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Secretion of testicular steroids and gonadotrophins in hypothyroidism
Author(s) -
Kumar A.,
Mohanty B. P.,
Rani L.
Publication year - 2007
Publication title -
andrologia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.633
H-Index - 59
eISSN - 1439-0272
pISSN - 0303-4569
DOI - 10.1111/j.1439-0272.2007.00798.x
Subject(s) - medicine , endocrinology , testosterone (patch) , euthyroid , hyperprolactinaemia , hormone , triiodothyronine , endocrine system , prolactin , chemistry
Summary Inconsistent alterations in gonadal steroidogenesis and pituitary functions have been reported in hypothyroid males. We have compared the lipid and endocrine profiles of the euthyroid and hypothyroid [thyroid‐stimulating hormone (TSH) >100 mIU l −1 ] males. Hypothyroidism was found to be associated with an increase in the circulating level of total cholesterol and LDL‐cholesterol (LDL‐C) and a reduction in the levels of progesterone and testosterone, without any change in the serum levels of oestradiol and gonadotrophins. The failure of gonadotrophins to rise could be accounted by a normal level of serum oestradiol in the hypothyroid male. A mild hyperprolactinaemia was also noted in the hypothyroid patients. The reduction in serum testosterone level could be explained by (i) a reduced uptake of LDL‐C by the Leydig cells and thereby a reduction in the synthesis of progesterone and consequentially testosterone, (ii) a further reduction in the rate of conversion of progesterone to testosterone, (iii) a higher rate of conversion of testosterone to oestradiol, (iv) a decrease in serum triiodothyronine and (v) hyperprolactinaemia. Rise in TSH needs to be investigated as a cause of the suppression of gonadal steroidogenesis.