Low sleep efficiency does not impact upper or lower limb vascular function in young adults.

NEW FINDINGS What is the central question of this study? This study sought to investigate if young adults reporting low sleep quality possessed lower vascular function and altered autonomic nervous system modulation when compared to young adults reporting high sleep quality. What is the main finding and its importance? The study revealed that in young adults reporting low sleep quality, neither vascular nor autonomic function was significantly different when compared to young adults reporting high sleep quality. These findings suggest that young adults are either not substantially impacted by, or can adequately adapt to the negative consequences commonly associated with poor sleep. ABSTRACT Purpose This study sought to investigate if young adults reporting low sleep quality also possessed lower vascular function, potentially stemming from altered autonomic nervous system modulation, when compared to young adults reporting high sleep quality. Methods Thirty-one healthy young adults (age 24±4 yrs) underwent a 7-night sleep assessment (Actigraph GT3X accelerometer). Following the sleep assessment, subjects meeting specific criteria were separated into high (HSE; ≥85%; n = 11; 8 M/3 F) and low (LSE; <80%; n = 11; 9 M/2 F) sleep efficiency groups. Peripheral vascular function was assessed in the upper and lower limb, utilizing the flow mediated dilation (FMD) technique in the arm (brachial artery (BA)) and leg (superficial femoral artery (SFA)). Heart rate variability was evaluated during 5 minutes of rest and employed frequency parameters reflective of parasympathetic and/or sympathetic nervous system modulation (high (HF) and low (LF) frequency parameters). Results By experimental design, significant differences in sleep quality between groups were reported with the LSE group possessing greater time awake after sleep onset, number of awakenings, and average time per awakening when compared to the HSE group. In spite of these differences in sleep quality, no significant differences in upper and lower limb vascular function and HRV measures were revealed when comparing the LSE and HSE groups. Additionally, in all subjects (n = 31), no correlations between sleep efficiency and vascular function/autonomic modulation were revealed. Conclusion This study revealed that low sleep quality does not impact upper or lower limb vascular function or autonomic nervous system modulation in young adults. This article is protected by copyright. All rights reserved.