Androgens are male hormones that are secreted by the cells of the testicles and adrenal cortex. These biologically active substances take part in puberty, determine libido, partly affect the growth and proportions of the body, metabolism, and the work of the central nervous system. The main active androgens in men are testosterone and its derivative dihydrotestosterone . The level of these hormones can be judged on the sexual abilities of a man, his health and even intelligence and character. To assess the concentration of testosterone can be using laboratory tests (blood, saliva). In addition, approximately determine the level of androgens can be and in appearance.
Androgens affect the appearance of a man at any age. The level of testosterone in the period of intrauterine development in addition to the structure of the external genital organs determines some other parameters of the body. So, the ratio of the length of the index and ring finger indicates the concentration of androgens. Usually in men this ratio is 1: 1.1 (the ring finger is longer). In the English literature this index is designated as 2D: 4D digit rati.
Fig. 1 - The ratio of the lengths of the ring and index finger, you can learn about the predominance of sex hormones in the period of fetal development. The first case indicates the predominance of male sex hormones.
According to another formula, you can determine the approximate age of puberty. It is known that the sooner a man woke up his libido, spermatogenesis and wet emissions began, the stronger his sexual constitution is . That is, by the age of puberty one can judge the level of testosterone in the future.
To assess the onset of puberty, you need to calculate the ratio of height and length of the legs of a man. This indicator is called the trochanter index . The length of the legs is measured in the standing position from the floor to the greater trochanter of the thigh bone (trochanter) (Fig. 1). Growth is determined using a stadiometer, preferably in the morning. Next, divide the resulting figure on the length of the legs. In men with high testosterone levels, the trochanter index is usually 1.99 or more. At low androgen values, the ratio of growth and length of legs may be less than 1.92 (see table 1).
Table 1 - Connection of the trochanter index with the sexual constitution.
It is also possible to speak about the correct puberty and the normal sexual constitution, if the man has a relatively low voice and there is an “Adam's apple” (kadyk) on his neck.
On the concentration of testosterone in a given period of life says:
- development of skeletal muscles;
- fatty deposits;
- hair growth on the body and face;
- skin condition;
- cognitive abilities.
The development of skeletal muscles
Muscle tissue is directly supported by testosterone as a strong anabolic hormone. Androgens increase both muscle strength and fiber mass. In men with normal and high levels of testosterone, the muscles of the arms, back, upper shoulder girdle are well developed. Usually, in order to maintain a good physical form, it is enough just to have a correct lifestyle and daily household loads. If a man complements the regime with sports training, then with a high level of testosterone, good results are expected of him without the use of biological additives and special nutrition.
Men with a strong sexual constitution and a normal / high level of androgens can easily maintain weight within physiological limits. The development of obesity is always talking about reducing testosterone. If a man is about 180 cm tall, his waist should be less than 94 cm. The deposition of adipose tissue in the area of the mammary glands (false gynecomastia ), hips, buttocks can also indicate relative hypoandrogenism.
Hair growth on the body and face
The growth of hair on the face and body of men also depends on testosterone and its metabolites. With a high rate of these hormones, abundant hair growth in the area of the beard, mustache, whiskers is observed. Usually, a man should shave daily to keep his skin smooth. Also, vegetation appears on the chest, abdomen, lower back, legs and arms. At normal and high levels of male hormones, a characteristic form of hair growth in the genital area is observed (in the form of a rhombus from one of the peaks of the midline abdomen to the navel).
Over time, high testosterone values can lead to androgen-dependent alopecia - that is, male-pattern baldness. In this case, the hair falls on the crown and in the fronto-temporal areas.
A side effect of your own testosterone is considered and its effect on the sebaceous and sweat glands. With a high content of androgens, seborrhea develops. In men, acne, enlarged pores, and oily skin can appear. In addition, there may be increased sweating.
Indirectly, the concentration of testosterone says behavior and intellectual ability. If in normal situations a man often reacts decisively and aggressively, often takes the initiative, demonstrates self-confidence and interacts well with the team, then the level of his androgens is probably high. If his mood is unstable, often emotional breakdowns, apathy, depression - it is possible to identify a low blood testosterone .
Male sex steroids affect the ability to:
- to concentrate attention;
- think analytically;
- memorize material well;
- make quick decisions;
- navigate in space.
If a man possesses such abilities, then his testosterone level was sufficient both in the period of pre-natal development and during later life.
The exact method of determining androgens in the body is the analysis of blood plasma. The material is obtained from a vein.
In blood, you can evaluate several indicators:
- total testosterone ;
- free testosterone ;
- bioavailable testosterone;
- calculated androgen index ;
- calculated free testosterone .
In addition, you may need to measure sex-binding globulin, dihydrotestosterone and other indicators.
For testing for total and free testosterone, they use radioimmunoassay technology, dual (equilibrium) dialysis, ultracentrifugation, precipitation. Radioimmune analysis is the most affordable, but unfortunately it is inferior to other technologies in reliability and accuracy.
Total testosterone is measured in units: ng / dl, mol / l. For men of working age, the standard is 8.9-42 ng / dl (according to some recommendations, the lower limit is 12 ng / dl). Free testosterone is usually expressed in pg / ml, pmol / l. The norm for men from 18 to 55 years: 1-28 pg / ml .
Determination of testosterone in saliva
A simple and reliable method for assessing testosterone is the analysis of saliva for this hormone.
Advantages of the technique:
- non-invasive (no damage to the body);
- easy collection of material.
The norm is considered a range of 200-500 pmol / l.
Fig. 2 - Determination of free testosterone in saliva is an accurate, non-invasive, but not very affordable method.
Studies have shown that the level of testosterone in saliva correlates well with the concentration of the biologically active fraction of the hormone in the blood. Assessment kits use a competitive enzyme immunoassay.
Preparation for blood or saliva tests
Material intake (blood, saliva) should occur in the morning hours (8-11). On the eve it is important to avoid alcohol, excessive physical exertion, overeating.
2 days prior to the diagnosis, certain medications should be canceled (in consultation with the doctor). Steroids, thyroid hormones, adrenocorticotropin, estradiol, or gonadotropins can affect the results of the analysis (see “How to take an analysis of testosterone - the rules of preparation” ).
Endocrinologist Tsvetkova I.G.