Abstract WP378: Sleep Duration and Aortic Stiffness: the Multi-Ethnic Study of Atherosclerosis

Large-arterial stiffness is recognized as a subclinical marker of cardiovascular disease (CVD). Self-reported short and long habitual sleep duration has been implicated in increased arterial stiffness. However, studies that use objective assessments of sleep duration while accounting for confounding effects of sleep apnea are scarce. We examined the association between habitual sleep duration, as assessed by actigraphy, and magnetic resonance imaging (MRI)- based aortic stiffness, controlling for other CV risk factors including sleep apnea. Method: We included participants in the Multi-Ethnic Study of Atherosclerosis who had undergone MRI assessment of aortic distensibility and a sleep study. Sleep duration was assessed by wrist actigraphy for 7-days and aortic stiffness by aortic pulse wave velocity (aPWV), ascending aorta distensibility (AAD), and descending aorta distensibility (DAD) using MRI. Multiple linear regressions were used to evaluate the association between sleep duration (defined as: short:< 6 hours, normal: 6-8 hours, and long: > 8 hours) and aPWV, AAD, or DAD, adjusting for demographic, life style factors, common cardiovascular risk, and apnea-hypopnea index. Results: The sample consisted of 908 participants (Mean age 68.4±9.1 years, 55.3% women). There was a significant linear trend of increased aPWV across short, normal, and long sleep durations (8.4 ± 3.6 vs. 8.7 ± 4.2 vs. 9.9 ± 4.9, respectively, p=0.008). In multivariable model, participants with short sleep duration (n=252), had average 0.87 m/s (95% CI: -1.47, -.27) lower PWV and 0.23 mmHg -1 (95% CI: .01, .45) higher DAD, compared with those with normal sleep duration (n=552). No significant difference in PWV or DAD was found between those with normal and long sleep duration. No associations were noted between sleep duration and AAD. Sleep duration had no significant interactions with age, gender or race. Conclusion: This study shows that short sleep duration, as assessed by actigraphy, is significantly associated with low aortic stiffness measured by MRI in a large community-based cohort. Future studies on the association between sleep duration and aortic stiffness are warranted to confirm these findings and elucidate potential underlying mechanisms.