Increased plasma gonadotropin levels in spontaneous hyperthyroidism reproduced by thyroxine but not by triiodothyronine administration to normal subjects
In nine hyperthyroid women studied in the follicular phase of the menstrual cycle basal plasma LH concentrations and LH and FSH responses to GnRH were increased compared to those in nine normal women. The increased gonadotropin levels could not be related to changes in body weight or plasma estradiol or serum sex hormone-binding globulin levels, and they approached normal levels during or after tr