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

Limited research has focused on the independent effects of PM 2.5 chemical components sulfate (SO 4 2- ), nitrate (NO 3 - ), ammonium (NH 4 + ), 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. The study included 5,442 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 1,299 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 ug/m 3 ) and PM 2.5 chemical components, including SO 4 2- (2.14 ug/m 3 ) NO 3 - (1. 3 6 ug/m 3 ) NH 4 + (0.92 ug / m 3 ) OM (2.57 ug/m 3 ) and BC(0.70 ug/m 3 ), 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. 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. • For each increase of 1 SD in PM 2.5 , the risk of developing high low-density lipoprotein cholesterolemia increases by 136% (HR=2.36, 95% CI: 1.98-2.81), and LDL-C levels increase by 0.78 mmol/L (95% CI: 0.73-0.84). • The association was more substantial impact on minority population, individuals without exhaust ventilation, and those not using clean fuels.