Future risk of diabetes among Indians with metabolic and phenotypic obesity: Results from the 10-year follow-up of the Chennai Urban Rural Epidemiology Study (CURES–158)

Aim To investigate the risk of type 2 diabetes (T2DM) among the combinations of BMI categories and metabolic syndrome in Asian Indians. Materials and methods Individuals from the Chennai Urban Rural Epidemiology Study cohort ( n = 1,368), free of diabetes at baseline were stratified by BMI and metabolic health as metabolically healthy non-obese (MHNO), metabolically healthy obese (MHO), metabolically obese non-obese (MONO) and metabolically obese obese (MOO). Phenotypic obesity was defined as BMI ≥ 25 kg/m 2 and metabolic obesity as presence of any two of the metabolic abnormalities: hyperglycemia, high blood pressure, high triglyceridemia or low HDL cholesterol. Hazard ratios for progression to diabetes were estimated using Cox proportional hazard regression. Results During median 9.1 years of follow-up, incident cases of diabetes were highest among MOO–45.1%, followed by MONO–41.3%, MHO–27.1% and MHNO–15.9%. Incidence rates of diabetes among MOO, MONO, MHO and MHNO were 57.8, 50.9, 30.4 and 18.1 per 1000 person years, respectively. Hazard ratio for diabetes development were 1.71 in MHO, 2.87 in MONO, and 3.39 in MOO compared with MHNO. Conclusions Increased BMI and metabolic risk factor clustering independently contribute to the increased risk of T2DM in obese individuals. Screening for metabolic abnormalities should be performed routinely in clinic to identify high-risk individuals and institute appropriate preventive measures.