Exposure to ambient air pollution and blood lipids in adults: The 33 Communities Chinese Health Study

Little information exists on the lipidemic effects of air pollution, particularly in developing countries. We aimed to investigate the associations of long-term exposure to ambient air pollutants with lipid levels and dyslipidemias in China.In 2009, a total of 15,477 participants aged 18-74 years were recruited from the 33 Communities Chinese Health Study conducted in three Northeastern China cities. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were measured in participants' blood specimens. Three year (2006-08) average air pollution concentrations were assessed using data from 33 communities (particles with diameters ≤1.0 μm (PM1) and ≤2.5 μm (PM2.5) were predicted using a spatial statistical model) or 11 air monitoring stations (particles with diameters ≤10 μm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3)). Associations were evaluated by two-level logistic and generalized linear regression models.We detected many significant associations between exposure to air pollutants (especially for PM1 and PM2.5) and blood lipid levels. Most of the associations suggested deleterious effects on blood lipid markers (e.g., a 10 μg/m3 increase in PM1 was associated with 1.6% (95% confidence interval (CI): 1.1, 2.0), 2.9% (95% CI: -3.3, 9.3), and 3.2% (95% CI: 2.6, 3.9) higher levels of TC, TG, and LDL-C, respectively, but 1.4% (95% CI: -1.8, -0.9) lower HDL-C levels), although beneficial associations were found for O3. In analysis with dyslipidemias, all the observed associations suggested deleterious lipidemic effects of air pollutants, and no significant beneficial association was observed for O3. Stratified analyses showed that the associations were stronger in overweight or obese participants; sex and age modified the associations, but the pattern of effects was mixed.Long-term ambient air pollution was associated with both altered lipid profiles and dyslipidemias, especially among overweight or obese participants.