Intimate association of visceral obesity with non-alcoholic fatty liver disease in healthy Asians: A case-control study

Background and Aim: To identify factors associated with non-alcoholic fatty liver disease (NAFLD) in healthy Asian subjects. Methods: A propensity score-matched case-control study was designed. To investigate the effects of demographic and clinical factors on the presence of NAFLD, a baseline-category logit model was used. Potential living liver donors with no hepatic steatosis (<5%: n=1353, group 1) were considered the baseline category, and subjects with mild (5-33%: n=724, group 2) and moderate/severe (>33%: n=116, group 3) hepatic steatosis were defined as cases. Age and gender were matched between cases and controls, which resulted in 83 matched subjects in each of the three groups. The area of abdominal (visceral and subcutaneous) fat was directly measured in all subjects by unenhanced computed tomography. Results: Serum aspartate aminotransferase, alanine aminotransferase (ALT), gamma-glutamyltranspeptidase, total cholesterol and triglyceride levels, and visceral fat amount were directly correlated with the grade of hepatic steatosis, and high-density lipoprotein cholesterol levels were inversely correlated with it (all P values <0.05). In a multivariate model, visceral fat amount was significantly correlated with both mild (group 2) and moderate to severe (group 3) NAFLD, with respective odds ratios (ORs) of 1.03 relative to group 1 (Ps<0.05). Body mass index (BMI), ALT, and subcutaneous fat were significant predictors of only moderate to severe NAFLD (ORs of 0.54, 1.20, and 1.02, respectively, for group 3 vs group 1; Ps<0.05). Conclusions: Our results indicate that visceral adiposity makes non-obese subjects more susceptible to NAFLD, compared with subcutaneous fat and BMI.