Association between air pollution and hospitalization for acute exacerbation of kidney failure: A nationwide time-stratified case-crossover study in China

Background: Air pollution is a potential risk factor for kidney disease; however, the impact on kidney failure exacerbation is underexplored. This study assessed the short-term effects of air pollution on hospitalization for kidney failure exacerbation. Methods: This nationwide, time-stratified, case-crossover study included 45,249 hospitalized patients with kidney failure from 153 hospitals in 20 Chinese provinces between 2013 and 2020. Air pollutant concentrations were obtained from the closest monitoring stations. Conditional logistic regression models were used to determine the associations between air pollutants and hospitalizations, with exposure-response curves fitted and stratified analyses conducted. Results: For each interquartile range increase in pollutants (lag 0-2 days), there was a significant increase in kidney failure hospitalization: 3.46 % for PM2.5, 3.64 % for PM2.5-10, 7.88 % for NO2, and 4.37 % for CO. No significant associations were observed for O3 and SO2. NO2 had a linear exposure-response curve; PM2.5 and PM2.5-10 showed stronger effects at lower exposures, while CO's effect increased at higher exposures. Furthermore, the impact was greater during the cold season. Conclusions: This large-scale national study highlights the significant association between short-term exposure to PM2.5, PM2.5-10, NO2, and CO and kidney failure exacerbation, providing novel insights into the combined effects of air pollution on kidney failure.