The Assessment of Bioavailable Androgen Levels from the Serum Free Testosterone Level
| Autor: | Hiroshi Maruta, Akihito Nanbu, Yasuhiro Yamaguchi, Naoki Itoh, Tsugio Umehara, Yoshiaki Kumamoto, Nobukazu Suzuki, Keigo Akagashi, Naohito Mikuma, Taiji Tsukamoto |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Adult
Male Aging medicine.medical_specialty medicine.drug_class medicine.medical_treatment Biological Availability Male infertility Sex hormone-binding globulin Reference Values Sex Hormone-Binding Globulin Internal medicine medicine Humans Testosterone Clinical significance Infertility Male Aged Aged 80 and over biology business.industry Testosterone (patch) Luteinizing Hormone Middle Aged Androgen medicine.disease Bioavailability Testosterone level Endocrinology biology.protein Hemodialysis Follicle Stimulating Hormone business |
| Zdroj: | Folia Endocrinologica Japonica. 67:23-32 |
| ISSN: | 0029-0661 |
| DOI: | 10.1507/endocrine1927.67.1_23 |
| Popis: | Recently, it has been concluded that measurement of the serum free testosterone level is crucial for evaluating male gonadal function. However, the extent of the decline of serum free testosterone levels with aging and the actual levels in male infertility have not yet been clearly defined. In this study, the clinical significance of serum free testosterone levels was evaluated in a total of 248 subjects, including 120 healthy adult males (54 males aged 20-39, 26 males aged 40-59 and 41 males aged more than 60), 94 infertile males, 28 male hemodialysis patients, and 6 patients with Klinefelter's syndrome. Since the serum free testosterone levels correlate significantly with serum LH and FSH levels among 120 normal adult males, it appears that free testosterone has a biological action on the organ. In the subjects aged over 60, serum free testosterone levels were significantly decreased compared with the decrease of serum total testosterone. Thus, biologically active androgen levels decreased with aging. Serum free testosterone levels tended to decrease significantly from 40 years onwards. In infertile males, serum total testosterone levels were equal to those in normal adult males, but their serum free testosterone levels were significantly lower. This decrease of serum free testosterone may be one of the causes of their hypospermatogenesis. In male hemodialysis patients, serum total and free testosterone levels were not lower than in normal adult males. It is considered that the decline of percentage of serum free testosterone levels in aged males and infertile males was caused by increased serum sex hormone binding globulin (SHBG) levels. Several workers have shown that the production of SHBG is regulated by sex steroid hormones. In this study, however, serum SHBG levels were not correlated with the E2/T ratio. We concluded that measurement of the serum free testosterone level is of value in the endocrinological evaluation of male gonadal function. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|