Sleep irregularity a possible marker of subclinical atherosclerosis

Duration of sleep irregularity is associated with several measures of subclinical atherosclerosis, according to a study.

The study used data from the MESA Sleep Ancillary Study and included 2,032 individuals (mean age 68.6 years, 37.9 percent White) who completed 7‐day wrist actigraphy. They also underwent assessments of coronary artery calcium, carotid plaque presence, carotid intima‐media thickness, and the ankle‐brachial index.

Researchers quantified sleep regularity over 7 days, including sleep duration and sleep onset timing. They used relative risk regression models to estimate associations and adjusted the models for potential confounders.

Compared with participants who had more regular sleep durations (≤60 minutes), those with greater sleep duration irregularity (>120 minutes) tended to have high coronary artery calcium burden (>300; prevalence ratio, 1.33, 95 percent confidence interval [CI], 1.03–1.71) and abnormal ankle‐brachial index (<0.9; prevalence ratio, 1.75, 95 percent CI, 1.03–2.95).

Moreover, participants with irregular sleep timing (>90 minutes) vs those with more regular sleep timing (≤30 minutes) were more likely to have high coronary artery calcium burden (prevalence ratio, 1.39, 95 percent CI, 1.07–1.82).

The associations were robust to adjustments for cardiovascular disease risk factors and average sleep duration, obstructive sleep apnoea, and sleep fragmentation.

The findings suggest that sleep regularity may be a modifiable target for reducing atherosclerosis risk. More studies are needed to examine the effect of cardiovascular risk reduction interventions targeting sleep irregularity.