Moderate alcohol consumption, glucose metabolism and lipolysis: the effect on adiponectin and tumor necrosis factor alpha.

Moderate alcohol consumption has a cardioprotective effect on coronary artery disease. Among the beneficial effects of alcohol, a suppression of the plasma free fatty acid (FFA) concentration has been shown but the mechanism which accounts for this action is not clear. We assessed whether moderate alcohol intake affects plasma adiponectin levels and tumor necrosis factor (TNF)-alpha, two regulators of lipolysis. Oral glucose tolerance tests were performed twice on 22 volunteers: "the alcohol study" and "control study". In the former, red wine was sipped to maintain steady state alcohol concentration. Samples for plasma glucose, insulin, FFA, adiponectin, and TNF-alpha concentrations were obtained. In the latter, tap water was sipped. Insulin action has been assessed by the Oral Glucose Insulin Sensitivity (OGIS) Model. The mean blood alcohol concentration was 5+/-2 mg/dl. No differences were observed between the two studies in the OGIS (406+/-19 ml x min(-1) x m(-2) with alcohol and 402+/-20 without, respectively). Baseline FFA levels were lower in the alcohol study; however, post-glucose inhibition was comparable. No differences in the TNF-alpha and adiponectin responses were observed. A significant correlation was observed between the OGIS index and the fasting adiponectin level (r=0.589, p<0.0001). Moderate red wine intake improves post-glucose FFA profiles but does not modify the plasma concentrations of both TNF-alpha and of adiponectin concentrations: the latter is significantly and positively associated to the insulin action. Further studies are needed to clarify the antilipolytic effect of moderate alcohol intake.