Insulin resistance, inflammation, and the metabolic syndrome following Roux- en-Y Gastric Bypass surgery in severely obese subjects

Several studies have demonstrated the benefits of massive weight reduction following Roux-en-Y gastric bypass (RYGBP) on the metabolic syndrome (1–3). However, the time course of the effects of RYGBP on the metabolic syndrome components and its potential underlying mechanisms has not been reported. In recent years, it has been proposed that low-grade chronic inflammation is a critical factor underlying the metabolic syndrome (4–6). Alternatively, it has been proposed that the metabolic syndrome would be better explained by a combination of factors including but not limited to low-grade systemic inflammation (7). The aim of our study was to evaluate the time course of metabolic syndrome components, insulin sensitivity and inflammatory markers, following laparoscopic RYGBP in severely obese subjects. To discriminate the effects of modest (10% of initial body weight) versus massive weight loss on the evaluated parameters, we assessed subjects at 6 and 52 weeks after surgery. A total of 36 Caucasian, severely obese subjects about to undergo RYGBP surgery (8) were evaluated (Table 1). Twenty normal-weight healthy volunteers, matched for sex and age with the obese subjects, served as controls (Table 1). The study was approved by the hospital ethics committee. Written informed consent was obtained from all participants. The 36 obese, operated subjects were evaluated within 8 weeks before RYGBP and again at 6 and 52 weeks after RYGBP. Control subjects were evaluated on a single occasion. The diagnosis of the metabolic syndrome was based on the revised Adult Treatment Panel III criteria (9). Anthropometrical and blood pressure measurements were performed as previously described (10). Venous blood was collected after an overnight fast. Plasma glucose, total cholesterol, HDL cholesterol, triglyceride levels, insulin, adiponectin, and insulin sensitivity (homeostasis model assessment of insulin resistance [HOMA-IR]) were assessed …