Replacing Sleep, Sedentary Behavior With Physical Activity Beneficial in Knee Osteoarthritis
Wrist-worn accelerometers and sleep diaries were used to collect data on participants' physical activity and sleep schedules, respectively.
Replacing at least 10 minutes a day of time spent sedentary, asleep, or in light physical activity with moderate physical activity may be associated with significant reductions in bodily pain interference and knee pain in adults at risk for osteoarthritis (OA) knee pain, according to a study published in Osteoarthritis and Cartilage.
Observational data for 185 patients with or at risk for knee OA from the Physical Activity and Sleep Monitoring Pilot Study of the Osteoarthritis Initiative (OAI) were examined in the cross-sectional analysis. The investigators used isotemporal substitution methods to evaluate potential associations between OA-related pain and the trading of 1 wake activity or sleep for another activity. Wrist-worn accelerometers and sleep diaries were used to collect data on participants' physical activity (ie, sedentary behavior, light physical activity, and moderate physical activity) and sleep schedules, respectively. The primary outcomes of interest were bodily pain interference and knee pain.
At baseline, bodily pain interference and knee pain were reported by 84 participants. Accelerometer monitoring data from the overall cohort indicated an average of 7 hours per day spent in sleep, 11 hours per day spent in sedentary behavior, 4.5 hours per day devoted to light physical activity, and only 14 minutes per day engaged in moderate physical activity.
Substituting sleep, sedentary behavior, or light physical activity with 10 minutes per day of moderate physical activity was associated with 21% to 25% lower odds of bodily pain interference. Significant associations were found when moderate physical activity (10 minutes per day) replaced: sleep (odds ratio [OR], 0.79; 95% CI, 0.61-1.02), sedentary behavior (adjusted OR, 0.74; 95% CI, 0.57-0.95), and light physical activity (adjusted OR, 0.75; 95% CI, 0.57-0.98). In addition, substitution of sleep (adjusted OR, 0.46; 95% CI, 0.21-0.98), sedentary behavior (adjusted OR, 0.41; 95% CI, 0.19-0.89), and light physical activity (adjusted OR, 0.42; 95% CI, 0.19-0.95) with moderate physical activity was found to reduce the odds of bodily pain interference.
The study's small sample size, observational nature, and cross-sectional design represent the main limitations of this analysis.
"These results inform future research and practice that in addition to promoting moderate [physical activity] participation, restless sleep may be an important factor to address in managing pain among people with chronic knee symptoms."
Song J, Dunlop DD, Semanik PA, et al. Reallocating time spent in sleep, sedentary behavior and physical activity and its association with pain: a pilot sleep study from the Q4 Osteoarthritis Initiative [published online July 23, 2018]. Osteoarthritis Cartilage. doi: 10.1016/j.joca.2018.07.002 1063-4584