Long-Term Exposure to Fine Particulate Constituents and Vascular Damage in a Population with Metabolic Abnormality in China

Abstract

Aim: To date, PM_2.5-associated vascular damage in metabolic abnormalities has remained controversial. We knew little about the vascular damage of PM_2.5 constituents. Thus, this study aimed to investigate the relationship between long-term exposure to PM_2.5 and its constituents and vascular damage in metabolic abnormalities.

Methods: A total of 124,387 participants with metabolic abnormalities (defined as at least one metabolic disorder, such as obesity, elevated blood pressure, elevated triglyceride level, elevated fasting glucose level, or low HDL cholesterol level) were recruited in this study from 11 representative centers in China between January 2011 and December 2017. PM_2.5 and its constituents (black carbon [BC], organic matter [OM], sulfate [SO₄^2-], nitrate [NO₃^-], and ammonium salts [NH₄^＋]) were extracted. Elevated brachial-ankle pulse wave velocity (baPWV) (≥ 1,400 cm/s) and declined ankle-brachial index (ABI) (＜0.9) indicated vascular damage. Multivariable logistic regression and Quantile g-Computation models were utilized to explore the impact on outcomes.

Results: Of the 124,387 participants (median age, 49 years), 87,870 (70.64%) were men. One-year lag exposure to PM_2.5 and its constituents was significantly associated with vascular damage in single pollutant models. The adjusted odds ratios (OR) for each 1-µg/m³ increase in PM_2.5 was 1.013 (95% CI, 1.012-1.015) and 1.031 (95% CI, 1.025-1.037) for elevated baPWV and decreased ABI, respectively. PM_2.5 constituents were also associated with vascular damage in multi-pollutant models. Among the PM_2.5 constituents, BC (47.17%), SO₄^2- (33.59%), and NH₄^＋ (19.23%) have the highest contribution to elevated baPWV and NO₃^- (47.89%) and BC (23.50%) to declined ABI.

Conclusion: Chronic exposure to PM_2.5 and PM_2.5 constituents was related to vascular damage in the abnormal metabolic population in China. The heterogeneous contribution of different PM_2.5 constituents to vessel bed damage is worthy of attention when developing targeted strategies.

Keywords: Ambient air pollution; Ankle-brachial index; Brachial-ankle pulse wave velocity; PM2.5 constituents; Vascular injury.