Reducing PM2.5 exposure lowers dyslipidemia risk: a longitudinal quasi-experimental study

Evidence demonstrating the beneficial effects of improved air quality on lipid health is scarce. This study addresses this gap by examining whether reducing PM2.5 exposure can decrease the risk of dyslipidemia. We conducted a longitudinal quasi-experimental study using the Taiwan MJ and Hong Kong MJ cohorts from 2000 to 2018. A total of 8808 adults with consistently high PM2.5 exposure (≥ 25 μg/m3) were paired with 4612 adults whose PM2.5 exposure decreased from high to low levels (< 25 μg/m3) using propensity score matching. Cox regression models with time-dependent covariates were used to analyze the associations between PM2.5 reduction and the risk of dyslipidemia, as well as individual lipid abnormalities. We found that participants with reducing PM2.5 exposure had a significantly lower risk of dyslipidemia compared to their counterparts (hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.68-0.84). Nonlinear concentration-response relationships were observed. Similar associations were found for elevated TC (HR, 0.61; 95% CI, 0.51-0.74) and LDL-C (HR, 0.69; 95% CI, 0.57-0.84), and decreased HDL-C (HR, 0.59; 95% CI, 0.47-0.75). Reducing PM2.5 exposure significantly lowers the risk of dyslipidemia and improves lipid profiles, providing direct evidence of the health benefits associated with air quality improvement.