The Association of Urinary Polycyclic Aromatic Hydrocarbons Biomarkers and Markers of Inflammation, Diabetes Mellitus and Cardiovascular Disease

Polycyclic aromatic hydrocarbons are potent atmospheric pollutants, released into air during incomplete combustion of fuel, industrial or domestic coal, wood, cigarette smoke and other organic materials. In addition to being carcinogenic, several animal studies have reported positive associations between polycyclic aromatic hydrocarbons and inflammation, oxidative stress and the development and progression of atherosclerosis. Occupational studies have reported positive associations between polycyclic aromatic hydrocarbons and cardiovascular morbidity and mortality. Moreover, there is evidence that polycyclic aromatic hydrocarbons may cause disruption of the endocrine system. It is still not clear if lower background exposure to polycyclic aromatic hydrocarbons, independent of the adverse health effects of smoking, is associated with increased risk of inflammation, diabetes mellitus and cardiovascular disease in the general population. We examined participants from the merged National Health and Nutrition Examination Survey 2001-02, 2003-2004, and 2005-2006. Our exposures of interest were eight urinary monohydroxy polycyclic aromatic hydrocarbons and our outcomes were serum markers of systemic inflammation, including: serum C-reactive protein and total white blood cell count, diabetes mellitus and self-reported cardiovascular disease. Urinary biomarkers of the low molecular weight polycyclic aromatic hydrocarbons were found to be positively associated with serum C-reactive protein, total white blood cell count and diabetes mellitus independent of potential confounders. Levels of 1-hydroxypyrene, the urinary metabolite of the higher molecular weight PAH, pyrene, showed a less strong association with serum C-reactive protein and diabetes mellitus. The evidence on the association between polycyclic aromatic hydrocarbons and self-reported cardiovascular disease was limited, only 1-hydroxynapthalene, summed biomarkers of low molecular weight polycyclic aromatic hydrocarbons, and 1- hydroxypyrene showed statistically significant positive associations with cardiovascular disease independent of potential confounders. In conclusion, this study provides evidence on the positive association of background exposure to polycyclic aromatic hydrocarbons and serum C-reactive protein, total white blood cell count, diabetes mellitus and cardiovascular disease. Further prospective studies are needed to replicate or refute our findings