Association between ambient PM₁ and the prevalence of chronic kidney disease in China: A nationwide study

Particulate of diameter ≤ 1 µm (PM₁) presents a novel risk factor of adverse health effects. Nevertheless, the association of PM₁ with the risk of chronic kidney disease (CKD) in the general population is not well understood, particularly in regions with high PM₁ levels like China. Based on a nationwide representative survey involving 47,204 adults and multi-source ambient air pollution inversion data, the present study evaluated the association of PM₁ with CKD prevalence in China. The two-year average PM₁, particulate of diameter ≤ 2.5 µm (PM_2.5), and PM_1–2.5 values were accessed using a satellite-based random forest approach. CKD was defined as estimated glomerular filtration rate < 60 ml/min/1.73 m² or albuminuria. The results suggested that a 10 μg/m³ rise in PM₁ was related to a higher CKD risk (odds ratio [OR], 1.13; 95% confidence interval [CI] 1.08–1.18) and albuminuria (OR, 1.11; 95% CI, 1.05–1.17). The association between PM₁ and CKD was more evident among urban populations, older adults, and those without comorbidities such as diabetes or hypertension. Every 1% increase in the PM₁/PM_2.5 ratio was related to the prevalence of CKD (OR, 1.03; 95% CI, 1.03–1.04), but no significant relationship was found for PM_1–2.5. In conclusion, the present study demonstrated long-term exposure to PM₁ was associated with an increased risk of CKD in the general population and PM₁ might play a leading role in the observed relationship of PM_2.5 with the risk of CKD. These findings provide crucial evidence for developing air pollution control strategies to reduce the burden of CKD.