Preventing Type 2 Diabetes
Obesity is a risk factor for type 2 diabetes. However, abdominal obesity has been more closely linked to metabolic complications that increase type 2 diabetes risk than excess body weight. Excess intra-abdominal (visceral) fat has also been shown to precede the development of type 2 diabetes. In this regard, reducing intra-abdominal fat through weight loss can improve metabolic risk variables, including glucose-insulin parameters. Several intervention studies have reported that lifestyle modification programs stressing physical activity and healthy eating could substantially reduce the risk of type 2 diabetes in high-risk patients with abdominal obesity and impaired glucose tolerance. These lifestyle modification programs were shown to be remarkably effective despite the fact that they only produced less than a 5% weight loss. By itself, physical activity has a significant metabolic impact by improving indices of plasma glucose-insulin homeostasis, even in the absence of weight loss. Although healthy lifestyle choices should be the first-line therapy to balance energy expenditure and energy intake, pharmacological measures should also be considered for high-risk abdominally obese patients who are not able to successfully improve their lifestyle. While a few studies have examined the prevention, delay, or treatment of type 2 diabetes with drugs such as thiazolidinediones (drugs that improve insulin sensitivity) or weight loss drugs, clinical trials aimed at reducing intra-abdominal adiposity are needed.