The anticipated global epidemic of diabetes, largely as a consequence of increased rates of obesity, will particularly impact on people of South Asian and African Caribbean descent, two populations at elevated risk of insulin resistance. This article contrasts the consequent heightened risk of heart disease on the one hand in South Asians, and the paradoxical protection from heart disease in African Caribbeans on the other. Protection from the hypertriglyceridaemic effects of insulin resistance is likely to account for much of the African Caribbean paradox, although the mechanisms remain unclear. The growing evidence that insulin resistance is commonly observed in people with Type 1 diabetes, as well as those with Type 2 diabetes, and that features of insulin resistance may play a crucial role in the development of microvascular, as well as macrovascular complications, is also discussed. This indicates novel targets for the prevention and treatment of diabetes complications.