The dose–effect relationships of cigarette and alcohol consumption with depressive symptoms: a multiple-center, cross-sectional study in 5965 Chinese middle-aged and elderly men

Background Although association of depressive symptoms with cigarette or alcohol is well documented, the dose–response relationship between them is rarely studied. This study aims to evaluate dose–response relationships of cigarette and alcohol consumption with depressive symptoms in Chinese middle-aged and elderly men, providing evidence to guide cigarette and alcohol control. Methods This multiple-center, cross-sectional study including 5965 Chinese men aged 40–79 years was conducted in 2013–2016 in China. Depressive symptoms were evaluated by Beck Depression Inventory-Short Form. History of cigarette smoking and alcohol drinking were collected with a structured questionnaire. Prevalence of depressive symptoms was compared depending on cigarette and alcohol consumption. Adjusted odds ratios (OR) and 95% confidence interval (CI) were estimated by binary logistic regression. Interpolation analysis was applied to test dose–effect relationships. Results A parabolic-shaped relationship was observed between cigarette consumption and depressive symptoms. Compared to never smokers, 59.0% (OR = 1.59, 95% CI 1.30–1.94) and 29.0% (OR = 1.29, 95% CI 1.08–1.54) higher odds of depressive symptoms were observed in men smoking < 10 cigarettes/day and 10–20 cigarettes/day, whereas, similar odds of depressive symptoms among men smoking > 20 cigarettes/day ( P = 0.092). An inverted J-shaped relationship was observed between alcohol consumption and depressive symptoms. Compared to never drinkers, a tendency of higher prevalence of depressive symptoms (OR = 1.16, 95% CI 0.99–1.36) was observed in men drinking < 140 g/week, and similar prevalence was observed in those drinking 140–280 g/week ( P = 0.920), whereas, 29.4% (OR = 0.71, 95% CI 0.57–0.88) lower odds in men drinking > 280 g/week. Conclusions Associations of cigarette smoking and alcohol drinking with depressive symptoms differ with consumption in middle-aged and elderly men. Health-care providers should exercise great caution on depressive symptoms in conducting cigarette and alcohol control.