High air pollution exposure, vitamin D deficiency and ever smokers were associated with higher prevalence of hypercholesterolemia: A cross-sectional study from the 2008-2014 Korea National Health and Nutrition Examination Survey

Abstract

Air pollutants directly and indirectly cause vitamin D deficiency (VDD). In addition, smoking increases oxidative stress and accelerates skin aging, thereby reducing the body's vitamin D concentration. Previous study reported that VDD increases total cholesterol concentration by reducing vitamin D receptor activity. We hypothesized that high air pollution exposure, smoking, and VDD would increase hypercholesterolemia. We investigated associations between long-term exposure to air pollutants, smoking status, VDD, and their combination with hypercholesterolemia using data from the 2008-2014 Korea National Health and Nutrition Examination Survey (KNHANES). We used linked data from the KNHANES to the daily moving average of air-pollution data from 730 days before the examination date, using participants' addresses in latitude and longitude coordinates. Results were analyzed using a survey logistic regression model for complex sample analyses. We included 28,134 adults with data on serum vitamin D, cholesterol concentrations, smoking status, and air pollutant concentrations. After adjusting for potential covariates, adults with exposure to high concentrations of air pollutants and ever smokers showed significantly higher risks of VDD (odds ratios [ORs], 1.70; 95 % confidence intervals [CIs], 1.44-2.00). In the group with high air-pollutant exposure, adults with low vitamin D status and ever smokers had significantly higher risks of hypercholesterolemia (ORs, 1.55; 95 % CIs, 1.09-2.19) than adults with high vitamin D status and never smokers. We found that high air-pollutant exposure, ever smokers, and VDD may increase hypercholesterolemia prevalence in Korean adults. Therefore, to reduce hypercholesterolemia risk, adults living in areas with high air-pollution exposure may need adequate vitamin D intake and to avoid smoking.

Keywords: Air pollutants; Hypercholesterolemia; Smoking; Total cholesterol; Vitamin D deficiency.