Age-specific associations between habitual snoring and cardiovascular diseases in China: a 10-year cohort study

Background Limited convincing evidence is available of the relationship between habitual snoring and cardiovascular diseases (CVDs). Research Question Is habitual snoring associated with total CVD and CVD subtypes in different age groups of Chinese adults? Study Design and Methods The China Kadoorie Biobank study enrolled more than 0.5 million adults aged 30 to 79 years from 10 regions in China. Snoring status and other baseline characteristics were collected from 2004 to 2008, using an interviewer-administered laptop-based questionnaire. The current analysis included 489,583 participants without stroke or coronary heart disease at baseline. Cox proportional hazards models were used to calculate the adjusted hazard ratios (HRs) and 95% CIs of cardiovascular diseases (CVDs) for habitual snoring vs nonhabitual snoring. Results During a median follow-up of 9.6 years, 130,935 participants developed CVDs. Associations between habitual snoring and CVDs varied with age. Among participants aged younger than 50 years at baseline, habitual snoring was associated with an increased risk of total CVD (HR, 1.11; 95% CI, 1.07-1.14) after adjustment for known CVD risk factors, including systolic BP. The corresponding HRs (95% CIs) for ischemic heart disease, ischemic stroke, and hemorrhagic stroke were 1.18 (1.12-1.24), 1.12 (1.05-1.19), and 1.05 (0.92-1.19), respectively. However, such associations in adults aged 50 to 64 years were much weaker, and no statistically significant association was observed among individuals aged ≥65 years. Age-specific risk estimates were generally similar across sex and obesity subgroups. Interpretation Habitual snoring was associated with increased risks of total CVD, ischemic heart disease, ischemic stroke, but not hemorrhagic stroke in Chinese, and these associations were mainly limited to those aged