-/- mice demonstrated accumulation of phospholipids and TGs harboring long-chain polyunsaturated fatty acids (PUFAs), known substrates for EL lipolysis. In vitro and in vivo, EL and LPL together promoted greater TG lipolysis than either extracellular lipase alone. Our data positions EL as a key collaborator of LPL to mediate efficient lipolysis of TRLs in humans and mice.
View details for DOI 10.1371/journal.pgen.1009802
View details for PubMedID 34543263
Regulatory variants in TCF7L2 are associated with thoracic aortic aneurysm.
American journal of human genetics
Thoracic aortic aneurysm (TAA) is characterized by dilation of the aortic root or ascending/descending aorta. TAA is a heritable disease that can be potentially life threatening. While 10%-20% of TAA cases are caused by rare, pathogenic variants in single genes, the origin of the majority of TAA cases remains unknown. A previous study implicated common variants in FBN1 with TAA disease risk. Here, we report a genome-wide scan of 1,351 TAA-affected individuals and 18,295 control individuals from the Cardiovascular Health Improvement Project and Michigan Genomics Initiative at the University of Michigan. We identified a genome-wide significant association with TAA for variants within the third intron of TCF7L2 following replication with meta-analysis of four additional independent cohorts. Common variants in this locus are the strongest known genetic risk factor for type 2 diabetes. Although evidence indicates the presence of different causal variants for TAA and type 2 diabetes at this locus, we observed an opposite direction of effect. The genetic association for TAA colocalizes with an aortic eQTL of TCF7L2, suggesting a functional relationship. These analyses predict an association of higher expression of TCF7L2 with TAA disease risk. Invitro, we show that upregulation of TCF7L2 is associated with BCL2 repression promoting vascular smooth muscle cell apoptosis, a key driver of TAA disease.
View details for DOI 10.1016/j.ajhg.2021.06.016
View details for PubMedID 34265237
Prioritizing the Role of Major Lipoproteins and Subfractions as Risk Factors for Peripheral Artery Disease.
Background: Lipoprotein-related traits have been consistently identified as risk factors for atherosclerotic cardiovascular disease, largely on the basis of studies of coronary artery disease (CAD). The relative contributions of specific lipoproteins to risk of peripheral artery disease (PAD) have not been well-defined. We leveraged large-scale genetic association data to investigate effects of circulating lipoprotein-related traits on PAD risk. Methods: Genome-wide association study summary statistics for circulating lipoprotein-related traits were used in the MR Bayesian model averaging framework to prioritize the most likely causal major lipoprotein and subfraction risk factors for PAD and CAD. MR was used to estimate the effect of ApoB-lowering on PAD risk using gene regions proxying lipid-lowering drug targets. Genes relevant to prioritized lipoprotein subfractions were identified using transcriptome-wide association studies. Results: ApoB was identified as the most likely causal lipoprotein-related risk factor for both PAD (marginal inclusion probability [MIP] 0.86, p = 0.003) and CAD (MIP 0.92, p = 0.005). Genetic proxies for ApoB (apolipoprotein B)-lowering medications were associated with reduced risk of both PAD (OR 0.87 per 1 standard deviation decrease in ApoB, 95% CI 0.84 to 0.91, p = 9 x 10-10) and CAD (OR 0.66, 95% CI 0.63 to 0.69, p = 4 x 10-73), with a stronger predicted effect of ApoB-lowering on CAD (ratio of effects 3.09, 95% CI 2.29 to 4.60, p < 1 * 10-6). Extra-small-VLDL particle concentration (XS.VLDL.P) was identified as the most likely subfraction associated with PAD risk (MIP 0.91, p = 2.3 x 10-4), while large-LDL particle concentration (L.LDL.P) was the most likely subfraction associated with CAD risk (MIP 0.95, p = 0.011). Genes associated with XS.VLDL.P and L.LDL.P included canonical ApoB-pathway components, although gene-specific effects were variable. Lipoprotein(a) was associated with increased risk of PAD, independent of ApoB (OR 1.04, 95% CI 1.03 to 1.04, 95% CI 1.0 x 10-33). Conclusions: ApoB was prioritized as the major lipoprotein fraction causally responsible for both PAD and CAD risk. However, ApoB-lowering drug targets and ApoB-containing lipoprotein subfractions had diverse associations with ASCVD, and distinct subfraction-associated genes suggest possible differences in the role of lipoproteins in the pathogenesis of PAD and CAD.
View details for DOI 10.1161/CIRCULATIONAHA.121.053797
View details for PubMedID 34139859
Epidemiology and Genetics of Venous Thromboembolism and Chronic Venous Disease.
2021; 128 (12): 1988-2002
Venous disease is a term that broadly covers both venous thromboembolic disease and chronic venous disease. The basic pathophysiology of venous thromboembolism and chronic venous disease differ as venous thromboembolism results from an imbalance of hemostasis and thrombosis while chronic venous disease occurs in the setting of tissue damage because of prolonged venous hypertension. Both diseases are common and account for significant mortality and morbidity, respectively, and collectively make up a large health care burden. Despite both diseases having well-characterized environmental components, it has been known for decades that family history is an important risk factor, implicating a genetic element to a patient's risk. Our understanding of the pathogenesis of these diseases has greatly benefited from an expansion of population genetic studies from pioneering familial studies to large genome-wide association studies; we now have multiple risk loci for each venous disease. In this review, we will highlight the current state of knowledge on the epidemiology and genetics of venous thromboembolism and chronic venous disease and directions for future research.
View details for DOI 10.1161/CIRCRESAHA.121.318322
View details for PubMedID 34110897
Genetic Determinants of Peripheral Artery Disease.
2021; 128 (12): 1805-1817
Peripheral artery disease-atherosclerosis of the abdominal aorta and lower extremity vascular bed-is a complex disease with both environmental and genetic determinants. Unmitigated disease is associated with major functional decline and can lead to chronic limb-threatening ischemia, amputation, and increased mortality. Over the last 10 years, major advances have been made in identifying the genetic basis of this common, complex disease. In this review, we provide an overview of the primary types of genetic analyses performed for peripheral artery disease, including heritability and linkage studies, and more recently biobank-based genome-wide association studies. Looking forward, we highlight areas of future study including efforts to identify causal peripheral artery disease genes, rare variant and structural variant analyses using whole-exome and whole-genome sequencing data, and the need to include individuals of diverse genetic ancestries.
View details for DOI 10.1161/CIRCRESAHA.121.318327
View details for PubMedID 34110906
Risk factors mediating the effect of body mass index and waist-to-hip ratio on cardiovascular outcomes: Mendelian randomization analysis.
International journal of obesity (2005)
BACKGROUND: Higher body mass index (BMI) and waist-to-hip ratio (WHR) increase the risk of cardiovascular disease, but the extent to which this is mediated by blood pressure, diabetes, lipid traits, and smoking is not fully understood.METHODS: Using consortia and UK Biobank genetic association summary data from 140,595 to 898,130 participants predominantly of European ancestry, Mendelian randomization mediation analysis was performed to investigate the degree to which systolic blood pressure (SBP), diabetes, lipid traits, and smoking mediated an effect of BMI and WHR on the risk of coronary artery disease (CAD), peripheral artery disease (PAD) and stroke.RESULTS: The odds ratio of CAD per 1-standard deviation increase in genetically predicted BMI was 1.49 (95% CI 1.39 to 1.60). This attenuated to 1.34 (95% CI 1.24 to 1.45) after adjusting for genetically predicted SBP (proportion mediated 27%, 95% CI 3% to 50%), to 1.27 (95% CI 1.17 to 1.37) after adjusting for genetically predicted diabetes (41% mediated, 95% CI 18% to 63%), to 1.47 (95% CI 1.36 to 1.59) after adjusting for genetically predicted lipids (3% mediated, 95% -23% to 29%), and to 1.46 (95% CI 1.34 to 1.58) after adjusting for genetically predicted smoking (6% mediated, 95% CI -20% to 32%). Adjusting for all the mediators together, the estimate attenuated to 1.14 (95% CI 1.04 to 1.26; 66% mediated, 95% CI 42% to 91%). A similar pattern was observed when considering genetically predicted WHR as the exposure, and PAD or stroke as the outcome.CONCLUSIONS: Measures to reduce obesity will lower the risk of cardiovascular disease primarily by impacting downstream metabolic risk factors, particularly diabetes and hypertension. Reduction of obesity prevalence alongside control and management of its mediators is likely to be most effective for minimizing the burden of obesity.
View details for DOI 10.1038/s41366-021-00807-4
View details for PubMedID 34002035
Association Between Genetic Variation in Blood Pressure and Increased Lifetime Risk of Peripheral Artery Disease.
Arteriosclerosis, thrombosis, and vascular biology
OBJECTIVE: We aimed to estimate the effect of blood pressure (BP) traits and BP-lowering medications (via genetic proxies) on peripheral artery disease. Approach and Results: Genome-wide association studies summary statistics were obtained for BP, peripheral artery disease (PAD), and coronary artery disease. Causal effects of BP on PAD were estimated by 2-sample Mendelian randomization using a range of pleiotropy-robust methods. Increased systolic BP (SBP), diastolic BP, mean arterial pressure (MAP), and pulse pressure each significantly increased risk of PAD (SBP odds ratio [OR], 1.20 [1.16-1.25] per 10 mmHg increase, P=1*10-24; diastolic BP OR, 1.27 [1.18-1.35], P=4*10-11; MAP OR, 1.26 [1.19-1.33], P=6*10-16; pulse pressure OR, 1.31 [1.24-1.39], P=9*10-23). The effects of SBP, diastolic BP, and MAP were greater for coronary artery disease than PAD (SBP ratio of Ors, 1.06 [1.0-1.12], P=0.04; MAP ratio of OR, 1.15 [1.06-1.26], P=8.6*10-4; diastolic BP ratio of OR, 1.21 [1.08-1.35], P=6.9*10-4). Considered jointly, both pulse pressure and MAP directly increased risk of PAD (pulse pressure OR, 1.26 [1.17-1.35], P=3*10-10; MAP OR, 1.14 [1.06-1.23], P=2*10-4). The effects of antihypertensive medications were estimated using genetic instruments. SBP-lowering via beta-blocker (OR, 0.74 per 10 mmHg decrease in SBP [95% CI, 0.65-0.84]; P=5*10-6), loop diuretic (OR, 0.66 [0.48-0.91], P=0.01), and thiazide diuretic (OR, 0.57 [0.41-0.79], P=6*10-4) associated variants were protective of PAD.CONCLUSIONS: Higher BP is likely to cause PAD. BP-lowering through beta blockers, loop diuretics, and thiazide diuretics (as proxied by genetic variants) was associated with decreased risk of PAD. Future study is needed to clarify the specific mechanisms by which BP influences PAD.
View details for DOI 10.1161/ATVBAHA.120.315482
View details for PubMedID 33853351
Multi-trait association studies discover pleiotropic loci between Alzheimer's disease and cardiometabolic traits.
Alzheimer's research & therapy
2021; 13 (1): 34
BACKGROUND: Identification of genetic risk factors that are shared between Alzheimer's disease (AD) and other traits, i.e., pleiotropy, can help improve our understanding of the etiology of AD and potentially detect new therapeutic targets. Previous epidemiological correlations observed between cardiometabolic traits and AD led us to assess the pleiotropy between these traits.METHODS: We performed a set of bivariate genome-wide association studies coupled with colocalization analysis to identify loci that are shared between AD and eleven cardiometabolic traits. For each of these loci, we performed colocalization with Genotype-Tissue Expression (GTEx) project expression quantitative trait loci (eQTL) to identify candidate causal genes.RESULTS: We identified three previously unreported pleiotropic trait associations at known AD loci as well as four novel pleiotropic loci. One associated locus was tagged by a low-frequency coding variant in the gene DOCK4 and is potentially implicated in its alternative splicing. Colocalization with GTEx eQTL data identified additional candidate genes for the loci we detected, including ACE, the target of the hypertensive drug class of ACE inhibitors. We found that the allele associated with decreased ACE expression in brain tissue was also associated with increased risk of AD, providing human genetic evidence of a potential increase in AD risk from use of an established anti-hypertensive therapeutic.CONCLUSION: Our results support a complex genetic relationship between AD and these cardiometabolic traits, and the candidate causal genes identified suggest that blood pressure and immune response play a role in the pleiotropy between these traits.
