The state of the reproductive system in men with infertility in patients with subclinical hypothyroidism

It has been established that infertile men with subclinical hypothyroidism, there is a decrease in the average values of testosterone levels in the blood. It has been shown that the formation of testicular dysfunction in them occurs according to the type of normogonadotropic hypogonadism. Impaired fertilization capacity of sperm in subclinical hypothyroidism is due to a decrease in the number of motile and viable spermatozoa.

It is currently known that thyroid hormone deficiency in hypothyroidism can lead to impaired spermatogenic and endocrine functions of the testes in adult men. At the same time, so-called "subclinical hypothyroidism" is quite common in medical practice, in which clinical manifestations of thyroid gland (TG) hypofunction are diagnosed against the background of normal thyroid hormone levels, in particular free thyroxine (free T4) levels and elevated blood levels of thyroid-stimulating hormone (TSH). There is evidence that the incidence of subclinical hypothyroidism is five to six times higher than the prevalence of overt hypothyroidism. Subclinical hypothyroidism is the mildest form of thyroid insufficiency with minimal clinical symptoms that are eliminated by prescribing thyroid hormones. There is an opinion that subclinical hypothyroidism, like overt hypothyroidism, is associated with hyperandrogenemia in men. However, how sperm parameters change, as well as the levels of gonadotropic hormones in infertile men with subclinical hypothyroidism, is currently practically unstudied.

The aim of this work is to study the levels of hormones of the pituitary-gonadal system in the blood and spermogram parameters in men in infertile marriages with subclinical hypothyroidism.

Of those who had been in an infertile marriage for more than a year, 21 men aged 22-39 years were examined. The diagnosis of subclinical hypothyroidism was established based on clinical examination, ultrasound examination of the thyroid gland, determination of blood levels of thyroid-stimulating hormone and free thyroxine using the enzyme immunoassay. All patients underwent analysis of spermogram parameters in accordance with the WHO criteria, and serum levels of testosterone (T), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) were determined using enzyme immunoassay kits.

Similarly, 12 practically healthy men of the same age with spermogram parameters corresponding to the WHO norm were examined and formed the control group.

Statistical processing of the obtained data was carried out by the method of variation statistics using a standard package of statistical calculations. The reliability of the differences in average values was determined by the Student criterion. The data are presented as X±Sx.

The examined patients showed a significant increase in the average values of thyroid-stimulating hormone relative to the control values. At the same time, the levels of T4CB, although they were within the reference values of the norm, were significantly reduced compared to the average values of the hormone in practically healthy men. Primary latent dysfunction of the thyroid gland in patients with infertility led to a significant decrease in the testosterone level against the background of an increase in the levels of follicle-stimulating and luteinizing hormones (p < 0.001). A decrease in their T/LH values relative to the control indicates that in patients with subclinical hypothyroidism, there is a hyporealization of the effect of luteinizing hormone on the testes, typical of patients with primary and normogonadotropic hypogonadism. It should be noted that, unlike overt hypothyroidism, in patients with subclinical hypothyroidism, the average prolactin values did not differ from the control (p > 0.05).

At the same time, analyzing the frequency of compliance with the norm of the levels of hormones of the pituitary-gonadal system, it was found that in a significant majority of patients, the values of follicle-stimulating and luteinizing hormones, as well as prolactin, were within the reference values of the norm. Nevertheless, in 47.6% of patients, the testosterone level was below 12.0 nmol / l, which indicates the presence of hypoandrogenemia. This nature of changes in the hormones of the pituitary-gonadal system in infertile men with subclinical hypothyroidism indicates the formation of dysfunction of the sex glands in this contingent of people according to the type of normogonadotropic hypogonadism.

It is noteworthy that, unlike the classic variants of prepubertal hypogonadism in men with reduced testicular sizes, the testicular volumes in patients with subclinical hypothyroidism did not differ from normal values. At the same time, the sperm concentrations per milliliter of ejaculate in most of them were within the WHO norm. Nevertheless, the average value of this spermogram parameter was significantly lower compared to the indicator in practically healthy men.

In turn, the average values of the percentage of mobile and viable forms of spermatozoa in patients with subclinical hypothyroidism were significantly lower than not only the control values, but also the lower limit of the WHO standards. Such changes in spermogram parameters indicate the formation of asthenozoospermia in the examined patients.

The data obtained in the work show that not only with obvious but also subclinical hypothyroidism in men of reproductive age there may be an androgen-deficient state. In this case, the normogonadotropic variant of testicular dysfunction is mainly formed.

Infertility in men with subclinical hypothyroidism is mainly due to impaired sperm motility and viability, indicating impaired functional maturity. Sufficient testosterone levels in the blood are necessary to ensure full maturation of sperm in the epididymis. At the same time, the incidence of asthenozoospermia in patients was found in 81% of cases, while testosterone levels were reduced in only 47.6% of patients. Consequently, not only hypoandrogenic status is important in the mechanism of this pathospermia formation, but also, possibly, impaired pro- and antioxidant balance in the testes, as in overt hypothyroidism, which is the cause of insufficient sperm maturity and impaired motility. This should be taken into account when treating pathospermia in men with subclinical hypothyroidism.

J. S. Spivak. The state of the reproductive system in men with infertility, patients with subclinical hypothyroidism // International Medical Journal - No. 4 - 2012