Abstract Body (Do not enter title and authors here): Background: Several studies have explored the association between sleep duration and cardiovascular outcomes, but the results have been contradictory. Additionally, there are limited studies conducted within the Asian population.

Goal: This study aims to assess the relationship between sleep duration and cardiovascular outcomes in the Asian population.

Methods: This cross-sectional study used data from a survey of employees at the Electricity Generating Authority of Thailand (EGAT). Baseline demographics, sleep history, and the presence of cardiovascular diseases were collected in 2012. Self-reported usual sleep and wake times were used to calculate sleep duration. Participants were categorized into 3 groups based on sleep duration: short (< 6 hours), normal (6-8 hours), and long (> 8 hours). Logistic regression analysis was used to assess the association between sleep duration and cardiovascular outcomes, with the normal sleep duration group as a reference. Adjustments were made for variables as shown in the table.

Results: Among 1571 participants enrolled, 6%, 77%, and 17% were categorized into the short, normal, and long sleep duration groups, respectively. The mean (SD) age was 69 (4.6) years, and 73% were male, consistent across all groups. The median (IQR) sleep duration was 5 (4.5-5.0) hours, 7 (6.5-8.0) hours, and 9 (8.5-9.5) hours for the short, normal, and long sleep duration groups. Among these three groups, participants in the long sleep duration group had higher levels of HbA1C (p=0.049) and triglyceride (p=0.005), but a lower level of HDL cholesterol (p=0.003). Multiple logistic regression analysis demonstrated that long sleep duration was significantly associated with stroke, with an odd ratio (OR) of 3.25 (95% CI 1.27-8.36), and showed a non-significant trend towards a higher risk of coronary heart disease. We found no significant association between short sleep duration and cardiovascular outcomes.

Conclusion: Long sleep duration is associated with an increased risk of cardiovascular diseases, especially stroke. Additional studies with larger sample sizes are needed to investigate the effects of short sleep duration.