Association between long-term exposure to PM2.5 chemical components and metabolic syndrome in middle-aged and older adults

Abstract

Background: Previous studies indicated that exposure to ambient fine particulate matter (PM_2.5) could increase the risk of metabolic syndrome (MetS). However, the specific impact of PM_2.5 chemical components remains uncertain.

Methods: A national cross-sectional study of 12,846 Chinese middle-aged and older adults was conducted. Satellite-based spatiotemporal models were employed to determine the 3-year average PM_2.5 components exposure, including sulfates (SO₄ ^2-), nitrates (NO₃ ^-), ammonia (NH₄ ⁺), black carbon (BC), and organic matter (OM). Generalized linear models were used to investigate the associations of PM_2.5 components with MetS and the components of MetS, and restricted cubic splines curves were used to establish the exposure-response relationships between PM_2.5 components with MetS, as well as the components of MetS.

Results: MetS risk increased by 35.1, 33.5, 33.6, 31.2, 32.4, and 31.4% for every inter-quartile range rise in PM_2.5, SO₄ ^2-, NO₃ ^-, NH₄ ⁺, OM and BC, respectively. For MetS components, PM_2.5 chemical components were associated with evaluated risks of central obesity, high blood pressure (high-BP), high fasting glucose (high-FBG), and low high-density lipoprotein cholesterol (low-HDL).

Conclusion: This study indicated that exposure to PM_2.5 components is related to increased risk of MetS and its components, including central obesity, high-BP, high-FBG, and low-HDL. Moreover, we found that the adverse effect of PM_2.5 chemical components on MetS was more sensitive to people who were single, divorced, or widowed than married people.

Keywords: air pollution; marital status; metabolic dysfunction; middle-aged and older adults; particulate matter.