Prevalence of non-alcoholic fatty liver disease in urban south Indians in relation to different grades of glucose intolerance and metabolic syndrome.

AIM: To estimate prevalence of non-alcoholic fatty liver disease (NAFLD) and its association with glucose intolerance (type 2 diabetes (DM), prediabetes) and metabolic syndrome (MS) in urban south Indians.

METHODS: This study was carried out in 541 subjects (response rate 92%) of the original sample of 26,001 subjects in the Chennai Urban Rural Epidemiology Study maintaining the representativeness. Anthropometry and lipid estimations were done in all and oral glucose tolerance test in all, except self-reported diabetic subjects. NAFLD was diagnosed by ultrasonography and MS by modified Adult Treatment Panel III (ATP III) criteria. DM, impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) were defined using WHO consulting group criteria.

RESULTS: Overall prevalence of NAFLD was 32% (173/541 subjects) (men: 35.1%, women: 29.1%, p=0.140). Prevalence of most cardio-metabolic risk factors was significantly higher in NAFLD subjects. Prevalence of NAFLD (54.5%) was higher in subjects with DM compared to those with prediabetes (IGT or IFG) (33%), isolated IGT (32.4%), isolated IFG (27.3%) and normal glucose tolerance (NGT) (22.5%) (DM vs. prediabetes: p<0.05, DM vs. NGT: p<0.001, prediabetes vs. NGT: p<0.05). Even after adjusting for age, gender and waist circumference, NAFLD was associated with diabetes (OR: 2.9, 95% C.I.: 1.9-4.6, p<0.001) and MS (OR: 2.0, 95% C.I.: 1.3-3.1, p<0.001).

CONCLUSION: NAFLD is present in a third of urban Asian Indians and its prevalence increases with increasing severity of glucose intolerance and in MS. This is the first population-based prevalence of NAFLD from south Asia which faces the brunt of the diabetes epidemic.