Citation: Hepatology. 66(3):825-833, 2017 Sep.Journal: Hepatology (Baltimore, Md.).Published: 2017ISSN: 0270-9139.Full author list: Takyar V; Nath A; Beri A; Gharib AM; Rotman Y.UI/PMID: 28470683.Subject(s): Adult | Aged | Aged, 80 and over | *Biomedical Research | Body Mass Index | Case-Control Studies | Clinical Trials as Topic | Cross-Sectional Studies | *Healthy Volunteers/cl [Classification] | Humans | Liver Function Tests | Male | Middle Aged | *Non-alcoholic Fatty Liver Disease/pa [Pathology] | Predictive Value of Tests | Reference Values | Reproducibility of Results | Retrospective Studies | Young AdultInstitution(s): MedStar Washington Hospital CenterDepartment(s): Medicine/Internal MedicineActivity type: Journal Article.Medline article type(s): Journal ArticleDigital Object Identifier: https://dx.doi.org/10.1002/hep.29247 (Click here)Abbreviated citation: Hepatology. 66(3):825-833, 2017 Sep.Abstract: INTRODUCTION: Healthy volunteers are crucial for biomedical research. Inadvertent inclusion of subjects with non-alcoholic fatty liver disease (NAFLD) as controls can compromise study validity and subject safety. Given the rising prevalence of NAFLD in the general population, we sought to identify its prevalence and potential impact in volunteers for clinical trials.Abstract: METHODS: Cross-sectional study of subjects with "Healthy Volunteer" diagnosis between 2011-2015 and no known liver disease. Subjects were defined presumed NAFLD (pNF, ALT>20 for women or >31 for men and BMI>25), healthy non-NAFLD controls (HC, normal ALT and BMI), or indeterminate.Abstract: RESULTS: 3160 subjects participated as healthy volunteers in 149 clinical trials, (1-29 trials per subject). 1732 (55%) had BMI>25 kg/m<sup>2</sup> and 1382 (44%) had abnormal ALT. pNF was present in 881 subjects (27.9%) and these subjects were older than HC, and had higher triglycerides, LDL-C, and HbA1c and lower HDL-C (p<0.001 for all) . The 149 trials included 101 non-interventional, 33 interventional and 15 vaccine trials. The impact on study validity of recruiting NAFLD subjects as controls was estimated as likely, probable and unlikely in 10, 41 and 98 trials, respectively. The proportion of pNF subjects (28-29%) did not differ by impact. Only 14% of trials used both BMI and ALT for screening. ALT cut-offs for screening were based on local reference values. Grade 3-4 ALT elevations during the study period were rare but more common in pNF subjects than HC (4 vs. 1).Abstract: CONCLUSION: NAFLD is common and often overlooked in volunteers for clinical trials, despite its potential impact on subject safety and validity of study findings. Increased awareness of NAFLD prevalence and stricter ALT cut-offs may ameliorate this problem. This article is protected by copyright. All rights reserved.Abstract: Copyright c 2017 by the American Association for the Study of Liver Diseases.