The association between long-term exposure to ambient PM and high-density lipoprotein cholesterol level among chinese middle-aged and older adults.

Background: Recently, the impact of PM on human health has been intensively studied, especially the respiratory system. High-density lipoprotein plays a crucial role in removing excess cholesterol from cells and transporting it to the liver for excretion. However, the effects of ambient PM2.5 on high-density lipoprotein (HDL) level have not been further studied. Our research aims to investigate the potential association between ambient PM concentrations and high-density lipoprotein (HDL) levels within the middle-aged and older adults in China.

Methods: We employed data from individuals aged 45 years and above who were participants in Wave 3 of the China Health and Retirement Longitudinal Study (CHARLS). The high-quality, high-resolution PM exposure concentration data for each participant were obtained from the ChinaHighAirPollutants (CHAP) dataset, while the HDL levels were derived from blood samples collected during CHARLS Wave 3. This analysis constitutes a cross-sectional study involving a total of 12,519 participants. To investigate associations, we conducted multivariate linear regression analysis, supplemented by subgroup analysis.

Results: In this cross-sectional investigation, we discerned a negative association between prolonged exposure to ambient PM constituents and high-density lipoprotein (HDL) levels. The observed correlation between ambient PM and HDL levels suggests that older individuals residing in areas with elevated PM concentrations exhibit a reduction in HDL levels (Beta: -0.045; 95% CI: -0.056, -0.035; P < 0.001). Upon adjusting for age in Model I, the Beta coefficient remained consistent at -0.046 (95% CI: -0.056, -0.035; p < 0.001). This association persisted even after accounting for various potential confounding factors (Beta = -0.031, 95% CI: -0.041, -0.021, p < 0.001).

Conclusions: Our study reveals a statistically significant negative correlation between sustained exposure to higher concentrations of ambient PM and high-density lipoprotein (HDL) levels among Chinese middle-aged and older individuals.