Type 2 diabetes mellitus: the grand overview.

Type 2 diabetes currently accounts for over 100 billion dollars in annual healthcare expenditure in the United States and 28% of the national (Medicare) healthcare budget for elderly Americans. In our inner-city hospital, 20% of all 950 beds are occupied by patients with diabetes; and 28-38% of patients receiving cardiac care in Coronary Care Units, catheterization laboratories or cardiovascular surgery, have diabetes as an underlying disorder. Both computer modelling and controlled clinical trials suggest that intensive therapy of diabetes can reduce significantly the morbidity and costs associated with this increasingly common disorder. Early detection of carbohydrate intolerance holds great promise for preventing the onset, progression and complications of Type 2 diabetes. To date our efforts have been futile, with 20% of newly diagnosed Type 2 diabetic patients already complicated by retinopathy and 14% complicated by peripheral vascular disease. It is now clear that high-risk individuals can be identified, and intervention trials are underway to test the hypothesis that Type 2 diabetes (and its attendant cardiovascular risks) can be prevented. The Study to Prevent Non-Insulin-Dependent Diabetes Mellitus (STOP NIDDM) in Canada and Europe has randomized 1200 individuals with impaired glucose tolerance (IGT) into a three-year trial to prevent disease progression. The Diabetes Prevention Program (DPP) in the US has randomized almost 3000 individuals with IGT into a six-year, three-arm study testing the efficacy of intensive lifestyle and pharmacological therapy in disease progression. Together, these studies should provide a public health model for the recognition of high-risk individuals and interventions to stem the epidemic of Type 2 diabetes. For those patients suffering with Type 2 diabetes already, pancreas transplantation remains an extreme intervention with the potential for 'curing' diabetes. Although applied usually to patients with Type 1 diabetes, experience is accumulating of transplantation in Type 2 diabetic patients with end-stage renal disease. Outcomes for these individuals are as good as for Type 1 diabetes. Islet-cell transplants, in fact, have been more successful in Type 2 diabetes compared with Type 1. Improved islet-cell availability, better immunosuppression, and the possibility of antigen masking make this technology a major hope for the future.