Exploring Associations Between Sleep, Physical Activity And Glycaemic Control

<div>Background:</div><div>Physical activity and sleep are lifestyle behaviours associated with health and well-being. However, few studies have examined a potential interaction among the two behaviours and most investigations of these relationships relied on self-report. Wrist accelerometers can capture the whole 24-hour physical behaviour profile but limited data on the validity of these to measure sleep exists.</div><div>Aims:</div><div>1) Assess the criterion validity of an automated sleep detection algorithm for common research-grade raw acceleration accelerometers worn on both wrists against polysomnography.</div><div>2) Establish comparability of sleep outcomes between common research-grade raw acceleration accelerometer brands, wrist placements, and sleep log condition (with/without) in free-living setting.</div><div>3) Examine the effect of exercise on sleep and the bidirectional associations with accelerometer-assessed physical activity in men with obesity.</div><div>4) Examine associations between chronotype, accelerometer-assessed sleep duration and physical activity, and short-term glycaemic control in people with type 2 diabetes.</div><div>Key findings:</div><div>1) The automated sleep detection algorithm applied to three commonly used accelerometers, worn on either wrist, provides comparable estimates of sleep compared to polysomnography but a poor measure of wakefulness during the sleep period.</div><div>2) At group level, sleep data were comparable from different accelerometers worn on either wrist irrespective of the accelerometer brand when the sleep log was not used.</div><div>3) An exercise intervention had a chronic but not an acute effect on sleep duration. Day-to-day, more physical activity predicted earlier timing of sleep onset, but worse sleep quality during the following night and vice versa.</div><div>4) Being a morning or evening chronotype was not associated with short-term glycaemic control in adults with type 2 diabetes. Achieving optimal sleep duration and increasing moderate-to-vigorous physical activity could be important for daily glucose regulation.</div><div>Conclusions:</div><div>Wrist accelerometry can be used to assess sleep and provides concurrent measures of physical activity and sleep. Evidence of an inter-relationship between the two behaviours and their association with glucose profiles highlights the importance of measuring the full 24-hour day of physical behaviours in future studies.</div>