Disturbances during sleep decreases capability to control posture and balance according to researchers from the department of engineering and Warwick Medical School at the University of Warwick.
This is the first study demonstrating the relationship between disrupted sleep and the reduced capability to control posture and balance, and it could pave the way to new interventions to prevent falls in later life, should the results be confirmed by other studies on older adults.
The research shows that fragmented and disrupted sleep leads to acute balance deficit. The study was conducted by the School of Engineering in collaboration with Warwick Medical School at the University of Warwick.
A sample of healthy adults underwent sleep and balance assessment over two consecutive days, in order to determine the links between day-to-day variations in sleep quality and balance.
State-of-the-art wearable sensors were used for in-home sleep monitoring and balance testing. These findings are relevant to pave the way to the design of fall prevention programs in populations and settings where normal sleep is frequently disrupted, such as older people and hospital wards.
Dr Leandro Pecchia, team leader of the research from the School of Engineering at the University of Warwick says: “We all have direct experience of this. When we do not sleep well, we may feel a little dizzy and our capability to control our posture and balance is somehow diminished. When we are fit and in good health, our body is able to adapt and we develop a strategy to keep our balance, avoiding falls and incidents. This ability is reduced with ageing or when there are other concomitant conditions that may compromise our ability to adapt.”
Professor Francesco Cappuccio, head of the sleep, health & society programme at the University of Warwick’s medical school, explains: “The results obtained in healthy normal volunteers are surprising, given the ability at younger ages to compensate for such acute and short-lived sleep disruptions. We would expect more dramatic effects when these experiments be replicated in older people, whose vulnerability to sleep disruption, postural hypotension and risk of falls is much greater”.
Pecchia continues: “These results could contribute to the understanding of in-hospital falls. Hospitalised older patients find themselves in a frail condition, sleeping in an unfamiliar environment, with unusual nocturnal light and noises from other patients and nurses, and perhaps being administered more than one drug. Waking-up to go to the toilet can be more challenging than we can imagine. Having a nurse for each bed is not practical in the modern National Health Service (NHS) and not well accepted by many older people. We need to learn how to use available technology to detect early the changes in sleep so that we can design personalised interventions that may avoid falls in the next day. One of the problems in fall prevention is that we know a frail subject will fall, but it is very difficult to predict when. Our study is first step towards finding a solution.”
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.
Luis Montesinos, Rossana Castaldo, Francesco P Cappuccio, Leandro Pecchia