Laboratory studies of testosterone levels are the main methods for examining men with reproductive system pathologies. These studies are usually carried out in the morning to fix the maximum level of sex hormones.
Hormonal examination in men with suspected impaired sexual and reproductive function always includes determining the level of total testosterone . In case the hormone level is:
- within normal limits , but there are characteristic symptoms of its deficiency, it is necessary to determine sex hormone binding globulin ( SHBG ), for the subsequent calculation of free and biologically active testosterone ;
- below normal , they also determine the level of luteinizing (LH) and follicle-stimulating (FSH) hormones, for the differential diagnosis of the nature of hypogonadism (primary or secondary).
The lack of testosterone, according to most laboratories, is a mark of 12 nmol / l or 3.46 ng / ml (see table 1). If the values obtained are lower than borderline norms, a more complete hormone screening is needed, including the study of free and bioavailable testosterone, as well as other related hormones.
Table 1 - Normal values of some hormonal indicators for men.
|HORMONAL INDICATORS||NORMAL VALUES|
|Total testosterone, nmol / l||12-33|
|Biologically active testosterone, nmol / l||3.5-12|
|GSPG, nmol / l||15-60|
The quantitative indicator of testosterone is successfully used to diagnose hypogonadism in young men. It is much easier to diagnose hypogonadism at a young age than it is in the elderly, since the level of testosterone in this case is significantly reduced, and there are also bright clinical signs.
With age-related decrease in the level of sex hormones , total testosterone is not always lower than normal, therefore, in this case, the most informative indicator is the definition of free testosterone. To determine the free testosterone, you can use the calculation formula. The calculation of free testosterone is an affordable and reliable method.
Some researchers may also use a calculation indicator called the free androgen index . However, its diagnostic value is not recognized by all researchers.
Who needs a sex hormone test?
The main group of men with high risk of androgen deficiency and in need of a hormonal examination, have the following symptoms and conditions:
- erectile dysfunction and / or decreased libido;
- decreased bone density (osteopenia / osteoporosis );
- long-term use of glucocorticoid drugs;
- chronic systemic diseases (type 2 diabetes mellitus, ischemic heart disease);
- gynecomastia ;
- alcohol and drug abuse;
- obesity and metabolic syndrome;
- decreased physical activity.