Leisure-time physical activity and risk of depression: A dose-response meta-analysis of prospective cohort studies

Background: There has never been a dose-response meta-analysis of the relationship between physical activity and the risk of depression. Hence, we aimed to explore the dose-response relationship between leisure-time physical activity (LTPA) and the risk of depression through a meta-analysis to provide a basis for the prevention of depression. Methods: PubMed and Web of Science databases were searched using a computer to collect prospective cohort studies on the relationship between LTPA and depression between January 1997 and July 2021. A dose-response meta-analysis was performed using the Stata 14 software to calculate the combined effect size relative risk (RR and 95% confidence interval CI). Results: Twelve cohort studies included 310,359 subjects who met the inclusion criteria. The categorical dose-response analysis results showed that the risk of incident depression was 27%, 17%, and 8% lower for the light, moderate, and highest dose LTPA participants, respectively (RR: 0.73, 95% CI: 0.64-0.82; RR: 0.83, 95% CI: 0.78-0.87; RR: 0.92, 95% CI: 0.86-0.99), compared with the lowest LTPA category. Continuous dose-response analysis showed a nonlinear relationship between LTPA and the risk of incident depression (P = .04). The risk of incident depression was reduced by 3% (RR: 0.97, 95% CI: 0.95-0.98) for every 5 MET-h/week increase in LTPA < 25 MET-h/week; when LTPA was higher than 25 MET-h/week, a 4% increase in the risk of depression for every 5 MET-h/week increase was observed (RR: 1.04, 95% CI: 1.02-1.05). Conclusions: There was a nonlinear relationship between LTPA and the risk of incident depression. Moderate and low doses of LTPA were protective factors in preventing the risk of incident depression, while high doses of LTPA may increase the risk of incident depression.