Vitamin D status in relation to inflammatory risk and albuminuria associated with polycyclic aromatic hydrocarbon exposure in the US population

Abstract

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with both systematic inflammation and renal dysfunction. Reports have suggested that anti-inflammatory properties of vitamin D may provide protection against renal injury. This cross-sectional study tested the hypothesis that serum 25-hydroxyvitamin D [25(OH)D] moderates the inflammation and albuminuria associated with PAH exposure. Data were obtained from 5,982 subjects aged 20-79 years in the National Health and Nutrition Examination Survey (2001-2010). PAH exposure was estimated by urinary PAH metabolites. Inflammation was defined as serum C-reactive protein (CRP) > 3 mg/L and albuminuria as urinary albumin-to-creatinine ratio > 30 mg/g. The results found that greater PAH exposure was linked with inflammation and albuminuria. Individuals with PAH exposure also tended to have lower 25(OH)D and lower vitamin D was associated with both elevated CRP (Odds ratio [OR] = 1.28, 95% confidence interval [CI] = 1.07-1.54) and urinary albumin (1.35, 95%CI = 1.03-1.77) for any given PAH exposure. Those with lower serum 25(OH)D-to-urinary PAH ratios were likewise at a greater risk of elevated CRP and albuminuria. The findings support prior suggestions that exposure to PAHs is associated with inflammation and albuminuria but suggests further that the risk is higher when vitamin D is lower. Thus, nutritional status becomes an important variable in PAH risk assessment.

Keywords:

• Adults
• air pollution
• chemical exposure
• exposure assessment
• Inflammatory risk
• kidney diseases
• PAH exposure
• renal diseases
• risk assessment
• toxicology
• Vitamin D

Acknowledgements

We thank Drs. Reeder Sams, John Cowden and Ms. Christine Cai for their valuable comments.

Disclaimers

The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of their institutional affiliations including the U.S. Environmental Protection Agency. The corresponding author has full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. The authors declare that they have no competing financial interests.

Funding

The author(s) reported there is no funding associated with the work featured in this article.