Body Mass Index and Risk of Nonalcoholic Fatty Liver Disease: Two Electronic Health Record Prospective Studies

• Published in: The journal of clinical endocrinology and metabolism 2016-03, Vol.101 (3), p.945-952
• Main Authors: Loomis, A. Katrina, Kabadi, Shaum, Preiss, David, Hyde, Craig, Bonato, Vinicius, St. Louis, Matthew, Desai, Jigar, Gill, Jason M. R, Welsh, Paul, Waterworth, Dawn, Sattar, Naveed
• Format: Article
• Language: English
• Subjects: Adult; Body Mass Index; Diabetes Complications - epidemiology; Electronic Health Records; Female; Humans; Male; Middle Aged; Non-alcoholic Fatty Liver Disease - epidemiology; Original; Prospective Studies; Risk Factors; Sex Factors; Smoking - epidemiology
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2015-3444

Context: The relationship between rising body mass index (BMI) and prospective risk of nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) is virtually absent. Objective: Determine the extent of the association between BMI and risk of future NAFLD diagnosis, stratifying by sex and diabetes. Design: Two prospective studies using Humedica and Health Improvement Network (THIN) with 1.54 and 4.96 years of follow-up, respectively. Setting: Electronic health record databases. Participants: Patients with a recorded BMI measurement between 15 and 60 kg/m2, and smoking status, and 1 year of active status before baseline BMI. Patients with a diagnosis or history of chronic diseases were excluded. Interventions: None. Main Outcome Measure: Recorded diagnosis of NAFLD/NASH during follow-up (Humedica International Classification of Diseases, Ninth Revision code 571.8, and read codes for NAFLD and NASH in THIN). Results: Hazard ratios (HRs) were calculated across BMI categories using BMI of 20–22.5 kg/m2 as the reference category, adjusting for age, sex, and smoking status. Risk of recorded NAFLD/NASH increased linearly with BMI and was approximately 5-fold higher in Humedica (HR = 4.78; 95% confidence interval, 4.17–5.47) and 9-fold higher in THIN (HR = 8.93; 7.11–11.23) at a BMI of 30–32.5 kg/m2 rising to around 10-fold higher in Humedica (HR = 9.80; 8.49–11.32) and 14-fold higher in THIN (HR = 14.32; 11.04–18.57) in the 37.5- to 40-kg/m2 BMI category. Risk of NAFLD/NASH was approximately 50% higher in men and approximately double in those with diabetes. Conclusions: These data quantify the consistent and strong relationships between BMI and prospectively recorded diagnoses of NAFLD/NASH and emphasize the importance of weight reduction strategies for prevention and management of NAFLD.