Association between exposure to fine particulate matter and kidney function: Results from the Korea National Health and Nutrition Examination Survey

Background: The incidence and prevalence of chronic kidney disease (CKD) are increasing worldwide. Recent studies have shown that air pollution is associated with poorer kidney function. We evaluated the association of long-term exposure to air pollutants with kidney function, and with risk of CKD using data from the seventh Korean National Health and Nutrition Examination Survey (KNHANES). Methods: KNHANES data from 2016 through 2018 and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation were used to calculate estimated glomerular filtration rates (eGFRs) and define the CKD patients with eGFRs <60 mL/min/1.73 m². After applying the sampling weights based on the complex survey design, we conducted multivariate linear regression and logistic regression analyses to examine the association of air pollutant exposure with kidney function and CKD risk, after adjusting for covariates, including gender, body mass index, education level, household income, smoking status, alcohol consumption, comorbidities, and serum triglyceride. Results: A total of 15,983 adults aged ≥20 years were included in the analysis. Long-term exposure to PM_2.5, PM₁₀, NO₂, and CO was associated with decreases in eGFR levels (PM_2.5: −4.67, 95% confidence interval (CI): −6.16, −3.18; PM₁₀: −2.19, 95% CI: −2.84, −1.54; NO₂: −1.56, 95% CI: −2.16, −0.97; CO: −1.34, 95% CI: −1.96, −0.71). Long-term exposure to PM_2.5 (odds ratio (OR): 1.97, 95% CI: 1.14, 3.42) and PM₁₀ (OR: 1.45, 95% CI: 1.10, 1.91) was associated with an increased the risk of CKD. Conclusions: Annual exposure to PM_2.5, PM₁₀, NO₂, and CO was significantly associated with decreased eGFR. Long-term exposure to PM_2.5 and PM₁₀ was associated with an increased risk of CKD.