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 μm and ≤10 μm (PM2.5 and PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2) and ozone (O3) were all positively associated with TC, TG, and LDL-C and negatively associated with HDL-C, in single pollutant models. Each 10 μg/m3 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.
['Zhang|Kaihua|K|', 'Wang|Haoyuan|H|', 'He|Weiliang|W|', 'Chen|Gongbo|G|', 'Lu|Peng|P|', 'Xu|Rongbin|R|', 'Yu|Pei|P|', 'Ye|Tingting|T|', 'Guo|Suying|S|', 'Li|Shanshan|S|', 'Xie|Yinyu|Y|', 'Hao|Zhihua|Z|', 'Wang|Hebo|H|', 'Guo|Yuming|Y|']
D000368:Aged D000393:Air Pollutants D000397:Air Pollution D002681:China D004781:Environmental Exposure D006801:Humans D008055:Lipids D008137:Longitudinal Studies D009585:Nitrogen Dioxide D052638:Particulate Matter
Blood lipids Gaseous pollutants Particulate matter