Academic Appointments

  • Clinical Scholar, Medicine

Honors & Awards

  • Humanism and Excellence in Teaching Award, Arnold P. Gold Foundation (2020)
  • Julian Wolfsohn Award, Stanford University (2019)

Professional Education

  • Chief Residency, Stanford University, Internal Medicine (2023)
  • Residency, Stanford University, Internal Medicine (2022)
  • Medical School, David Geffen School of Medicine at UCLA (2019)

All Publications

  • The current trends in the health burden of primary liver cancer across the globe. Clinical and molecular hepatology Konyn, P., Ahmed, A., Kim, D. 2023

    View details for DOI 10.3350/cmh.2023.0092

    View details for PubMedID 36916167

  • Causes and Risk Profiles of Mortality among Individuals with Nonalcoholic Fatty Liver. Clinical and molecular hepatology Konyn, P., Ahmed, A., Kim, D. 2022


    Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the United States and worldwide. Though nonalcoholic fatty liver per se may not be independently associated with an increased risk for all-cause mortality, it is associated with a number of harmful metabolic risk factors, such as type 2 diabetes mellitus, hyperlipidemia, obesity, a sedentary lifestyle, and an unhealthy diet. The fibrosis stage is a predictor of all-cause mortality in NAFLD. Mortality in individuals with NAFLD has been steadily increasing, and the most common cause-specific mortality for NAFLD is cardiovascular disease, followed by extra-hepatic cancer, liver-related mortality, and diabetes. High-risk profiles for mortality in NAFLD include PNPLA3 I148M polymorphism, low thyroid function and hypothyroidism, and sarcopenia. Achieving weight loss through adherence to a high-quality diet and sufficient physical activity is the most important predictor of improvement in NAFLD severity and the benefit of survival. Given the increasing health burden of NAFLD, future studies with more long-term mortality data may demonstrate an independent association between NAFLD and mortality.

    View details for DOI 10.3350/cmh.2022.0351

    View details for PubMedID 36417893

  • Reply: Does Fatty Liver Play a Role in the Risk of All-Cause and Cause-Specific Mortality in Patients with Gallstone Disease? Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Kim, D., Konyn, P., Ahmed, A. 2022

    View details for DOI 10.1016/j.cgh.2022.08.002

    View details for PubMedID 35963540

  • Gallstone Disease and its Association with Nonalcoholic Fatty Liver Disease, All-Cause and Cause-Specific Mortality. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Konyn, P., Alshuwaykh, O., Dennis, B. B., Cholankeril, G., Ahmed, A., Kim, D. 2022


    BACKGROUND AND AIMS: Presence of gallstone disease may influence outcomes in patients with nonalcoholic fatty liver disease (NAFLD). We studied the impact of gallstone disease on mortality in individuals with and without NAFLD.METHODS: Prospective cohort study using the Third National Health and Nutrition Examination Survey (1988-1994) with mortality data through 2015. Gallstone disease was defined as ultrasonographic evidence of gallstones or absence of the gallbladder (prior cholecystectomy). NAFLD was defined using standardized ultrasonographic criteria.RESULTS: Gallstone disease and cholecystectomy were independently associated with NAFLD (odds ratio [OR]: 1.75, 95% confidence interval [CI]: 1.43-2.15 for gallstone disease and OR: 2.77, 95% CI: 2.01-3.83 for cholecystectomy compared to no gallstone disease). During the median follow-up of 23 years, gallstone disease was associated with a higher risk of overall all-cause mortality (hazard ratio [HR]: 1.19, 95% CI: 1.05-1.37) and cause-specific mortality. Gallstone disease was associated with a higher risk of all-cause mortality in non-NAFLD sub-cohort (HR: 1.42, 95% CI 1.23-1.64), but not in NAFLD (HR: 1.03, 95% CI: 0.87-1.22). Gallstone disease was associated with a higher risk of cardiovascular (HR: 1.40, 95% CI 1.10-1.78) and cancer (HR: 1.71, 95% CI: 1.18-2.48)-related mortality in non-NAFLD sub-cohort. Gallstone disease was associated with increased cardiovascular mortality (HR: 1.36, 95% CI: 1.05-1.77) in NAFLD.CONCLUSION: Gallstone disease is an independent risk factor for NAFLD, but gallstone disease is not associated with all-cause mortality in individuals with NAFLD. Screening for gallstone disease in individuals at risk for developing NAFLD may help with risk stratification for all-cause mortality related to gallstone disease.

