Aim: There are few data regarding associations between sleep duration and subclinical atherosclerosis in Japan. The aim of this study was to evaluate associations of self-reported sleep duration with calcification in the coronary arteries (CAC) and carotid intima media thickness (IMT) in Japanese men.
Methods: This was a cross-sectional survey of 1093 randomly selected men from Kusatsu City, Japan. Average sleep duration on weekdays was estimated through questionnaire; CAC by computed tomography; and carotid IMT by ultrasonography.
Results: The prevalence of CAC was 50.0% for participants with sleep duration ＜5.5 h, 43.9% with 5.5-6.4 h, 50.0% with 6.5-7.4 h, 49.3% with 7.5-8.4 h, and 62.5% with ≥8.5 h. In univariate analysis, participants with sleep duration ≥8.5 h had significantly higher prevalence of CAC than those with 6.5-7.4 h (p=0.043). After adjustment for age and other risk factors, however, the association was not significant (p=0.776). The average IMT was 0.85 mm for participants with sleep duration ＜5.5 h, 0.83 mm with 5.5-6.4 h, 0.85 mm with 6.5-7.4 h, 0.88 mm with 7.5-8.4 h, and 0.90 mm with ≥8.5 h. None of the differences in IMT observed in crude or multivariable-adjusted analyses was significant (all p＞0.1).
Conclusion: Self-reported sleep duration was not associated with increased CAC or carotid IMT in a general population of Japanese men.
Keywords: Cardiovascular risk; Carotid intima media thickness; Coronary artery calcification; Epidemiology; Sleep duration.