STUDY OBJECTIVES

The purpose of this study was to conduct a comprehensive assessment of sleep and circadian rhythms in individuals with and without coronary artery disease (CAD).

METHODS

This was a cross-sectional study. Participants were 32 individuals, mean age = 70.9, female 46.9%, 19 with CAD, and 13 without CAD. We assessed sleep quality and 24-hour rest-activity rhythms for 14 days using wrist actigraphy and self-report measures, and circadian rhythm using dim light melatonin onset.

RESULTS

Melatonin levels prior to habitual bedtime were significantly lower in individuals with CAD than in those without CAD (median area under the curve = 12.88 vs 26.33 pg/ml × h, = .049). The median circadian timing measured by dim light melatonin onset was the same for the 2 groups with 20:26 [hours:minutes] for individuals with CAD and 19:53 for the control group ( = .64, = .14). Compared to the control group, the CAD group had significantly lower amplitude ( = .03, =-.48), and lower overall rhythmicity (pseudo--statistic = .004, = -.65) in their 24-hour rest-activity rhythms.

CONCLUSIONS

This is one of the first studies to comprehensively assess both sleep and circadian rhythm in individuals with CAD. Compared to non-CAD controls, individuals with CAD had lower levels of melatonin prior to habitual bedtime and a lower 24-hour rest-activity rhythm amplitude and overall rhythmicity. Future studies using larger sample sizes should further investigate the possibility of suppressed circadian rhythmicity in individuals with CAD.

CITATION

Moon C, Benson CJ, Albashayreh A, Perkhounkova Y, Burgess HJ. Sleep, circadian rhythm characteristics, and melatonin levels in later life adults with and without coronary artery disease. . 2023;19(2):283-292.