Background: Little is known regarding the impact of quantity and quality of sleep on the incidence of cardiovascular disease. The aim of this study was to investigate the possible independent association of late bedtime and premature coronary artery disease (PCAD).
Methods: Between October 2016 and November 2019, we conducted a cross-sectional population-based study on 30101 participants aged 20–65 years in Khuzestan Comprehensive Health Study (KCHS). Data on major risk factors of cardiovascular disease, habit history, physical activity, and sleep behavior was gathered and participants underwent blood pressure, anthropometric, and serum lipid and glucose profile measurements. PCAD was defined as documented history of developing obstructive coronary artery disease before 45 years in men and before 55 years in women.
Results: Of a total of 30101 participants (64.1% female, mean age: 41.7±11.7 years) included in this study, 1602 (5.3%, 95% confidence interval: 5.1%–5.6%) had PCAD. Late bedtime was reported in 7613 participants (25.3%, 95% confidence interval: 24.9%–25.8%). Age-sex standardized prevalence for PCAD and late bedtime were 3.62 (3.43-3.82) and 27.8 (27.2–28.4), respectively. There was no significant difference (P=0.558) regarding prevalence of PCAD between those with late bedtime (5.5%, 95% CI: 4.9%–6.0%) and those with early bedtime (5.3%, 95% CI: 5.0%–5.6%). However, after adjustment for potential confounders, late bedtime was independently associated with PCAD (OR=1.136, 95% CI=1.002–1.288, P=0.046).
Conclusion: In this study, late bedtime was significantly associated with presence of PCAD. Future prospective studies should elucidate the exact role of late bedtime in developing coronary atherosclerosis prematurely.