All-Cause and Cardiovascular Mortality in Relation to Sleep Duration: A Community-Based Cohort With Over 30 Years of Follow-Up.

The study investigated the association between sleep duration and the risks of all-cause and cardiovascular death, and elucidated the mediating role of atherosclerotic markers in these associations to identify potential biological pathways. We used data from the Chin-Shan Community Cardiovascular Cohort in Taiwan, a prospective study. After excluding individuals with incomplete data and those with cardiovascular diseases, 3305 participants were included. Participants were classified into three sleep duration groups as short (≤ 6 h), normal (7-8 h) and long (≥ 9 h) through structured questionnaires. Cox proportional hazard models and restricted cubic splines assessed the associations and non-linear trends. Causal mediation analysis was performed to identify potential mediators. During a median of 30.8 years of follow-up, after adjusting for potential confounding factors, long sleep duration was significantly associated with increased risks of all-cause mortality (adjusted hazard ratio: 1.17, 95% confidence interval: 1.01, 1.35), while short sleep duration showed no significant difference. Long sleep duration was not significantly associated with cardiovascular mortality (adjusted hazard ratio: 1.18, 95% confidence interval: 0.89, 1.56). Short sleep duration showed no significant association with either outcome. No significant interactions were found in sub-group analyses by age, sex, body mass index, hypertension and diabetes. This study found that longer sleep duration increases the risk of all-cause mortality, which may be partially mediated by systolic blood pressure.