Prevalence, characteristics and mortality outcomes of obese, nonobese and lean NAFLD in the United States, 1999–2016

Background Updated prevalence and outcome data for nonobese NAFLD for the multi‐ethnic US population is limited. Objectives We aimed to investigate the prevalence, clinical characteristics and mortality of obese and nonobese individuals with NAFLD in the United Sates. Methods A retrospective study was conducted using the 1999–2016 NHANES databases. We determined hazard ratio stratified by obesity status in NAFLD individuals using Cox regression and log‐rank test. Results Overall NAFLD prevalence was 32.3%: 22.7% were obese and 9.6% were nonobese, with increasing trend over time for obese NAFLD, but not nonobese NAFLD. Amongst those with NAFLD, 29.7% (95% CI: 27.8%‐31.7%) were nonobese, of which 13.6% had lean NAFLD. Nonobese NAFLD was more common in older (40.9% if ≥ 65 vs. 24.2% if