Medical Student London Health Sciences Centre, Ontario, Canada
Background: Sleep is increasingly understood as a critical determinant of cardiovascular health. Although growing evidence supports a link between poor sleep and subclinical atherosclerosis, variation in study designs, sleep measurement methods, and population differences has made the relationship difficult to interpret. Carotid intima-media thickness (CIMT) is a validated surrogate marker of subclinical atherosclerosis and a predictor of future cardiovascular events. The objective of this systematic review was to evaluate whether poor sleep quality or abnormal sleep duration are associated with increased CIMT.
METHODS AND RESULTS: We searched MEDLINE and EMBASE from inception to February 2025 for studies evaluating subjective or objective sleep metrics of quality and duration in relation to CIMT. After screening 2060 records, 26 studies were included in our analysis. The included studies encompassed a wide range of populations, with mean ages spanning from 40.0 to 79.9 years and the proportion of female participants ranging from 0% to 100%, reflecting substantial demographic diversity across cohorts. Eleven studies reported that poor sleep quality, measured via Pittsburgh Sleep Quality Index (PSQI), actigraphy, or electroencephalogram, was significantly associated with increased CIMT. Various actigraphic metrics, including poor sleep efficiency and Wake After Sleep Onset (WASO)–a marker of fragmented sleep–were associated with increased CIMT. Nine studies found that aberrant sleep duration conferred higher CIMT, with most showing a significant association between short sleep duration and increased CIMT. Notably, two studies demonstrated a U-shaped association: Wolff et al. (2008) reported elevated CIMT with both 5 hours (0.038 mm [95% CI 0.002–0.074]) and 10 hours (0.043 mm [95% CI 0.015–0.070]) of sleep compared to 8 hours (reference), while Oikonomou et al. (2021) observed higher CIMT with < 6 hours (1.02 ± 0.45 mm) and >8 hours (1.07 ± 0.52 mm) of sleep compared to 7–8 hours (0.96 ± 0.38 mm), both p < 0.001.
Conclusion: Across diverse populations and assessment methods, poor sleep quality and short sleep duration were associated with increased CIMT, a validated marker of subclinical atherosclerosis. In some studies, excessive sleep duration–possibly reflecting fragmented or non-restorative sleep, or underlying comorbidities–was also associated with elevated CIMT. As sleep disruption becomes increasingly common, improving sleep quality and duration may offer a promising strategy for both primary and primordial prevention of cardiovascular disease.
