Environmental exposure to metals and male reproductive hormones: circulating testosterone is inversely associated with blood molybdenum.
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.
Meeker
John D
JD
Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan 48109, USA. meekerj@umich.edu
Rossano
Mary G
MG
Protas
Bridget
B
Padmanahban
Vasantha
V
Diamond
Michael P
MP
Puscheck
Elizabeth
E
Daly
Douglas
D
Paneth
Nigel
N
Wirth
Julia J
JJ
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
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