Free testosterone (Vermeulen) (Serum (s))
| Testcode: | FTESTV |
| Specimens: | 2 ml Serum (s) |
| Preanalytics/Notes: | More than 97 % of testosterone is bound to binding proteins: mainly (approx. 66-78%) with a high affinity to SHBG (sex hormone-binding globulin), but also with low affinity to albumin (approx. 20-32%). Only about 1-3 % is available as free hormone. The bioavailable testosterone (approx. 35 % of total testosterone) includes the sum of the testosterone that is free and weakly bound to albumin. Vermeulen et al. have described a computational method which allows a valid estimate of free and bioavailable testosterone from the concentration of total testosterone, SHBG and albumin. Vermeulen A, Verdonck L, Kaufman JM A critical evaluation of simple methods for the estimation of free testosterone in serum J Clin Endocrinol Metab 84:3666-3672, 1999. Please also provide information that total testosterone, SHBG and albumin are to be determined. Patients receiving high doses of biotin (> 5 mg / day) should be sampled at least 8 hours after the last application, as high levels of biotin may interfere with the test systme.
|
| Method: | Calculated result |
| Dimension: | µg/l |
| Set-up: | Mon Tue Wed Thu Fri Sat Sun |
| Indication/Significance: | The free testosterone after Vermeulen is calculated from total testosterone, SHBG and albumin and is a reliable measure for the biologically active free testosterone. This determination is recommended in situations where the determination of testosterone is impaired by factors of influence (disturbed protein binding, hyperthyroidism, intake of antiepileptic drugs). |
| Interpretation: |
Testosterone is bound to more… Testosterone is bound to more than 97% of binding proteins: mainly (about 66-78%) with high affinity to SHBG (sex hormone-binding globulin), but also low-affinity albumin (about 20-32%). Only about 1-3% are available as a free hormone. The sum of the free and weakly albumin-bound testosterone is the bioavailable testosterone (approximately 35% of the total testosterone). Vermeulen et al. have described a computational method that provides a valid estimate of free and bioavailable testosterone from the total testosterone, SHBG and albumin concentrations. References: Vermeulen A, Verdonck L, Kaufman JM. A critical evaluation of simple methods for the estimation of free testosterone in serum. J Clin Endocrinol Metab 84: 3666-3672, 1999. |
Reference range / valuation (openclose)
| male | ||
|---|---|---|
| from 0 - 19 Years | ||
| No reference range known for this age | ||
| from 20 Years - 48 Years | 0,057 - 0,178 µg/l | |
| from 49 Years - 120 Years | 0,047 - 0,136 µg/l | |
| female | ||
|---|---|---|
| from 0 - 19 Years | ||
| No reference range known for this age | ||
| from 20 Years - 48 Years | 0,001 - 0,010 µg/l | |
| from 49 Years - 120 Years | < 0,006 µg/l | |
Representation of age: "from" refers to the commenced year(s) (month) of age; "until" refers to the completed year(s) (month) of age.
initial letter
Abrechnung GOÄ
Die Kosten werden für den i. d. R. genutzten 1,15-fachen GOÄ-Satz dargestellt. Wird die Untersuchung nicht in Ihrem regionalen Labor durchgeführt, erfolgt die Analyse in dem Labor, das im Leistungsverzeichnis genannt ist. In diesem Fall gilt der dort für die Untersuchung angegebene Preis.