Association of urinary polycyclic aromatic hydrocarbons and serum C-reactive protein

The association of 9 urinary monohydroxy polycyclic aromatic hydrocarbons (OH-PAHs) with serum C-reactive protein (CRP) was investigated using the National Health and Nutrition Examination Survey (NHANES) 2003-2004. The unweighted number of participants included was 999, which represented 139,362,776 persons in the non-institutionalized US population. In adjusted logistic regressions, two OH-PAHs, 2-hydroxyphenanthrene and 9-hydroxyfluorene, were associated with elevated CRP (>3mg/l). Logistic regressions were adjusted for age, gender, race, exercise, body mass index, smoking status, diabetes, and hypertension. 2-Hydroxyphenanthrene >148ng/g creatinine had an odds ratio of 3.17 (95% CI 1.73-5.81) compared to 2-hydroxyphenanthrene < or =48ng/g creatinine, and 9-hydroxyfluorene >749ng/g creatinine had an odds ratio of 2.28 (95% CI 1.08-4.83) compared to 9-hydroxyfluorene < or =160ng/g creatinine. Intermediate levels of 2-hydroxyphenanthrene (49-148ng/g creatinine), and 9-hydroxyfluorene (161-749ng/g creatinine) were also significantly associated with elevated CRP compared to the respective reference categories. In a combined analysis, OH-PAHs were classified as low, medium, and high. Low OH-PAH was 2-hydroxyphenanthrene < or =48ng/g creatinine and 9-hydroxyfluorene < or =160ng/g creatinine. High OH-PAH was 2-hydroxyphenanthrene >148ng/g creatinine or 9-hydroxyfluorene >749ng/g creatinine. Participants not assigned to the low or high categories were classified as having medium OH-PAH concentrations. Compared to the low OH-PAH group, high OH-PAH had an odds ratio of 3.60 (95% CI 2.01-6.46) in an adjusted logistic regression. Given that inflammation (characterized here by CRP) is an important factor in the development of atherosclerosis and cardiovascular disease, these results suggest a role for OH-PAHs in the progression of atherosclerosis.