Incidence and risk factors for dysglycaemia in Asian-Indians: a 10-year population-based prospective cohort study.

BACKGROUND: Diabetes prevalence estimates suggest an increasing trend in South-East Asia region, but studies on its incidence are limited. The current study aims to estimate the incidence of type 2 diabetes and pre-diabetes in a population-based cohort from India. METHODS: A subset of Chandigarh Urban Diabetes Study cohort (n=1878) with normoglycaemia or pre-diabetes at baseline was prospectively followed after a median of 11 (0.5-11) years. Diabetes and pre-diabetes were diagnosed as per WHO guidelines. The incidence with 95% CI was calculated in 1000 person-years and Cox proportional hazard model was used to find the association between the risk factors and progression to pre-diabetes and diabetes. RESULTS: The incidence of diabetes, pre-diabetes and dysglycaemia (either pre-diabetes or diabetes) was 21.6 (17.8-26.1), 18.8 (14.8-23.4) and 31.7 (26.5-37.6) per 1000 person-years, respectively. Age (HR 1.02, 95% CI 1.01 to 1.04), family history of diabetes (HR 1.56, 95% CI 1.09 to 2.25) and sedentary lifestyle (HR 1.51, 95% CI 1.05 to 2.17) predicted conversion from normoglycaemia to dysglycaemia, while obesity (HR 2.43, 95% CI 1.21 to 4.89) predicted conversion from pre-diabetes to diabetes. CONCLUSION: A high incidence of diabetes and pre-diabetes in Asian-Indians suggests a faster conversion rate to dysglycaemia, which is partly explained by sedentary lifestyle and consequent obesity in these individuals. The high incidence rates call for a pressing need for public health interventions targeting modifiable risk factors.