Why this test?
- benign prostatic hyperplasia (BPH),
- androgenetic alopecia in both sexes,
- primary and secondary hypogonadism in men,
- age-related androgen deficiency,
- characterized by decreased libido and progressive erectile men dysfunction,
Morris syndrome (one of the forms of testicular feminization), which develops due to insensitivity to androgens, congenital disorder of 5-alpha-reductase synthesis.
To monitor the success of the use of 5-alpha-reductase inhibitors in BPH or androgenic alopecia.
To clarify the causes of hyperandrogenism, especially hyperandrogenic dermopathy in women.
In what cases is it prescribed?
With symptoms of BPH (prostate enlargement, urination disorders)
With baldness (both in men and in women).
When using drugs that inhibit the action of 5-alpha-reductase, in order to control the success of the treatment.
With a decrease in libido, erectile dysfunction in men.
With the absence of testicles or a decrease in their size, cryptorchidism, abnormally small size of the penis, lack of hair on the pubic area and under the armpits.
During puberty in boys.
With hirsutism, acne, seborrhea, menstrual cycle disorders in women.
Dihydrotestosterone (DHT) is present in the body of both men and women. It is formed from testosterone only with the help of a special enzyme - 5-alpha-reductase. In case of men, it is produced by the testicles and to a lesser extent by the adrenal glands, while in case of women, on the contrary, it is produced to a greater extent by the adrenal glands and to a lesser extent by the ovaries.
In case of men up to 70% of DHT is formed in peripheral tissues from free testosterone under the action of 5-alpha-reductase, the rest - directly in the testicles. In case of women, it is mainly synthesized from androstenedione.
DHT binds much more strongly to the androgen receptors of tissues than its predecessor testosterone, so that, despite its lower concentration, it has a more pronounced androgenic effect. For example, DHT stimulates the proliferation of prostate cells much more strongly than testosterone, which is one of the main reasons for the development of prostate hyperplasia (which is why 5-alpha-reductase inhibitors are currently successfully used to treat it).
Thus, an excessive increase in the level of DHT, including those associated with the use of testosterone drugs, leads to progressive growth of the prostate gland. During the course of treatment with 5-alpha-reductase inhibitors, it is necessary to control the content of DHT, which is interdependent with the size of the gland.
In case of men, DHT also affects other "target organs": hair follicles, external genitalia, skeletal muscles. A decrease in the secretion of DHT, associated with insufficient synthesis of both testosterone (for example, in hypogonadism) and 5-alpha-reductase, leads to disorders of sexual development in boys: to the absence of hair on the face, pubic hair, under the armpits, to reduced sizes of the genitals penis and testicles, anomalies of the structure of the penis, insufficient muscle mass. With age, a low level of DHT causes erectile dysfunction and a decrease in libido.
An excess of dihydrotestosterone in both sexes suppresses the growth of hair on the head and causes their increased loss. In women, such baldness refers to the syndrome of hyperandrogenic dermopathy (SHA) - a serious violation of the hormonal background, which leads to abnormalities of the menstrual cycle and even infertility.
Since baldness, acne can be one of the first signs of SGA, determining the level of DHT is appropriate for a comprehensive assessment of hormonal status and early diagnosis of hyperandrogenism in women. The human genome contains two genes encoding different isoforms of 5-alpha reductase: SRD5A1 and SRD5A2. They are located on the fifth and second chromosomes, respectively.
Mutations in the SRD5A2 gene cause pseudovaginal perineoscrotal hypospadias (a boy's genitals at birth develop according to the female type), since dihydrotestosterone affects the formation of the embryo's genitals.