Cardiovascular Risk Is Elevated in Lean Subjects with Nonalcoholic Fatty Liver Disease

Background/Aims: Nonalcoholic fatty liver disease (NAFLD) and obesity are independently associated with an increased risk for atherosclerotic cardiovascular disease (ASCVD), the leading cause of mortality in patients with NAFLD. Many NAFLD patients are lean, but their ASCVD risk compared to obese subjects with NAFLD is unclear. Methods: Data from the 2008 to 2011 Korea National Health and Nutrition Examination Surveys database were analyzed (n=4,786). NAFLD was defined as a comprehensive NAFLD score ≥40 or a liver fat score ≥-0.640. ASCVD risk was evaluated using the American College of Cardiology/American Heart Association guidelines. Results: The frequency of subjects without NAFLD, with obese NAFLD, and with lean NAFLD was 62.4% (n=2,987), 26.6% (n=1,274), and 11.0% (n=525), respectively. Subjects with lean NAFLD had a significantly higher ASCVD score and prevalence of a high ASCVD risk (mean 15.6±14.0, 51.6%) than those with obese NAFLD and without NAFLD (mean 11.2±11.4, 39.8%; mean 7.9±10.9, 25.5%; all p<0.001). Subjects with lean NAFLD and significant liver fibrosis showed a significantly higher odds ratio for a high risk for ASCVD than those with obese NAFLD with or without significant liver fibrosis (odds ratio, 2.60 vs 1.93; p=0.023). Conclusions: Subjects with lean NAFLD had a significantly higher ASCVD score and prevalence of high risk for ASCVD than those with obese NAFLD. Similarly, lean subjects with significant liver fibrosis had a higher probability of ASCVD than obese subjects in the subpopulation with NAFLD.