{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T22:17:08Z","timestamp":1783549028903,"version":"3.55.0"},"reference-count":0,"publisher":"Oxford University Press (OUP)","issue":"1","content-domain":{"domain":["eje.bioscientifica.com"],"crossmark-restriction":true},"short-container-title":["eur j endocrinol"],"published-print":{"date-parts":[[2006,7]]},"abstract":"<jats:p><jats:italic>Objective<\/jats:italic>: Estrogen and androgen administration modulate the pituitary\u2013thyroid axis through alterations in thyroid hormone-binding globulin (TBG) metabolism, but the effects of sex steroids on extrathyroidal thyroxine (T<jats:sub>4<\/jats:sub>) to triiodothyronine (T<jats:sub>3<\/jats:sub>) conversion in humans are unknown.<\/jats:p>\n      <jats:p><jats:italic>Design and methods<\/jats:italic>: 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) 100 mg\/day alone (<jats:italic>n<\/jats:italic>=10) or in combination with either oral ethinyl estradiol (or-EE) 100 \u03bcg\/day (<jats:italic>n<\/jats:italic>=14) or transdermal 17\u03b2-estradiol (td-E) 100 \u03bcg twice a week (<jats:italic>n<\/jats:italic>=12). Female-to-male transsexuals were treated with i.m. testosterone 250 mg twice a week. A <jats:italic>t-<\/jats:italic>test was used to test for differences within groups and ANOVAwith <jats:italic>post hoc<\/jats:italic> analysis to test for differences between the groups.<\/jats:p>\n      <jats:p><jats:italic>Results<\/jats:italic>: Or-EE increased TBG (100 \u00b1 12%, <jats:italic>P<\/jats:italic>&lt;.001) and testosterone decreased TBG (\u221214 \u00b1 4%, <jats:italic>P<\/jats:italic> =0.01), but free T<jats:sub>4<\/jats:sub> 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 T<jats:sub>3<\/jats:sub>\/T<jats:sub>4<\/jats:sub> ratios (\u22129 \u00b1 3%, <jats:italic>P<\/jats:italic>=0.04), suggesting that T<jats:sub>4<\/jats:sub> to T<jats:sub>3<\/jats:sub> conversion was lower. Testosterone increased T<jats:sub>3<\/jats:sub>\/T<jats:sub>4<\/jats:sub> ratios (30 \u00b1 9%, <jats:italic>P<\/jats:italic>=0.02), which probably reflects higher T<jats:sub>4<\/jats:sub> to T<jats:sub>3<\/jats:sub> conversion.<\/jats:p>\n      <jats:p><jats:italic>Conclusion<\/jats:italic>: Oral but not transdermal estradiol increases TBG, whereas testosterone lowers TBG. Testosterone increases T<jats:sub>3<\/jats:sub>\/T<jats:sub>4<\/jats:sub> ratios. Estradiol does not affect T<jats:sub>3<\/jats:sub>\/T<jats:sub>4<\/jats:sub> ratios, irrespective of the route of administration.<\/jats:p>","DOI":"10.1530\/eje.1.02192","type":"journal-article","created":{"date-parts":[[2006,6,22]],"date-time":"2006-06-22T16:56:10Z","timestamp":1150995370000},"page":"11-16","update-policy":"https:\/\/doi.org\/10.1530\/crossmarkpolicy-1","source":"Crossref","is-referenced-by-count":34,"title":["The effects of sex-steroid administration on the pituitary\u2013thyroid axis in transsexuals"],"prefix":"10.1093","volume":"155","author":[{"given":"Peter H","family":"Bisschop","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Arno W","family":"Toorians","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erik","family":"Endert","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wilmar M","family":"Wiersinga","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Louis J","family":"Gooren","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eric","family":"Fliers","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","container-title":["European Journal of Endocrinology"],"original-title":[],"link":[{"URL":"https:\/\/eje.bioscientifica.com\/view\/journals\/eje\/155\/1\/1550011.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/eje.bioscientifica.com\/view\/journals\/eje\/155\/1\/1550011.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,2,14]],"date-time":"2023-02-14T16:34:03Z","timestamp":1676392443000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/ejendo\/article\/155\/1\/11\/6695695"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2006,7]]},"references-count":0,"journal-issue":{"issue":"1"},"URL":"https:\/\/doi.org\/10.1530\/eje.1.02192","relation":{},"ISSN":["0804-4643","1479-683X"],"issn-type":[{"value":"0804-4643","type":"print"},{"value":"1479-683X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2006,7]]}}}