title: Biomarkers of exposure to molybdenum and other metals in relation to testosterone among men from the United States National Health and Nutrition Examination Survey 2011-2012.
abstract: OBJECTIVE
  To examine the potential associations between biomarkers of metal exposure and serum testosterone in men of reproductive age in the general US population.
  
  
  METHODS
  Cross-sectional epidemiology study with adjustment for potential confounders.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Men recruited in the United States National Health and Nutrition Examination Survey (NHANES).
  
  
  METHODS
  Metal concentrations measured in whole blood, urine, and/or serum samples collected from 484 men.
  
  
  METHODS
  Serum T concentration.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan.
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Lewis
authors.affiliation: Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan. Electronic address: meekerj@umich.edu.
authors.forename: John D
authors.initials: JD
authors.lastname: Meeker
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D004651:Employment; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000097:blood* / Q000652:urine*; D006801:Humans; D008297:Male; D008670:Metals / Q000097:blood* / Q000652:urine*; D008875:Middle Aged; D044469:Racial Groups / Q000706:statistics & numerical data*; D012307:Risk Factors; D013223:Statistics as Topic; D013739:Testosterone / Q000097:blood*; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D004785:Environmental Pollutants; D008670:Metals; D013739:Testosterone
keywords: Biomarkers; epidemiology; exposure; metals; testosterone