Association between Secondhand Smoke Exposure and the Incidence of Stroke in Never Smoker According to Alcohol Intake: 19-Year Prospective Cohort Study in Korea.

Objectives: Our study aimed to investigate both the independent and combined effects of secondhand smoking (SHS) and alcohol intake on the occurrence of stroke.

Methods: Utilizing the Korean Genome Epidemiology Study prospective cohort data, our primary exposure variables were SHS exposure and alcohol intake. The occurrence of stroke served as the main outcome of interest. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression analysis. To assess the synergistic influence of SHS and alcohol intake on stroke incidence, a joint test was conducted.

Results: SHS exposure correlated with an HR of 1.53 (95% CI = 1.19 to 1.98) for stroke risk. The combined exposure to SHS and alcohol yielded an elevated stroke risk, with an HR of 1.75 (95% CI = 1.20 to 2.55).

Conclusions: Our research highlights the combined influence of SHS exposure and alcohol intake on stroke susceptibility.