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

KEY POINTS: Long-term exposure to fine particulate matter was associated with faster decline in kidney function among patients with polycystic kidney disease. Associations were stronger in younger patients and those with preserved kidney function at baseline. The association was weaker among patients prescribed tolvaptan.

BACKGROUND

Polycystic kidney disease (PKD) is the fourth leading cause of ESKD. 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 (PM 2 . 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 PM 2 . 5 exposure was estimated with a high-resolution (1 km 2 ) machine learning-based model. Linear mixed-effects models were applied to assess the association between PM 2 . 5 exposure and changes in eGFR, adjusting for demographic, socioeconomic, and lifestyle covariates.

RESULTS

Each 1 µ g/m 3 higher lag 0-1 year PM 2 . 5 was associated with a -0.09 ml/min per 1.73 m 2 change in eGFR (95% confidence interval [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 PM 2 . 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 ESKD in this vulnerable population.