Associations of Urinary Polycyclic Aromatic Hydrocarbons With Bone Mineral Density at Specific Body Sites in U.S. Adults, National Health and Nutrition Examination Survey 2001 to 2004.

Objective: We aimed to analyze the association between certain types of urinary polycyclic aromatic hydrocarbons (PAHs) and bone mineral density (BMD) at specific sites of the body.

Methods: A total of 2978 eligible participants from the National Health and Nutrition Examination Survey 2001 to 2004 were included in this study. Data of 8 urinary PAHs and BMDs of 3 skeleton sites and the total body were analyzed. Univariate and multivariate linear regression analyses were performed to explore the association between urinary PAHs and BMDs. Subgroup analyses stratified by sex and body mass index were also performed.

Results: After adjustment for all confounders, elevated 3-fluorene (β = 0.046; 95% confidence intervals [CIs], 0.007-0.084) and 2-fluorene (β = 0.054; 95% CI, 0.007-0.100) levels were associated with greater left arm BMD, whereas no statistical differences were observed in the relationship between other PAHs and BMDs (all P > .05). Higher 3-fluorene and 2-fluorene levels were still associated with increased left arm BMD in men (P < .05), whereas the higher 2-phenanthrene level was related to decreased left arm BMD (β = -0.062; 95% CI, -0.105 to -0.019), right arm BMD (β = -0.059; 95% CI, -0.091 to -0.027), and total BMD (β = -0.065; 95% CI, -0.119 to -0.012) in women. Similar results were also found in different body mass index populations (all P < .05).

Conclusion: Certain urinary PAHs are associated with BMDs at specific body sites. Future studies are needed to illustrate the mechanisms behind the association to establish a causal relationship.