Fine particulate matter constituents and sub-clinical outcomes of cardiovascular diseases: A multi-center study in China

Abstract

Background: Limited evidence is available on the associations of long-term exposure to various fine particulate matter (PM_2.5) constituents with sub-clinical outcomes of cardiovascular disease (CVD) in China.

Objectives: We aimed to explore the associations of PM_2.5 and its constituents with blood pressure (BP), fasting glucose, and cardiac electrophysiological (ECG) properties based on a national survey of 5852 Chinese adults, who participated in the Sub-Clinical Outcome of Polluted Air study, from July 2017 to March 2019.

Methods: Annual residential exposure to PM_2.5 and its constituents of each subject was predicted by a satellite-based mode. We assessed the associations between five main constituents [organic matter (OM), black carbon (BC), sulfate (SO₄^2-), nitrate (NO₃^-), ammonium (NH₄⁺)] of PM_2.5 and systolic BP (SBP), diastolic BP (DBP), fasting glucose, and ECG measurements (PR, QRS, QT, and QTc interval) using multivariable linear regression models.

Results: Long-term PM_2.5 exposure was significantly associated with increased levels of fasting glucose, DBP, and ECG measurements. An IQR increase in OM (8.2 μg/m³) showed considerably stronger associations with an elevated fasting glucose of 0.39 mmol/L (95%CI confidence interval: 0.28, 0.49) compared with other PM_2.5 constituents. Meanwhile, an IQR increase in NO₃^-, NH₄⁺ and OM had stronger associations with DBP and ECG parameters compared with BC and SO₄^2-.

Conclusions: This nationwide multi-center study in China indicated that some constituents (i.e., OM, NO₃^-, and NH₄⁺) might be mainly responsible for the association of PM_2.5 with sub-clinical outcomes of CVD including BP, fasting glucose, and ECG measurements.

Keywords: Blood pressure; Electrocardiogram; Fasting glucose; Multi-center study; PM(2.5) constituents.