Day-to-day variations in sleep quality affect standing balance in healthy adults

Luis Montesinos,Rossana Castaldo,Francesco P Cappuccio,Leandro Pecchia

doi:10.1038/s41598-018-36053-4

Abstract

Acute sleep deprivation is known to affect human balance and posture control. However, the effects of variations in sleep quality and pattern over consecutive days have received less attention. This study investigated the associations between day-to-day variations in sleep quality and standing balance in healthy subjects. Twenty volunteers (12 females and 8 males; age: 28.8 ± 5.7 years, body mass index: 23.4 ± 3.4 kg/m2, resting heart rate: 63.1 ± 8.7 bpm) with no history of sleep disorders or balance impairments participated in the study. Sleep and balance were assessed over two consecutive days. Sleep quality variations were assessed using sleep diary, actigraphy and heart rate variability (HRV) measures. Sleep was monitored at home, using an unobtrusive wearable device. Balance was assessed in a gait lab using foot centre of pressure (COP) displacement during quiet standing. Subjects with a day-to-day deterioration in sleep quantity and quality (i.e., decreased duration and increased fragmentation, increased nocturnal activity and decreased HRV) exhibited significant changes in balance (i.e., larger COP area, amplitude and standard deviation). Conversely, subjects with no significant alterations in sleep quantity and quality showed no significant changes in COP displacements. These results confirmed our hypothesis that changes in sleep quality and pattern over consecutive days may affect balance.

Highlights

Human balance is a fundamental skill required to perform most of our daily-life activities
This study investigated the associations between day-to-day variations in sleep quality and balance during quiet standing
We hypothesised that postural steadiness, measured by foot centre of pressure (COP) displacement, may be affected by changes in sleep quality over two consecutive nights and that deterioration in sleep quality impairs balance control

Summary

Introduction

Human balance is a fundamental skill required to perform most of our daily-life activities. Vision plays a substantial role in static balance after 24-h sleep deprivation, as suggested by wider and more fluctuating COP displacements observed when subjects are tested with eyes closed than when they are tested with eyes open[12]. After 26 hours of sleep deprivation, subjects showed higher body sway under the single-task condition and lower body sway under the dual-task condition, suggesting that cognitive load plays an important role in balance control under sleep deprivation. These findings suggest that the effects of sleep deprivation on postural steadiness found www.nature.com/scientificreports/. Balance assessment was performed via foot COP displacement using an insole pressure measurement system

Methods

Results

Conclusion