The association between ambient air pollution and blood lipids: A longitudinal study in Shijiazhuang, China

Background: Few studies have explored the associations between ambient air pollution and blood lipid levels. This study aimed to fill this knowledge gap based on a routine health examination cohort in Shijiazhuang, China. Methods: We included 7063 participants who took the routine health examination for 2-3 times at Hebei General Hospital from January 2016 to December 2018. Individual serum levels of cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured. Their three-month average exposure to air pollution prior to the routine health examinations was estimated using inverse distance weighted method. We used linear mixed-effects regression models to examine the associations between air pollution and levels of blood lipids while controlling for age, gender, body mass index (BMI), smoking, alcohol drinking, temperature, humidity, with a random effect for each individual. Results: Particles with diameters <= 2.5 mu m and <= 10 mu m (PM2.5 and PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2) and ozone (O-3) were all positively associated with TC, TG, and LDL-C and negatively associated with HDL-C, in single pollutant models. Each 10 mu g/m(3) increment of 3-month average PM2.5 was associated with 0.65% [95% confidence interval (CI): 0.03%-1.28%], 0.56% (95%CI: 0.33%-0.79%) and 0.63% (95%CI: 0.35%-0.91%) increment in TG, TC, and LDL-C, and 0.91% (95%CI: 0.68%-1.13%) decrease in HDL-C. In two-pollutant models, the effects of gaseous pollutants on blood lipids were weakened, while those of PMs were strengthened. Stronger associations were presented in the elderly (>= 60 years) and overweight/obese (BMI >= 24) participants. Conclusions: Ambient air pollution had significantly adverse effects on blood lipid levels, especially in overweight/obese and elderly individuals. Capsule: Significant associations between increased air pollution and worse blood lipid levels were found, especially in overweight/obese and elderly individuals. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The study found significant associations between air pollution and blood lipid levels, especially in overweight/obese and elderly individuals. The effects of gaseous pollutants on blood lipids were weakened in two-pollutant models, while those of particulate matters were strengthened.