Combined effects of chronic PM2.5 exposure and habitual exercise on renal function and chronic kidney disease: A longitudinal cohort study

Background: We investigated the combined effects of chronic PM2.5 exposure and habitual exercise on the decline of renal function and the incidence of chronic kidney disease (CKD) in a large cohort in Taiwan. Methods: The present data analysis included a total of 108,615 participants aged 18 years or above who were recruited between 2001 and 2016. All participants underwent at least two medical examinations. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) equation. The incident of eGFR decline 60 mL/min/1.73 m2 or a newly self-reported physiciandiagnosed CKD in the subsequent visits. The satellite-based spatiotemporal model was used to estimate PM2.5 exposure at each participant's address. Information on habitual exercise was collected using a standard selfadministered questionnaire. The Cox regression model with time-dependent covariates was used for data analyses. Results: Higher habitual exercise was associated with lower risks of renal function decline and CKD development, whereas higher PM2.5 exposure was associated with higher risks of renal function decline and CKD development. We found no significant interaction effect between PM2.5 and habitual exercise, with an HR (95% CI) of 1.02 (0.97, 1.07) for incident eGFR decline 30% and 1.00 (0.95, 1.05) for CKD development. Compared to participants with inactive-exercise and high-PM2.5, participants with high-exercise and low-PM2.5 had 74% and 61% lower risks of renal function decline and CKD development, respectively. Conclusion: Increased habitual exercise and reduced PM2.5 exposures are associated with lower risks of renal function decline and CKD development. Habitual exercise reduces risks of renal function decline and CKD development regardless of the levels of chronic PM2.5 exposure. Our study suggests that habitual exercise is a safe approach for kidney health improvement even for people residing in relatively polluted areas and should be promoted.

Automated summary

The study found that increased habitual exercise and reduced PM2.5 exposure are associated with lower risks of renal function decline and chronic kidney disease development. Regardless of the levels of chronic PM2.5 exposure, habitual exercise reduces the risks of renal function decline and CKD development, suggesting that exercise is a safe approach for kidney health improvement, even in polluted areas.