Laboratory proficiency testing for testosterone should be based on the ability to accurately and precisely measure a sample containing a known concentration of testosterone, not upon agreement with peers using the same method, a panel of endocrinologists concluded in a new Endocrine Society guideline on testosterone measurement.
In “Utility, Limitations and Pitfalls in Measuring Testosterone: An Endocrine Society Position Statement,” which was published online in the Journal of Clinical Endocrinology and Metabolism, the panel urged physicians ordering and using androgen assays to know the type and quality of the assay that is being used, along with the properly established and validated reference intervals for that assay (J. Clin. Endocrinol. Metab. 2007;92:405–13).
The panel also noted that, in the absence of other information, direct assays perform poorly at low testosterone concentrations such as those found in women, children, and hypogonadal men, and therefore should be avoided. The guideline summarizes and evaluates the laboratory methods in use currently to measure testosterone.
In the October issue of the Journal of Clinical Endocrinology and Metabolism, the Endocrine Society issued a strong word of caution on the topic of androgen therapy with a new clinical practice guideline that recommends against diagnosing and treating androgen deficiency in women. That guideline cites the “lack of a well-defined clinical syndrome” and the “lack of normative data on total or free testosterone levels across the lifespan” as reasons against making the diagnosis (J. Clin. Endocrinol. Metab. 2006; 91:3697–710).
Dr. Andre Guay, director of the Center for Sexual Function at the Lahey Clinic in Peabody, Mass., admitted that “the measurement of total testosterone leaves a lot to be desired.” But he added that the androgen therapy guidelines “don't emphasize the clinical point that before a clinician should treat, there needs to be [both] some biochemical measure of low androgen and the proper clinical symptoms. We don't treat with only a testosterone level or with a symptom alone.”
However, Dr. Neil Goodman, professor of medicine at the University of Miami, argued that inaccurate results aren't useful to clinicians. “If we can't measure the test accurately, then how are we going to know if someone is deficient?” he asked, “If you send a woman's blood to five different labs, you're going to get five different answers.”
Dr. Goodman said that endocrinologists and the companies that make the laboratory instruments to measure testosterone are moving toward adopting a standard, which will likely be tandem mass spectrometry.
American Association of Clinical Endocrinologists (AACE) President Dr. Steven Petak said that testosterone testing using radioimmunoassay “can be adequately standardized for detection of hyperandrogenism in women, providing the laboratory normal ranges have been adequately determined based on women without hyperandrogenic symptoms and with normal cycles by basal body temperature charts.” Dr. Petak noted that AACE has published guidelines pertaining to hyperandrogenism as well as menopause guidelines that include androgen assessment along with caveats pertaining to the measurement of androgens.
The Endocrine Society's position statement on measuring testosterone was chaired by Dr. William Rosner and included Dr. Richard Auchus, Dr. Ricardo Azziz, Dr. Patrick Sluss, and Dr. Hershel Raff.
The AACE has hyperandrogenism guidelines and menopause guidelines that include androgen assessment. DR. PETAK