Salivary testosterone levels not accurate in postmenopausal women receiving testosterone treatment

Flyckt R, et al. Comparison of salivary versus serum testosterone levels in postmenopausal women receiving transdermal testosterone supplementation versus placebo. Menopause 2009; 16(4):680-688.

Commentary By: Tori Hudson, ND

Investigators compared circulating serum levels of total testosterone, free testosterone and bio-available testosterone (consisting of free testosterone and albumin-bound testosterone) with salivary levels in postmenopausal women with hypoactive sexual desire disorder (HSDD). Fifty-six women were given either a 300 mcg transdermal testosterone patch or placebo twice weekly for the treatment of their HSDD in a double-blind, parallel group, placebo-controlled study. Serum and salivary samples were collected concomitantly at weeks 24 and 52 in the naturally menopausal women and at weeks 12, 24 and 52 in the surgically postmenopausal women. Serum samples were validated by Quest/Nichols Institute using immunoassay methods for total, free and bio-available testosterone. The salivary measurements were validated by radioimmunoassay at Aeron Laboratory. Salivary levels of testosterone measurements did not increase at weeks 12, 24 or 52, after testosterone treatment, while post treatment levels were increased, and in the physiological range of premenopausal women, with serum analysis. In essence, salivary testosterone measurements did not increase with treatment, and did correlate strongly with serum testosterone measurements. This finding was true of bio-available testosterone, free testosterone and total testosterone. The conclusion of the authors was that salivary assays are not accurate or precise methods of measuring conditions of androgen insufficiency in postmenopausal women when treated with transdermal testosterone.

Commentary: Salivary testing of hormones has been an appealing method of testing hormones for many practitioners and patients due to their being both less invasive and less expensive than serum levels. While many issues are involved in why the salivary measurements did not perform well here, one obvious one is that levels of testosterone are even lower in the saliva than in the plasma. Salivary levels can also vary greatly, depending on how the salivary secretion is stimulated and the method of testing used (radioimmunoassay or ELISA). Other technological challenges exist for both serum and salivary testing in the accuracy of actual measurements of testosterone using radiolabeled testosterone, in cross reactivity of similar sex steroids and in trying to measure these low levels of testosterone in women, versus the 10-fold higher levels in men.

In postmenopausal women, whether surgical or naturally menopausal, I would not typically find it necessary to measure testosterone levels, using any method of measurement. Testosterone levels are expectedly low (as are estrogen and progesterone levels), and I would not often find it necessary to know its degree of low. There are always those complex menopause cases that require creative thinking and a more intellectual analysis. In these, I would consider a full array of testing including hormone and neurotransmitter testing. Such testing can offer a better understanding of the complex neuroendocrinology, and the interplay of neurotransmitter levels with the sex steroids.

Tori Hudson, ND, graduated from the National College of Naturopathic Medicine and has served the college in several capacities, including: Medical Director, Associate Academic Dean, and Academic Dean. She has been practicing for 25 years, is currently a clinical professor at The National College of Naturopathic Medicine and Bastyr University, is medical director of her clinic in Portland, Ore., and director of product research and education for VITANICA. She is the author of Women's Encyclopedia of Natural Medicine second edition. Dr. Hudson serves on several editorial boards, advisory panels, and as a consultant to the natural products industry.