    View details for DOI 10.1016/j.cgh.2022.04.043

    View details for PubMedID 35643414

  • Mortality Trends in Chronic Liver Disease and Cirrhosis in the United States, before and during COVID-19 Pandemic. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Kim, D., Bonham, C. A., Konyn, P., Cholankeril, G., Ahmed, A. 2021

    View details for DOI 10.1016/j.cgh.2021.07.009

    View details for PubMedID 34256143

  • Physical Activity is Associated with Nonalcoholic Fatty Liver Disease and Significant Fibrosis measured by Fibroscan. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Kim, D., Konyn, P., Cholankeril, G., Ahmed, A. 2021


    BACKGROUND: /Aims: Studies evaluating the association of 2018 Physical Activity (PA) Guidelines for Americans (PA Guidelines) with nonalcoholic fatty liver (NAFLD) and significant fibrosis/cirrhosis are needed. We evaluated the association of meeting PA Guidelines with NAFLD and significant fibrosis/cirrhosis by transient elastography in the US.METHODS: A cross-sectional analysis was performed using the 2017-2018 US National Health and Nutrition Examination Survey data. NAFLD and significant fibrosis/cirrhosis were defined by transient elastography in the absence of other causes of chronic liver disease. The detailed PA questionnaire assessed the leisure-time, occupation, and transportation-related PA. PA was categorized based on the PA Guidelines.RESULTS: Of the 4,304 subjects, leisure-time PA, which met the PA Guidelines (≥150 minutes/week), was associated with 44% lower risk of NAFLD (odds ratio [OR]: 0.56, 95% confidence interval [CI]: 0.46-0.67). Subjects who reported 1-2 times (150-299 minutes/week) or over 2 times (≥300 minutes/week) the recommended amount of PA Guidelines had 40% (OR: 0.60, 95% CI: 0.41-0.90) and 49% (OR: 0.51, 95% CI: 0.40-0.65) lower odds of NAFLD, respectively. Over 8 hours of sitting time had a 44% higher risk of NAFLD (OR: 1.44, 95% CI: 1.01-2.05), when we considered leisure-time PA and sitting time simultaneously. Over 2 times (≥300 minutes/week) recommended amount of PA Guidelines for leisure-time PA had 59% (OR: 0.41, 95% CI: 0.22-0.74) lower risk for significant fibrosis and 63% (OR: 0.37, 95% CI: 0.21-0.64) lower odds of cirrhosis.CONCLUSIONS: Meeting PA Guidelines for leisure-time PA has beneficial effects on NAFLD and over two times recommended amount of PA Guidelines had lower risk for significant fibrosis or cirrhosis.

    View details for DOI 10.1016/j.cgh.2021.06.029

    View details for PubMedID 34214678

  • Trends in the Mortality of Biliary Tract Cancers Based on Their Anatomical Site in the United States From 2009 to 2018. The American journal of gastroenterology Kim, D., Konyn, P., Cholankeril, G., Bonham, C. A., Ahmed, A. 2021; 116 (5): 1053–62


    INTRODUCTION: Recent trends in the incidence and mortality of biliary tract cancers are unknown. We estimated the trends in biliary tract cancers-related incidence and mortality stratified by anatomical site, age, sex, and race/ethnicity in the US adults.METHODS: We performed a population-based trend analysis using the US national incidence (2009-2017) and mortality records (2009-2018). We identified age-standardized incidence and mortality from intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma, gallbladder cancer, and ampulla of Vater cancer using appropriate ICD-10 code. Temporal mortality was calculated by joinpoint trend analysis with estimates of annual percentage change (APC) described as each trend segment.RESULTS: The incidence rates of ICC increased linearly (APC 8.9%, 95% confidence interval [CI] 7.8%-10.0%) while gallbladder cancer-related incidence rates remained stable early and decreased significantly later in the study (APC -2.8%, 95% CI -5.5% to -0.0% [2014-2017]). Age-standardized mortality from biliary tract cancers steadily increased with an annual increase of 2.0% (95% CI 1.6%-2.3%). Although there was a linear increase in the ICC-related mortality (APC 3.5%, 95% CI 3.1%-3.8%), extrahepatic cholangiocarcinoma-related mortality tended to remain stable earlier and increased later (APC 7.0%, 95% CI 4.6%-9.5% [2013-2018]). By contrast, gallbladder cancer-related mortality steadily decreased over 10 years (APC -1.6%, 95% CI -2.1% to -1.1%). Significant differences in mortality and changes in trends over time were observed in non-Hispanic blacks, Hispanics, and non-Hispanic Asians.DISCUSSION: In this analysis of nationally representative data, changing mortality trends in various biliary tract cancers was noted with a disproportionately higher burden of fatality in minorities.

