Actigraphy-based sleep and muscle sympathetic nerve activity in humans

Short and insufficient sleep are prevalent and associated with cardiovascular disease, with the sympathetic nervous system as a suspected mediator. The purpose of the present study was to investigate the association between objective, actigraphy-based total sleep time (TST), sleep efficiency (SE), and cardiovascular and sympathetic regulation in healthy adults. We hypothesized that short TST and low SE would be associated with elevated resting blood pressure, heart rate (HR), and muscle sympathetic nerve activity (MSNA). Participants included 94 individuals [46 males, 48 females, age: 30 15 yr, body mass index (BMI): 26 +/- 4 kg/m(2)]. All participants underwent at least 7 days of at-home, wristwatch actigraphy monitoring (avg: 10 +/- 3 days). Seated blood pressures were assessed using brachial blood pressure measurements, followed by a 10-minute supine autonomic testing session consisting of continuous HR (electrocardiogram), beat-by-beat blood pressure (finger plethysmograph), and MSNA (microneurography) monitoring. Partial correlations were used to determine the relationship between sleep and cardiovascular parameters while accounting for the influence of age, sex, and BMI. TST was not associated with MAP (R = -0.105, P = 0.321), HR (R = 0.093, P = 0.383), or MSNA burst frequency (BF; R = -0.168, P = 0.112) and burst incidence (BI; R = -0.162, P = 0.124). Similarly, SE was not associated with MAP (R = -0.088, P = 0.408), HR (R = -0.118, P = 0.263), MSNA BF (R = 0.038, P = 0.723), or MSNA BI (R = 0.079, P = 0.459). In contrast to recent preliminary findings, our results do not support a significant association between actigraphy-based sleep duration or efficiency and measures of resting blood pressure, heart rate, and MSNA.