Walking, But Not Other Physical Activity at a Higher Intensity, Is Associated With Improved Kidney Function: A Cross-Sectional Health Survey of General Adult Population

Background Chronic kidney disease is common and brings significant health burden. The purpose of this study was to investigate the relationship between physical activity and kidney function. Methods: This was a cross-sectional study set in the Nanjing Community Cardiovascular Risk Survey, using random cluster sampling. Questionnaires were completed, wherever possible, through face-to-face interviews. Data on age, sex, body mass index, weekly physical activity, and kidney function were collected. Physical activity was measured by the metabolic equivalent of task-minutes per week and grouped into “walking,” “moderate,” and “vigorous” according to intensity. Kidney function was measured by the estimated glomerular filtration rate (eGFR, in mL/min/1.73 m2). Regression modeling was used to investigate the proposed relationship with adjustment for other confounding factors. Results: A total of 5824 participants were included, with an average age of 52; 44% were male. The eGFR in average was 76 mL/min/1.73 m2, with 19% ≥ 90, 67% between 60 and 89, and 14% < 60. In average, the total physical activity during a week was 3644 MET-minutes per week. Moderate activity contributed 64% of the total activity, followed by walking (23%) and vigorous activity (13%). Overall, the total activity was weakly associated with eGFR (P = .039). However, in stratified analysis, only walking-related activity was associated with eGFR (P < .0001) after confounding adjustment. Conclusions: Walking is associated with improved kidney function