View details for DOI 10.1186/s13195-021-00773-z
View details for PubMedID 33541420
Genetics of Smoking and Risk of Atherosclerotic Cardiovascular Diseases: A Mendelian Randomization Study.
JAMA network open
2021; 4 (1): e2034461
Importance: Smoking is associated with atherosclerotic cardiovascular disease, but the relative contribution to each subtype (coronary artery disease [CAD], peripheral artery disease [PAD], and large-artery stroke) remains less well understood.Objective: To determine the association between genetic liability to smoking and risk of CAD, PAD, and large-artery stroke.Design, Setting, and Participants: Mendelian randomization study using summary statistics from genome-wide associations of smoking (UK Biobank; up to 462 690 individuals), CAD (Coronary Artery Disease Genome Wide Replication and Meta-analysis plus the Coronary Artery Disease Genetics Consortium; up to 60 801 cases, 123 504 controls), PAD (VA Million Veteran Program; up to 24 009 cases, 150 983 controls), and large-artery stroke (MEGASTROKE; up to 4373 cases, 406 111 controls). This study was conducted using summary statistic data from large, previously described cohorts. Review of those publications does not reveal the total recruitment dates for those cohorts. Data analyses were conducted from August 2019 to June 2020.Exposures: Genetic liability to smoking (as proxied by genetic variants associated with lifetime smoking index).Main Outcomes and Measures: Risk (odds ratios [ORs]) of CAD, PAD, and large-artery stroke.Results: Genetic liability to smoking was associated with increased risk of PAD (OR, 2.13; 95% CI, 1.78-2.56; P=3.6*10-16), CAD (OR, 1.48; 95% CI, 1.25-1.75; P=4.4*10-6), and stroke (OR, 1.40; 95% CI, 1.02-1.92; P=.04). Genetic liability to smoking was associated with greater risk of PAD than risk of large-artery stroke (ratio of ORs, 1.52; 95% CI, 1.05-2.19; P=.02) or CAD (ratio of ORs, 1.44; 95% CI, 1.12-1.84; P=.004). The association between genetic liability to smoking and atherosclerotic cardiovascular diseases remained independent from the effects of smoking on traditional cardiovascular risk factors.Conclusions and Relevance: In this mendelian randomization analysis of data from large studies of atherosclerotic cardiovascular diseases, genetic liability to smoking was a strong risk factor for CAD, PAD, and stroke, although the estimated association was strongest between smoking and PAD. The association between smoking and atherosclerotic cardiovascular disease was independent of traditional cardiovascular risk factors.
View details for DOI 10.1001/jamanetworkopen.2020.34461
View details for PubMedID 33464320
Urate, Blood Pressure, and Cardiovascular Disease: Evidence From Mendelian Randomization and Meta-Analysis of Clinical Trials.
Hypertension (Dallas, Tex. : 1979)
Serum urate has been implicated in hypertension and cardiovascular disease, but it is not known whether it is exerting a causal effect. To investigate this, we performed Mendelian randomization analysis using data from UK Biobank, Million Veterans Program and genome-wide association study consortia, and meta-analysis of randomized controlled trials. The main Mendelian randomization analyses showed that every 1-SD increase in genetically predicted serum urate was associated with an increased risk of coronary heart disease (odds ratio, 1.19 [95% CI, 1.10-1.30]; P=4*10-5), peripheral artery disease (1.12 [95% CI, 1.03-1.21]; P=9*10-3), and stroke (1.11 [95% CI, 1.05-1.18]; P=2*10-4). In Mendelian randomization mediation analyses, elevated blood pressure was estimated to mediate approximately one-third of the effect of urate on cardiovascular disease risk. Systematic review and meta-analysis of randomized controlled trials showed a favorable effect of urate-lowering treatment on systolic blood pressure (mean difference, -2.55 mm Hg [95% CI, -4.06 to -1.05]; P=1*10-3) and major adverse cardiovascular events in those with previous cardiovascular disease (odds ratio, 0.40 [95% CI, 0.22-0.73]; P=3*10-3) but no significant effect on major adverse cardiovascular events in all individuals (odds ratio, 0.67 [95% CI, 0.44-1.03]; P=0.07). In summary, these Mendelian randomization and clinical trial data support an effect of higher serum urate on increasing blood pressure, which may mediate a consequent effect on cardiovascular disease risk. High-quality trials are necessary to provide definitive evidence on the specific clinical contexts where urate lowering may be of cardiovascular benefit.
View details for DOI 10.1161/HYPERTENSIONAHA.120.16547
View details for PubMedID 33356394
Genetic predisposition to smoking in relation to 14 cardiovascular diseases
EUROPEAN HEART JOURNAL
2020; 41 (35): 3304-+
The aim of this study was to use Mendelian randomization (MR) to determine the causality of the association between smoking and 14 different cardiovascular diseases (CVDs).Our primary genetic instrument comprised 361 single-nucleotide polymorphisms (SNPs) associated with smoking initiation (ever smoked regularly) at genome-wide significance. Data on the associations between the SNPs and 14 CVDs were obtained from the UK Biobank study (N = 367 643 individuals), CARDIoGRAMplusC4D consortium (N = 184 305 individuals), Atrial Fibrillation Consortium (2017 dataset; N = 154 432 individuals), and Million Veteran Program (MVP; N = 190 266 individuals). The main analyses were conducted using the random-effects inverse-variance weighted method and complemented with multivariable MR analyses and the weighted median and MR-Egger approaches. Genetic predisposition to smoking initiation was most strongly and consistently associated with higher odds of coronary artery disease, heart failure, abdominal aortic aneurysm, ischaemic stroke, transient ischaemic attack, peripheral arterial disease, and arterial hypertension. Genetic predisposition to smoking initiation was additionally associated with higher odds of deep vein thrombosis and pulmonary embolism in the UK Biobank but not with venous thromboembolism in the MVP. There was limited evidence of causal associations of smoking initiation with atrial fibrillation, aortic valve stenosis, thoracic aortic aneurysm, and intracerebral and subarachnoid haemorrhage.This MR study supports a causal association between smoking and a broad range of CVDs, in particular, coronary artery disease, heart failure, abdominal aortic aneurysm, ischaemic stroke, transient ischaemic attack, peripheral arterial disease, and arterial hypertension.
View details for DOI 10.1093/eurheartj/ehaa193
View details for Web of Science ID 000593360900007
View details for PubMedID 32300774
View details for PubMedCentralID PMC7544540
Mendelian Randomization Analysis of Hemostatic Factors and Their Contribution to Peripheral Artery Disease.
Arteriosclerosis, thrombosis, and vascular biology
BACKGROUND: Peripheral artery disease (PAD) is the third most common form of atherosclerotic vascular disease and is characterized by significant functional disability and increased cardiovascular mortality. Recent genetic data support a role for a procoagulation protein variant, the factor V Leiden mutation, in PAD. The role of other hemostatic factors in PAD remains unknown.OBJECTIVE: To evaluate the role of hemostatic factors in PAD using Mendelian randomization. Approach and Results: Two-sample Mendelian randomization to evaluate the roles of FVII (factor VII), FVIII (factor VIII), FXI (factor XI), VWF (von Willebrand factor), and fibrinogen in PAD was performed using summary statistics from GWAS for hemostatic factors performed within the Cohorts for Heart and Aging Research in the Genome Epidemiology Consortium and from GWAS performed for PAD within the Million Veteran Program. Genetically determined FVIII and VWF, but not FVII, FXI, or fibrinogen, were associated with PAD in Mendelian randomization experiments (FVIII: odds ratio, 1.41 [95% CI, 1.23-1.62], P=6.0*10-7, VWF: odds ratio, 1.28 [95% CI, 1.07-1.52], P=0.0073). In single variant sensitivity analysis, the ABO locus was the strongest genetic instrument for both FVIII and VWF.CONCLUSIONS: Our results suggest a role for hemostasis, and by extension, thrombosis in PAD. Further study is warranted to determine whether VWF and FVIII independently affect the biology of PAD.
View details for DOI 10.1161/ATVBAHA.119.313847
View details for PubMedID 32847391
Dynamic incorporation of multiple in silico functional annotations empowers rare variant association analysis of large whole-genome sequencing studies at scale.
Large-scale whole-genome sequencing studies have enabled the analysis of rare variants (RVs) associated with complex phenotypes. Commonly used RV association tests have limited scope to leverage variant functions. We propose STAAR (variant-set test for association using annotation information), a scalable and powerful RV association test method that effectively incorporates both variant categories and multiple complementary annotations using a dynamic weighting scheme. For the latter, we introduce 'annotation principal components', multidimensional summaries of in silico variant annotations. STAAR accounts for population structure and relatedness and is scalable for analyzing very large cohort and biobank whole-genome sequencing studies of continuous and dichotomous traits. We applied STAAR to identify RVs associated with four lipid traits in 12,316 discovery and 17,822 replication samples from the Trans-Omics for Precision Medicine Program. We discovered and replicated new RV associations, including disruptive missense RVs of NPC1L1 and an intergenic region near APOC1P1 associated with low-density lipoprotein cholesterol.
View details for DOI 10.1038/s41588-020-0676-4
View details for PubMedID 32839606
Concomitant carotid endarterectomy and cardiac surgery does not decrease postoperative stroke rates
JOURNAL OF VASCULAR SURGERY
2020; 72 (2): 589-+
The timing of operative revascularization for patients with concomitant carotid artery stenosis and coronary artery disease remains controversial. We examined the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database to evaluate the association of combined carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG) with postoperative outcomes.All patients undergoing CABG with known carotid stenosis of >80% were identified from 2011 to 2016. Individuals were stratified by use of cardiopulmonary bypass and whether a concomitant CEA was performed at the time of CABG. Multivariate logistic regression was used to model the probability of combined CABG and CEA. The resulting propensity scores were used to match individuals on the basis of clinical and operative characteristics to evaluate primary (30-day mortality and in-hospital transient ischemic attack and stroke) and secondary (STS morbidity composite events and length of stay) end points, with P < .05 required to declare statistical significance.After propensity score matching, 994 off-pump CABG patients (497 CABG only and 497 CABG-CEA) and 5952 on-pump CABG patients (2976 CABG only and 2976 CABG-CEA) were identified. For patients who received on-pump operations, those undergoing CABG-CEA had no observed difference in rate of in-hospital stroke (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.72-1.21; P = .6), higher incidence of STS morbidity composite events (OR, 1.15, 95% CI, 1.01-1.31; P = .03), longer length of stay (7.0 [interquartile range, 5.0-9.0] days vs 6.0 [interquartile range, 5.0-9.0] days; P < .005), and no observed difference in 30-day mortality (OR, 1.28; 95% CI, 0.97-1.69; P = .08) compared with those undergoing CABG only. For off-pump procedures, CABG-CEA patients had no observed difference in rate of in-hospital stroke (OR, 0.80; 95% CI, 0.37-1.69; P = .56) compared with those undergoing CABG only.Whereas the differences are relatively small, these data suggest that a combined CABG-CEA approach is unlikely to provide significant stroke reduction benefit compared with CABG only. However, comparison with staged approaches merits further investigation.
