Leisure time physical activity and risk of pneumonia mortality: a dose-response meta-analysis.

Introduction: This meta-analysis of cohort studies aimed to examine the dose-response relationships between LPTA (leisure time physical activity) and pneumonia mortality to provide some suggestions for the prevention of respiratory disease mortality.

Evidence Acquisition: PubMed, WOS database were systematically searched for eligible studies until November 1, 2020. The prospective cohort study on the relationship between LPTA and pneumonia mortality was collected. The meta-analysis was performed using STATA 14 software (StataCorp LLC, College Station, TX, USA) to calculate the combined effect size (HR) of pneumonia mortality and its 95% CI in a categorical dose-response relationship. The restrictive cubic spline model was used to fit the continuous dose-response relationship.

Evidence Synthesis: Eight cohort studies including 370,045 subjects who met the inclusion criteria were selected for the study. The categorical dose-relational analysis revealed that the highest dose compared to the lowest LTPA dose reduced the risk of pneumonia mortality by 32% (HR=0.68; 95% CI: 0.64-0.73). The continuous dose-response relationship results showed a negative nonlinear relationship between LTPA and the risk of pneumonia mortality (Pnon-linearity<0.05). The risk of pneumonia death HR decreased by 16% (P<0.01, HR=0.84; 95% CI: 0.82-0.86) for each additional 5 MET-h/week when LTPA below 20 MET-h/week. When LTPA was higher than 20 MET-h/week, the risk of pneumonia death HR decreased of 6% for each additional 5 MET-h/week (P<0.01, HR=0.94; 95% CI: 0.93-0.94).

Conclusions: All doses of LTPA are protective factors of pneumonia mortality risk and the protective effect on pneumonia mortality is enhanced if LTPA increases. The degree of enhancement is weakened when LTPA is higher than 20 MET-h/week.