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HelpTest Code TTBS Testosterone, Total and Bioavailable, Serum
Test Down Notes
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Reporting Name
Testosterone, Total and Bioavail, SUseful For
Recommended second-level test for suspected increases or decreases in physiologically active testosterone:
-Assessment of androgen status in cases with suspected or known sex hormone-binding globulin binding abnormalities
-Assessment of functional circulating testosterone in early pubertal boys and older men
-Assessment of functional circulating testosterone in women with symptoms or signs of hyperandrogenism but normal total testosterone levels
-Monitoring of testosterone therapy or antiandrogen therapy in older men and in females
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| BATS | Testosterone, Bioavailable, S | No | Yes |
| TTST | Testosterone, Total, S | Yes | Yes |
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Serum RedOrdering Guidance
This is the preferred second-level test for suspected increases or decreases in physiologically active testosterone.
Necessary Information
Patient's age and sex are required.
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.6 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum Red | Refrigerated (preferred) | 14 days | |
| Frozen | 60 days |
Reference Values
TESTOSTERONE, TOTAL:
Males
0-5 months: 75-400 ng/dL
6 months-9 years: <7-20 ng/dL
10-11 years: <7-130 ng/dL
12-13 years: <7-800 ng/dL
14 years: <7-1,200 ng/dL
15-16 years: 100-1,200 ng/dL
17-18 years: 300-1,200 ng/dL
≥19 years: 240-950 ng/dL
Tanner Stages*
I (prepubertal): <7-20
II: 8-66
III: 26-800
IV: 85-1,200
V (young adult): 300-950
Females
0-5 months: 20-80 ng/dL
6 months-9 years: <7-20 ng/dL
10-11 years: <7-44 ng/dL
12-16 years: <7-75 ng/dL
17-18 years: 20-75 ng/dL
≥19 years: 8-60 ng/dL
Tanner Stages*
I (prepubertal): <7-20
II: <7-47
III: 17-75
IV: 20-75
V (young adult): 12-60
*Puberty onset (transition from Tanner stage I to Tanner stage II) occurs for boys at a median age of 11.5 (±2) years and for girls at a median age of 10.5 (±2) years. There is evidence that it may occur up to 1 year earlier in obese girls and in African American girls. For boys, there is no definite proven relationship between puberty onset and body weight or ethnic origin. Progression through Tanner stages is variable. Tanner stage V (young adult) should be reached by age 18.
TESTOSTERONE, BIOAVAILABLE:
Males
≤19 years: Not established
20-29 years: 83-257 ng/dL
30-39 years: 72-235 ng/dL
40-49 years: 61-213 ng/dL
50-59 years: 50-190 ng/dL
60-69 years: 40-168 ng/dL
≥70 years: Not established
Females (non-oophorectomized)
≤19 years: not established
20-50 years (on oral estrogen): 0.80-4.0 ng/dL
20-50 years (not on oral estrogen): 0.80-10 ng/dL
>50 years: Not established
Day(s) Performed
Monday through Friday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
84403
84410
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TTBS | Testosterone, Total and Bioavail, S | 58716-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 82978 | Testosterone, Bioavailable, S | 2990-0 |
| 8533 | Testosterone, Total, S | 2986-8 |
Interpretation
Total testosterone and general interpretation of testosterone abnormalities:
In male patients:
Decreased testosterone levels indicate partial or complete hypogonadism. In hypogonadism, serum testosterone levels are usually below the reference range. The cause is either primary or secondary/tertiary (pituitary/hypothalamic) testicular failure.
Primary testicular failure is associated with increased luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, and decreased total, bioavailable, and free testosterone levels. Causes include:
-Genetic causes (eg, Klinefelter syndrome, XXY males)
-Developmental causes (eg, testicular maldescent)
-Testicular trauma or ischemia (eg, testicular torsion, surgical mishap during hernia operations)
-Infections (eg, mumps)
-Autoimmune diseases (eg, autoimmune polyglandular endocrine failure)
-Metabolic disorders (eg, hemochromatosis, liver failure)
-Orchidectomy
Secondary/tertiary hypogonadism, also known as hypogonadotrophic hypogonadism, shows low testosterone and low, or inappropriately "normal," LH/FSH levels. Causes include:
-Inherited or developmental disorders of hypothalamus and pituitary (eg, Kallmann syndrome, congenital hypopituitarism)
-Pituitary or hypothalamic tumors
-Hyperprolactinemia of any cause
-Malnutrition
-Excessive exercise
-Cranial irradiation
-Head trauma
-Medical or recreational drugs (eg, estrogens, gonadotropin releasing hormone [GnRH] analogs, cannabis)
Increased testosterone levels:
-In prepubertal boys, increased levels of testosterone are seen in precocious puberty. Further work-up is necessary to determine the cause of precocious puberty.
-In men, testicular or adrenal tumors or androgen abuse might be suspected if testosterone levels exceed the upper limit of the normal range by more than 50%.
Monitoring of testosterone replacement therapy:
Aim of treatment is normalization of serum testosterone and LH. During treatment with depot-testosterone preparations, trough levels of serum testosterone should still be within the normal range, while peak levels should not be significantly above the normal young adult range.