View details for DOI 10.1016/j.jvs.2019.10.072
View details for Web of Science ID 000564329400030
View details for PubMedID 32067876
A missense variant in Mitochondrial Amidoxime Reducing Component 1 gene and protection against liver disease
2020; 16 (4): e1008629
Analyzing 12,361 all-cause cirrhosis cases and 790,095 controls from eight cohorts, we identify a common missense variant in the Mitochondrial Amidoxime Reducing Component 1 gene (MARC1 p.A165T) that associates with protection from all-cause cirrhosis (OR 0.91, p = 2.3*10-11). This same variant also associates with lower levels of hepatic fat on computed tomographic imaging and lower odds of physician-diagnosed fatty liver as well as lower blood levels of alanine transaminase (-0.025 SD, 3.7*10-43), alkaline phosphatase (-0.025 SD, 1.2*10-37), total cholesterol (-0.030 SD, p = 1.9*10-36) and LDL cholesterol (-0.027 SD, p = 5.1*10-30) levels. We identified a series of additional MARC1 alleles (low-frequency missense p.M187K and rare protein-truncating p.R200Ter) that also associated with lower cholesterol levels, liver enzyme levels and reduced risk of cirrhosis (0 cirrhosis cases for 238 R200Ter carriers versus 17,046 cases of cirrhosis among 759,027 non-carriers, p = 0.04) suggesting that deficiency of the MARC1 enzyme may lower blood cholesterol levels and protect against cirrhosis.
View details for DOI 10.1371/journal.pgen.1008629
View details for Web of Science ID 000531363700048
View details for PubMedID 32282858
View details for PubMedCentralID PMC7200007
- Minority-centric meta-analyses of blood lipid levels identify novel loci in the Population Architecture using Genomics and Epidemiology (PAGE) study PLOS GENETICS 2020; 16 (3)
Discovery of 318 new risk loci for type 2 diabetes and related vascular outcomes among 1.4 million participants in a multi-ancestry meta-analysis.
We investigated type 2 diabetes (T2D) genetic susceptibility via multi-ancestry meta-analysis of 228,499 cases and 1,178,783 controls in the Million Veteran Program (MVP), DIAMANTE, Biobank Japan and other studies. We report 568 associations, including 286 autosomal, 7 X-chromosomal and 25 identified in ancestry-specific analyses that were previously unreported. Transcriptome-wide association analysis detected 3,568 T2D associations with genetically predicted gene expression in 687 novel genes; of these, 54 are known to interact with FDA-approved drugs. A polygenic risk score (PRS) was strongly associated with increased risk of T2D-related retinopathy and modestly associated with chronic kidney disease (CKD), peripheral artery disease (PAD) and neuropathy. We investigated the genetic etiology of T2D-related vascular outcomes in the MVP and observed statistical SNP-T2D interactions at 13 variants, including coronary heart disease (CHD), CKD, PAD and neuropathy. These findings may help to identify potential therapeutic targets for T2D and genomic pathways that link T2D to vascular outcomes.
View details for DOI 10.1038/s41588-020-0637-y
View details for PubMedID 32541925
PCSK9 loss of function is protective against extra-coronary atherosclerotic cardiovascular disease in a large multi-ethnic cohort.
2020; 15 (11): e0239752
Therapeutic inhibition of PCSK9 protects against coronary artery disease (CAD) and ischemic stroke (IS). The impact on other diseases remains less well characterized.We created a genetic risk score (GRS) for PCSK9 using four single nucleotide polymorphisms (SNPs) at or near the PCSK9 locus known to impact lower LDL-Cholesterol (LDL-C): rs11583680, rs11591147, rs2479409, and rs11206510. We then used our GRS to calculate weighted odds ratios reflecting the impact of a genetically determined 10 mg/dL decrease in LDL-C on several pre-specified phenotypes including CAD, IS, peripheral artery disease (PAD), abdominal aortic aneurysm (AAA), type 2 diabetes, dementia, chronic obstructive pulmonary disease, and cancer. Finally, we used our weighted GRS to perform a phenome-wide association study.Genetic and electronic health record data that passed quality control was available in 312,097 individuals, (227,490 White participants, 58,907 Black participants, and 25,700 Hispanic participants). PCSK9 mediated reduction in LDL-C was associated with a reduced risk of CAD and AAA in trans-ethnic meta-analysis (CAD OR 0.83 [95% CI 0.80-0.87], p = 6.0 x 10-21; AAA OR 0.76 [95% CI 0.68-0.86], p = 2.9 x 10-06). Significant protective effects were noted for PAD in White individuals (OR 0.83 [95% CI 0.71-0.97], p = 2.3 x 10-04) but not in other genetic ancestries. Genetically reduced PCSK9 function associated with a reduced risk of dementia in trans-ethnic meta-analysis (OR 0.86 [95% CI 0.78-0.93], p = 5.0 x 10-04).Genetically reduced PCSK9 function results in a reduction in risk of several important extra-coronary atherosclerotic phenotypes in addition to known effects on CAD and IS, including PAD and AAA. We also highlight a novel reduction in risk of dementia, supporting a well-recognized vascular component to cognitive impairment and an opportunity for therapeutic repositioning.
View details for DOI 10.1371/journal.pone.0239752
View details for PubMedID 33166319
- Genetic Architecture of Abdominal Aortic Aneurysm in the Million Veteran Program. Circulation 2020
Cross-trait analyses with migraine reveal widespread pleiotropy and suggest a vascular component to migraine headache.
International journal of epidemiology
Nearly a fifth of the world's population suffer from migraine headache, yet risk factors for this disease are poorly characterized.To further elucidate these factors, we conducted a genetic correlation analysis using cross-trait linkage disequilibrium (LD) score regression between migraine headache and 47 traits from the UK Biobank. We then tested for possible causality between these phenotypes and migraine, using Mendelian randomization. In addition, we attempted replication of our findings in an independent genome-wide association study (GWAS) when available.We report multiple phenotypes with genetic correlation (P < 1.06 × 10-3) with migraine, including heart disease, type 2 diabetes, lipid levels, blood pressure, autoimmune and psychiatric phenotypes. In particular, we find evidence that blood pressure directly contributes to migraine and explains a previously suggested causal relationship between calcium and migraine.This is the largest genetic correlation analysis of migraine headache to date, both in terms of migraine GWAS sample size and the number of phenotypes tested. We find that migraine has a shared genetic basis with a large number of traits, indicating pervasive pleiotropy at migraine-associated loci.
View details for DOI 10.1093/ije/dyaa050
View details for PubMedID 32306029
Minority-centric meta-analyses of blood lipid levels identify novel loci in the Population Architecture using Genomics and Epidemiology (PAGE) study.
2020; 16 (3): e1008684
Lipid levels are important markers for the development of cardio-metabolic diseases. Although hundreds of associated loci have been identified through genetic association studies, the contribution of genetic factors to variation in lipids is not fully understood, particularly in U.S. minority groups. We performed genome-wide association analyses for four lipid traits in over 45,000 ancestrally diverse participants from the Population Architecture using Genomics and Epidemiology (PAGE) Study, followed by a meta-analysis with several European ancestry studies. We identified nine novel lipid loci, five of which showed evidence of replication in independent studies. Furthermore, we discovered one novel gene in a PrediXcan analysis, minority-specific independent signals at eight previously reported loci, and potential functional variants at two known loci through fine-mapping. Systematic examination of known lipid loci revealed smaller effect estimates in African American and Hispanic ancestry populations than those in Europeans, and better performance of polygenic risk scores based on minority-specific effect estimates. Our findings provide new insight into the genetic architecture of lipid traits and highlight the importance of conducting genetic studies in diverse populations in the era of precision medicine.
View details for DOI 10.1371/journal.pgen.1008684
View details for PubMedID 32226016
The relationship between circulating lipids and breast cancer risk: A Mendelian randomization study.
2020; 17 (9): e1003302
A number of epidemiological and genetic studies have attempted to determine whether levels of circulating lipids are associated with risks of various cancers, including breast cancer (BC). However, it remains unclear whether a causal relationship exists between lipids and BC. If alteration of lipid levels also reduced risk of BC, this could present a target for disease prevention. This study aimed to assess a potential causal relationship between genetic variants associated with plasma lipid traits (high-density lipoprotein, HDL; low-density lipoprotein, LDL; triglycerides, TGs) with risk for BC using Mendelian randomization (MR).Data from genome-wide association studies in up to 215,551 participants from the Million Veteran Program (MVP) were used to construct genetic instruments for plasma lipid traits. The effect of these instruments on BC risk was evaluated using genetic data from the BCAC (Breast Cancer Association Consortium) based on 122,977 BC cases and 105,974 controls. Using MR, we observed that a 1-standard-deviation genetically determined increase in HDL levels is associated with an increased risk for all BCs (HDL: OR [odds ratio] = 1.08, 95% confidence interval [CI] = 1.04-1.13, P < 0.001). Multivariable MR analysis, which adjusted for the effects of LDL, TGs, body mass index (BMI), and age at menarche, corroborated this observation for HDL (OR = 1.06, 95% CI = 1.03-1.10, P = 4.9 × 10-4) and also found a relationship between LDL and BC risk (OR = 1.03, 95% CI = 1.01-1.07, P = 0.02). We did not observe a difference in these relationships when stratified by breast tumor estrogen receptor (ER) status. We repeated this analysis using genetic variants independent of the leading association at core HDL pathway genes and found that these variants were also associated with risk for BCs (OR = 1.11, 95% CI = 1.06-1.16, P = 1.5 × 10-6), including locus-specific associations at ABCA1 (ATP Binding Cassette Subfamily A Member 1), APOE-APOC1-APOC4-APOC2 (Apolipoproteins E, C1, C4, and C2), and CETP (Cholesteryl Ester Transfer Protein). In addition, we found evidence that genetic variation at the ABO locus is associated with both lipid levels and BC. Through multiple statistical approaches, we minimized and tested for the confounding effects of pleiotropy and population stratification on our analysis; however, the possible existence of residual pleiotropy and stratification remains a limitation of this study.We observed that genetically elevated plasma HDL and LDL levels appear to be associated with increased BC risk. Future studies are required to understand the mechanism underlying this putative causal relationship, with the goal of developing potential therapeutic strategies aimed at altering the cholesterol-mediated effect on BC risk.
View details for DOI 10.1371/journal.pmed.1003302
View details for PubMedID 32915777
Association of Premature Natural and Surgical Menopause With Incident Cardiovascular Disease
AMER MEDICAL ASSOC. 2019: 2411-2421
Recent guidelines endorse using history of menopause before age 40 years to refine atherosclerotic cardiovascular disease risk assessments among middle-aged women. Robust data on cardiovascular disease risk in this population are lacking.To examine the development of cardiovascular diseases and cardiovascular risk factors in women with natural and surgical menopause before age 40 years.Cohort study (UK Biobank), with adult residents of the United Kingdom recruited between 2006 and 2010. Of women who were 40 to 69 years old and postmenopausal at study enrollment, 144 260 were eligible for inclusion. Follow-up occurred through August 2016.Natural premature menopause (menopause before age 40 without oophorectomy) and surgical premature menopause (bilateral oophorectomy before age 40). Postmenopausal women without premature menopause served as the reference group.The primary outcome was a composite of incident coronary artery disease, heart failure, aortic stenosis, mitral regurgitation, atrial fibrillation, ischemic stroke, peripheral artery disease, and venous thromboembolism. Secondary outcomes included individual components of the primary outcome, incident hypertension, hyperlipidemia, and type 2 diabetes.Of 144 260 postmenopausal women included (mean [SD] age at enrollment, 59.9 [5.4] years), 4904 (3.4%) had natural premature menopause and 644 (0.4%) had surgical premature menopause. Participants were followed up for a median of 7 years (interquartile range, 6.3-7.7). The primary outcome occurred in 5415 women (3.9%) with no premature menopause (incidence, 5.70/1000 woman-years), 292 women (6.0%) with natural premature menopause (incidence, 8.78/1000 woman-years) (difference vs no premature menopause, +3.08/1000 woman-years [95% CI, 2.06-4.10]; P < .001), and 49 women (7.6%) with surgical premature menopause (incidence, 11.27/1000 woman-years) (difference vs no premature menopause, +5.57/1000 woman-years [95% CI, 2.41-8.73]; P < .001). For the primary outcome, natural and surgical premature menopause were associated with hazard ratios of 1.36 (95% CI, 1.19-1.56; P < .001) and 1.87 (95% CI, 1.36-2.58; P < .001), respectively, after adjustment for conventional cardiovascular disease risk factors and use of menopausal hormone therapy.Natural and surgical premature menopause (before age 40 years) were associated with a small but statistically significant increased risk for a composite of cardiovascular diseases among postmenopausal women. Further research is needed to understand the mechanisms underlying these associations.
