A recent study has shown that thyroid disease can affect the secretion of male hormones, impacting male sexual function and fertility.
According to the international academic journal The Aging Male, on May 4, a research team from the University of Brescia in Italy reviewed 31 animal and 25 human studies analyzing the relationship between thyroid disease and male sexual function, clarifying these findings.
For healthy sperm production, the pituitary gland must secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH), and the testes must secrete testosterone. Severe stress or overwork can increase prolactin levels, which in turn reduce FSH, LH, and male hormones, causing infertility.
The researchers further analyzed the papers and found that damage to the thyroid hormone affects the hypothalamic-pituitary-gonadal axis. Hormones FSH and LH, secreted from the anterior pituitary, increased after thyroid recovery. Consequently, it has been observed that male infertility patients often develop gonadal dysfunction before the onset of hypothyroidism.
According to a study involving 2,511 infertile couples, overt hypothyroidism has a more negative impact on pregnancy. Men with asymptomatic hypothyroidism had a pregnancy rate of 42%, while those with hypothyroidism had a rate of 32%.
Thyroid disorders have also been linked to a decrease in male libido. According to one study, 37.5% of patients with hypothyroidism showed a decline in libido. Also, 80% of men suffering from hypothyroidism reported symptoms of andropause, according to the ADAM (Androgen Deficiency in the Aging Male) test results.
In additional research, the research team found a prevalence of thyroid antibodies in 7.5% of infertile men. In particular, an increase in TPO-Ab (thyroid peroxidase antibody) was closely related to oligospermia and azoospermia. If TPO-Ab is elevated, the chances of developing Hashimoto’s thyroiditis, hyperthyroidism, and Graves’ disease are high.
The research team stated, “Since thyroid disorders affect male fertility, they can provide insights for treatments for infertile couples. This study elucidates the impact of hypothyroidism and hyperthyroidism on male fertility.”
Meanwhile, the research findings were published in the February issue of the international academic journal The Aging Male.