Recommended physical activity and all cause and cause specific mortality in US adults
Recommended physical activity and all cause and cause specific mortality in US adults: prospective cohort study
Authors
Min Zhao, Sreenivas P Veeranki, Costan G Magnussen, Bo Xi8
Reference
BMJ 2020;370:m2031
http://dx.doi.org/10.1136/bmj.m2031
Background
Inadequate physical activity (PA) is a worldwide public health problem. Results from previous studies assessing association between meeting PA guidelines and mortality have been inconsistent
Methodology
Population based cohort study in United States
Self-reported aerobic PA and muscle strengthening activity collected as part of National Health Interview Survey (1997 to 2014) and linked with US National Death Index (up to December 2015)
Participants were classified into groups based on whether they met 2018 US PA guidelines: insufficient activity, meeting muscle strengthening guidelines only, meeting aerobic guideline only and meeting both guidelines.
There were 479 856 participants with median follow-up of 8.75 years.
Conclusion/s
15.9% participants met both guidelines, 23.7% met aerobic activity guidelines alone and 4.5% muscle strengthening activity alone.
Compared with participants who had insufficient activity, risk of all-cause mortality in those meeting:
muscle strengthening guidelines 11% lower (hazard ratio (HR) 0.89, 95% confidence intervals 0.85 to 0.94)
aerobic guidelines 29% lower (HR 0.71, 95% CI 0.69 to 0.72)
both guidelines 40% lower (HR 0.60, 95% CI 0.57 to 0.62)
Similar associations seen for deaths from cardiovascular disease, cancer, and chronic lower respiratory tract diseases.
Subgroup analysis found greater survival benefits amongst adults with chronic health conditions who met either aerobic or both guidelines, compared to those who were healthy
Fig 1 | Association between meeting the 2018 physical activity guidelines for Americans and all cause and cause specific mortality from three diseases.
Other comments
Strengths: Large study representative of US population. Confounding factors well accounted for.
Limitations: nearly 10% participants excluded due to missing data. PA self-reported at single time point, muscle strengthening reported as frequency only and aerobic activity leisure time activity only. Authors noted limitations in PA reporting may lead to magnitude of the true association being underestimated.
