Associations of smoking and alcohol consumption with impaired β-cell function in Chinese men

Background: The aims of the present study were to examine the association of cigarette smoking and alcohol consumption with impaired β-cell function in Chinese men, particularly the interaction of smoking and alcohol consumption on impaired insulin secretion. Methods: A population-based cross-sectional study was performed in 3957 Chinese men aged ≥40 years. The homeostatic model assessment of β-cell function (HOMA-β) was calculated, and impaired β-cell function was defined as less than the lowest quartile HOMA-βcut-off point. Results: The prevalence of impaired β-cell function in current smokers and heavy drinkers (≥200g/week) was significantly higher than in non-smokers and non-drinkers, respectively. Compared with non-smoking, current smoking had an exacerbating relationship with impaired β-cell function (odds ratio [OR] 1.78; 95% confidence interval [CI] 1.47-2.15; P<0.001). No significant association was found between impaired β-cell function and former smoking (P=0.21), although low and heavy drinking were associated with an increased risk of impaired β-cell function (OR 1.40 [95% CI 1.07-1.81] and 2.14 [95% CI 1.77-2.58], respectively) compared with non-drinking. The combination of current smoking and heavy drinking was associated with the highest risk of impaired β-cell function (OR 3.16; 95% CI 2.43-4.12; P<0.0001) after adjustment for confounders. We did not detect an additive interaction between current smoking and heavy drinking on the association with impaired β-cell function. Conclusions: Cigarette smoking and alcohol consumption were significantly and independently associated with impaired β-cell function in Chinese men.