title: Environmental exposure to metals and male reproductive hormones: circulating testosterone is inversely associated with blood molybdenum.
abstract: OBJECTIVE
  To explore associations between exposure to metals and male reproductive hormone levels.
  
  
  METHODS
  Cross-sectional epidemiology study with adjustment for potential confounders.
  
  
  METHODS
  University Medical Center.
  
  
  METHODS
  Men recruited through two infertility clinics in Michigan.
  
  
  METHODS
  Metal concentrations and reproductive hormone levels were measured in blood samples collected from 219 men.
  
  
  METHODS
  Serum FSH, LH, inhibin B, T, and sex hormone-binding globulin levels.
  
  
  RESULTS
  Cadmium, copper, and lead were all significantly or suggestively positively associated with T when modeled individually, findings that are consistent with limited previous human and animal studies. Conversely, molybdenum was associated with reduced T. A significant inverse trend between molybdenum and T remained when additionally considering other metals in the model, and a positive association between T and zinc was also found. Finally, in exploratory analysis there was evidence for an interaction between molybdenum and zinc, whereby high molybdenum was associated with a 37% reduction in T (relative to the population median level) among men with low zinc.
  
  
  CONCLUSIONS
  Although reductions in T and reproductive toxicity after molybdenum exposure have been previously demonstrated in animal studies, more research is needed to determine whether molybdenum poses a risk to human reproductive health.
authors.affiliation: Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan 48109, USA. meekerj@umich.edu
authors.forename: John D
authors.initials: JD
authors.lastname: Meeker
authors.forename: Mary G
authors.initials: MG
authors.lastname: Rossano
authors.forename: Bridget
authors.initials: B
authors.lastname: Protas
authors.forename: Vasantha
authors.initials: V
authors.lastname: Padmanahban
authors.forename: Michael P
authors.initials: MP
authors.lastname: Diamond
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Puscheck
authors.forename: Douglas
authors.initials: D
authors.lastname: Daly
authors.forename: Nigel
authors.initials: N
authors.lastname: Paneth
authors.forename: Julia J
authors.initials: JJ
authors.lastname: Wirth
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D004785:Environmental Pollutants / Q000009:adverse effects / Q000097:blood*; D043373:Follicle Stimulating Hormone, Human / Q000097:blood; D006801:Humans; D007265:Inhibins / Q000097:blood; D016014:Linear Models; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008670:Metals / Q000009:adverse effects / Q000097:blood*; D008824:Michigan; D008982:Molybdenum / Q000009:adverse effects / Q000097:blood*; D012098:Reproduction / Q000187:drug effects*; D018570:Risk Assessment; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D013739:Testosterone / Q000097:blood*; D015032:Zinc / Q000097:blood
chemical_list: D015415:Biomarkers; D004785:Environmental Pollutants; D043373:Follicle Stimulating Hormone, Human; D008670:Metals; D012738:Sex Hormone-Binding Globulin; C422364:inhibin B; D013739:Testosterone; D007265:Inhibins; D008982:Molybdenum; D007986:Luteinizing Hormone; D015032:Zinc