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? We sought to investigate whether young adults reporting low sleep quality possessed lower vascular function and altered autonomic nervous system modulation when compared with 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 with 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: The aim of the study was to investigate whether young adults reporting low sleep quality also possessed lower vascular function, potentially stemming from altered autonomic nervous system modulation, when compared with young adults reporting high sleep quality. Thirty-one healthy young adults (age 24 ± 4 years) underwent a 7 night sleep assessment (Actigraph GT3X accelerometer). After the sleep assessment, subjects meeting specific criteria were separated into high (HSE; ≥85%; n = 11; eight men and three women) and low (LSE; <80%; n = 11; nine men and two women) sleep efficiency groups. Peripheral vascular function was assessed in the upper and lower limb, using the flow-mediated dilatation technique in the arm (brachial artery) and leg (superficial femoral artery). Heart rate variability was evaluated during 5 min of rest and used frequency parameters reflective of parasympathetic and/or sympathetic nervous system modulation (high- and low-frequency parameters). By experimental design, significant differences in sleep quality between groups were reported, with the LSE group exhibiting a longer time awake after sleep onset, higher number of awakenings and longer average time per awakening when compared with the HSE group. Despite these differences in sleep quality, no significant differences in upper and lower limb vascular function and heart rate variability 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. This study revealed that low sleep quality does not impact upper or lower limb vascular function or autonomic nervous system modulation in young adults.