Cutoff points of abdominal obesity indices in screening for non-alcoholic fatty liver disease in Asians

Background/aims: Abdominal obesity is associated with metabolic syndrome and non-alcoholic fatty liver disease (NAFLD). Although there have been many studies to determine the optimal cutoff points of waist circumference or visceral fat area in screening for metabolic syndrome, there have been no reports to establish adequate cutoff points of abdominal obesity indices in screening for NAFLD. Therefore, we examined the appropriate cutoff points of abdominal obesity indices associated with NAFLD in Korean men and women using receiver operating characteristic (ROC) curve analysis. Furthermore, we compared the usefulness of various abdominal obesity indices measured using computed tomography (CT), dual-energy X-ray absorptiometry (DXA) and anthropometric parameters for detecting NAFLD. Methods: We analysed the baseline data of an ongoing prospective, observational cohort study, including a total of 456 healthy subjects 20-88 years of age. NAFLD was diagnosed by unenhanced CT using the liver attenuation index. Results: All ROC curves of waist circumference, waist-to-height ratio, DXA-measured trunk fat mass and CT-measured visceral fat area were significantly above the diagonal line. There were no significant differences in the area under the curve values among these abdominal obesity indices in each gender. The appropriate cutoff point of waist circumference in screening for NAFLD was 89 cm for men and 84 cm for women and the optimal cutoff point of waist-to-height ratio was 0.52 for men and 0.53 for women with very high negative predictive values. Conclusions: The simple anthropometric parameters, such as waist circumference and waist-to-height ratio, are as useful as DXA and CT for predicting NAFLD in Korean adults.