Combined influence of nonalcoholic fatty liver and body size phenotypes on diabetes risk

BACKGROUND We aimed to determine the association between nonalcoholic fatty liver disease (NAFLD) and diabetes risk among body size phenotypes which was based on cross-classification of body mass index (BMI) categories (normal or overweight/obesity) and metabolic status (metabolically health or metabolically at-risk). METHODS We conducted a cross-sectional analysis using a cohort of 10,761 apparently healthy Chinese adults who underwent comprehensive health checkups including abdominal ultrasonography. Subjects were classified as metabolically at-risk by having any two of the following, consistent with the Adult Treatment Panel-III metabolic syndrome definition: (1) systolic/diastolic blood pressure ≥130/85 mmHg, (2) triglycerides ≥1.7 mmol/L, (3) fasting blood glucose ≥5.6 mmol/L, (4) HDL-cholesterol ≥1.0/1.3 mmol/L for men/women. RESULTS Among participants without metabolically at-risk, multivariate-adjusted odds ratios (ORs) for diabetes from NAFLD compared with those without NAFLD in the normal-weight (BMI <23 kg/m(2)) and overweight/obese (BMI ≥23 kg/m(2)) group were 2.10 (1.85-3.93) and 1.85 (1.35-2.53), respectively. Among participants with metabolically at-risk, the significant association between NAFLD and diabetes was lost, regardless of obesity status. There were only 27.1% subjects with the presence of the three factors (overweight/obesity, NAFLD, and metabolically at-risk) occurring together, while the three factors occurring together was common (56.16%) in diabetic individuals. The multivariate-adjusted ORs for diabetes were 1.1 (0.61-1.98) for overweight/obesity, 2.23 (1.05-5.14) for NAFLD, and 8.04 (5.0-12.09) for metabolically at-risk. The OR for the presence of all the three factors occurring together was 23.22 (13.96-38.63). CONCLUSIONS NAFLD was associated with diabetes risk among participants without metabolically at-risk. The clustering of overweight/obesity, NAFLD, and metabolically at-risk is common in diabetic subjects and strikingly and markedly increases the diabetes risk.