OBJECTIVETo investigate the effect of body mass index (BMI) on new-onset non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM).

METHODSSubjects with T2DM were recruited from the population of individuals attending the Affiliated General Hospital of North China University for routine health examination between 2006 and 2007 and offered participation in this community-based prospective cohort study. Enrollees were categorized into groups according to weight assessed by baseline BMI (underweight, normal, overweight, and obese groups). Cumulative incidence of NAFLD was compared between each group and the effect of baseline BMI on new-onset NAFLD was assessed by Cox regression analysis.

RESULTSThe cumulative incidence of NAFLD increased in conjunction with increases in weight (low weight: 69%, normal weight: 73%, overweight: 90%, obese: 97%; P<0.01). Subjects in the overweight and obese groups showed an increased risk of NAFLD (relative risk (RR)=2.00, 95% CI: 1.76-2.29 and =2.87, 95% CI: 2.42-3.40; P<0.01), compared to those in the normal weight group. Moreover, after adjustment for baseline factors (e.g.age, sex) risk of NAFLD remained higher for the overweight and obese subjects (RR=1.73, 95% CI: 1.49-2.00 and =2.12, 95% CI: 1.73-2.60; P<0.01).

CONCLUSIONRisk of NAFLD in T2DM patients increases in parallel to increase in weight assessed by BMI. BMI appeared to be an independent risk factor for NAFLD.