View details for DOI 10.1001/jama.2019.19191
View details for Web of Science ID 000505209400015
View details for PubMedID 31738818
View details for PubMedCentralID PMC7231649
Long-Term Cardiovascular Risk in Women With Hypertension During Pregnancy
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2019; 74 (22): 2743-2754
History of a hypertensive disorder of pregnancy (HDP) among women may be useful to refine atherosclerotic cardiovascular disease risk assessments. However, future risk of diverse cardiovascular conditions in asymptomatic middle-aged women with prior HDP remains unknown.The purpose of this study was to examine the long-term incidence of diverse cardiovascular conditions among middle-aged women with and without prior HDP.Women in the prospective, observational UK Biobank age 40 to 69 years who reported ≥1 live birth were included. Noninvasive arterial stiffness measurement was performed in a subset of women. Cox models were fitted to associate HDP with incident cardiovascular diseases. Causal mediation analyses estimated the contribution of conventional risk factors to observed associations.Of 220,024 women included, 2,808 (1.3%) had prior HDP. The mean age at baseline was 57.4 ± 7.8 years, and women were followed for median 7 years (interquartile range: 6.3 to 7.7 years). Women with HDP had elevated arterial stiffness indexes and greater prevalence of chronic hypertension compared with women without HDP. Overall, 7.0 versus 5.3 age-adjusted incident cardiovascular conditions occurred per 1,000 women-years for women with versus without prior HDP, respectively (p = 0.001). In analysis of time-to-first incident cardiovascular diagnosis, prior HDP was associated with a hazard ratio (HR) of 1.3 (95% CI: 1.04 to 1.60; p = 0.02). HDP was associated with greater incidence of CAD (HR: 1.8; 95% CI: 1.3 to 2.6; p < 0.001), heart failure (HR: 1.7; 95% CI: 1.04 to 2.60; p = 0.03), aortic stenosis (HR: 2.9; 95% CI: 1.5 to 5.4; p < 0.001), and mitral regurgitation (HR: 5.0; 95% CI: 1.5 to 17.1; p = 0.01). In causal mediation analyses, chronic hypertension explained 64% of HDP's association with CAD and 49% of HDP's association with heart failure.Hypertensive disorders of pregnancy are associated with accelerated cardiovascular aging and more diverse cardiovascular conditions than previously appreciated, including valvular heart disease. Cardiovascular risk after HDP is largely but incompletely mediated by development of chronic hypertension.
View details for DOI 10.1016/j.jacc.2019.09.052
View details for Web of Science ID 000498899600005
View details for PubMedID 31727424
View details for PubMedCentralID PMC6981240
Genomic and transcriptomic association studies identify 16 novel susceptibility loci for venous thromboembolism
2019; 134 (19): 1645-1657
Venous thromboembolism (VTE) is a significant contributor to morbidity and mortality. To advance our understanding of the biology contributing to VTE, we conducted a genome-wide association study (GWAS) of VTE and a transcriptome-wide association study (TWAS) based on imputed gene expression from whole blood and liver. We meta-analyzed GWAS data from 18 studies for 30 234 VTE cases and 172 122 controls and assessed the association between 12 923 718 genetic variants and VTE. We generated variant prediction scores of gene expression from whole blood and liver tissue and assessed them for association with VTE. Mendelian randomization analyses were conducted for traits genetically associated with novel VTE loci. We identified 34 independent genetic signals for VTE risk from GWAS meta-analysis, of which 14 are newly reported associations. This included 11 newly associated genetic loci (C1orf198, PLEK, OSMR-AS1, NUGGC/SCARA5, GRK5, MPHOSPH9, ARID4A, PLCG2, SMG6, EIF5A, and STX10) of which 6 replicated, and 3 new independent signals in 3 known genes. Further, TWAS identified 5 additional genetic loci with imputed gene expression levels differing between cases and controls in whole blood (SH2B3, SPSB1, RP11-747H7.3, RP4-737E23.2) and in liver (ERAP1). At some GWAS loci, we found suggestive evidence that the VTE association signal for novel and previously known regions colocalized with expression quantitative trait locus signals. Mendelian randomization analyses suggested that blood traits may contribute to the underlying risk of VTE. To conclude, we identified 16 novel susceptibility loci for VTE; for some loci, the association signals are likely mediated through gene expression of nearby genes.
View details for DOI 10.1182/blood.2019000435
View details for Web of Science ID 000495894200012
View details for PubMedID 31420334
View details for PubMedCentralID PMC6871304
Genome-wide association analysis of venous thromboembolism identifies new risk loci and genetic overlap with arterial vascular disease.
Venous thromboembolism is a significant cause of mortality1, yet its genetic determinants are incompletely defined. We performed a discovery genome-wide association study in the Million Veteran Program and UK Biobank, with testing of approximately 13 million DNA sequence variants for association with venous thromboembolism (26,066 cases and 624,053 controls) and meta-analyzed both studies, followed by independent replication with up to 17,672 venous thromboembolism cases and 167,295 controls. We identified 22 previously unknown loci, bringing the total number of venous thromboembolism-associated loci to 33, and subsequently fine-mapped these associations. We developed a genome-wide polygenic risk score for venous thromboembolism that identifies 5% of the population at an equivalent incident venous thromboembolism risk to carriers of the established factor V Leiden p.R506Q and prothrombin G20210A mutations. Our data provide mechanistic insights into the genetic epidemiology of venous thromboembolism and suggest a greater overlap among venous and arterial cardiovascular disease than previously thought.
View details for DOI 10.1038/s41588-019-0519-3
View details for PubMedID 31676865
Mapping eGFR loci to the renal transcriptome and phenome in the VA Million Veteran Program.
2019; 10 (1): 3842
Chronic kidney disease (CKD),defined by low estimated glomerular filtration rate (eGFR), contributes to global morbidity and mortality. Here we conduct a transethnic Genome-Wide Association Study of eGFR in 280,722 participants of the Million Veteran Program (MVP), with replication in 765,289 participants from the Chronic Kidney Disease Genetics (CKDGen) Consortium. We identify 82 previously unreported variants, confirm 54 loci, and report interesting findings including association of the sickle cell allele of betaglobin among non-Hispanic blacks. Our transcriptome-wide association study of kidney function in healthy kidney tissue identifies 36 previously unreported and nine known genes, and maps gene expression to renal cell types. In a Phenome-Wide Association Study in 192,868 MVP participants using a weighted genetic score we detect associations with CKD stages and complications and kidney stones. This investigation reinterprets the genetic architecture of kidney function to identify the gene, tissue, and anatomical context of renal homeostasis and the clinical consequences of dysregulation.
View details for DOI 10.1038/s41467-019-11704-w
View details for PubMedID 31451708
Genome-wide association study of peripheral artery disease in the Million Veteran Program.
Peripheral artery disease (PAD) is a leading cause of cardiovascular morbidity and mortality; however, the extent to which genetic factors increase risk for PAD is largely unknown. Using electronic health record data, we performed a genome-wide association study in the Million Veteran Program testing ~32 million DNA sequence variants with PAD (31,307 cases and 211,753 controls) across veterans of European, African and Hispanic ancestry. The results were replicated in an independent sample of 5,117 PAD cases and 389,291 controls from the UK Biobank. We identified 19 PAD loci, 18 of which have not been previously reported. Eleven of the 19 loci were associated with disease in three vascular beds (coronary, cerebral, peripheral), including LDLR, LPL and LPA, suggesting that therapeutic modulation of low-density lipoprotein cholesterol, the lipoprotein lipase pathway or circulating lipoprotein(a) may be efficacious for multiple atherosclerotic disease phenotypes. Conversely, four of the variants appeared to be specific for PAD, including F5 p.R506Q, highlighting the pathogenic role of thrombosis in the peripheral vascular bed and providing genetic support for Factor Xa inhibition as a therapeutic strategy for PAD. Our results highlight mechanistic similarities and differences among coronary, cerebral and peripheral atherosclerosis and provide therapeutic insights.
View details for DOI 10.1038/s41591-019-0492-5
View details for PubMedID 31285632
Genetic Association of Finger Photoplethysmography-Derived Arterial Stiffness Index With Blood Pressure and Coronary Artery Disease
ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY
2019; 39 (6): 1253-1261
Objective- Arterial stiffness index (ASI) is independently associated with blood pressure (BP) and coronary artery disease (CAD) epidemiologically. However, it is unknown whether these associations represent causal relationships. Here, we assess whether genetic predisposition to increased ASI is associated with elevated BP and CAD risk. Approach and Results- We first performed a large-scale epidemiological association of finger photoplethysmography-derived ASI in the UK Biobank, finding significant associations with systolic BP (β=0.55 mm Hg; [95% CI, 0.45-0.65]; P=5.77×10-24; N=137 858), diastolic BP (β=1.05 mm Hg; [95% CI, 0.99-1.11]; P=7.27×10-272; N=137 862), and incident CAD (hazard ratio, 1.08; [95% CI, 1.04-1.11]; P=1.5×10-6; N=3692 cases, 126 615 controls) in multivariable models. We then performed an ASI genome-wide association study analysis in 131 686 participants from the UK Biobank. Across participants not in the ASI genome-wide association study, a 6-variant ASI polygenic risk score was calculated. Each SD increase in genetic ASI was associated with systolic BP (β=4.63 mm Hg; [95% CI, 2.1-7.2]; P=3.37×10-4; N=208 897), and diastolic BP (β=2.61 mm Hg; [95% CI, 1.2-4.0]; P=2.85×10-4; N=208 897); however, no association was observed with incident CAD (hazard ratio, 1.12; [95% CI, 0.55-2.3]; P=0.75; N=223 061; 7534 cases). The lack of CAD association observed was replicated among 184 305 participants (60 810 cases) from the CARDIOGRAMplusC4D (Coronary Artery Disease Genetics Consortium; odds ratio, 0.56; [95% CI, 0.26-1.24]; P=0.15). Conclusions- Our data support the conclusion that finger photoplethysmography-derived ASI is an independent, genetically causal risk factor for BP, but do not support the notion that ASI is a suitable surrogate for CAD risk.
View details for DOI 10.1161/ATVBAHA.119.312626
View details for Web of Science ID 000468782700029
View details for PubMedID 31070453
View details for PubMedCentralID PMC6531323
- Genome-wide association study of alcohol consumption and use disorder in 274,424 individuals from multiple populations NATURE COMMUNICATIONS 2019; 10
Association of APOL1 Risk Alleles with Cardiovascular Disease in African Americans in the Million Veteran Program.
