Physical Activity, Less TV Watching Associated With Lower Risk of Obstructive Sleep Apnea

An active lifestyle characterized by higher levels of exercise and less time spent sitting and watching TV may lower the risk of obstructive sleep apnea (OSA), according to study findings published last week in the European Respiratory Journal.

With 1 billion adults aged 30 to 69 years estimated to be affected by mild to severe OSA worldwide, several risk factors have been implicated in the pathogenesis of the condition, which include obesity, systemic inflammation, and insulin resistance.

Moreover, lifestyle behaviors of physical activity and sedentary time have been independently linked with the exacerbation of these risk factors and ultimately OSA as well, but study authors note that epidemiological evidence on the associations with OSA primarily consists of cross-sectional studies with incomplete exposure assessment and inadequate control for confounding.

Seeking to address limitations of these previous studies and provide further insights into exercise-based strategies for OSA prevention, researchers evaluated the independent and joint associations of physical activity and sedentary behavior with risk of incident OSA in 3 ongoing  prospective cohort studies of US health care professionals: the Nurses’ Health Study (NHS), Nurses’ Health Study II (NHSII), and Health Professionals Follow-up Study (HPFS).

“We hypothesized that (1) physical activity and sedentary behavior were independently associated with OSA incidence, (2) the observed associations were partly explained by metabolic dysfunction and body fluid retention, and (3) physical inactivity interacted synergistically with sedentary behavior to influence OSA incidence,” they noted.

In the analysis, 50,332 women from NHS (2002-2012), 68,265 women from NHSII (1995-2013), and 19,320 men from HPFS (1996-2012) were prospectively followed and assessed via questionnaires every 2 to 4 years for recreational physical activity, measured by metabolic equivalent of task (MET)–hours/week, and sitting time spent watching TV and at work/away from home.

Total physical activity was evaluated in 5 categories by MET-hours/week (< 6.0, 6.0-11.9, 12.0-20.9, 21.0-35.9, and ≥ 36.0), with cutoff points also used to differentiate between sedentary time (< 4.0, 4.0-6.9, 7.0-13.9, 14.0-27.9, and ≥ 28.0 hours/week).

Based on 2,004,663 person-years of follow-up, 8733 incident cases of OSA were found across the study cohort. In their findings, participants who spent the least amount of time per week (< 4.0 hours) sitting watching TV were shown to be 78% less likely to develop OSA than those who spent at least 28 hours per week (pooled multivariable-adjusted HR, 1.78; 95% CI, 1.60-1.98; P_trend < .001).

In comparison, people who spent the most sedentary time at work/away from home were 49% more likely than those with the least time to develop the condition (pooled multivariable-adjusted HR, 1.49; 95% CI, 1.38-1.62; P_trend < .001).

"The difference in OSA risk between sedentary work and time spent sitting watching TV could be explained by other behaviors that are related to those activities,” said Tianyi Huang, ScD, MSc, assistant professor of Medicine, Harvard Medical School, and associate epidemiologist, Brigham and Women's Hospital, in a statement.

After adjusting for metabolic factors such as body mass index and waist circumference, the association between physical activity and sitting hours at work/away from home was attenuated but remained significant (P_trend < .001), whereas the association with sitting hours watching TV was not significant (P_trend < .18).

“Snacking and drinking sugary drinks is more likely to go along with watching TV compared with being sedentary at work or elsewhere, such as sitting during traveling. This could lead to additional weight gain, which we know to be a risk factor [for] OSA," added Huang.

Furthermore, after adjusting for potential confounders, participants with the highest physical activity level (≥ 36.0 MET-hours/week) had a 54% lower risk of developing OSA than those with less than 6.0 MET-hours/week (pooled HR, 0.46; 95% CI, 0.43-0.50; P_trend < .001).

"We saw a clear relationship between levels of physical activity, sedentary behavior, and OSA risk. People who followed the current World Health Organization physical activity guidelines of getting at least 150 minutes of moderate activity per week, and who spent less than 4 hours per day sitting watching TV, had substantially lower OSA risk,” Huang said. “Importantly, we saw that any additional increase in physical activity, and/or a reduction in sedentary hours, could have benefits that reduce the risk of developing OSA.”

Reference

Liu Y, Yang L, Stampfer MJ, Redline S, Tworoger SS, Huang T. Physical activity, sedentary behavior, and incidence of obstructive sleep apnea in three prospective US cohorts. Eur Respir J. Published online July 21, 2021. doi:10.1183/13993003.00606-2021