Early effects of smoking cessation and weight gain on plasma adiponectin levels and insulin resistance.

BACKGROUND Tobacco smoking is a major risk factor for atherosclerotic and cardiovascular disease. Studies have found evidence that smoking cessation is associated with weight gain, which is itself a leading cause of cardiovascular disease. Aim The present study sought to determine how smoking cessation and associated weight gain affect adiponectin levels and insulin resistance. METHODS Fifty-two male habitual smokers were treated for 2 months with transdermal nicotine patches, and the 28 subjects who successfully quit smoking were analyzed. Subjects were divided into two sub-groups according to their weight change: weight maintainers and weight gainers. Serum adiponectin levels and the homeostasis model assessment ratio (HOMA-R) were evaluated at the beginning of the study, and at 1 week and 9 weeks after cessation of patch use. RESULTS In weight gainers (n=18), serum adiponection levels tended to increase at 1 week after the end of treatment (mean difference 0.4 ± 1.0 µg/mL, p=0.08). Moreover, after 9 weeks, adiponectin levels were significantly decreased in weight gainers (mean difference between 1 week and 9 weeks 0.8 ± 0.9 µg/mL, p=0.002). In weight maintainers, adiponectin levels increased slightly after smoking cessation, but changes were not significant. In weight gainers, HOMA-R index was significantly increased (mean difference between baseline and 9 weeks 0.4 ± 0.7, p=0.01), while in weight maintainers, HOMA-R index showed no differences throughout the study. CONCLUSION Our findings suggest that the adverse effects of weight gain attenuate some of the beneficial effects of smoking cessation.