Actigraphy-derived Sleep Metrics Are Not Related To Central Hemodynamics Or Arterial Stiffness In Healthy Adults

Abstract

Insufficient sleep is an emerging risk factor for cardiovascular disease. PURPOSE: To evaluate the hypothesis that decrements in vascular function, due to poor sleep, may serve as a mechanistic link between sleep and cardiovascular disease, we explored relationships of actigraphy-derived sleep metrics with central hemodynamics and arterial stiffness in healthy young adults. METHODS: A total of 23 women and 27 men (23 ± 5 yrs), free of known cardiovascular, metabolic, and renal disease, and not using sleep medication, participated in this study. ActiGraph GT9X wrist-worn accelerometers were used to measure sleep efficiency, total sleep time, wake after sleep onset, and number of awakenings over a seven-day period. Vascular health measures including central pressures and augmentation index at a heart rate of 75 beats per minute (AIx75) were quantified via pulse wave analysis, and carotid femoral pulse wave velocity (cf-PWV) was assessed using applanation tonometry. Gender-specific z-scores for each of the sleep metrics were summed to assign each participant a “sleep score” (higher score = better sleep), and relationships between sleep scores and vascular health measures were explored using Pearson correlation coefficients. RESULTS: In men, sleep score (range: -4.92 to 9.10) was not related (P > 0.05) to central systolic (114 ± 15 mmHg, r = -0.26) or diastolic (72 ± 7 mmHg, r = -0.21) pressures. Similarly, in women, sleep score (range: -5.02 to 5.34) was not related (P > 0.05) to central systolic (103 ± 11 mmHg, r = -0.09) or diastolic (72 ± 10 mmHg, r = -0.21) pressures. Sleep score also failed to predict (P > 0.05) indices of arterial stiffness, AIx75 (men = 3.1 ± 12.3%, r = 0.04; women = 5.2 ± 9.5%, r = -0.25) and cf-PWV (men = 6.2 ± 0.8 m/s, r = -0.12; women = 5.7 ± 0.5 m/s, r = -0.10). CONCLUSIONS: In young healthy individuals, actigraphy-derived sleep characteristics were not related to central hemodynamics or non-invasive indices of arterial stiffness. Previously documented relationships between sleep and vascular function may be limited to less healthy populations, poorer sleepers, or only for certain sleep metrics.