Irregularities in sleep duration and timing increase the likelihood of the presence of subclinical biomarkers indicative of cardiovascular disease and atherosclerosis, according to study findings published in the Journal of the American Heart Association.
Irregular sleep has been associated with incident cardiovascular disease. However, the association between sleep regularity and atherosclerosis is not clear. For the study, researchers sought to assess the associations of sleep duration and sleep timing regularity with the risk of developing atherosclerosis among older, racially and ethnically diverse adults.
Researchers in the United States conducted a cross-sectional, multicenter, longitudinal, observational, cohort study, Multi-Ethnic Study of Atherosclerosis (MESA) Sleep Ancillary Study, where they enrolled 6814 participants who were racially and ethnically diverse, aged 45 to 84, between the years 2000 and 2002.
Of these 6814 participants, 4077 completed the fifth exam between the years 2010 and 2012. The fifth examination involved collection of subclinical biomarkers for CVD and atherosclerosis, such as carotid plaque presence, abnormal carotid intima-media thickness (cIMT), abnormal ankle-brachial index (ABI), and prevalence of coronary artery calcium (CAC).
Of these 4077 individuals, 2261 participated in the MESA Sleep Ancillary study from 2010-2013. The final cohort for this study included 2032 individuals with 5 days or more of actigraphy wear data available. Participants in the cohort were an average age of 68.6 and 53.6% were women. About 37.9% of participants identified as White, 27.6% as Black or African American, 23.4% as Hispanic America, and 11.1% as Chinese American.
Researchers obtained data over a 7-day period through a wearable device on the nondominant wrist. Such data included sleep duration, sleep onset time, sleep regularity for both duration and onset time, and sleep fragmentation index (assessing sleep continuity and disruption throughout the sleep period). Other relevant measurements included heart rate, sleep-disordered breathing, sleep stages, and wake after sleep onset.
Following adjustments for confounding lifestyle, demographic, and cardiovascular disease risk factors, the researchers discovered a correlation between greater sleep duration irregularity and higher coronary artery calcium burden (>300; prevalence ratio, 1.33; 95% CI, 1.03-1.71) and abnormal ABI measurements (<0.9; prevalence ratio, 1.75; 95% CI, 1.03-2.95).
In addition to sleep duration irregularity, individuals demonstrating irregular sleep timing (varying times of sleep onset time greater than a 90-minute range) also had increased likelihood of high coronary artery calcium burden (prevalence ratio, 1.39; 95% CI, 1.07-1.82) compared with those who had more regular sleep timing intervals of 30 minutes or less.
“Sleep irregularity, particularly sleep duration irregularity, was associated with several measures of subclinical atherosclerosis,” the researchers noted. “Sleep regularity may be a modifiable target for reducing atherosclerosis risk,” they concluded.
One study limitation was the cross-sectional, observational design, precluding assumptions of causality.
Disclosures: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see original source for full list of disclosures.
Full KM, Huang T, Shah NA, et al. Sleep irregularity and subclinical markers of cardiovascular disease: the multi-ethnic study of atherosclerosis. J Am Heart Assoc. Published online February 15, 2023. doi:10.1161/JAHA.122.027361