Quote from: DuchessBianca on December 19, 2016, 12:53:07 PM
I honestly can't be certain but it was more of a tongue in cheek joke with maybe a hint of truth. I just know pre HRT my TSH/FT4 at 243 pounds was healthy at 2.45 mi/Ul and now at the time of the test 6.5 months, down over 60 pounds through hard work/exercize/diet later that pretty much doubled + to 5.44 mi/Ul and is now outside the normal range of 0.40-4.50 causing me mild hypothyroidism. I've had 3 sets of blood work, before hrt, 2.5 months during and 6.5 months and pretty much everything has been perfect/consistent, testosterone was last tested in August and not the last test and that was well within female range at 34ng/ml, Estrogen is raised, outside of a slightly elevated prolactin level (for male range) thyroid is the only thing to flag out of range since being on HRT, all that weight loss pretty much cured all the other little things that were slightly elevated like liver and such due to access weight. The only thing I could guess is the cause is the estrogen as I read that it's possible for it to compete with thyroid hormone. The only symptoms I've ever felt was those associated with hypothyroidism so it's really the only thing I can guess as the cause for it due to everything else seeming to be perfectly how it should.
Indian J Endocrinol Metab. 2013 Nov-Dec; 17(6): 996–1004."High levels of estrogen increase the binding proteins and the bound form of thyroid hormone increases. There is almost 50% physiological increase in total thyroxine (T4) although
the free form remains unchanged.[10]"
Eur J Endocrinol. 2006 Jul;155(1):11-6."Estrogen and androgen administration modulate the pituitary-thyroid axis through alterations in thyroid hormone-binding globulin (TBG) metabolism, but the effects of sex steroids on extrathyroidal thyroxine (T4) to triiodothyronine (T3) conversion in humans are unknown."
"We studied 36 male-to-female and 14 female-to-male euthyroid transsexuals at baseline and after 4 months of hormonal treatment. Male-to-female transsexuals were treated with cyproterone acetate (CA) (...) alone (n = 10) or in combination with either oral ethinyl estradiol (or-EE) (...) (n = 14) or transdermal 17beta-estradiol (td-E) (...) twice a week (n = 12)."
"Or-EE increased TBG (100 +/- 12%, P < .001) and testosterone decreased TBG (-14 +/- 4%, P = 0.01), but free T4 did not change. Td-E and CA did not affect TBG concentrations. TSH was not different between groups at baseline or after treatment.
CA decreased T3/T4 ratios (-9 +/- 3%, P = 0.04), suggesting that T4 to T3 conversion was lower."
"Oral but not transdermal estradiol increases TBG, whereas testosterone lowers TBG. Testosterone increases T3/T4 ratios.
Estradiol does not affect T3/T4 ratios, irrespective of the route of administration."
