Cross-sectional.
National Institutes of Health Clinical Research Center.
Women with 46,XX spontaneous premature ovarian failure (n = 130).
Evaluation while off any estrogen therapy and then again after receiving a standardized hormone regimen. Regularly menstruating control women (n = 65) were sampled during the midfollicular phase.
Serum total T by RIA after extraction and column chromatography, free T by equilibrium dialysis, and sex hormone–binding globulin by immunoradiometric assay.
While off estrogen therapy patients had a median serum free-T concentration that was statistically significantly lower than controls (2.2 vs. 3.3 pg/mL). This dropped significantly lower to 1.9 pg/mL while the patients were on physiologic transdermal E2 therapy. This is despite the fact that sex hormone–binding globulin levels did not change. While on E2 therapy, 13 % of women (95 % confidence interval, 7.9 % –20.3 % ) had serum free-T levels below the lower limit of normal (<1.1 pg/mL).
As a group, young women with 46,XX spontaneous premature ovarian failure have reduced circulating free-T levels, both during an interval off of estrogen therapy and while on physiologic transdermal E2 therapy.