    View details for DOI 10.14309/ajg.0000000000001151

    View details for PubMedID 33929380

  • Metabolic dysfunction-associated fatty liver disease is associated with increased all-cause mortality in the United States. Journal of hepatology Kim, D., Konyn, P., Sandhu, K. K., Dennis, B. B., Cheung, A. C., Ahmed, A. 2021


    Recently, international experts have put forward a modified criterion to redefine nonalcoholic fatty liver disease (NAFLD) as metabolic-associated fatty liver disease (MAFLD). It is suspected that outcomes such as mortality may differ for these clinical entities. We studied the impact of MAFLD and NAFLD on the all-cause and cause-specific mortality in US adults.We analyzed data from 7,761 participants in the Third National Health and Nutrition Examination Survey and their linked mortality through 2015. NAFLD was diagnosed by ultrasonographic evidence of hepatic steatosis without other known liver diseases. MAFLD was defined based on the criteria proposed by an international expert panel. The Cox proportional hazard model was used to study all-cause mortality and cause-specific mortality between MAFLD and NAFLD with adjustments for known risk factors.During a median follow-up of 23 years, individuals with MAFLD had a 17% higher risk for all-cause mortality (hazard ratio [HR] 1.17, 95% confidence interval [CI] 1.04-1.32). Furthermore, MAFLD was associated with a higher risk for cardiovascular mortality. NAFLD per se did not increase the risk of all-cause deaths. Individuals who met both definitions were noted to have a higher risk for all-cause mortality (HR: 1.13, 95% CI: 1.00-1.26). Also, MAFLD without NAFLD had 1.7-fold higher all-cause mortality (HR: 1.66, 95% CI: 1.19-2.32). Individuals with advanced fibrosis and MAFLD had higher estimates for all-cause mortality than those with advanced fibrosis and NAFLD.In this US population-based study, MAFLD was associated with increased risk of all-cause mortality, while NAFLD demonstrated no association with all-cause mortality after adjusting for metabolic risk factors.Our findings provide further support to the idea that nonalcoholic fatty liver disease (NAFLD) is a part of a broader multi-system disease that also includes obesity, diabetes, high blood pressure, and high cholesterol. Therefore, re-defining NAFLD as metabolic dysfunction-associated fatty liver disease (MAFLD) may provide a better understanding of predictors that may increase the risk of death.

    View details for DOI 10.1016/j.jhep.2021.07.035

    View details for PubMedID 34380057

  • Current Epidemiology in Hepatocellular Carcinoma. Expert review of gastroenterology & hepatology Konyn, P., Ahmed, A., Kim, D. 2021


    IntroductionHepatocellular carcinoma (HCC) is the sixth most common cancer and the third-leading cause of cancer-related mortality in the world.Areas coveredThis review will discuss risk factors, demographic differences, global trends, and the economic burden of HCC. Viral hepatitis, particularly hepatitis B virus (HBV) infection, is the most common underlying liver disease leading to HCC in those with cirrhosis. Other important risk factors include alcoholic liver disease, nonalcoholic fatty liver disease, metabolic syndrome, etc. With the introduction of direct-acting antiviral agents for hepatitis C virus infection, routine vaccination against HBV, and increasing support for robust public screening programs, the incidence rates for HCC due to viral hepatitis is falling in many countries. Meanwhile, the prevalence of obesity and metabolic syndrome are on the rise, as is NAFLD-related HCC incidence. Asia and Africa have the highest incidence rates of HCC. In multiethnic countries, racial and ethnic minorities experience disparities in HCC incidence as well as mortality, representing an essential area for improvement in terms of healthcare inequity.Expert opinionInterventions to minimize the global burden of HCC aim to reduce rates of the most common risk factors and implement effective treatment of underlying etiology and comprehensive screening programs for HCC.

