Abstract
Diabetes mellitus is now occurring in epidemic proportions in many countries. Owing to the limited effectiveness of drug prophylaxis of diabetic complications after diabetes has developed, it may be more appropriate to investigate ways to prevent the onset of diabetes. A recent trial published by the Diabetes Prevention Programme Research Group investigated whether lifestyle changes or metformin were effective in delaying the onset of diabetes in subjects with impaired glucose tolerance. The goals of the intensive lifestyle intervention were to achieve and maintain a weight reduction of 7% through a low-calorie, low-fat diet and to engage in physical activity of moderate intensity, such as brisk walking, for at least 150 min/week. The effectiveness of the intensive lifestyle intervention on body weight was initially quite good but decreased over time. Metformin caused some weight loss but to a lesser extent than the intensive lifestyle intervention. Both therapies decreased the fasting plasma glucose levels to a similar extent initially. The intensive lifestyle intervention decreased plasma glycosylated haemoglobin levels to a greater extent than metformin. Both intensive lifestyle intervention and metformin reduced the incidence of diabetes, with the lifestyle intervention having the greater effect.