The dose-response relationship between physical activity and the risk of death from pneumonia in middle-aged and older adults: A meta-analysis.

Background: Deaths from COVID-19 are concentrated in older adults, and studies have reported that physical activity (PA) can reduce the risk of death from pneumonia.

Methods: Eight cohort studies and 2 case-control studies were included according to the inclusion and exclusion criteria established in this meta-analysis study followed the PRISMA guideline, 8 cohort studies and 2 case-control studies were finally included. Then, the research objects in these studies were classified to further study the dose-response relationship and non-dose-response relationship.

Results: The highest dose of PA reduced the risk of death by 59% (risk ratio = 0.41; 95% confidence interval: 0.23-0.58) compared with the lowest dose of PA in middle-aged and elderly people. Furthermore, when the PA level was <10 m/wk, the risk of death from pneumonia was reduced by 6% every 4.5 MET-h/wk increase. At a PA level > 10 m/wk, the risk of death from pneumonia increased by 5% every 4.5 MET-h/wk increase. At a PA level > 30 m/wk, PA is a risk factor for pneumonia-related death in middle-aged and elderly people.

Conclusions: This meta-analysis showed that PA was associated with a reduced risk of dying from pneumonia in middle-aged and older adults, and that there was a significant nonlinear negative dose-response relationship between PA levels and the risk of dying from pneumonia. Therefore, moderate exercise was recommended.