Dose-response risks of all-cause, cancer, and cardiovascular disease mortality according to sex-specific cigarette smoking pack-year quantiles.

Introduction: This study investigated the risks for all-cause death and death from cancer or cardiovascular diseases due to smoking status and behavior, focusing on differences in smoking duration and amount stratified by sex.

Methods: The integrated Korean Genome and Epidemiology Study provided data for 209770 individuals who were classified as never, former, or current smokers, based on their current smoking status. Pack-years were computed using daily average smoking amount and total smoking duration, and were categorized into quantiles separately for men and women. Based on the number of deaths in 2018, hazard ratios (HRs) were estimated for all-cause mortality, as well as for death caused by all cancers, lung cancer, and cardiovascular diseases according to pack-years adjusted for age, household income, marital status, body mass index, physical activity, and alcohol consumption.

Results: A significant increase in the risk of all-cause mortality was observed for current smokers (men HR=1.90; 95% CI: 1.69-2.14; women HR=2.25; 95% CI: 1.68-2.99) and former smokers (men HR=1.31; 95% CI: 1.17-1.47; women HR=2.35; 95% CI: 1.63-3.39) compared with that for those who had never smoked. Among men, HR for death from lung cancer was 3.13 (95% CI: 2.06-4.75) in former smokers and tended to increase with each pack-year quantile (range HR: 5.72-17.11). Among women, the HR was estimated to be 17.20 (95% CI: 6.22-47.57) only for >3rd quantile.

Conclusions: Smoking increases the risks of all-cause death. Considering the persistent risks post-smoking cessation, it is vital to focus on preventing smoking initiation and providing proactive support for successful smoking cessation and maintenance of a smoke-free lifestyle.