Abstract
PURPOSE: Habitual sleep positions might influence cardiovascular function, but its association with cardiovascular risk in the general population remains unknown. This study aimed to examine the relationship between the supine sleep position and the frequency of angina pectoris (angina), a common symptom of ischemic heart disease, and to explore whether body mass index (BMI) or sex moderate this relationship. METHODS: Data from the Sleep Heart Health Study (SHHS) were used. Supine sleep position was quantified as the percentage of total sleep duration spent in the supine position, measured by unattended home polysomnography (PSG) during the first SHHS visit. Angina frequency was defined by the number of episodes over a 15-year follow-up period. Multiple Poisson regression was conducted, adjusting for various conventional cardiovascular disease (CVD) risk factors. RESULTS: The study included 5,804 participants (52% female), with a mean age of 63 years and an average BMI of 28.16 kg/m(2). The average time spent in the supine position was 32.4%, and the mean number of angina episodes was 0.48. Longer time in the supine sleep position was independently associated with an increased risk of angina (IRR = 1.003, p < .0001); a 10% increase in supine sleep time was associated with a 3% increase in angina risk. BMI (p = .189) and sex (p = .117) did not significantly moderate this association. CONCLUSION: Sleeping in the supine position was significantly associated with more angina episodes. The study lacked information on other sleep positions. Identifying optimal sleep positions to support cardiovascular health could significantly contribute to CVD prevention.