Approximately 13% of African-American individuals carry two copies of the APOL1 risk alleles G1 or G2, which are associated with 1.5-2.5 fold increased risk of chronic kidney disease (CKD). There have been conflicting reports as to whether an association exists between APOL1 risk alleles and cardiovascular disease, independent of the effects of APOL1 on kidney disease. We sought to test the association of APOL1 G1/G2 alleles with coronary artery disease (CAD), peripheral artery disease (PAD), and stroke among African American individuals in the Million Veteran Program (MVP).We performed a time-to-event analysis of retrospective electronic health record (EHR) data using Cox proportional hazard and competing risks Fine and Gray sub-distribution hazard models. The primary exposure was APOL1 risk allele status. The primary outcome was incident CAD amongst individuals without CKD during the 12.5 year follow up period. Separately we analyzed the cross-sectional association of APOL1 risk allele status with lipid traits and 115 cardiovascular diseases using phenome-wide association.Among 30,903 African American MVP participants, 3,941 (13%) carried the two APOL1 risk allele high-risk genotype. Individuals with normal kidney function at baseline with two risk alleles had slightly higher risk of developing CAD compared to those with no risk alleles (Hazard Ratio (HR): 1.11, 95% Confidence Interval (CI): 1.01-1.21, p=0.039). Similarly, modest associations were identified with incident stroke (HR: 1.20, 95% CI: 1.05-1.36, p=0.007) and PAD (HR: 1.15, 95% CI:1.01-1.29, p=0.031). When modeling both cardiovascular and renal outcomes, APOL1 was strongly associated with incident renal disease, while no significant association with the cardiovascular disease endpoints could be detected. Cardiovascular phenome-wide association analyses did not identify additional significant associations with cardiovascular disease subsets.APOL1 risk variants display a modest association with cardiovascular disease and this association is likely mediated by the known APOL1 association with CKD.
View details for DOI 10.1161/CIRCULATIONAHA.118.036589
View details for PubMedID 31337231
Genome-wide association study of alcohol consumption and use disorder in 274,424 individuals from multiple populations.
2019; 10 (1): 1499
Alcohol consumption level and alcohol use disorder (AUD) diagnosis are moderately heritable traits. We conduct genome-wide association studies of these traits using longitudinal Alcohol Use Disorder Identification Test-Consumption (AUDIT-C) scores and AUD diagnoses in a multi-ancestry Million Veteran Program sample (N=274,424). We identify 18 genome-wide significant loci: 5 associated with both traits, 8 associated with AUDIT-C only, and 5 associated with AUD diagnosis only. Polygenic Risk Scores (PRS) for both traits are associated with alcohol-related disorders in two independent samples. Although a significant genetic correlation reflects the overlap between the traits, genetic correlations for 188 non-alcohol-related traits differ significantly for the two traits, as do the phenotypes associated with the traits' PRS. Cell type group partitioning heritability enrichment analyses also differentiate the two traits. We conclude that, although heavy drinking is a key risk factor for AUD, it is not a sufficient cause of the disorder.
View details for PubMedID 30940813
Trans-ethnic association study of blood pressure determinants in over 750,000 individuals.
2019; 51 (1): 51–62
In this trans-ethnic multi-omic study, we reinterpret the genetic architecture of blood pressure to identify genes, tissues, phenomes and medication contexts of blood pressure homeostasis. We discovered 208 novel common blood pressure SNPs and 53 rare variants in genome-wide association studies of systolic, diastolic and pulse pressure in up to 776,078 participants from the Million Veteran Program (MVP) and collaborating studies, with analysis of the blood pressure clinical phenome in MVP. Our transcriptome-wide association study detected 4,043 blood pressure associations with genetically predicted gene expression of 840 genes in 45 tissues, and mouse renal single-cell RNA sequencing identified upregulated blood pressure genes in kidney tubule cells.
View details for PubMedID 30578418
DNA Sequence Variation in ACVR1C Encoding the Activin Receptor-Like Kinase 7 Influences Body Fat Distribution and Protects Against Type 2 Diabetes
2019; 68 (1): 226-234
A genetic predisposition to higher waist-to-hip ratio adjusted for BMI (WHRadjBMI), a measure of body fat distribution, associates with increased risk for type 2 diabetes. We conducted an exome-wide association study of coding variation in UK Biobank (405,569 individuals) to identify variants that lower WHRadjBMI and protect against type 2 diabetes. We identified four variants in the gene ACVR1C (encoding the activin receptor-like kinase 7 receptor expressed on adipocytes and pancreatic β-cells), which independently associated with reduced WHRadjBMI: Asn150His (-0.09 SD, P = 3.4 × 10-17), Ile195Thr (-0.15 SD, P = 1.0 × 10-9), Ile482Val (-0.019 SD, P = 1.6 × 10-5), and rs72927479 (-0.035 SD, P = 2.6 × 10-12). Carriers of these variants exhibited reduced percent abdominal fat in DEXA imaging. Pooling across all four variants, a 0.2 SD decrease in WHRadjBMI through ACVR1C was associated with a 30% lower risk of type 2 diabetes (odds ratio [OR] 0.70, 95% CI 0.63, 0.77; P = 5.6 × 10-13). In an analysis of exome sequences from 55,516 individuals, carriers of predicted damaging variants in ACVR1C were at 54% lower risk of type 2 diabetes (OR 0.46, 95% CI 0.27, 0.81; P = 0.006). These findings indicate that variants predicted to lead to loss of ACVR1C gene function influence body fat distribution and protect from type 2 diabetes.
View details for DOI 10.2337/db18-0857
View details for Web of Science ID 000453906300022
View details for PubMedID 30389748
View details for PubMedCentralID PMC6302541
Atrial fibrillation genetic risk differentiates cardioembolic stroke from other stroke subtypes
2018; 4 (6): e293
We sought to assess whether genetic risk factors for atrial fibrillation (AF) can explain cardioembolic stroke risk.We evaluated genetic correlations between a previous genetic study of AF and AF in the presence of cardioembolic stroke using genome-wide genotypes from the Stroke Genetics Network (N = 3,190 AF cases, 3,000 cardioembolic stroke cases, and 28,026 referents). We tested whether a previously validated AF polygenic risk score (PRS) associated with cardioembolic and other stroke subtypes after accounting for AF clinical risk factors.We observed a strong correlation between previously reported genetic risk for AF, AF in the presence of stroke, and cardioembolic stroke (Pearson r = 0.77 and 0.76, respectively, across SNPs with p < 4.4 × 10-4 in the previous AF meta-analysis). An AF PRS, adjusted for clinical AF risk factors, was associated with cardioembolic stroke (odds ratio [OR] per SD = 1.40, p = 1.45 × 10-48), explaining ∼20% of the heritable component of cardioembolic stroke risk. The AF PRS was also associated with stroke of undetermined cause (OR per SD = 1.07, p = 0.004), but no other primary stroke subtypes (all p > 0.1).Genetic risk of AF is associated with cardioembolic stroke, independent of clinical risk factors. Studies are warranted to determine whether AF genetic risk can serve as a biomarker for strokes caused by AF.
View details for DOI 10.1212/NXG.0000000000000293
View details for Web of Science ID 000455099800017
View details for PubMedID 30584597
View details for PubMedCentralID PMC6283455
Effects of Genetic Variants Associated with Familial Hypercholesterolemia on Low-Density Lipoprotein-Cholesterol Levels and Cardiovascular Outcomes in the Million Veteran Program.
Circulation. Genomic and precision medicine
2018; 11 (12)
Familial hypercholesterolemia (FH) is characterized by inherited high levels of low-density lipoprotein cholesterol (LDL-C) and premature coronary heart disease (CHD). Over a thousand low-frequency variants in LDLR, APOB and PCSK9 have been implicated in FH but few have been examined at the population level. We aim to estimate the phenotypic effects of a subset of FH variants on LDL-C and clinical outcomes among 331,107 multi-ethnic participants.We examined the individual and collective association between putatively pathogenic FH variants included on the MVP biobank array and the maximum LDL-C level over an interval of 15 years (maxLDL). We assessed the collective effect on clinical outcomes by leveraging data from 61.7 million clinical encounters.We found 8 out of 16 putatively pathogenic FH variants with ≥30 observed carriers to be significantly associated with elevated maxLDL (9.4-80.2 mg/dL). Phenotypic effects were similar for European and African Americans despite substantial differences in carrier frequencies. Based on observed effects on maxLDL, we identified a total of 748 carriers (1:443) who had elevated maxLDL (36.5±1.4 mg/dL, p=1.2×10-152), and higher prevalence of clinical diagnoses related to hypercholesterolemia and CHD in a phenome-wide scan. Adjusted for maxLDL, FH variants collectively associated with higher prevalence of CHD (odds ratio, 1.59 [95% CI 1.36-1.86], p=1.1×10-8) but not peripheral artery disease.The distribution and phenotypic effects of putatively pathogenic FH variants were heterogeneous within and across variants. More robust evidence of genotype-phenotype associations of FH variants in multi-ethnic populations is needed to accurately infer at-risk individuals from genetic screening.
View details for DOI 10.1161/CIRCGEN.118.002192
View details for PubMedID 31106297
View details for PubMedCentralID PMC6516478
- Effects of Genetic Variants Associated with Familial Hypercholesterolemia on Low-Density Lipoprotein-Cholesterol Levels and Cardiovascular Outcomes in the Million Veteran Program CIRCULATION-GENOMIC AND PRECISION MEDICINE 2018; 11 (12)
Effect of Genetic Variation in Loss of Function Variants in PCSK9 on Atherosclerotic Vascular Disease
LIPPINCOTT WILLIAMS & WILKINS. 2018
View details for Web of Science ID 000528619403432
- Genetics of blood lipids among similar to 300,000 multi-ethnic participants of the Million Veteran Program NATURE GENETICS 2018; 50 (11): 1514-+
Risk factor profile and anatomic features of previously asymptomatic patients presenting with carotid-related stroke
MOSBY-ELSEVIER. 2018: 1390-1395
Although carotid atherosclerotic-mediated stroke remains a major cause of morbidity and mortality, some have suggested intervention in carotid stenosis should be limited to symptomatic patients given the advances in medical therapy. The present study was conducted to assess the atherosclerotic risk factor profiles, anatomic features, and clinical outcomes of previously asymptomatic patients admitted with stroke of carotid etiology.We reviewed the data from 3382 patients admitted to a tertiary referral center with an ischemic stroke during 2005 to 2015. We focused on patients admitted with a radiographically confirmed infarct ipsilateral to a documented carotid artery stenosis ≥50%, with the admitting neurology team adjudicating the stroke etiology as carotid related. Patients were excluded if they had had a previous transient ischemic attack, previous infarct ipsilateral to any carotid lesion, or previous carotid revascularization, intracranial hemorrhage, or malignancy. Patient demographic data, medical treatments before stroke, stroke admission carotid imaging, and stroke treatments and outcomes were assessed.A total of 219 carotid stroke patients (7% of all strokes) were identified, of whom 61% were white and 66% were men, with a mean age of 68 ± 12 years. Hypertension (79%) and smoking (33% current; 29% former) were predominant risk factors. On admission, 50% were receiving antiplatelet therapy (aspirin, n = 92 [41%]; clopidogrel, n = 9 [4%]; dual therapy, n = 11 [5%]) and 55% were receiving lipid-lowering agents (statin, n = 115 [53%]; other, n = 6 [2%]); 77 patients (35%) were receiving both antiplatelet and lipid-lowering therapy. Of the 219 patients, 156 (71%) presented with a moderate or severe stroke (National Institutes of Health stroke scale ≥5 at admission), 54 (25%) received lytic therapy, 96 (43%) presented with an occluded ipsilateral internal carotid artery, and 117 (53%) ultimately underwent carotid revascularization at a median of 4 days. Individuals receiving both antiplatelet and lipid-lowering therapy were significantly less likely to experience a moderate or severe stroke (44% vs 78%; P = .006).Internal carotid artery occlusion is the culprit lesion in 43% of carotid-related strokes in those without previous symptoms. Previously asymptomatic patients not receiving combined antiplatelet and lipid-lowering medical therapy presenting with carotid-related stroke are significantly more likely to experience a severe, debilitating stroke. However, those receiving appropriate risk-reduction medical therapy are still at risk of carotid-mediated stroke. These results suggest medical therapy alone is unlikely to be sufficient stroke prevention for patients with significant carotid stenosis.
