TOPLINE:
, but substituting it with any physical activity — or even sleeping, in case of women with inadequate sleep — may lead to better overall health.
METHODOLOGY:
- Previous studies have shown that replacing sedentary behavior with physical activity may improve mortality outcomes, but whether this increased lifespan is accompanied by better overall health remains an unanswered question.
- To understand the impact of sedentary behavior and physical activity on healthy aging, researchers analyzed data from the prospective cohort Nurses’ Health Study.
- They included 45,176 women aged > 50 years in 1992 (mean age, 59.2 years) who were free of major chronic diseases and were followed up for 20 years.
- In 1992, validated questionnaires were used to record exposure to sedentary behavior, different levels of physical activity, and sleep. The time spent watching television was the primary exposure in the sedentary behavior category.
- The main outcome was healthy aging, defined as survival to ≥ 70 years of age and maintenance of four domains of health — being free of 11 main chronic diseases and having no impairment of subjective memory, physical function, or mental health.
TAKEAWAY:
- At 20 years of follow-up, 8.6% of the women achieved healthy aging, while 41.4% had none of the 11 chronic diseases, 16.1% had no physical function impairment, 44.1% had no mental health limitation, and 51.9% reported no memory impairment.
- For each increase of 2 hours per day spent sitting and watching television, the odds of healthy aging dropped by 12% (95% confidence interval [CI], 7%-17%).
- Conversely, every additional 2 hours per day of low-level physical activity at work upped the odds of healthy aging by 6% (95% CI, 3%-9%); furthermore, each extra hour per day of standardized moderate to vigorous physical activity (normal pace walking or the equivalent) was associated with 14% higher odds (95% CI, 11%-16%) of healthy aging.
- In a theoretical modeling analysis, individuals could increase their odds of healthy aging by replacing 1 hour of television time per day with low levels of physical activity at home and work or with moderate to vigorous levels of physical activity — or even sleeping, for those who slept for ≤ 7 hours.
IN PRACTICE:
“These findings expand on the literature reporting that replacing sedentary behavior with light or moderate to vigorous physical activity is associated with decreased mortality by suggesting that this increased lifespan might be accompanied by better overall health,” the authors wrote.
SOURCE:
Hongying Shi, PhD, Department of Epidemiology and Health Statistics, School of Public Health, Wenzhou Medical University, Wenzhou, China, led this study, which was published online in JAMA Network Open.
LIMITATIONS:
The measures of different behaviors were self-reported and may, therefore, be less accurate than objective measurement methods. Measurement error may have attenuated the effect of low levels of physical activity. The single exposure assessment at baseline may not reflect the long-term pattern of these activities.
DISCLOSURES:
The lead author was supported by the National Social Science Foundation Project of China and the Zhejiang Provincial Philosophy and Social Sciences Planning Project. A co-author and the Nurses’ Health Study were supported by the US National Institutes of Health. The authors declared no conflicts of interest.
A version of this article first appeared on Medscape.com.