Objective: To examine the potential associations between biomarkers of metal exposure and serum testosterone in men of reproductive age in the general US population.
Design: Cross-sectional epidemiology study with adjustment for potential confounders.
Setting: Not applicable.
Patient(s): Men recruited in the United States National Health and Nutrition Examination Survey (NHANES).
Intervention(s): Metal concentrations measured in whole blood, urine, and/or serum samples collected from 484 men.
Main outcome measure(s): Serum T concentration.
Result(s): Concentrations of the metals were detected in 69%-100% of the samples. In adjusted analyses where metals were modeled as a continuous variable, we found significant inverse associations between urinary molybdenum and serum copper and serum T, whereas there were significant positive associations between blood lead and cadmium and serum T. When metals were categorized into quartiles, analyses for serum copper and blood lead and cadmium produced significant associations in the same direction as the continuous measures. A suggestive inverse association was observed between quartiles of urinary molybdenum and serum T, but the association was statistically significant when molybdenum was categorized into quintiles. Significant positive associations were also observed for quartiles of blood Se and serum Zn and serum T.
Conclusion(s): These findings add to the limited human evidence that exposure to molybdenum and other metals is associated with altered T in men, which may have important implications for male health. More research is needed to confirm the findings of our study.
Keywords: Biomarkers; epidemiology; exposure; metals; testosterone.
Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.