View details for DOI 10.1016/j.jvs.2018.01.064
View details for Web of Science ID 000447883100015
View details for PubMedID 29804741
Genetics of blood lipids among ~300,000 multi-ethnic participants of the Million Veteran Program.
The Million Veteran Program (MVP) was established in 2011 as a national research initiative to determine how genetic variation influences the health of US military veterans. Here we genotyped 312,571 MVP participants using a custom biobank array and linked the genetic data to laboratory and clinical phenotypes extracted from electronic health records covering a median of 10.0 years of follow-up. Among 297,626 veterans with at least one blood lipid measurement, including 57,332 black and 24,743 Hispanic participants, we tested up to around 32 million variants for association with lipid levels and identified 118 novel genome-wide significant loci after meta-analysis with data from the Global Lipids Genetics Consortium (total n>600,000). Through a focus on mutations predicted to result in a loss of gene function and a phenome-wide association study, we propose novel indications for pharmaceutical inhibitors targeting PCSK9 (abdominal aortic aneurysm), ANGPTL4 (type 2 diabetes) and PDE3B (triglycerides and coronary disease).
View details for PubMedID 30275531
Phenotypic Consequences of a Genetic Predisposition to Enhanced Nitric Oxide Signaling
2018; 137 (3): 222-232
Nitric oxide signaling plays a key role in the regulation of vascular tone and platelet activation. Here, we seek to understand the impact of a genetic predisposition to enhanced nitric oxide signaling on risk for cardiovascular diseases, thus informing the potential utility of pharmacological stimulation of the nitric oxide pathway as a therapeutic strategy.We analyzed the association of common and rare genetic variants in 2 genes that mediate nitric oxide signaling (Nitric Oxide Synthase 3 [NOS3] and Guanylate Cyclase 1, Soluble, Alpha 3 [GUCY1A3]) with a range of human phenotypes. We selected 2 common variants (rs3918226 in NOS3 and rs7692387 in GUCY1A3) known to associate with increased NOS3 and GUCY1A3 expression and reduced mean arterial pressure, combined them into a genetic score, and standardized this exposure to a 5 mm Hg reduction in mean arterial pressure. Using individual-level data from 335 464 participants in the UK Biobank and summary association results from 7 large-scale genome-wide association studies, we examined the effect of this nitric oxide signaling score on cardiometabolic and other diseases. We also examined whether rare loss-of-function mutations in NOS3 and GUCY1A3 were associated with coronary heart disease using gene sequencing data from the Myocardial Infarction Genetics Consortium (n=27 815).A genetic predisposition to enhanced nitric oxide signaling was associated with reduced risks of coronary heart disease (odds ratio, 0.37; 95% confidence interval [CI], 0.31-0.45; P=5.5*10-26], peripheral arterial disease (odds ratio 0.42; 95% CI, 0.26-0.68; P=0.0005), and stroke (odds ratio, 0.53; 95% CI, 0.37-0.76; P=0.0006). In a mediation analysis, the effect of the genetic score on decreased coronary heart disease risk extended beyond its effect on blood pressure. Conversely, rare variants that inactivate the NOS3 or GUCY1A3 genes were associated with a 23 mm Hg higher systolic blood pressure (95% CI, 12-34; P=5.6*10-5) and a 3-fold higher risk of coronary heart disease (odds ratio, 3.03; 95% CI, 1.29-7.12; P=0.01).A genetic predisposition to enhanced nitric oxide signaling is associated with reduced risks of coronary heart disease, peripheral arterial disease, and stroke. Pharmacological stimulation of nitric oxide signaling may prove useful in the prevention or treatment of cardiovascular disease.
View details for DOI 10.1161/CIRCULATIONAHA.117.028021
View details for Web of Science ID 000422767000003
View details for PubMedID 28982690
View details for PubMedCentralID PMC5771958
Exome-wide association study of plasma lipids in > 300,000 individuals
2017; 49 (12): 1758-+
We screened variants on an exome-focused genotyping array in >300,000 participants (replication in >280,000 participants) and identified 444 independent variants in 250 loci significantly associated with total cholesterol (TC), high-density-lipoprotein cholesterol (HDL-C), low-density-lipoprotein cholesterol (LDL-C), and/or triglycerides (TG). At two loci (JAK2 and A1CF), experimental analysis in mice showed lipid changes consistent with the human data. We also found that: (i) beta-thalassemia trait carriers displayed lower TC and were protected from coronary artery disease (CAD); (ii) excluding the CETP locus, there was not a predictable relationship between plasma HDL-C and risk for age-related macular degeneration; (iii) only some mechanisms of lowering LDL-C appeared to increase risk for type 2 diabetes (T2D); and (iv) TG-lowering alleles involved in hepatic production of TG-rich lipoproteins (TM6SF2 and PNPLA3) tracked with higher liver fat, higher risk for T2D, and lower risk for CAD, whereas TG-lowering alleles involved in peripheral lipolysis (LPL and ANGPTL4) had no effect on liver fat but decreased risks for both T2D and CAD.
View details for PubMedID 29083408
View details for PubMedCentralID PMC5709146
Heritability of Atrial Fibrillation
2017; 10 (6)
Previous reports have implicated multiple genetic loci associated with AF, but the contributions of genome-wide variation to AF susceptibility have not been quantified.We assessed the contribution of genome-wide single-nucleotide polymorphism variation to AF risk (single-nucleotide polymorphism heritability, h2g ) using data from 120 286 unrelated individuals of European ancestry (2987 with AF) in the population-based UK Biobank. We ascertained AF based on self-report, medical record billing codes, procedure codes, and death records. We estimated h2g using a variance components method with variants having a minor allele frequency ≥1%. We evaluated h2g in age, sex, and genomic strata of interest. The h2g for AF was 22.1% (95% confidence interval, 15.6%-28.5%) and was similar for early- versus older-onset AF (≤65 versus >65 years of age), as well as for men and women. The proportion of AF variance explained by genetic variation was mainly accounted for by common (minor allele frequency, ≥5%) variants (20.4%; 95% confidence interval, 15.1%-25.6%). Only 6.4% (95% confidence interval, 5.1%-7.7%) of AF variance was attributed to variation within known AF susceptibility, cardiac arrhythmia, and cardiomyopathy gene regions.Genetic variation contributes substantially to AF risk. The risk for AF conferred by genomic variation is similar to that observed for several other cardiovascular diseases. Established AF loci only explain a moderate proportion of disease risk, suggesting that further genetic discovery, with an emphasis on common variation, is warranted to understand the causal genetic basis of AF.
View details for DOI 10.1161/CIRCGENETICS.117.001838
View details for Web of Science ID 000418461400020
View details for PubMedID 29237688
View details for PubMedCentralID PMC5966046
Genetic Interactions with Age, Sex, Body Mass Index, and Hypertension in Relation to Atrial Fibrillation: The AFGen Consortium
2017; 7: 11303
It is unclear whether genetic markers interact with risk factors to influence atrial fibrillation (AF) risk. We performed genome-wide interaction analyses between genetic variants and age, sex, hypertension, and body mass index in the AFGen Consortium. Study-specific results were combined using meta-analysis (88,383 individuals of European descent, including 7,292 with AF). Variants with nominal interaction associations in the discovery analysis were tested for association in four independent studies (131,441 individuals, including 5,722 with AF). In the discovery analysis, the AF risk associated with the minor rs6817105 allele (at the PITX2 locus) was greater among subjects ≤ 65 years of age than among those > 65 years (interaction p-value = 4.0 × 10-5). The interaction p-value exceeded genome-wide significance in combined discovery and replication analyses (interaction p-value = 1.7 × 10-8). We observed one genome-wide significant interaction with body mass index and several suggestive interactions with age, sex, and body mass index in the discovery analysis. However, none was replicated in the independent sample. Our findings suggest that the pathogenesis of AF may differ according to age in individuals of European descent, but we did not observe evidence of statistically significant genetic interactions with sex, body mass index, or hypertension on AF risk.
View details for DOI 10.1038/s41598-017-09396-7
View details for Web of Science ID 000410297900017
View details for PubMedID 28900195
View details for PubMedCentralID PMC5595875
Genetic Variation at the Sulfonylurea Receptor, Type 2 Diabetes, and Coronary Heart Disease
2017; 66 (8): 2310-2315
Despite widespread clinical use in the treatment of type 2 diabetes, the impact of sulfonylurea therapy on cardiovascular outcomes remains uncertain. Studies of naturally occurring genetic variation can be used to anticipate the expected clinical consequences of a pharmacological therapy. A common missense variant in the gene encoding a component of the sulfonylurea receptor (ABCC8 p.A1369S) promotes closure of the target channel of sulfonylurea therapy and is associated with increased insulin secretion, thus mimicking the effects of sulfonylurea therapy. Using individual-level data from 120,286 participants in the UK Biobank and summary association results from four large-scale genome-wide association studies, we examined the impact of this variant on cardiometabolic traits, type 2 diabetes, and coronary heart disease. The p.A1369S variant was associated with a significantly lower risk of type 2 diabetes (odds ratio [OR] 0.93; 95% CI 0.91, 0.95; P = 1.2 × 10-11). The variant was associated with increased BMI (+0.062 kg/m2; 95% CI 0.037, 0.086; P = 8.1 × 10-7) but lower waist-to-hip ratio adjusted for BMI, a marker of abdominal fat distribution. Furthermore, p.A1369S was associated with a reduced risk of coronary heart disease (OR 0.98; 95% CI 0.96, 0.99; P = 5.9 × 10-4). These results suggest that, despite a known association with increased weight, long-term sulfonylurea therapy may reduce the risk of coronary heart disease.
View details for DOI 10.2337/db17-0149
View details for Web of Science ID 000406014600027
View details for PubMedID 28411266
View details for PubMedCentralID PMC5521864
A Genetic Variant Associated with Five Vascular Diseases Is a Distal Regulator of Endothelin-1 Gene Expression
2017; 170 (3): 522-+
Genome-wide association studies (GWASs) implicate the PHACTR1 locus (6p24) in risk for five vascular diseases, including coronary artery disease, migraine headache, cervical artery dissection, fibromuscular dysplasia, and hypertension. Through genetic fine mapping, we prioritized rs9349379, a common SNP in the third intron of the PHACTR1 gene, as the putative causal variant. Epigenomic data from human tissue revealed an enhancer signature at rs9349379 exclusively in aorta, suggesting a regulatory function for this SNP in the vasculature. CRISPR-edited stem cell-derived endothelial cells demonstrate rs9349379 regulates expression of endothelin 1 (EDN1), a gene located 600 kb upstream of PHACTR1. The known physiologic effects of EDN1 on the vasculature may explain the pattern of risk for the five associated diseases. Overall, these data illustrate the integration of genetic, phenotypic, and epigenetic analysis to identify the biologic mechanism by which a common, non-coding variant can distally regulate a gene and contribute to the pathogenesis of multiple vascular diseases.