Monitoring of antiandrogen therapy:
Aim is usually to suppress testosterone levels to castrate levels or below (no more than 25% of the lower reference range value).
In female patients:
Decreased testosterone levels may be observed in primary or secondary ovarian failure, analogous to the situation in men, alongside the more prominent changes in female hormone levels. Most women with oophorectomy have a significant decrease in testosterone levels.
Increased testosterone levels may be seen in:
-Congenital adrenal hyperplasia: Non-classical (mild) variants may not present in childhood but during or after puberty. In addition to testosterone, multiple other androgens or androgen precursors, such as 17-hydroxyprogesterone (OHPG / 17-Hydroxyprogesterone, Serum), are elevated, often to a greater degree than testosterone.
- Prepubertal girls: Analogous to boys, but at lower levels, increased levels of testosterone are seen in precocious puberty.
-Ovarian or adrenal neoplasms: High estrogen values also may be observed and LH and FSH are low or "normal." Testosterone-producing ovarian or adrenal neoplasms often produce total testosterone values above 200 ng/dL.
-Polycystic ovarian syndrome: Hirsutism, acne, menstrual disturbances, insulin resistance, and, frequently, obesity form part of this syndrome. Total testosterone levels may be normal or mildly elevated and uncommonly exceed 200 ng/dL.
Monitoring of testosterone replacement therapy:
The efficacy of testosterone replacement in female patients is under study. If it is used, then levels should always be kept within the normal range for female. Bioavailable or free testosterone levels should also be monitored to avoid overtreatment.
Monitoring of antiandrogen therapy:
Antiandrogen therapy is most frequently employed in the management of mild-to-moderate idiopathic female hyperandrogenism, as seen in polycystic ovarian syndrome. Total testosterone levels are a relatively crude guideline for therapy and can be misleading. Therefore, bioavailable or free testosterone (TGRP / Testosterone, Total and Free, Serum) also should be monitored to ensure treatment adequacy. However, there are no universally agreed biochemical end points and the primary treatment end point is the clinical response.
Testosterone, Total and Bioavailable:
Usually, bioavailable and free testosterone levels parallel the total testosterone levels. However, a number of conditions and medications are known to increase or decrease the sex hormone-binding globulin (SHBG) concentration, which may cause total testosterone concentration to change without necessarily influencing the bioavailable or free testosterone concentration, or vice versa:
-Treatment with corticosteroids and sex steroids (particularly oral conjugated estrogen) can result in changes in SHBG levels and availability of sex-steroid binding sites on SHBG. This may make diagnosis of subtle testosterone abnormalities difficult.
-Inherited abnormalities in SHBG binding
-Liver disease and severe systemic illness
-In pubertal boys and adult men, mild decreases of total testosterone without LH abnormalities can be associated with delayed puberty or mild hypogonadism. In this case, either bioavailable or free testosterone measurements are better indicators of mild hypogonadism than determination of total testosterone levels.
-In polycystic ovarian syndrome and related conditions, there is often significant insulin resistance, which is associated with low SHBG levels. Consequently, bioavailable or free testosterone levels may be more significantly elevated.
Either bioavailable or free testosterone (TGRP / Testosterone, Total and Free, Serum) should be used as supplemental tests to total testosterone in the above situations. The correlation coefficient between bioavailable and free testosterone (by equilibrium dialysis) is 0.9606. However, bioavailable testosterone is usually the preferred test, as it more closely reflects total bioactive testosterone, particularly in older men. Men at this age have elevated SHBG levels and may also have varying albumin levels due to coexisting illnesses.
Clinical Reference
1. Manni A, Pardridge WM, Cefalu W, et al. Bioavailability of albumin-bound testosterone. J Clin Endocrinol Metab. 1985;61(4):705-710
2. New MI, Josso N. Disorders of gonadal differentiation and congenital adrenal hyperplasia. Endocrinol Metab Clin North Am. 1988;17(2):339-366
3. Dumesic DA. Hyperandrogenic anovulation: a new view of polycystic ovary syndrome. Postgrad Obstet Gynecol. 1995;15(13)
4. Morley JE, Perry HM 3rd. Androgen deficiency in aging men: role of testosterone replacement therapy. J Lab Clin Med. 2000;135(5):370-378
5. Goldman AL, Bhasin S, Wu FCW, Krishna M, Matsumoto AM, Jasuja R. A reappraisal of testosterone's binding in circulation: physiological and clinical implications. Endocr Rev. 2017;38(4):302-324. doi:10.1210/er.2017-00025
6. Sizonenko PC, Paunier L: Hormonal changes in puberty III: correlation of plasma dehydroepiandrosterone, testosterone, FSH, and LH with stages of puberty and bone age in normal boys and girls and in patients with Addison's disease or hypogonadism or with premature or late adrenarche. J Clin Endocrinol Metab. 1975;41(5):894-904
7. Goudas VT1, Dumesic DA. Polycystic ovary syndrome. Endocrinol Metab Clin North Am. 1997;26(4):893-912
8. Braunstein GD. Androgen insufficiency in women: summary of critical issues. Fertil Steril. 2002;77 Suppl 4:S94-S99
Report Available
2 to 5 daysMethod Name
TTST: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
BATS: Differential Precipitation/Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
When Weakly Bound Testosterone is requested, Bioavailable Testosterone should be ordered.