The relationship between a Mediterranean diet and circulating adiponectin levels is influenced by cigarette smoking.

Aim: Adherence to a Mediterranean diet has been shown to lower the risk of developing several chronic diseases. The ability to augment circulating adiponectin levels is proposed as an underlying mechanism mediating the beneficial effects of this diet. We aimed to examine whether the positive relationship between the Mediterranean diet and adiponectin is altered by cigarette smoking, taking potential confounders into consideration.

Methods: Plasma adiponectin levels were enzymatically measured in 45 never smokers, 61 smokers and 34 ex-smokers who adhered to a Mediterranean style diet and in 41 never smokers who did not adhere to the diet.

Results: Plasma adiponectin levels increased significantly in nonsmoking diet adherents compared to nonsmoking non-diet adherents. Among the diet adherents adiponectin decreased significantly in both moderate and heavy smokers compared to never smokers and significantly increased in quitters compared to smokers. Multiple regression analysis, controlling for age, obesity, Mediterranean diet and insulin resistance revealed an independent inverse association of smoking with adiponectin. Adiponectin levels remained significant and similar in subjects stratified according to age (50 years), BMI (25 kg/m(2)) and HOMA-IR (1.6).

Conclusions: Despite its positive effects on adiponectin, the Mediterranean diet failed to negate the adiponectin-lowering effect of cigarette smoking, demonstrating the profound and independent capacity of cigarette smoke to negatively influence human health.