View details for DOI 10.1016/j.cell.2017.06.049
View details for Web of Science ID 000406462400011
View details for PubMedID 28753427
View details for PubMedCentralID PMC5785707
Protein-Truncating Variants at the Cholesteryl Ester Transfer Protein Gene and Risk for Coronary Heart Disease
2017; 121 (1): 81-+
Therapies that inhibit CETP (cholesteryl ester transfer protein) have failed to demonstrate a reduction in risk for coronary heart disease (CHD). Human DNA sequence variants that truncate the CETP gene may provide insight into the efficacy of CETP inhibition.To test whether protein-truncating variants (PTVs) at the CETP gene were associated with plasma lipid levels and CHD.We sequenced the exons of the CETP gene in 58 469 participants from 12 case-control studies (18 817 CHD cases, 39 652 CHD-free controls). We defined PTV as those that lead to a premature stop, disrupt canonical splice sites, or lead to insertions/deletions that shift frame. We also genotyped 1 Japanese-specific PTV in 27561 participants from 3 case-control studies (14 286 CHD cases, 13 275 CHD-free controls). We tested association of CETP PTV carrier status with both plasma lipids and CHD. Among 58 469 participants with CETP gene-sequencing data available, average age was 51.5 years and 43% were women; 1 in 975 participants carried a PTV at the CETP gene. Compared with noncarriers, carriers of PTV at CETP had higher high-density lipoprotein cholesterol (effect size, 22.6 mg/dL; 95% confidence interval, 18-27; P<1.0×10-4), lower low-density lipoprotein cholesterol (-12.2 mg/dL; 95% confidence interval, -23 to -0.98; P=0.033), and lower triglycerides (-6.3%; 95% confidence interval, -12 to -0.22; P=0.043). CETP PTV carrier status was associated with reduced risk for CHD (summary odds ratio, 0.70; 95% confidence interval, 0.54-0.90; P=5.1×10-3).Compared with noncarriers, carriers of PTV at CETP displayed higher high-density lipoprotein cholesterol, lower low-density lipoprotein cholesterol, lower triglycerides, and lower risk for CHD.
View details for DOI 10.1161/CIRCRESAHA.117.311145
View details for Web of Science ID 000403914900012
View details for PubMedID 28506971
View details for PubMedCentralID PMC5523940
Large-scale analyses of common and rare variants identify 12 new loci associated with atrial fibrillation.
2017; 49 (6): 946-952
Atrial fibrillation affects more than 33 million people worldwide and increases the risk of stroke, heart failure, and death. Fourteen genetic loci have been associated with atrial fibrillation in European and Asian ancestry groups. To further define the genetic basis of atrial fibrillation, we performed large-scale, trans-ancestry meta-analyses of common and rare variant association studies. The genome-wide association studies (GWAS) included 17,931 individuals with atrial fibrillation and 115,142 referents; the exome-wide association studies (ExWAS) and rare variant association studies (RVAS) involved 22,346 cases and 132,086 referents. We identified 12 new genetic loci that exceeded genome-wide significance, implicating genes involved in cardiac electrical and structural remodeling. Our results nearly double the number of known genetic loci for atrial fibrillation, provide insights into the molecular basis of atrial fibrillation, and may facilitate the identification of new potential targets for drug discovery.
View details for DOI 10.1038/ng.3843
View details for PubMedID 28416818
Genetic Evidence for Overlap in the Pathogenesis of Peripheral Artery Disease and Coronary Artery Disease
LIPPINCOTT WILLIAMS & WILKINS. 2017
View details for Web of Science ID 000408316600152
ANGPTL3 Deficiency and Protection Against Coronary Artery Disease
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2017; 69 (16): 2054-2063
Familial combined hypolipidemia, a Mendelian condition characterized by substantial reductions in all 3 major lipid fractions, is caused by mutations that inactivate the gene angiopoietin-like 3 (ANGPTL3). Whether ANGPTL3 deficiency reduces risk of coronary artery disease (CAD) is unknown.The study goal was to leverage 3 distinct lines of evidence-a family that included individuals with complete (compound heterozygote) ANGPTL3 deficiency, a population based-study of humans with partial (heterozygote) ANGPTL3 deficiency, and biomarker levels in patients with myocardial infarction (MI)-to test whether ANGPTL3 deficiency is associated with lower risk for CAD.We assessed coronary atherosclerotic burden in 3 individuals with complete ANGPTL3 deficiency and 3 wild-type first-degree relatives using computed tomography angiography. In the population, ANGPTL3 loss-of-function (LOF) mutations were ascertained in up to 21,980 people with CAD and 158,200 control subjects. LOF mutations were defined as nonsense, frameshift, and splice-site variants, along with missense variants resulting in <25% of wild-type ANGPTL3 activity in a mouse model. In a biomarker study, circulating ANGPTL3 concentration was measured in 1,493 people who presented with MI and 3,232 control subjects.The 3 individuals with complete ANGPTL3 deficiency showed no evidence of coronary atherosclerotic plaque. ANGPTL3 gene sequencing demonstrated that approximately 1 in 309 people was a heterozygous carrier for an LOF mutation. Compared with those without mutation, heterozygous carriers of ANGPTL3 LOF mutations demonstrated a 17% reduction in circulating triglycerides and a 12% reduction in low-density lipoprotein cholesterol. Carrier status was associated with a 34% reduction in odds of CAD (odds ratio: 0.66; 95% confidence interval: 0.44 to 0.98; p = 0.04). Individuals in the lowest tertile of circulating ANGPTL3 concentrations, compared with the highest, had reduced odds of MI (adjusted odds ratio: 0.65; 95% confidence interval: 0.55 to 0.77; p < 0.001).ANGPTL3 deficiency is associated with protection from CAD.
View details for DOI 10.1016/j.jacc.2017.02.030
View details for Web of Science ID 000399292100009
View details for PubMedID 28385496
View details for PubMedCentralID PMC5404817
Genetic Analysis of Venous Thromboembolism in UK Biobank Identifies the ZFPM2 Locus and Implicates Obesity as a Causal Risk Factor
2017; 10 (2)
UK Biobank is the world's largest repository for phenotypic and genotypic information for individuals of European ancestry. Here, we leverage UK Biobank to understand the inherited basis for venous thromboembolism (VTE), a leading cause of cardiovascular mortality.We identified 3290 VTE cases and 116 868 controls through billing code-based phenotyping. We performed a genome-wide association study for VTE with ≈9 000 000 imputed single-nucleotide polymorphisms. We performed a phenome-wide association study for a genetic risk score of 10 VTE-associated variants. To assess whether obesity is a causal factor for VTE, we performed Mendelian randomization analysis using a genetic risk score instrument composed of 68 body mass index-associated variants. The genome-wide association study for VTE replicated previous findings at the F5, F2, ABO, F11, and FGG loci. We identified 1 new locus-ZFPM2 rs4602861-at genome-wide significance (odds ratio, 1.11; 95% confidence interval, 1.07-1.15; P=4.9×10-10) and a new independent variant at the F2 locus (rs3136516; odds ratio, 1.10; 95% confidence interval, 1.06-1.13; P=7.60×10-9). In a phenome-wide association study, a 10 single-nucleotide polymorphism VTE genetic risk score was associated with coronary artery disease (odds ratio, 1.08; 95% confidence interval, 1.05-1.10 per unit increase in VTE odds; P=1.08×10-9). In a Mendelian randomization analysis, genetically elevated body mass index (a 1 SD increase) was associated with 57% higher risk of VTE (odds ratio, 1.57; 95% confidence interval, 1.08-1.97; P=0.003).For common diseases such as VTE, biobanks provide potential to perform genetic discovery, explore the phenotypic consequences for disease-associated variants, and test causal inference.
View details for DOI 10.1161/CIRCGENETICS.116.001643
View details for Web of Science ID 000425676700007
View details for PubMedID 28373160
View details for PubMedCentralID PMC5395047
Evaluation of the Pooled Cohort Equations for Prediction of Cardiovascular Risk in a Contemporary Prospective Cohort
AMERICAN JOURNAL OF CARDIOLOGY
2017; 119 (6): 881-885
Most guidelines suggest a baseline risk assessment to guide atherosclerotic cardiovascular disease (ASCVD) prevention strategies. The American Heart Association/American College of Cardiology Pooled Cohort Equations (PCEs) is one tool to assess baseline risk; however, the accuracy of this tool has been called into question. We aimed to examine the calibration and discrimination of the PCEs in the BioImage study, a contemporary multiethnic cohort of asymptomatic adults enrolled from 2008 to 2009 in the Humana Health System in Chicago, Illinois, and Fort Lauderdale, Florida. Our primary end point was hard ASCVD, defined as cardiovascular death, myocardial infarction, and stroke. A total of 3,635 adults who were not on lipid-lowering therapy at baseline were followed for a maximum of 4.6 years. The mean age was 68.6 years; 2000 (55%) participants were women and 935 patients reported being of non-white race (26%). Although 74 ASCVD events were observed over a median follow-up of 2.7 years, 198 events were predicted by the PCEs. The observed event rate was 7.9 per 1,000 participant-years (95% confidence interval [CI] 6.1 to 9.8), whereas the predicted rate by the PCEs was 21 per 1,000 participant-years (95% CI 20.7 to 21.8). This represents an overestimation of 167% (Hosmer-Lemeshow chi-square = 173; p <0.001). With regard to discrimination, the C-statistic of the PCEs was 0.65 (CI 0.58 to 0.71). In an analysis restricted to 3,080 participants without diabetes mellitus and with low-density lipoprotein cholesterol between 70 and 189 mg/dl, the PCEs similarly overestimated risk by 181% (152 predicted events vs 54 observed events; p <0.001). The PCEs substantially overestimate ASCVD risk in this middle-aged adult insured population. Refinement of existing risk prediction functions may be warranted.
View details for DOI 10.1016/j.amjcard.2016.11.042
View details for Web of Science ID 000397079300010
View details for PubMedID 28061997
Genetic Association of Waist-to-Hip Ratio With Cardiometabolic Traits, Type 2 Diabetes, and Coronary Heart Disease
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
2017; 317 (6): 626-634
In observational studies, abdominal adiposity has been associated with type 2 diabetes and coronary heart disease (CHD). Whether these associations represent causal relationships remains uncertain.To test the association of a polygenic risk score for waist-to-hip ratio (WHR) adjusted for body mass index (BMI), a measure of abdominal adiposity, with type 2 diabetes and CHD through the potential intermediates of blood lipids, blood pressure, and glycemic phenotypes.A polygenic risk score for WHR adjusted for BMI, a measure of genetic predisposition to abdominal adiposity, was constructed with 48 single-nucleotide polymorphisms. The association of this score with cardiometabolic traits, type 2 diabetes, and CHD was tested in a mendelian randomization analysis that combined case-control and cross-sectional data sets. Estimates for cardiometabolic traits were based on a combined data set consisting of summary results from 4 genome-wide association studies conducted from 2007 to 2015, including up to 322 154 participants, as well as individual-level, cross-sectional data from the UK Biobank collected from 2007-2011, including 111 986 individuals. Estimates for type 2 diabetes and CHD were derived from summary statistics of 2 separate genome-wide association studies conducted from 2007 to 2015 and including 149 821 individuals and 184 305 individuals, respectively, combined with individual-level data from the UK Biobank.Genetic predisposition to increased WHR adjusted for BMI.Type 2 diabetes and CHD.Among 111 986 individuals in the UK Biobank, the mean age was 57 (SD, 8) years, 58 845 participants (52.5%) were women, and mean WHR was 0.875. Analysis of summary-level genome-wide association study results and individual-level UK Biobank data demonstrated that a 1-SD increase in WHR adjusted for BMI mediated by the polygenic risk score was associated with 27-mg/dL higher triglyceride levels, 4.1-mg/dL higher 2-hour glucose levels, and 2.1-mm Hg higher systolic blood pressure (each P < .001). A 1-SD genetic increase in WHR adjusted for BMI was also associated with a higher risk of type 2 diabetes (odds ratio, 1.77 [95% CI, 1.57-2.00]; absolute risk increase per 1000 participant-years, 6.0 [95% CI, CI, 4.4-7.8]; number of participants with type 2 diabetes outcome, 40 530) and CHD (odds ratio, 1.46 [95% CI, 1.32-1.62]; absolute risk increase per 1000 participant-years, 1.8 [95% CI, 1.3-2.4]; number of participants with CHD outcome, 66 440).A genetic predisposition to higher waist-to-hip ratio adjusted for body mass index was associated with increased risk of type 2 diabetes and coronary heart disease. These results provide evidence supportive of a causal association between abdominal adiposity and these outcomes.
