Is long-term PM₁ exposure associated with blood lipids and dyslipidemias in a Chinese rural population?

Background: Air pollution has been shown to be associated with blood lipid levels. However, studies on long-term ambient particulate matter with aerodynamic diameter ≤1 μm (PM₁) exposure in high-exposure areas are still limited. This study aimed to explore the associations among long-term PM₁ exposure, blood lipids and dyslipidemias. Methods: Baseline data of The Henan Rural Cohort study was used in present study, including a total of 39,259 participants aged from 18 to 79 years. Daily levels of PM₁ were estimated by a spatiotemporal model using ground-level measurements of PM₁, satellite remote sensing data and other predictors, according to participants' home addresses. Individual exposure to PM₁ was the 3-year average before baseline investigation. Linear regression and logistic regression models were applied to examine the associations among PM₁, blood lipids ((total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C)), and prevalence of dyslipidemias. Results: The 3-year concentration of PM₁ was 55.7 ± 2.1 μg/m³. Each 1 μg/m³ increment of PM₁ was associated with an increase of 0.21% (95% confidence interval (CI): 0.11%–0.31%) in TC and 0.75% (95% CI: 0.61%–0.90%) in LDL-C, while decrease of 2.68% (95% CI: 2.43%–2.93%) in TG and 0.47% (95% CI: 0.35%–0.59%) in HDL-C. Each 1 μg/m³ increase in PM₁ was associated with 6% (95% CI: 4%–8%), 3% (95% CI: 2%–5%) and 5% (95% CI: 3%–7%) higher risks of hypercholesterolemia, hyperbetalipoproteinemia and hypoalphalipoproteinemia. Sex, age and BMI statistically modified the associations between PM₁ with blood lipid levels and dyslipidemias. Conclusions: Higher PM₁ exposure was associated with adverse changes of blood lipid levels and dyslipidemias. Males, older and overweight participants were susceptive to the adverse effects of PM₁.