Long-Term Exposure to Fine Particulate Matter and Kidney Function among Patients with Polycystic Kidney Disease

BACKGROUND: Polycystic kidney disease (PKD) is the fourth leading cause of end-stage kidney disease. Although the condition is primarily genetic, environmental exposures such as air pollution may influence disease progression. METHODS: We investigated whether long-term exposure to fine particulate matter (PM2.5) is associated with kidney function decline among individuals with PKD and whether this association differs by age, sex, initial kidney function, and tolvaptan use. Using the Korea National Health Information Database, we identified 18,898 adults with PKD who underwent at least two health screenings between 2016 and 2023. Annual mean PM2.5 exposure was estimated with a high-resolution (1 km2) machine learning-based model. Linear mixed-effects models were applied to assess the association between PM2.5 exposure and changes in estimated glomerular filtration rate (eGFR), adjusting for demographic, socioeconomic, and lifestyle covariates. RESULTS: Each 1 µg/m3 higher lag 0-1 year PM2.5 was associated with a -0.09 mL/min/1.73 m2 change in eGFR (95% CI, -0.16 to -0.01). More evident associations were observed among younger adults (-0.26; 95% CI, -0.42 to -0.09), individuals with preserved baseline kidney function (-0.14; 95% CI, -0.21 to -0.07), male (-0.10; 95% CI, -0.21 to 0), and individuals who were not prescribed tolvaptan (-0.12; 95% CI, -0.20 to -0.04). CONCLUSIONS: Chronic exposure to PM2.5 appears to be an environmental modifier of kidney function decline in PKD, particularly among younger individuals and those with preserved kidney function. Environmental risk reduction strategies, together with pharmacologic therapy, may help delay the onset of end-stage kidney disease in this vulnerable population.