Serum FSH, LH, and testosterone concentrations in presumably fertile men: effect of age.

OBJECTIVE

Delineation of change in male hormone and gonadotropin levels from age 21 to 85.

SUBJECTS

Healthy married volunteers with one or more children.

METHODS

A 5-mL venous blood sample, serum separated within one hour; testosterone measured by direct RIA, FSH and LH by immunoradiometric assay and magnetic separation.

RESULTS

FSH significantly higher from 6th decade, LH from 7th decade; testosterone lower from 6th decade.

CONCLUSIONS

Apparently, a rise in FSH and reduction in testosterone precede a rise in LH concentration.