Combined effects of ambient air pollution and PM2.5 components on renal function and the potential mediation effects of metabolic risk factors in China

Fuyuan Wen; Yunyi Xie; Bingxiao Li; Pandi Li; Han Qi; Fengxu Zhang; Yuan Sun; Ling Zhang

doi:10.1016/j.ecoenv.2023.115039

Combined effects of ambient air pollution and PM_2.5 components on renal function and the potential mediation effects of metabolic risk factors in China

Ecotoxicol Environ Saf. 2023 Jul 1:259:115039. doi: 10.1016/j.ecoenv.2023.115039. Epub 2023 May 24.

Authors

Fuyuan Wen¹, Yunyi Xie¹, Bingxiao Li¹, Pandi Li¹, Han Qi², Fengxu Zhang¹, Yuan Sun¹, Ling Zhang³

Affiliations

¹ Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, and Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China.
² Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, and Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China; The National Clinical Research Center for Mental Disorders and Beijing Key Laboratory of Mental Disorders, Beijing Anding Hospital and the Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China.
³ Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, and Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China. Electronic address: zlilyepi@ccmu.edu.cn.

PMID: 37235899
DOI: 10.1016/j.ecoenv.2023.115039

Abstract

Growing evidence links long-term air pollution exposure with renal function. However, little research has been conducted on the combined effects of air pollutant mixture on renal function and multiple mediation effects of metabolic risk factors. This study enrolled 8996 adults without chronic kidney disease (CKD) at baseline from the CHCN-BTH cohort study. Three-year exposure to air pollutants [particulate matter ≤ 2.5 µm (PM_2.5), PM₁₀, PM₁, ozone (O₃), nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and carbon monoxide (CO)] and PM_2.5 components [black carbon (BC), ammonium (NH₄⁺), nitrate (NO₃^-), sulfate (SO₄^2-) and organic matter (OM)] were assessed using well-validated machine learning methods. Linear mixed models were applied to investigate the associations between air pollutants and estimated glomerular filtration rate (eGFR). Quantile G-computation was used to assess the combined effects of pollutant mixtures. Causal mediation analysis and Bayesian mediation analysis were employed to estimate the mediation effects of metabolic risk factors. An interquartile range increases in BC (-0.256, 95 %CI: -0.331, -0.180) and OM (-0.603, 95 %CI: -0.810, -0.397) were significantly associated with eGFR decline; while O₃ (1.151, 95 %CI: 0.813, 1.489), PM₁₀ (0.721, 95 %CI: 0.309, 1.133), NH₄⁺ (0.990, 95 %CI: 0.638, 1.342), and NO₃^- (0.610, 95 %CI: 0.405, 0.815) were associated with higher eGFR. The combined effect of the PM_2.5 component mixture was found to be associated with lower eGFR (-1.147, 95 % CI: -1.456, -0.839), with OM contributing 72.4 % of the negative effect. Univariate mediation analyses showed that high-density lipoprotein (HDL) mediated 7.1 %, 6.9 %, and 6.1 % effects of O₃, BC, and OM, respectively. However, these mediation effects were not significant in Bayesian mediation analysis. These findings suggest the effect of the PM_2.5 component mixture on eGFR decline and the strong contribution of OM. Metabolic risk factors may not mediate the effects of air pollutants. Further study is warranted to clarify the potential mechanisms involved.

Keywords: Air pollution; Bayesian mediation analysis; Combined effects; Estimated glomerular filtration rate; PM(2.5) components.

MeSH terms

Adult
Air Pollutants* / analysis
Air Pollution* / adverse effects
Air Pollution* / analysis
Bayes Theorem
China
Cohort Studies
Environmental Exposure / analysis
Humans
Kidney / chemistry
Kidney / physiology
Nitrogen Dioxide / analysis
Particulate Matter / analysis
Risk Factors

Substances

Air Pollutants
Particulate Matter
Nitrogen Dioxide