Effect of PM2.5 exposure on circulating fibrinogen and IL-6 levels: A systematic review and meta-analysis

Background: Ambient fine particulate matter (PM2.5) pollution poses a great threat on global health. Previous studies have reported that PM2.5 regulates circulating fibrinogen and IL-6 levels in the development of cardiovascular and respiratory disease. However, the correlation between PM2.5 exposure and both biomarkers remains inconsistent. Methods: We searched related articles through PubMed, Web of Science and ScienceDirect. Random effects model was used to obtain a pooled estimate effect of both biomarkers as PM2.5 concentration increased by every 10 mg/m(3). Meta-regression analysis, sensitivity analysis and publication bias test were conducted to evaluate the heterogeneity, stability and reliability of this meta-analysis. Results: A total of 22 articles were included. Each 10 mg/m(3) increase in PM2.5 concentration was significantly correlated with a 1.76% increase in circulating fibrinogen level (95% CI: 0.38%-3.14%, P = 0.013) and a 4.66% increase in IL-6 level (95% CI: 1.14%-8.18%, P = 0.010). Subgroup analysis revealed that high-level PM2.5 exposure had a more significant association with circulating IL-6 level (11.67%, 95% CI: 0.66%-22.69%, P = 0.038) than low-level exposure, but this association was not observed in fibrinogen (2.50%, 95% CI: 0.78%-5.77%, P = 0.135). Sensitivity analysis and publication bias test confirmed the stability of the results. Conclusion: Circulating fibrinogen and IL-6 significantly increased with exposure to PM2.5, may serve as promising biomarkers for PM2.5-related adverse effects. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study found a significant correlation between PM2.5 exposure and increased levels of circulating fibrinogen and IL-6. Higher levels of PM2.5 exposure were more significantly associated with circulating IL-6 levels, while the association with circulating fibrinogen was less pronounced.