H. Benencia et al., THYROID PROFILE MODIFICATIONS DURING ORAL HORMONE REPLACEMENT THERAPYIN POSTMENOPAUSAL WOMEN, Gynecological endocrinology, 12(3), 1998, pp. 179-184
There are few data available about changes in thyroid hormone profiles
after hormone replacement therapy (HRT). We analyzed the effect of tw
o different oral estrogens/progestins (E/P) associations on thyroid ho
rmones and thyroxine-binding globulin (TBG) level in 14 postmenopausal
normal women distributed at random into two groups. Both groups recei
ved daily for a year 2 mg of estradiol valerianate per os. In Group A
(n = 7), estrogen war associated with norethisterone acetate. In Group
B, estrogen was associated with promegestone in a similar schedule to
Group A. Blood samples were withdrawn to measure estradiol (E2), thyr
oxine (T4), triiodothyronine (T3), free T4 (fT4), thyroid-stimulating
hormone (TSH) and TBG before and after 3, 6 and 12 months of treatment
. Estradiol level increased significantly in both groups, being higher
in Group A than in B. Under therapy, T4 and TBG level were increased
in both groups, but within the normal range. T4 mean level increased b
y 34% in Group A and 20% in Group B. TBG increment was slightly signif
icant for Group A (p < 0.02); With only a trend in Group B (p = 0.08).
T3, fT4 and TSH level did not change significantly and remained withi
n the normal range. Oral therapy with associated E/P producer moderate
increases in T4 and TBG level. Our results suggest that in postmenopa
usal women on oral HRT,fT4 and TSH level are the most useful tool to e
valuate the thyroid axis status.