Smoking cessation increases serum adiponectin levels in an apparently healthy Greek population

Background: Smoking has been associated with low serum levels of adiponectin, an adipocytokine with insulin-sensitizing, anti-inflammatory and anti-atherogenic properties. The objective of this study was to assess the early effect on adiponectin levels of smoking cessation supported by bupropion. Methods: Apparently healthy smokers of both sexes with no additional cardiovascular risk factors were administered 150 mg sustained-release bupropion twice daily for 9 weeks. Quitters constituted the active group and non-quitters the control group. Sandwich enzyme-linked immunosorbent assays were employed for the measurement of serum adiponectin and cotinine, the latter used for validation of self-reported abstinence. Results: Among the 106 participants (mean age 44.5 +/- 11.3 years, 57 females, Brinkman index 512.2 +/- 98.4, basal adiponectin 7.2 +/- 1.5 mg/L), 45 (42.5%) had quitted smoking at week 9. Quitters' post-cessation adiponectin levels were significantly increased (mean difference with baseline 1.9 +/- 0.8 mg/L, 95% Cl 1.2, 2.3; p < 0.001), while non-quitters' adiponectin remained unaltered. A multiple regression model including female gender (standardized beta coefficient = 0.480, p = 0.002), age (0.355, p = 0.003), body mass index (BMI) (-0.308, p = 0.005), waist circumference (-0.276, p = 0.008), smoking status (-0.255, p = 0.010), and cotinine levels (-0.233, p = 0.021) explained about two thirds of the variation in adiponectin levels (adjusted R-2 = 0.656). Conclusions: Serum adiponectin levels appear to increase considerably within 2 months after smoking cessation. This finding may provide further insight into the mechanisms related to the detrimental effects of smoking and the benefits of quitting. (C) 2009 Elsevier Ireland Ltd. All rights reserved.