Abstract 040: Sleep Regularity And Subclinical Markers Of Cardiovascular Disease: The Multi Ethnic Study Of Atherosclerosis (MESA)

Abstract

Background: Sleep irregularity has been linked to incident cardiovascular disease (CVD). Less is known about sleep regularity and associations with atherosclerosis. Our objective was to examine associations of sleep regularity with measures of atherosclerosis in the diverse MESA cohort. Methods: Participants from the MESA Sleep Study (2010-2013; N=2,032, Mean age: 68.6 ± 9.2 years; 53% Female, 38% White, 28% Black or African American, 23% Hispanic, 11% Chinese) completed 7-days of actigraphy. At the same exam, coronary artery calcium (CAC) was derived from computed tomography, carotid plaque presence and carotid intima-media thickness (cIMT) were derived from ultrasonography, and the ankle brachial index (ABI) was calculated from extremity measured systolic blood pressure. Sleep regularity was quantified by standard deviations in sleep durations and sleep onset time across wear days and categorized in 30 minute (mins) increments. Adjusted relative risk regression models were used to calculate prevalence ratios (PRs) and 95% confidence intervals (CI) for associations of measures of sleep regularity with each subclinical marker of CVD. Models adjusted for demographics, CVD risk factors, and objectively-assessed obstructive sleep apnea. Results: After multivariable adjustment, and compared to those with regular sleep durations (SD≤60 mins), participants with greater sleep duration irregularity (SD>120 mins) were more likely to have high CAC burden [CAC >300; PR (95% CI): 1.36 (1.03-1.78)], carotid plaque [1.10 (1.00-1.22)] and an abnormal ABI [ABI <0.9; 1.74 (1.00-3.02)]. Compared to participants with regular sleep timing (SD≤30 mins), those with irregular sleep timing (SD>90 mins) were 1.38 (1.04-1.83) times more likely to have high CAC burden. Associations did not vary by age or sex. Conclusion: Sleep regularity, particularly sleep duration regularity, was associated with measures of subclinical CVD in this diverse cohort. Sleep regularity is a modifiable sleep dimension worthy of further investigation.