Intra-abdominal obesity: an untreated risk factor for Type 2 diabetes and cardiovascular disease

The prevalence of Type 2 diabetes is showing a rapid progression worldwide, a phenomenon largely resulting from the epidemic proportions reached by obesity in various populations of the world. However, physicians have been puzzled by the heterogeneity of obesity as not every obese patient is characterized by chronic complications. In this regard, body fat distribution, especially intra-abdominal adipose tissue accumulation, has been found to be a key correlate of a cluster of diabetogenic, atherogenic, prothrombotic and inflammatory metabolic abnormalities increasing the risk of Type 2 diabetes and cardiovascular disease. In this regard, it has been recently demonstrated that abdominal obesity was independently associated with an increased risk of coronary heart disease and Type 2 diabetes independently of overall adiposity. Lifestyle modification programs have shown the benefits on cardiometabolic risk variables of a moderate weight loss as it has been found to be associated with a substantial loss of intra-abdominal fat in viscerally obese patients. However, to be successful, such programs require the support of a multidisciplinary team not available to most clinicians. In this context, it is proposed that pharmacotherapy of obesity should target abdominally obese patients at high risk of Type 2 diabetes and cardiovascular disease, such risk being encompassed by the notion of "cardiometabolic risk". The recent discovery of the endocannabinoid-cannabinoid receptor type 1 (CB1 receptor) system and of its impact on the regulation of energy metabolism represents a significant advance which could help physicians to target abdominal obesity and its related metabolic complications. In this regard, studies have shown that rimonabant (the first CB1 blocker developed) therapy could be useful for the management of clustering cardiovascular disease risk factors in high-risk abdominally obese patients through its marked effects on both abdominal adiposity and related metabolic risk factors.