RESUMO
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 150mg 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+/-1.5mg/L), 45 (42.5%) had quitted smoking at week 9. Quitters' post-cessation adiponectin levels were significantly increased (mean difference with baseline 1.9+/-0.8mg/L, 95% CI 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.
