Hypothalamic-Pituitary-Testicular Axis in Patients with Hyperthyroidism

Röjdmark, Sven; Berg, Anders; Källner, Göran

doi:10.1159/000181000

Cited by 36 publications

(17 citation statements)

References 18 publications

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“…However, the plasma level of free testosterone is not significantly different from normal (21,22), whereas bioavailable testosterone has been reported recently to be low (19). Basal levels of gonadotropins are usually normal, with LH and FSH responses to exogenous GnRH significantly greater than those of controls (25). Serum progesterone levels are also elevated in these patients (22).…”

Section: Discussionmentioning

confidence: 85%

A Prospective Controlled Study of the Impact of Hyperthyroidism on Reproductive Function in Males

Krassas¹,

Pontikides²,

Deligianni

et al. 2002

The Journal of Clinical Endocrinology &Amp; Metabolism

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The aim of this prospective controlled study was to ascertain the effect of hyperthyroidism on sperm quality and composition. We studied 23 thyrotoxic male patients, aged 43.8 +/- 2.4 yr (mean +/- SEM), and 15 healthy male controls of approximately the same age (42.2 +/- 2.2 yr). Two semen analyses at intervals of 2-3 wk were obtained before and about 5 months after euthyroidism was achieved either by methimazole alone (14 patients) or (131)I plus methimazole (9 patients). Total fructose, zinc (Zn), and magnesium (Mg) were also measured in seminal plasma in 16 patients, because 7 had semen volume less than 2 ml. In the control group semen analysis was performed only once. Mean (+/-SEM) semen volume was within normal range both in patients (3.3 +/- 0.2 ml) and controls (3.5 +/- 0.4 ml; P = NS). Mean sperm density was lower in patients, although the difference compared with controls did not reach statistical significance (35.7 +/- 5.3 vs. 51.5 +/- 6.1 x 10(6)/ml; P = 0.062). The same was found with sperm morphology (68 +/- 7% vs. 78 +/- 8%; P = NS). Finally, mean motility was lower in thyrotoxic males than in controls (28 +/- 8% vs. 57 +/- 7%; P < 0.01). After treatment, sperm density and motility improved [35.7 +/- 5.3 vs. 43.3 +/- 6.5 x 10(6)/ml (P = NS) and 28 +/- 8% vs. 45 +/- 7% (P < 0.05), respectively], but sperm morphology did not change (68 +/- 7% vs. 70 +/- 6%; P = NS). Mean values for fructose, Zn, and Mg did not differ between controls and patients either before or after achievement of euthyroidism [9.2 +/- 0.7, 3.0 +/- 0.5, and 4.2 +/- 0.7 nmol/liter vs. 8.6 +/- 0.9, 3.0 +/- 0.5, and 4.7 +/- 0.8 nmol/liter (patients before) and 9.1 +/- 0.7, 3.1 +/- 0.6, and 4.5 +/- 0.9 nmol/liter (patients after treatment) for fructose, Zn, and Mg, respectively]. Moreover, according to the treatment given, no statistically significant differences were found before or after treatment. Finally, seminal plasma fructose, Zn, and Mg levels did not correlate with sperm parameters or with pretreatment thyroid hormone levels. In conclusion, the results of our study indicate that male patients with hyperthyroidism have abnormalities in seminal parameters, mainly sperm motility. These abnormalities improve or normalize when the patients become euthyroid. Restoration of sperm parameters was independent of the treatment provided for the hyperthyroid syndrome. Moreover, seminal plasma elements, such as fructose, Zn, and Mg, did not correlate with sperm density, motility, or morphology.

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Section: Discussionmentioning

confidence: 85%

A Prospective Controlled Study of the Impact of Hyperthyroidism on Reproductive Function in Males

Krassas¹,

Pontikides²,

Deligianni

et al. 2002

The Journal of Clinical Endocrinology &Amp; Metabolism

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“…LH and FSH response to exogenous GnRH seems to be significantly greater in thyrotoxic patients in comparison to patients who were rendered euthyroid (44,45). It has been suggested that the LH elevation could be secondary to changes in sex steroid binding and peripheral metabolism, alterations in the hypothalamic-pituitary feedback, or due to the direct effect of thyroid hormones per se at this level (45). All these changes are fully reversible with restoration of the euthyroid state, and require no other specific treatment.…”

Section: Thyroid Hormone Disorders and Androgenic Hormonesmentioning

confidence: 99%

“…Several studies have shown that altered thyroid status has remarkable effects on Leydig cell differentiation in experimental animals dism, pituitary hyperplasia may occur causing multiple pituitary hormone deficiencies, including gonadotropin and corticotropin deficiencies (45). Low T3, high TSH and hyperprolactinemia caused by hypothyroidism could directly act on the Leydig cells in suppressing steroidogenesis (42,43,46).…”

