The effect of smoking on the association between long-Term alcohol consumption and dyslipidemia in a middle-Aged and older population

Aims: The joint effects of chronic alcohol consumption and smoking on dyslipidemia remain unclear in a prospective design. This study examined the effect of smoking on the association between long-term alcohol consumption and risk of incident dyslipidemia. Methods: A total of 4467 participants (1866 men and 2601women) aged 40–69 years without dyslipidemia were recruited at baseline. Alcohol consumption was assessed biennially using a questionnaire and classified as light, moderate or heavy drinker. Smoking status was examined at baseline and categorized into non-smokers and current smokers. Dyslipidemia was defined as the presence of one or more of following: hypertriglyceridemia (triglyceride ≥200 mg/dL), hypercholesterolemia (total cholesterol ≥240 mg/dL), low high-density lipoprotein-cholesterol (HDL-C) < 40 mg/dL, or high low-density lipoprotein cholesterol ≥160 mg/dL. Results: During a follow-up period of 12 years, 2872 (64.3%) participants developed dyslipidemia. In non-smoking men, light or moderate alcohol consumption was associated with a lower risk of incident dyslipidemia such as hypertriglyceridemia and hypercholesterolemia, whereas this association was not observed in current smoking men. Unlike non-smokers, the duration of alcohol drinking >10 years was associated with a higher risk of hypertriglyceridemia in current smoking men (hazard ratio = 1.57, 95% confidence interval: 1.07–2.30, P = 0.020). In addition, alcohol consumption was inversely associated with low HDL-C regardless of smoking status. In women, alcohol consumption was inversely associated with dyslipidemia hypercholesterolemia and low HDL-C regardless of alcohol amount. Conclusion: Smoking crucially confounds the association between long-term alcohol consumption and dyslipidemia, particularly in hypertriglyceridemia and hypercholesterolemia.