Test Code: 4001CPT: 84270
|Use||Sex hormone-binding globulin (SHBG) is a glycoprotein responsible for blood transport of testosterone and estradiol. Less than 2% of biologically active steroids are free in the circulation with the remainder being bound mostly to SHBG and albumin. The free hormone plus the albumin bound portion of hormones represents the “bioavailable” hormone.4 SHBG production is regulated by the androgen/estrogen balance, thyroid hormones, insulin, and dietary factors.4 The concentration of SHBG is increased by estrogens and decreased by androgens. Therefore, SHBG production is stimulated by estradiol and suppressed by testosterone. As a result, SHBG concentrations are higher in women versus men.9 Pregnant women have markedly higher SHBG serum concentrations due to their increased estrogen production.8 The measurement of SHBG can be an important indicator of a chronic or excessive androgenic activity where clinical symptoms would seem to indicate androgen in excess, but androgen levels are normal.|
|Clinical Utility||Elevated SHBG levels can be seen in persons with androgen insensitivities, hyperthyroidism, cirrhosis of the liver and is found in patients on oral contraceptives or antiepileptic drugs.4,5,6 Decreased concentrations of SHBG are often seen in men with hypothyroidism and androgen replacement therapy; where women with hirsutism, virilism, polycystic ovarian syndrome (PCOS), elevated androgen levels, obesity and acromegaly will also see a decrease in SHBG levels.4,7,8|
|Intended Patient Population||18+ and Older Adult Males|
|Patient Preparation||None Specified|
|Tube||Red, Green, Tiger|
|Volume||4mL Whole Blood (1mL Serum/Plasma)|
|Min Sample Volume||0.5 mLs|
|Reference Ranges||M ≥ 18 yrs old; 11-80 nmol/L|
|Analytical Measurement Range||0.161-200 nmol/L|
|Test Methodology||Chemiluminescent Immunoassay|
|Test Turnaround Time||7 Days|
|Limitations||For patients presenting with cirrhosis6 or sub-clinical thyroid conditions,9,10 carefully evaluate results as these conditions can potentially cause erroneous SHBG results.|
|Specimen Stability||7 Days RT
4 Days RF
|Laboratory Developed Test (LDT)||Yes|
|References||1. Selby C. Sex hormone binding globulin: origin, function and clinical significance. Ann Clin Biochem 1990; 27:
2. Munell F, Suarez-Quian C, Selva D, Tirado O, Reventos J. Androgen binding protein and reproduction: where do
we stand? J of Andrology 2002; 23: 598-609.
3. Manni A, Pardridge W, Cefalu W, Nisula B, Bardin CW, Santner S, Santen R. Bioavailability of albumin-bound
testosterone. J Clin Endocrinology and Metabolism 1985; 61: 705-710.
4. Burtis CA, Ashwood ER, Bruns DE. Tietz textbook of clinical chemistry and molecular diagnostics. Saunders, 2006. p. 2011-2012.
5. Ford HC, Cooke RR, Keightley EA, Feek CM. Serum levels of free and bound testosterone in hyperthyroidism.
Clinical Endocrinology 1992; 36: 187-192.
6. Luppa PB, Thaler M, Schulte-Frohlinde E, Schreiegg A, Huber U, Metzger J. Unchanged androgen-binding
properties of sex hormone-binding globulin in male patients with liver cirrhosis. Clin Chem Lab Med 2006; 44(8):
7. Kacsoh B. Endocrine physiology 4. McGraw-Hill, New York, NY, 2000; p.49.
8. Belgorsky A, Escobar ME, Rivarola MA. Validity of the calculation of non-sex hormone-binding globulin-bound
estradiol from total testosterone, total estradiol and sex hormone-binding globulin concentrations in human serum.
J. steroid Biochem. 1987; 28: 429-432.
9. Saller B, Broda N, Heydarian R, Görges R, Mann K. Utility of third generation thyrotropin assays in thyroid function
testing. Exp Clin Endocrinol Diabetes 1998; 106 (Suppl 4): S29-S33.
10. Beckett, GJ. The investigation of thyroid function. J Intl Fed Clin Chem 1994; 6 (5):186-190.