As part of a study on the aging process in Massachusetts, it has been shown that the testosterone concentration in the blood decreases on average by 1% per year from 40 years. In this context, the specialists also speak of andropause.
Other causes of testosterone deficiency are congenital or acquired disorders of hormone production in the pituitary and malformations or testicular lesions. Klinefelter syndrome is a congenital testosterone deficiency caused by chromosomal abnormalities.
How to diagnose testosterone deficiency?
The diagnosis of testosterone deficiency is made as part of a physical examination that provides information on the physical condition, morphology, muscle strength of the patient and determination of testosterone levels in the blood. In addition, there may be differential diagnostic tests to determine/exclude physical conditions and imaging methods to measure bone density.
Hormonal deficiency is not known if subjective complaints result. In elderly men, a (mild) testosterone deficiency is normal. If a treatment is desired, the doctor may prescribe an alternative to testosterone (hormone replacement therapy).
The contribution of artificial hormones can be in the form of tablets, injection, capsules, hormonal patches or testosterone gel. Erectile dysfunction (erectile dysfunction, impotence) can be treated with 5-PDE inhibitors (such as Viagra).
Recent scientific studies have shown that there is also a link between deficiency and the effectiveness of a drug treatment of impotence. The effect of PDE-5 inhibitors is limited or even halted by pronounced hormonal deficiency. In men who are being treated for erectile dysfunction with PDE-5 inhibitors, substitution of testosterone may also be necessary.
In a US study, because of low testosterone levels, PDE-5 inhibitors were effective in almost half of the subjects who had not already taken sexual stimulants. The researchers’ recommendation was to treat patients with erectile dysfunction primarily with testosterone substitution.
The side effects of testosterone replacement therapy have not yet been fully studied. The results of the study suggest that hormone treatment could significantly increase the risk of heart attacks and strokes.
The fact that the therapy increases the risk of prostate cancer is not scientifically proven. It is possible, however, that the growth of pre-existing precancerous diseases (cancer precursors) may be accelerated by the drug.
Contraindications to testosterone therapy include benign hyperplasia and prostate tumors, prostate cancer or precursors of cancer, the high rate of red blood cells (polycythemia) and sleep apnea. The same applies to liver lesions, high blood pressure and edema (water retention).
What is the normal concentration of testosterone in the body?
The concentration of testosterone in the blood serum of adult men is between 2.41 and 8.27 nanograms or between 10.4 and 34.7 nanomoles per liter. These values are reached when the corresponding blood test is performed in the morning. The nocturnal testosterone level is 20 to 40% lower than this value.
Only a small amount of free testosterone circulates in the blood, most of which is bound to transport proteins and other proteins. They protect the hormone from too rapid degradation. However, only free testosterone is metabolically active.