Dose-response relationship between different physical activity types and depressive symptoms in middle-aged and...

Evidence on the dose-response connection involving depressive symptoms and various types of physical activity in urban and rural populations is scarce. This study compares the dose-response connection across depressive symptoms and different types of activity in populations living in rural and urban areas.

The study is based on a cross-sectional weighted sample from the 2020 China Health and Retirement Longitudinal Study (CHARLS). Physical activity and depressive symptoms were assessed using self-reported activity from the CHARLS questionnaire and the Centre for Epidemiological Studies Depression Scale. Physical activity was computed in metabolic equivalents (METs) and depressive symptom cutoff is 10. 1 MET is the amount of oxygen used during rest (3.5 mL O2/kg/min). Multivariate logistic regression analyses were used to determine the dose-response relationship between different types of physical activity and depressive symptoms.

Physical activity of different types showed a varying relationship with depressive symptoms with dose in rural populations. However, in urban populations, recreational physical activity exhibited a negative correlation with depressive symptoms, while non-recreational activity displayed a positive correlation. Specifically, in the rural population, 600-3,000 METs-min/week of recreational physical activity was inversely linked to depressive symptoms, but recreational physical activity exceeding 3,000 METs-min/week was associated with a 13.2% risk increase in depressive symptoms (OR = 1.132, 95% CI: 1.131-1.132), and over 6,000 METs-min/week of non-recreational activity was similarly associated with an increased risk of depressive symptoms. In the urban population, recreational physical activity was related to a reduced incidence of depressive symptoms, with a maximum reduction of 71.7% at doses up to 9,000-12,000 METs min/week (OR = 0.283, 95% CI:0.282-0.284), and 6,000-9,000 non-recreational physical activities, the odds of increased risk of depressive symptoms were highest (OR = 2.224, 95% CI:2.221-2.227).

Our study found a non-linear dose correlation between physical activities and depressive symptoms. The dose-response connection between different physical activity types and depressive symptoms varies between rural and urban areas. Recreational physical activity is recommended for urban and reasonable amounts of nonrecreational physical activity for rural populations to reduce the risk of depressive symptoms. However, causal interpretations cannot be made due to the cross-sectional design of the study.