In wake of the newly-announced features of the Apple Watch, many wearable devices prompt individuals to stand up or even further encourage people to go for a walk by counting their steps. Certainly these measures aim to reduce a sedentary lifestyle, a lifestyle that is associated with obesity, diabetes and cardiovascular disease. Evidence now supports that being sedentary can disrupt your sleep as well.
A recent study by Buman and colleagues published in this month's issue of Chest reports on findings of the 2013 National Sleep Foundation Sleep in America Poll, a cross sectional study of 1,000 adults. (1) The authors discovered that increased total sitting time was associated with poor sleep quality. Moreover, for each additional hour of sitting while viewing television, resulted in taking longer to fall asleep, waking up earlier, and developing obstructive sleep apnea, a condition characterized by frequent intermittent blockage of the upper airway during sleep. Sleep apnea is associated with poor sleep quality and harmful periodic reduced body oxygenation. The association of sitting time and sleep disruption were independent of the body mass index, but the level of one's physical activity did modify the association of TV time and obstructive sleep apnea.
The sedentary lifestyle of many Americans is very concerning because fewer and fewer children and adults are participating in regular physical activity in favor of more sedentary activities such as television viewing, Internet surfing or playing video games. Because cardiovascular disease remains the leading cause of morbidity and mortality in America, any measure that reduces total sitting time and total "screen" time in favor of physical activity and exercise is an important strategy to prevent cardiovascular disease.
Recent evidence has also emerged linking total sleep time, sleep quality and obstructive sleep apnea to developing obesity, diabetes, and cardiovascular disease. Poor sleep quality and reduced total sleep time is linked to stress and systemic inflammation that can trigger and propagate metabolic disease including diabetes, and disturbances in vascular function that illicit cardiovascular disease. These events have been described as early as childhood, which is especially disturbing since childhood is a critical period for normal growth and development. Aberrations in normal child development can have life long lasting effects.
In addition to reducing physical activity, television and computer viewing can have other harmful effects, because new LCD and LED screens emit blue lights that delay the circadian phase rendering it more difficult to fall asleep. Accordingly screen time is routinely blamed for late sleep times for many adolescents.
Excessive sitting time reduces physical activity, promoting cardiovascular disease, and excessive sitting also disturbs sleep, which itself promotes cardiovascular disease. Therefore the detrimental effects of inactivity are compounded. The advent of devices that will remind us to get off the sofa and move our bodies will have lasting effects on the quality of one's sleep and health.
1 Buman MP, Kline CE, Youngstedt SD, Phillips B, Tulio de Mello M, Hirshkowitz M. Sitting and television viewing: novel risk factors for sleep disturbance and apnea risk? Results from the 2013 national sleep foundation sleep in America poll. Chest. 2015 Mar 1;147(3):728-34.