A new study by investigators from Brigham and Women’s Hospital examined the relationship between active lifestyles and the risk of obstructive sleep apnea (OSA). The study followed around 130,000 men and women in the United States over a follow-up period of 10-to-18 years and found that higher levels of physical activity and lower levels of sedentary behavior were associated with a lower risk of OSA. Their results are published in the European Respiratory Journal.
“In our study, higher levels of physical activity and fewer hours of TV watching, and sitting either at work or away from home were associated with lower OSA incidence after accounting for potential confounders,” says Tianyi Huang, MSc, ScD, an associate epidemiologist at the Brigham, in a release. “Our results suggest that promoting an active lifestyle may have substantial benefits for both prevention and treatment of OSA.”
Using the Nurses’ Health Study (NHS), Nurses’ Health Study II (NHSII) and Health Professionals Follow-Up Study (HPFS), the research team used statistical modeling to compare physical activity and sedentary hours with diagnoses of OSA. Both moderate and vigorous physical activity were examined separately and both were strongly correlated with lower risk of OSA, showing no appreciable differences in the intensity of activity. But stronger associations were found for women, adults over the age of 65 and those with a BMI greater than or equal to 25 kg/m2.
“Most prior observational studies on the associations of physical activity and sedentary behavior with OSA were cross-sectional, with incomplete exposure assessment and inadequate control for confounding,” Huang says. “This is the first prospective study that simultaneously evaluates physical activity and sedentary behavior in relation to OSA risk.”
This study also differs from others because of its large sample size and detailed assessment of physical activity and sedentary behaviors. The research team was able to take many associated factors into account, including participants’ age, body mass index, and whether they smoked or drank alcohol.
The authors note that all collected data, both of OSA diagnosis and physical activity or sedentary behavior, were self-reported. While all study participants were health professionals, mild OSA is often difficult to detect and can remain clinically unrecognized. Furthermore, only recreational physical activity was taken into consideration, leaving out any physical activity in occupational settings. Sedentary behavior was only counted as sitting while watching TV and sitting away from home or at work.
Huang says, “We saw a clear relationship between levels of physical activity, sedentary behaviour 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 four hours per day sitting watching TV, had substantially lower OSA risk. 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.
“The difference in OSA risk between sedentary work and time spent sitting watching TV could be explained by other behaviours that are related to those activities. For example, 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 travelling. This could lead to additional weight gain, which we know to be a risk factor OSA.”
According to Huang, the next research steps would be to collect data using actigraphy, home sleep apnea tests and polysomnography, rather than self-reports.
In light of the findings, investigators encourage physicians to highlight the benefits of physical activity to lower OSA risk.
“We found that physical activity and sedentary behavior are independently associated with OSA risk,” Huang says. “That is, for people who spend long hours sitting every day, increasing physical activity in their leisure time can equally lower OSA risk. Similarly, for those who are not able to participate in a lot of physical activity due to physical restrictions, reducing sedentary hours by standing or doing some mild activities could also lower OSA risk. However, those who can lower sedentary time and increase physical activity would have the lowest risk.”
Anita Simonds, who was not involved in the research, is president of the European Respiratory Society and consultant in Respiratory and Sleep Medicine at Royal Brompton Hospital, UK. She says in a release, “OSA is a common and pervasive disorder that can have a serious impact on the quality of people’s lives. Although OSA can be managed with modern treatments, only a minority of studies focus on prevention. Health professionals should prioritise prevention and support people who are at-risk of developing OSA to be more active before it is too late.
“This study adds to the evidence on the importance of maintaining an active lifestyle on preventing lung disease, and it is encouraging that even a small increase in physical activity or reduction in sedentary hours could reap potential benefits. It is therefore an important message to get across to our patients and their families in primary care and respiratory clinics.”