Compared with participants with high physical activity and healthy sleep, those with no moderate-to-vigorous physical activity exhibited higher risks of all-cause, total cardiovascular, and total cancer mortality.
Level of physical activity may influence the significant health risk posed by poor sleep, according to study findings published in the British Journal of Sports Medicine.
As 2 complex lifestyle behaviors, physical activity and poor sleep have been associated with all-cause, cardiovascular (CVD), and cancer mortality. Although both variables have been independently associated with these adverse health outcomes, researchers note that the lack of a standardized sleep measurement might impede the ability to investigate potential joint effects with other behaviors.
However, a recent study of 70,973 participants followed for 15 years suggested that low physical activity could exaggerate the adverse association between inadequate sleep duration and all-cause and CVD mortality risk.
“Physical activity and sleep could be codependent and influence health conditions through related pathways,” explained the study authors. “For example, physical activity might improve health outcomes through improving metabolic fitness (eg, reducing insulin resistance), maintaining a stable circadian rhythm and a healthy sleep pattern, and enhancing energy expenditure.”
With the potential joint health effects of sleep and physical activity remaining largely unknown, researchers investigated the association with all-cause, total CVD, CVD subtypes (coronary heart disease, hemorrhagic stroke, ischemic stroke), and total cancer and lung cancer mortality.
In the observational study of 380,055 people (mean [SD] age, 55.9 [8.1] years; 55% women) from the UK Biobank, participants’ baseline physical activity levels, measured in metabolic equivalent of task (MET) minutes, were categorized as high (≥1200 MET-minutes/week), medium (600 to <1200 MET-minutes/week), or low (0 to <600 MET-minutes/week). Additionally, a no moderate-to-vigorous physical activity (MVPA) category was defined to reflect the potential health benefits of insufficient physical activity compared with no MVPA.
Sleep was categorized into healthy, intermediate, and poor with an established composited sleep score derived from chronotype, sleep duration, insomnia, snoring, and daytime sleepiness. Participants’ mortality risks were ascertained to May 2020.
After an average (SD) follow-up time of 11.1 (1.2) years, 15,503 all-cause deaths were reported (4095 events from total CVD and 9064 from total cancer, including 1932 from coronary heart diseases, 359 from hemorrhagic stroke, 450 from ischemic stroke, and 1595 from lung cancer).
Sleep scores exhibited dose-response associations with all-cause, total CVD, and ischemic stroke mortality, with high physical activity level associated with the lowest risk of all-cause mortality. In assessing the joint association of sleep and physical activity with mortality, participants with high physical activity and healthy sleep were set as the reference group.
Compared with these participants, those with no MVPA had higher mortality risks for all outcomes except for hemorrhagic stroke, while participants mutually with poor sleep and no MVPA exhibited the highest mortality risks for:
The deleterious associations of poor sleep with all outcomes, except for stroke, were amplified with lower physical activity.
"As emerging evidence supports a synergistic effect of sleep and physical activity on health outcomes, future trials concurrently targeting both behaviors are warranted," concluded the study authors.
Huang B, Duncan MJ, Cistulli PA, et al. Sleep and physical activity in relation to all-cause, cardiovascular disease and cancer mortality risk. Br J Sports Med. Published online June 29, 2021. doi:10.1136/bjsports-2021-104046