    View details for DOI 10.1080/17474124.2021.1991792

    View details for PubMedID 34624198

  • Decline in Annual Mortality of Hepatitis C Virus-related Hepatocellular Carcinoma in the United States, From 2009 to 2018. Gastroenterology Kim, D., Konyn, P., Cholankeril, G., Wong, R. J., Younossi, Z. M., Ahmed, A. 2020

    View details for DOI 10.1053/j.gastro.2020.05.007

    View details for PubMedID 32389664

  • Rural-Urban Geographical Disparities in Hepatocellular Carcinoma Incidence Among US Adults, 2004-2017. The American journal of gastroenterology Wong, R. J., Saab, S. n., Konyn, P. n., Sundaram, V. n., Khalili, M. n. 2020


    To evaluate impact of urbanicity and household income on hepatocellular carcinoma (HCC) incidence among US adults.HCC incidence was evaluated by rural-urban geography and median annual household income using 2004-2017 Surveillance, Epidemiology, and End Results data.Although overall HCC incidence was highest in large metropolitan regions, average annual percent change in HCC incidence was greatest among more rural regions. Individuals in lower income categories had highest HCC incidence and greatest average annual percent change in HCC incidence.Disparities in HCC incidence by urbanicity and income likely reflect differences in risk factors, health-related behaviors, and barriers in access to healthcare services.

    View details for DOI 10.14309/ajg.0000000000000948

    View details for PubMedID 32976121

  • New Face of Hepatitis C DIGESTIVE DISEASES AND SCIENCES Wu, T., Konyn, P. G., Cattaneo, A. W., Saab, S. 2019; 64 (7): 1782-1788


    Chronic hepatitis C viral (HCV) infection continues to carry a high burden of disease despite recent and emerging advancements in treatment. The persistently high prevalence of HCV is attributed to the rising opioid epidemic, with a history of injection drug use as the primary risk factor for infection. As a result, the epidemiology of HCV-infected individuals is changing. Previously a disease of "Baby Boomers," males, and non-Hispanic blacks, the new generation of patients with HCV includes younger adults from 20 to 39 years of age, both men and women similarly represented, and non-Hispanic whites. Shifting trends in these demographics may be attributed to the use of injection drugs, which also has suggested impact on fibrosis progression in infected individuals. Awareness of the changing face of HCV is necessary to expand and revise recommendations regarding screening, outreach, and care engagement of infected individuals, in order to best identify patients at-risk for infection.

    View details for DOI 10.1007/s10620-019-05511-y

    View details for Web of Science ID 000472169300011

    View details for PubMedID 30756208

  • Management Approaches to Hepatitis B Virus Vaccination Nonresponse. Gastroenterology & hepatology Yanny, B., Konyn, P., Najarian, L. M., Mitry, A., Saab, S. 2019; 15 (2): 93-99


    Background: Despite the availability of hepatitis B virus (HBV) vaccination, HBV remains a cause of significant morbidity and mortality around the world. Immunologic response and the development of immunity to the HBV vaccine vary significantly among patients. Multiple studies have looked at patients who are at risk of nonresponse and have offered their own approaches to patients who do not respond. This article reviews the best approaches to HBV vaccine nonresponse. Methods: We searched the PubMed database for all articles on HBV vaccination response from 1981 to January 2018. Recommended and tested approaches to nonresponse were identified. Results: A total of 71 adequate-quality studies with 2354 patients were identified. Repeat vaccination with the same dose increased immunologic seroconversion in 85.7% of patients who previously reported nonresponse and in over 80% of patients with end-stage renal disease, HIV infection, hepatitis C virus (HCV) infection, advanced age, hypoalbuminemia, liver cirrhosis, and hemodialysis (HD) dependence. Patients with inflammatory bowel disease, celiac disease, and diabetes had a milder response (67.5%). Increasing the vaccination dose to 40 µg improved seroconversion in HIV-infected, HCV-infected, and HD patients of initial nonresponse. The use of a subcutaneous injection route increased response by 12% in patients infected with HIV. Conclusion: Patients not responding to an initial vaccine series and not actively infected with HBV benefited from reimmunization by repeating the vaccine series or receiving a single-dose vaccine booster. Although the overall response rate was approximately 90% of previous nonresponders, the rate varied among the populations studied.

