Forms of ovarian insufficiency
Pathophysiology distinguishes two fundamentally different variants of hypogonadism, depending on the level of the regulatory axis lesion.
Primary ovarian insufficiency (primary hypogonadism) The essence of this form is that the ovarian tissue itself loses the ability to produce sufficient amounts of sex hormones. The main laboratory marker of this condition is a compensatorily increased blood level of follicle-stimulating hormone (FSH). This phenomenon is explained by the negative feedback principle: the pituitary gland "sees" the shortage of peripheral hormones and tries to stimulate the gonads more strongly.
Causes of acquired ovarian insufficiency include:
- Autoimmune damage (immune autoaggression directed against one's own tissues).
- Infectious damage (including inflammation of the ovaries — oophoritis).
- Iatrogenic factors (exposure to radiation therapy and the use of chemotherapeutic agents).
Secondary (extraovarian, hypogonadotropic) hypogonadism In this form, the ovaries themselves are intact, and the problem lies in a deficiency of stimulating factors. The development of the condition is caused by a shortage of hypothalamic gonadotropin-releasing hormone or a deficiency of gonadotropic hormones of the adenohypophysis (such as FSH and LH). Depending on the clinical course, secondary hypogonadism can be transient or persist continuously, turning into a chronic form.
Hormonal imbalances: hyperandrogenism and hyperestrogenism
In addition to sex steroid deficiency, ovarian pathology is often accompanied by the excessive production of certain groups of hormones or hyperreactivity of tissues to their effects.
Hyperandrogenism syndrome This is a condition characterized by increased production and/or enhanced effects of androgens. The main causes of the pathology include overproduction of luteinizing hormone-releasing hormone, ovarian tumors, hyperinsulinemia, hypersecretion of androgens by the adrenal cortex, and an enzymatic defect — 3β-hydroxysteroid dehydrogenase deficiency.
Typical manifestations of hyperandrogenism are divided into:
- Laboratory: elevated blood concentrations of testosterone and androstenedione above normal values, as well as an altered gonadotropin ratio (the LH/FSH index usually exceeds 3).
- Clinical: development of hirsutism, obesity, amenorrhea, and persistent infertility.
Hyperestrogenism syndrome A condition of excessive production or action of estrogens. The main cause lies not in direct hypersecretion by the ovaries, but in peripheral conversion — the transformation of excess androgens into estrogens, which actively occurs in adipose tissue and the skin. Abnormally high estrogen content is registered in the blood and urine, which leads to a decrease in the production of gonadotropic hormones via a negative feedback mechanism. In girls, this condition provokes precocious puberty of the isosexual type.
Pathology of the male reproductive system
Disruptions in sex steroid production in men also lead to hypogonadism and reproductive disorders. Excessive production of male sex hormones is often associated with tumor and hyperplastic processes.
Main causes of hormonal disorders in men:
- Androgen-producing testicular tumors: Leydig cell tumors (actively synthesize testosterone), as well as Sertoli cell tumors and arrhenoblastomas, which produce various androgens.
- Leydig cell hyperplasia: leads to the synthesis of a massive excess of testosterone.
- Adrenal pathology: congenital adrenal hyperplasia or tumors provoke the release of large amounts of adrenal androgens into the bloodstream.
Clinically, these pathologies, along with deficiency states, are accompanied by a decrease in sexual desire (libido), the development of impotence, and infertility.
Male infertility is defined as the inability to conceive a child within one year, provided that regular sexual intercourse is maintained without the use of contraceptive methods. It is important to note that the ability to perform sexual intercourse may be completely preserved. Moreover, in so-called isolated infertility, a man's sexual function, voice timbre, and male physique may remain absolutely normal.
Briefly: answers to topical questions
What are the causes of primary male hypogonadism?
Primary causes of male hypogonadism cited in the source include inherited/congenital forms.
Example:
- Variants of Klinefelter syndrome — characterized by decreased androgen production and impaired spermatogenesis.
Acquired testicular damage — trauma, viral infections (orchitis), circulatory disorders, radiation, and medications (drugs, spironolactone, cimetidine) — are classified in the source as secondary (acquired) forms of the pathology.
What genetic syndromes cause primary hypogonadism in women?
Primary (hypergonadotropic) hypogonadism in women is caused by chromosomal abnormalities and congenital developmental disorders of the gonads.
Such syndromes include:
- Turner syndrome — a typical form of gonadal dysgenesis with a 45,X karyotype or 45,X/46,XX mosaicism.
- Pure gonadal dysgenesis — characterized by a 46,XX or 46,XY karyotype in the presence of a female phenotype.
- Swyer syndrome — a variant of pure gonadal dysgenesis with a 46,XY karyotype.
In female patients, ovarian tissue is practically absent, being replaced by fibrous streaks, which leads to severe sex hormone deficiency.
What enzyme deficiency leads to hyperandrogenism syndrome?
Causes of hyperandrogenism directly cited in the source include:
- 3β-hydroxysteroid dehydrogenase deficiency.
Hyperandrogenism is characterized by increased production and/or action effects of androgens.
The feedback rule for primary lesions: "If the peripheral gland breaks down (primary insufficiency), the center will always shout louder" — FSH increases compensatorically.
Class and exam questions
What is the main laboratory sign of primary hypogonadism?
The blood level of follicle-stimulating hormone (FSH) increases compensatorically as the pituitary gland attempts to stimulate the ovaries via a negative feedback mechanism.
What is the phenomenon of peripheral conversion in hyperestrogenism?
This is the process of transforming excess androgens into estrogens, which occurs directly in skin cells and adipose tissue.
Is male infertility always accompanied by impotence?
No, not always. In isolated infertility, sexual function, the ability to perform sexual intercourse, as well as body build and voice timbre can remain within the normal range.
What else to study on this topic
- Mechanisms of autoimmune ovarian tissue damage in premature ovarian failure
- The role of hyperinsulinemia in the pathogenesis of hyperandrogenism
- Pathophysiology of 3β-hydroxysteroid dehydrogenase deficiency
- Differential diagnosis of androgen-producing testicular tumors
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