Epidemiology of diabetes in India--three decades of research.

India has nearly 33 million diabetic subjects today, which is briefly contributed by the urban population. The scenario is changing rapidly due to socio-economic transition occurring in the rural areas also. Availability of improved modes of transport, and less strenuously as in the vicinity have resulted in decreased physical activities. Better economic conditions have produced changes in diet habits. The conditions are more favourable for expression of diabetes in the population, which already has a racial and genetic susceptibility of the disease. Recent epidemiological data show that the situations are similar throughout the country. Prediabetic conditions like impaired glucose tolerance and impaired fasting glucose are also on the rise, indicating the possibility of further rise in the prevalence of diabetes. Metabolic syndrome, which is a constellation of cardiovascular risk factors, of which hyperglycaemia and insulin resistance are components, is also widely prevalent. The conversion to diabetes is enhanced by the low thresholds for the risk factors, such as age, body mass index and upper body adiposity. Indians have a genetic phenotype characterized by low body mass index, but with high upper body adiposity, high body fat percentage and high level of insulin resistance. With a high genetic predisposition and the high susceptibility to the environmental insults, the Indian population faces a high risk for diabetes and its associated complications. Early diagnosis of high risk groups and appropriate intervention by lifestyle modification may solution for the disease burden.