View details for DOI 10.1001/jama.2016.21042
View details for Web of Science ID 000394870900017
View details for PubMedID 28196256
View details for PubMedCentralID PMC5571980
Genetic analysis in UK Biobank links insulin resistance and transendothelial migration pathways to coronary artery disease.
2017; 49 (9): 1392-1397
UK Biobank is among the world's largest repositories for phenotypic and genotypic information in individuals of European ancestry. We performed a genome-wide association study in UK Biobank testing ∼9 million DNA sequence variants for association with coronary artery disease (4,831 cases and 115,455 controls) and carried out meta-analysis with previously published results. We identified 15 new loci, bringing the total number of loci associated with coronary artery disease to 95 at the time of analysis. Phenome-wide association scanning showed that CCDC92 likely affects coronary artery disease through insulin resistance pathways, whereas experimental analysis suggests that ARHGEF26 influences the transendothelial migration of leukocytes.
View details for DOI 10.1038/ng.3914
View details for PubMedID 28714974
View details for PubMedCentralID PMC5577383
Phenotypic Characterization of Genetically Lowered Human Lipoprotein(a) Levels
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2016; 68 (25): 2761-2772
Genomic analyses have suggested that the LPA gene and its associated plasma biomarker, lipoprotein(a) (Lp[a]), represent a causal risk factor for coronary heart disease (CHD). As such, lowering Lp(a) levels has emerged as a therapeutic strategy. Beyond target identification, human genetics may contribute to the development of new therapies by defining the full spectrum of beneficial and adverse consequences and by developing a dose-response curve of target perturbation.The goal of this study was to establish the full phenotypic impact of LPA gene variation and to estimate a dose-response curve between genetically altered plasma Lp(a) and risk for CHD.We leveraged genetic variants at the LPA gene from 3 data sources: individual-level data from 112,338 participants in the U.K. Biobank; summary association results from large-scale genome-wide association studies; and LPA gene sequencing results from case subjects with CHD and control subjects free of CHD.One SD genetically lowered Lp(a) level was associated with a 29% lower risk of CHD (odds ratio [OR]: 0.71; 95% confidence interval [CI]: 0.69 to 0.73), a 31% lower risk of peripheral vascular disease (OR: 0.69; 95% CI: 0.59 to 0.80), a 13% lower risk of stroke (OR: 0.87; 95% CI: 0.79 to 0.96), a 17% lower risk of heart failure (OR: 0.83; 95% CI: 0.73 to 0.94), and a 37% lower risk of aortic stenosis (OR: 0.63; 95% CI: 0.47 to 0.83). We observed no association with 31 other disorders, including type 2 diabetes and cancer. Variants that led to gain of LPA gene function increased the risk for CHD, whereas those that led to loss of gene function reduced the CHD risk.Beyond CHD, genetically lowered Lp(a) levels are associated with a lower risk of peripheral vascular disease, stroke, heart failure, and aortic stenosis. As such, pharmacological lowering of plasma Lp(a) may influence a range of atherosclerosis-related diseases.
View details for DOI 10.1016/j.jacc.2016.10.033
View details for Web of Science ID 000392990600007
View details for PubMedID 28007139
View details for PubMedCentralID PMC5328146
Gene-gene Interaction Analyses for Atrial Fibrillation
2016; 6: 35371
Atrial fibrillation (AF) is a heritable disease that affects more than thirty million individuals worldwide. Extensive efforts have been devoted to the study of genetic determinants of AF. The objective of our study is to examine the effect of gene-gene interaction on AF susceptibility. We performed a large-scale association analysis of gene-gene interactions with AF in 8,173 AF cases, and 65,237 AF-free referents collected from 15 studies for discovery. We examined putative interactions between genome-wide SNPs and 17 known AF-related SNPs. The top interactions were then tested for association in an independent cohort for replication, which included more than 2,363 AF cases and 114,746 AF-free referents. One interaction, between rs7164883 at the HCN4 locus and rs4980345 at the SLC28A1 locus, was found to be significantly associated with AF in the discovery cohorts (interaction OR = 1.44, 95% CI: 1.27-1.65, P = 4.3 × 10-8). Eight additional gene-gene interactions were also marginally significant (P < 5 × 10-7). However, none of the top interactions were replicated. In summary, we did not find significant interactions that were associated with AF susceptibility. Future increases in sample size and denser genotyping might facilitate the identification of gene-gene interactions associated with AF.
View details for DOI 10.1038/srep35371
View details for Web of Science ID 000387283300001
View details for PubMedID 27824142
View details for PubMedCentralID PMC5099695
Perioperative and long-term impact of chronic kidney disease on carotid artery interventions
JOURNAL OF VASCULAR SURGERY
2016; 64 (5): 1295-1302
Chronic kidney disease (CKD) increases morbidity and mortality after vascular procedures and adversely affects late survival of patients. The presence of CKD also confers increased risk of stroke in patients with asymptomatic carotid stenosis. Patients undergoing carotid intervention in the Vascular Study Group of New England database were stratified by CKD status referable to periprocedural and late outcomes.All carotid artery stenting and carotid endarterectomies (CEAs) performed from 2003 to 2013 were stratified by CKD severity as mild (estimated glomerular filtration rate [eGFR] >60 mL/min/1.73 m2), moderate (eGFR 30-59), and severe (eGFR <30). The impact of CKD on outcomes of carotid procedures was evaluated using univariate and multivariate methods.Of 12,568 patients identified, 11,746 (93%) underwent CEA and 822 (7%) underwent carotid artery stenting. Procedures were performed for symptomatic disease in 40%. CKD severity was mild in 58%, moderate in 35%, and severe in 7%. The 30-day stroke rate was very low across all CKD groups (1.76% mild vs 1.84% moderate and 1.34% severe; P = .009). The 30-day mortality increased with worsening renal function (0.4% mild vs 0.9% moderate and 0.9% severe; P = .01). Independent predictors of 30-day stroke or death included American Society of Anesthesiologists (ASA) class 4 or 5 (odds ratio, 2.3; 95% confidence interval [CI], 1.5-3.4; P = .0001). Multivariable Cox hazards regression showed that severe CKD (hazard ratio [HR], 1.8; 95% CI, 1.3-2.6), ASA class 4 or 5 (HR, 1.7; 95% CI, 1.3-2.2), preoperative cortical symptoms (HR, 1.5; 95% CI, 1.2-1.8), history of diabetes (HR, 1.4; 95% CI, 1.1-1.7), and age (HR, 1.03/y; 95% CI, 1.02-1.04) independently (all P < .01) predicted neurologic events or death at median follow-up of 12.7 months (interquartile range, 10.3-15.2 months). CKD did not increase the risk of neurologic events at 1-year follow-up. Predictors (P < .05) of late death included moderate CKD (HR, 1.3; 95% CI, 1.01-1.7), severe CKD (HR, 2.2; 95% CI, 1.6-2.9), ASA class 4 or 5 (HR, 1.6; 95% CI, 1.2-2.0), history of diabetes (HR, 1.4; 95% CI, 1.2-1.7), chronic obstructive pulmonary disease (HR, 1.4; 95% CI, 1.1-1.8), and cortical symptoms (HR, 1.3; 95% CI, 1.05-1.6). The 1-, 5-, and 10-year survival rates decreased with worsening renal function (log-rank test, P < .001), but patients with severe CKD maintained a 71% survival at 5 years.CKD severity increases risk of perioperative mortality as well as late mortality. Patients with CKD benefit from stroke-free survival especially after CEA. Unlike patients with peripheral arterial occlusive disease, for whom severe CKD reduces median survival to ∼2.5 years, patients with CKD and carotid disease exhibit much longer survival. This suggests that carotid interventions have utility in carefully selected patients with moderate and severe CKD, particularly in symptomatic disease.
View details for DOI 10.1016/j.jvs.2016.04.038
View details for Web of Science ID 000390042100014
View details for PubMedID 27776697
Low-Dose IL-2 for In Vivo Expansion of CD4(+) and CD8(+) Regulatory T Cells in Nonhuman Primates
AMERICAN JOURNAL OF TRANSPLANTATION
2012; 12 (9): 2532-2537
IL-2 is a known potent T cell growth factor that amplifies lymphocyte responses in vivo. This capacity has led to the use of high-dose IL-2 to enhance T cell immunity in patients with AIDS or cancer. However, more recent studies have indicated that IL-2 is also critical for the development and peripheral expansion of regulatory T cells (Tregs). In the current study, low-dose IL-2 (1 million IU/m(2) BSA/day) was administered to expand Tregs in vivo in naïve nonhuman primates. Our study demonstrated that low-dose IL-2 therapy significantly expanded peripheral blood CD4(+) and CD8(+) Tregs in vivo with limited expansion of non-Treg cells. These expanded Tregs are mainly CD45RA(-) Foxp3(high) activated Tregs and demonstrated potent immunosuppressive function in vitro. The results of this preclinical study can serve as a basis to develop Treg immunotherapy, which has significant therapeutic potential in organ/cellular transplantation.
View details for DOI 10.1111/j.1600-6143.2012.04133.x
View details for Web of Science ID 000307945000033
View details for PubMedID 22682297
View details for PubMedCentralID PMC3429727
Dynamic Multibody Protein Interactions Suggest Versatile Pathways for Copper Trafficking
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
2012; 134 (21): 8934-8943
As part of intracellular copper trafficking pathways, the human copper chaperone Hah1 delivers Cu(+) to the Wilson's Disease Protein (WDP) via weak and dynamic protein-protein interactions. WDP contains six homologous metal binding domains (MBDs) connected by flexible linkers, and these MBDs all can receive Cu(+) from Hah1. The functional roles of the MBD multiplicity in Cu(+) trafficking are not well understood. Building on our previous study of the dynamic interactions between Hah1 and the isolated fourth MBD of WDP, here we study how Hah1 interacts with MBD34, a double-domain WDP construct, using single-molecule fluorescence resonance energy transfer (smFRET) combined with vesicle trapping. By alternating the positions of the smFRET donor and acceptor, we systematically probed Hah1-MBD3, Hah1-MBD4, and MBD3-MBD4 interaction dynamics within the multidomain system. We found that the two interconverting interaction geometries were conserved in both intermolecular Hah1-MBD and intramolecular MBD-MBD interactions. The Hah1-MBD interactions within MBD34 are stabilized by an order of magnitude relative to the isolated single-MBDs, and thermodynamic and kinetic evidence suggest that Hah1 can interact with both MBDs simultaneously. The enhanced interaction stability of Hah1 with the multi-MBD system, the dynamic intramolecular MBD-MBD interactions, and the ability of Hah1 to interact with multiple MBDs simultaneously suggest an efficient and versatile mechanism for the Hah1-to-WDP pathway to transport Cu(+).
View details for DOI 10.1021/ja3018835
View details for Web of Science ID 000304570700037
View details for PubMedID 22578168
View details for PubMedCentralID PMC3375613