Even low levels of physical activity reduce mortality in elderly
1. Current health recommendations for older adults include 150 minutes per week of moderate-to-vigorous-intensity physical activity (MVPA), however, levels of physical activity lower than the recommendation also lead to decreased mortality.
2. Increased physical activity was associated with decreased mortality in a dose-dependent manner.
Evidence Rating Level: 1 (Excellent)
Study Rundown: The Physical Activity Guidelines Advisory Committee Report recommends that older adults perform a minimum of 150 minutes of moderate-to-vigorous-intensity physical activity (MVPA) each week in order to maintain their health and reduce their mortality. However, estimates suggest that less than 40% of seniors are able to meet this recommendation, citing poor health and lack of education as major barriers. This meta-analysis thus sought to determine the effect of lower levels of MVPA on mortality in patients older than 60 years.
The study extracted data from 9 prospective cohort studies that associated MVPA with all-cause mortality in adults older than 60 years. To compare physical activity levels across the studies, this meta-analysis converted activities into Metabolic Equivalent of Task (MET) units. In this unit system, resting energy expenditure over an hour is equivalent to 1 MET and the recommended 150 minutes per week of MVPA corresponds to approximately 500 METs per week. The analysis found that low levels of physical activity (less than 500 METs per week) were associated with a 22% decrease in all-cause mortality when compared to sedentary lifestyles. Specifically, much of this result came from reduced cardiovascular disease, although a significant decrease in cancer mortality was also found. The study also determined that increasing levels of MVPA (500 – 999 METs and >1000 METs), led to further reductions in mortality; 28% and 35% respectively.
Though this study was limited by possible biases in each of the 9 studies, and 61% of its participants came from just 2 studies, it is the first meta-analysis that focuses on the dose relationship of MVPA to all-cause mortality. The findings endorse that a lower level of physical activity can be recommended to older adults that are unable to meet the current MVPA recommendations with expected positive effects on mortality.
Click to read the study in the British Journal of Sports Medicine
Relevant Reading: Physical Activity and public health in older adults: recommendations from the American College of Sports Medicine and the American Heart Association
In-Depth [systematic review and meta-analysis]: This systematic review and meta-analysis utilized data from 9 prospective cohort studies representing 122,417 participants with a mean follow-up time of 9.8 ±2.7 years to characterize the relationship between increasing levels of MVPA and mortality in adults older than 60 years. A low dose of MVPA, corresponding to 1-499 METs per week, which is lower than the current minimum recommendations, was associated with a 22% decrease in all-cause mortality (RR: 0.78, p < 0.0001) as compared to lifestyles with 0 METs per week. In those adults who followed the current recommendations, getting 500 – 999 METs of activity each week, a 28% reduction in mortality was found (RR: 0.72, p < 0.0001). Adults getting even more activity, > 1000 METs each week, had a 35% lower mortality (RR: 0.65, p < 0.0001).
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