Age- and sex-specific attributable impact of modifiable risk factors on atherosclerotic cardiovascular disease in Korea: a nationwide population-based cohort study

Background: While modifiable risk factors are central to the development of atherosclerotic cardiovascular disease (ASCVD), their relative contributions differ by age, sex, region, and period. However, contemporary evidence on these patterns in the large-scale Korean population remains scarce. We aimed to quantify the age- and sex-specific burden of major modifiable risk factors for ASCVD in a large nationwide cohort. Methods: This retrospective cohort study included 6,249,852 Korean adults without prior ASCVD who underwent the National Health Screening between 2009 and 2010. The primary outcome was incident ASCVD, defined as cardiovascular death, myocardial infarction, or ischemic stroke. Participants were followed for these outcomes through linkage to the Korean National Health Insurance Service claims database and Statistics Korea mortality data. Population-attributable fractions (PAFs) for risk factors-body mass index, systolic blood pressure (SBP), smoking, diabetes, and non-HDL-cholesterol-were estimated from multivariable-adjusted Cox proportional hazards models and stratified by age and sex. Findings: In this cohort (mean age 46.9 ± 13.7 years; 52.2% men), 279,093 ASCVD events occurred (incidence rate, 3.58/1000 person-years) during a median follow-up of 13.0 years. The five risk factors collectively explained 46.2% of the ASCVD burden, with the greatest contribution from SBP, followed by smoking, non-HDL-cholesterol, diabetes, and obesity. PAFs were higher in men (52.8%) than women (30.4%), and highest in men aged