Testosterone, Total (Serum)
UFHPL Epic order code: LAB124
This immunoassay is intended for the in vitro quantitative determination of testosterone in human serum and plasma.
Diminished testosterone production is one of many potential causes of infertility in males.3,4 Low testosterone concentrations can be caused by testicular failure (primary hypogonadism) or inadequate stimulation by pituitary gonadotropins (secondary hypogonadism). Since men with hypogonadism often have high SHBG levels, the measurement of free or bioavailable testosterone has been advocated when total testosterone levels are normal in men with symptoms of androgen deficiency.5 Significant physiological changes occur in men as they age, in part due to a gradual decline in testosterone levels.6,7 It is generally accepted that the principal cause of this age-related decrease in testosterone production is testicular failure, although diminished gonadotropin production may play a role.5 By 75 years of age, the average male testosterone drops to 65% of average level in young adults. “Andropause” is a term that has been used to refer to the constellation of symptoms associated with the age-related decline in testosterone production in men.5,8 The adult male reference range for testosterone was established by Bhasin and coworkers in a community-based sample of healthy young men from the Framingham Heart Study, Generation 3.9 The reference population included only men younger than 40 years of age who had no history of cardiovascular disease, diabetes, obesity, hypertension, cancer, or hypercholesterolemia.9 This study found that men of all ages who tested with testosterone levels <348 ng/dL were more likely to suffer from symptoms associated with androgen deficiency than men with higher serum testosterone levels.9 Much smaller amounts of testosterone and dihydrotestosterone are produced in women than in men.2,3 Weaker adrenal androgens and ovarian precursor molecules including androstenedione, DHEA, and DHEA sulfate can have significant androgenic effects in women. The ovary and adrenal glands produce some testosterone, but the majority of the testosterone in women is derived from the peripheral conversion of other steroids. Often, the first sign of testosterone excess in women is the development of male pattern hair growth, which is referred to as hirsutism.1,3,4,11 It should be noted that some women experience hair growth similar to that caused by increased testosterone due to racial or genetic causes and not due to excessive androgens. Measurement of the testosterone may help to distinguish racial or genetic causes of hirsutism from the abnormal pathology, particularly in women with mixed ethnic backgrounds. Women with more excessive testosterone levels may also experience virilization, with symptoms including increased muscle mass, redistribution of body fat, enlargement of the clitoris, deepening of the voice, and acne and increased perspiration. These women can also suffer from androgenic alopecia, the female equivalent of male pattern baldness.
Many women with slowly progressive androgenic symptoms are diagnosed as having polycystic ovary syndrome (PCOS).11-13 PCOS is relatively common, affecting approximately 6% of women of reproductive age.6 Women with this complex syndrome experience symptoms of androgen excess associated with menstrual abnormalities and infertility. Most women with the syndrome have polycystic ovaries that can be detected by ultrasonography, although this finding is not essential for diagnosis.3,4,10 Chronic anovulation experienced by patients with PCOS increases their risk of developing endometrial cancer. Women with PCOS are often overweight and are likely to suffer from insulin resistance putting them at increased risk for developing type 2 diabetes mellitus.2,12 Obesity and insulin resistance can result in acanthosis nigricans, a skin condition that is characterized by hyperpigmented, velvety plaques of body folds.2 Lipid abnormalities, including decreased high-density lipoprotein cholesterol levels and elevated triglyceride levels as well as impaired fibrinolysis, are seen in women with PCOS.12 Cardiovascular disease is more prevalent, and women with PCOS have a significantly increased risk for myocardial infarction.12
- Testosterone on Elecsys 1010/2010 and Modular Analytics E170, package insert 2007-04, V 10, Indianapolis, IN: Roche Diagnostics, 2007. PubMed 9263703
- Ismail AA, Astley P, Burr WA, et al. The role of testosterone measurement in the investigation of androgen disorders. Ann Clin Biochem. 1986; 23(Pt 2):113-134. PubMed 3532913
- Gronowski AM, Landau-Levine M. Reproductive endocrine function. In: Burtis CA, Ashwood ER, edsTietz Textbook of Clinical Chemistry. 3rd ed. Philadelphia, Pa: WB Saunders Co;1999:1601-1641.
- Petak SM, Baskin HJ, Bergman DA, et al. AACE Clinical Practice Guidelines for the evaluation and treatment of hypogonadism in adult male patients. Endocrinol Pract. 1996; 2:440-453.
- Bain J. Andropause. Testosterone replacement therapy for aging men. Can Fam Physician. 2001; 47:91-97. PubMed 11212438
- Leifke E, Gorenoi V, Wichers C, et al. Age-related changes of serum sex hormones, insulin-like growth factor-1 and sex-hormone binding globulin levels in men: Cross-sectional data from a healthy male cohort. Clin Endocrinol. 2000; 53(6):689-695. PubMed 11155090
- Basaria S, Dobs AS. Hypogonadism and androgen replacement therapy in elderly men. Am J Med. 2001; 110(7):563-572. PubMed 11343670
- Bhasin S, Bagatell CJ, Bremner WJ, et al. Issues in testosterone replacement in older men. J Clin Endocrinol Metab. 1998; 83:3435-3448. PubMed 9768643
- Bhasin S, Pencina M, Jasuja GK, et al. Reference ranges for testosterone in men generated using liquid chromatography tandem mass spectrometry in a community-based sample of healthy nonobese young men in the Framingham Heart Study and applied to three geographically distinct cohorts. J Clin Endocrinol Metab. 2011; 96(8):2430-2439. PubMed 21697255
- Ehrmann DA, Barnes RB, Rosenfield RL. Hyperandrogenism, hirsutism, and polycystic ovary syndrome. In: DeGroot LJ, Jameson JL, eds. Endocrinology. 4th ed. Philadelphia, Pa: WB Saunders Co:2001;2122-2137.
- Barth JH. Investigations in the assessment and management of patients with hirsutism. Curr Opin Obstet Gynecol. 1997; 9(3):187-192. PubMed 9263703
- Hunter MH, Sterrett JJ. Polycystic ovary syndrome: It's not just infertility. Am Fam Physician. 2000; 62(5):1079-1088,1090. PubMed 10997532
- Lobo RA, Carmina E. The importance of diagnosing the polycystic ovary syndrome. Ann Intern Med. 2000; 132(12):989-993. PubMed 10858183
- If a red-top tube is used, transfer the separated serum to a plastic transport tube.
Sample Volume: 0.8 mL
Minimum Volume: 0.3 mL (Repeat testing is not possible with this specimen volume.)
Storage: Refrigerate specimens after collection.
- Ambient: 14 days
- Refrigerated: 14 days
- Frozen: 14 days
- Freeze/Thaw cycles: Stable (x3)RfereItrls
- Citrate plasma specimen
- Improper labeling
Electrochemiluminescence immunoassay (ECLIA)
|I||< 3||< 3 - 6|
|II||< 3 - 432||< 3 - 10|
|III||65 - 778||< 3 - 24|
|IV||180 - 763||< 3 - 27|
|V||188 - 882||5 - 38|
|Adult Male||Adult Female|
|> 19 years old: 348 - 1197||20 - 49 years old: 8 - 48|
|> 49 years old: 3 - 41|
Monday - Friday