Particulate Matter and Albuminuria, Glomerular Filtration Rate, and Incident CKD

Background and objectives Exposure to particulate matter (PM) <2.5 μm in aerodynamic diameter (PM_2.5) has been linked to detrimental health effects. This study aimed to describe the relationship between long-term PM_2.5 exposure and kidney disease, including eGFR, level of albuminuria, and incident CKD.

Design, setting, participants, & measurements The study included 10,997 participants from the Atherosclerosis Risk in Communities cohort who were followed from 1996–1998 through 2016. Monthly mean PM_2.5 concentrations (μg/m³) were estimated at geocoded participant addresses using geographic information system–based, spatiotemporal generalized additive mixed models—including geospatial covariates such as land use—and then averaged over the 12-month period preceding participant examination. Covariate-adjusted, cross-sectional associations of PM_2.5, baseline eGFR, and urinary albumin-creatinine ratio (UACR) were estimated using linear regression. PM_2.5 and incident CKD (defined as follow-up eGFR <60 ml/min per 1.73 m² with ≥25% eGFR decline relative to baseline, CKD-related hospitalization or death based on International Classification of Diseases 9/10 codes, or development of ESKD) associations were estimated using Cox proportional hazards regression. Modeling was stratified by study site, and stratum-specific estimates were combined using random-effects meta-analyses.

Results Baseline mean participant age was 63 (±6) years and eGFR was 86 (±16) ml/min per 1.73 m². There was no significant PM_2.5-eGFR association at baseline. Each 1-μg/m³ higher annual average PM_2.5 was associated with higher UACR after adjusting for demographics, socioeconomic status, and clinical covariates (percentage difference, 6.6%; 95% confidence interval [95% CI], 2.6% to 10.7%). Each 1-μg/m³ higher annual average PM_2.5 was associated with a significantly higher risk of incident CKD (hazard ratio, 1.05; 95% CI, 1.01 to 1.10).

Conclusions Exposure to higher annual average PM_2.5 concentrations was associated with a higher level of albuminuria and higher risk for incident CKD in a community-based cohort.