    View details for PubMedID 31011303

    View details for PubMedCentralID PMC6469266

  • Hepatocellular Carcinoma Clinical Epidemiology of Chronic Liver Disease Suraweera, D., Konyn, P., Vu, T., Saab, S. Springer, Cham.. 2018: 229-249
  • Extrahepatic Manifestations of Primary Biliary Cholangitis GUT AND LIVER Chalifoux, S. L., Konyn, P. G., Choi, G., Saab, S. 2017; 11 (6): 771-780


    Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by progressive destruction of the intrahepatic bile ducts, leading to cholestasis. PBC is known to have both hepatic and extrahepatic manifestations. Extrahepatic manifestations are seen in up to 73% of patients with PBC, with the most common being Sjogren's syndrome, thyroid dysfunction and systemic sclerosis. It is thought that patients with PBC are at increased risk of developing these extrahepatic manifestations, almost all of which are autoimmune, because patients with autoimmune disease are at higher risk of developing another autoimmune condition. Due to the high prevalence of extrahepatic diseases in patients with PBC, it is important to complete a thorough medical history at the time of diagnosis. Prompt recognition of extrahepatic disease can lead to improved patient outcomes and quality of life. The following review summarizes the most common extrahepatic conditions associated with PBC.

    View details for DOI 10.5009/gnl16365

    View details for Web of Science ID 000414775200007

    View details for PubMedID 28292174

    View details for PubMedCentralID PMC5669592

  • Medical Management of Metabolic Complications of Liver Transplant Recipients. Gastroenterology & hepatology Barnard, A., Konyn, P., Saab, S. 2016; 12 (10): 601-608


    Improved short- and long-term survival of liver transplant recipients has led to increased focus on complications of both the early and late posttransplant periods. A variety of metabolic complications have been observed in the post-orthotopic liver transplant population, including hypertension, hyperlipidemia, obesity, diabetes mellitus, nonalcoholic fatty liver disease, and nonalcoholic steatohepatitis. Although only a small proportion of patients experience metabolic complications prior to transplantation, the prevalence of these complications posttransplantation reaches or exceeds that of the general population. This is of particular concern, as cardiovascular disease is the second leading cause of death in the late transplant period. A number of mechanisms mediate these metabolic complications, including reversal of cirrhosis pathophysiology, patient lifestyle factors, and immunosuppressive medications. Titration and modification of immunosuppression have been demonstrated to improve and sometimes even eliminate these conditions. Therefore, given the multiple etiologies contributing to the metabolic derangements, an effective management approach must incorporate lifestyle modifications, immunosuppression titration, and medical management. Best practices and understanding of the mechanisms underlying these complications allow for discussion of initial therapies and strategies; however, further study is necessary to determine the optimal management of metabolic complications over time.

    View details for PubMedID 27917074

    View details for PubMedCentralID PMC5114502

  • Limited Knowledge of Acetaminophen in Patients with Liver Disease JOURNAL OF CLINICAL AND TRANSLATIONAL HEPATOLOGY Saab, S., Konyn, P. G., Viramontes, M. R., Jimenez, M. A., Grotts, J. F., Hamidzadah, W., Dang, V. P., Esmailzadeh, N. L., Choi, G., Durazo, F. A., El-Kabany, M. M., Han, S. B., Tong, M. J. 2016; 4 (4): 281-287


    Background and Aims: Unintentional acetaminophen overdose remains the leading cause of acute liver failure in the United States. Patients with underlying liver disease are at higher risk of poor outcomes from acetaminophen overdose. Limited knowledge of acetaminophen may be a preventable contributor to elevated rates of overdose and thus acute liver failure. The purpose of this study is to assess knowledge of acetaminophen dosing and presence of acetaminophen in common combination products in patients with liver disease. Methods: We performed a cross-sectional study of patients with liver disease at the Pfleger Liver Institute at the University of California, Los Angeles between June 2015 and August 2016. Patients completed a demographic questionnaire and an acetaminophen knowledge survey. Additional information was obtained from the medical record. Results: Of 401 patients with liver disease, 30 (15.7%) were able to correctly identify that people without liver disease can safely take up to 4 g/day of acetaminophen. The majority of patients (79.9%-86.8%) did not know that Norco® (hydrocone/acetaminophen), Vicodin® (hydrocone/acetaminophen) and Percocet® (oxycodone/acetaminophen) contained acetaminophen. Only 45.3% of the patients knew that Tylenol® #3 contained acetaminophen. Conclusions: We conclude that patients with liver disease have critically low levels of knowledge of acetaminophen, putting them at risk both of acetaminophen overdose, as well as undermedication, and inadequate management of chronic pain. We recommend an increase in education efforts regarding acetaminophen dosage and its safety in the setting of liver disease. Increasing education for those at risk of low acetaminophen knowledge is essential to minimizing acetaminophen overdose rates and optimizing pain management.

    View details for DOI 10.14218/JCTH.2016.00049

    View details for Web of Science ID 000451346400001

    View details for PubMedID 28097095

    View details for PubMedCentralID PMC5225146