Section: Thyroid Hormone and Testicular Functionmentioning

confidence: 99%

Clinical implications of altered thyroid status in male testicular function

Wajner

Wagner

Maia

2009

Arq Bras Endocrinol Metab

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Thyroid hormones are involved in the development and maintenance of virtually all tissues. Although for many years the testis was thought to be a thyroid-hormone unresponsive organ, studies of the last decades have demonstrated that thyroid dysfunction is associated not only with abnormalities in morphology and function of testes, but also with decreased fertility and alterations of sexual activity in men. Nowadays, the participation of triiodothyronine (T3) in the control of Sertoli and Leydig cell proliferation, testicular maturation, and steroidogenesis is widely accepted, as well as the presence of thyroid hormone transporters and receptors in testicular cells throughout the development process and in adulthood. But even with data suggesting that T3 may act directly on these cells to bring about its effects, there is still controversy regarding the impact of thyroid diseases on human spermatogenesis and fertility, which can be in part due to the lack of well-controlled clinical studies. The current review aims at presenting an updated picture of recent clinical data about the role of thyroid hormones in male gonadal function. RESUMOOs hormônios da tireoide estão envolvidos virtualmente no desenvolvimento e na manutenção de todos os tecidos. As gônadas masculinas foram, por décadas, consideradas insensíveis aos hormônios tireoidianos. No entanto, estudos mais recentes têm demonstrado que disfunções tireoidianas estão associadas não somente a anormalidades na morfologia e na função dos testículos, mas também à diminuição da fertilidade e alterações na atividade sexual masculina. Atualmente, o papel da triiodotironina (T3) no controle da proliferação das células de Sertoli e Leydig, maturação testicular e esteroidogênese é amplamente aceito, bem como a presença de transportadores e receptores para o hormônio tireoidiano nos testículos durante o período de desenvolvimento e a idade adulta. No entanto, apesar dos dados que indicam que o T3 atua diretamente nos testículos humanos, persistem controvérsias em relação ao impacto das doenças tireoidianas sobre a espermatogênese e a fertilidade, o que pode ser em parte devido à escassez de estudos clínicos nessa área. Essa revisão tem por objetivo apresentar um panorama de dados clínicos atualizados sobre o papel dos hormônios tireoidianos na função gonadal masculina. Arq Bras Endocrinol Metab. 2009;53(8):976-82 Descritores

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“…The neuropsychiatric effects of thyroid dysfunction may independently contribute to sexual dysfunction in men with untreated thyroid disease; however, several biochemical relationships have also been observed. There is an increased gonadotroph response to GnRH in men with untreated hyperthyroidism compared to when treatment had rendered the men euthyroid, suggesting a possible role of thyroid hormone in sensitization of gonadotrophs (61). Hypothyroidism has been associated with low total testosterone levels, assumed to be due to low SHBG levels (13,62).…”

Section: Thyroid Issuesmentioning

confidence: 99%

Testosterone replacement therapy: role of pituitary and thyroid in diagnosis and treatment

Crawford

Kennedy

2016

Transl. Androl. Urol.

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Crosstalk among hormones characterizes endocrine function, and assessment of the hypogonadal man should take that into consideration. In men for whom testosterone deficiency is a concern, initial evaluation should include a thorough history and physical exam in which other endocrinopathies are being considered. Hypogonadism can be associated with both pituitary and thyroid dysfunction, for which appropriate biochemical evaluation should be undertaken in certain clinical scenarios. If low serum testosterone is confirmed measurement of luteinizing and follicle stimulating hormones (LH and FSH respectively) is essential to establish whether the hypogonadism is primary or secondary. In secondary hypogonadism measurement of prolactin is always necessary, and measurement of other pituitary hormones, along with pituitary imaging, may be indicated. Checking thyroid function may also be enlightening, and can raise additional therapeutic considerations. Correction of other pituitary axes may attenuate the need for testosterone replacement therapy in some cases.

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Hypothalamic-Pituitary-Testicular Axis in Patients with Hyperthyroidism

Cited by 36 publications

References 18 publications

A Prospective Controlled Study of the Impact of Hyperthyroidism on Reproductive Function in Males

A Prospective Controlled Study of the Impact of Hyperthyroidism on Reproductive Function in Males

Clinical implications of altered thyroid status in male testicular function

Testosterone replacement therapy: role of pituitary and thyroid in diagnosis and treatment

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