Dear Editor,
The popular press predicted (reference 1) that there would be a surge in demand for testosterone hormone replacement therapy for menopausal women in response to the documentary films presented by Davina McCall in 2021 and 2022 and so, it came to pass. Laboratory requests received for measurement of testosterone in women over 45 years of age increased 7-fold from 15 requests in January 2021 to 105 requests in May 2022 and the majority of these requests are for women taking testosterone as HRT, either as a baseline measurement prior to starting treatment or for monitoring. As a result of the effect of oestrogens on sex hormone binding globulin, using a measure of free testosterone is more appropriate than the total testosterone concentration for monitoring these patients and from 590 results obtained for the free androgen indices (the testosterone/SHBG ratio expressed as a percentage) for these patients in 2022, there were 34 results with raised concentrations ranging from 4.8 to 44.0 (median 7.5). The reference interval for the free androgen index is 0.5 to 4.7 for women over 50 years of age and the reference interval for a male patient of the same age is 19.3 to 118.4. The possibility of analytical interference causing a falsely high result was excluded where appropriate by measurement of testosterone using a mass spectrometry assay. Current British Menopause Society guidance suggests that when monitoring women using testosterone as HRT, the free androgen index should be maintained at <5, but clinical improvement in symptoms is more important than aiming for a specific concentration on treatment (reference 2). Although sample contamination from topically applied testosterone gel remains a possibility, these results suggest that in addition to testosterone not being a licensed medication for hormone replacement therapy in women, there may be a significant risk of over-replacement.
Regards,
Dr Jinny Jeffery (D.Phil, FRCPATH)
Clinical Scientist, Derriford Combined Laboratory, Derriford Hospital, Plymouth. UK
References
1. https://www.theguardian.com/society/2022/may/01/hrt-demand-expected-to-s… [accessed 13th November 2022].
2. British Menopause Society Tools for Clinicians: Testosterone replacement in menopause. Post Reproductive Health. 2019;25(1):40-42. doi:10.1177/2053369119835665.
They predicted this would happen…