Long-term exposure to PM2.5 and its components on human high low-density lipoprotein cholesterolemia: A 10-year cohort study in southwest China

Abstract

Background

Limited research has focused on the independent effects of PM_2.5 chemical components sulfate (SO₄^2-), nitrate (NO₃^-), ammonium (NH₄⁺), organic matter (OM), and black carbon (BC) on high low-density lipoprotein cholesterolemia. Therefore, our research aims to investigate the potential casual links between long-term PM_2.5 and its components exposure and high low-density lipoprotein cholesterolemia, while identifying potentially susceptible subpopulations.

Methods

The study included 5442 participants from the Guizhou Population Health Cohort Study (GPHCS), which lasted for 10 years. A time-dependent Cox proportional hazards regression model was applied to calculate hazard ratios (HRs) and 95 % confidence intervals (CIs) for the risk of high low-density lipoprotein cholesterolemia. General linear models (GLMs) were utilized to evaluate the association between PM_2.5 and its components with low density lipoprotein cholesterol (LDL-C) levels.

Results

There was a total of 17,339.94 person-years (PYs), among which 1299 cases of high low-density lipoprotein cholesterolemia were found. All pollutants were associated with the incidence of high low-density lipoprotein cholesterolemia (P < 0.05) except for BC. Each 1 SD increase in PM_2.5 (4.51 μg/m³₎ and PM_2.5 chemical components, including SO₄^2- (2.14 μg/m³) NO₃^- (1.36 μg/m³) NH₄⁺ (0.92 μg/m³) OM (2.57 μg/m³) and BC(0.70 μg/m³), was associated with increased LDL-C levels by 0.78 mmol/L (95 % CI: 0.73–0.84), 0.42 mmol/L (95 % CI: 0.36–0.48), 0.58 mmol/L (95 % CI: 0.53–0.62), 0.50 mmol/L (95 % CI: 0.46–0.55), 0.40 mmol/L (95 % CI: 0.34–0.45), and 0.31 mmol/L (95 % CI: 0.25–0.37), respectively. Subgroup analysis revealed long-term exposure to PM_2.5 and its components had a more substantial impact on minority population, individuals without exhaust ventilation, and those not using clean fuels.

Conclusion

This study shows that long-term exposure to PM_2.5 and its components was associated with an increased risk of high low-density lipoprotein cholesterolemia and elevated LDL-C levels, especially among minorities and those without exhaust ventilation or clean fuels.