Endocrine Abstracts

Background: CAIS is an X-linked recessive disorder that renders the androgen receptors non-functional. Hormone replacement therapy is required for maintenance of secondary sexual characteristics, symptom relief, cardiovascular and bone health. However, the role of androgen supplementation in CAIS remains uncertain.

Case presentation : A 45-year-old female with CAIS presents to the menopause clinic complaining of fatigue, hair loss and low libido. She had her testes removed 13 years ago, whereby the Urologist advised her to seek GP advice if she began to experience menopause symptoms. At the menopause clinic, the Gynecologist advised the patient to start estrogen replacement to alleviate her symptoms, explaining the benefits and risks. As well as counseling the patient on smoking cessation, weight loss and exercise. A DEXA scan was also ordered. In view of the patient’s low libido, the potential role of testosterone replacement was considered, though evidence for benefit in CAIS is limited. However, a randomized, double-blind crossover trial designed by Birnbaum et al, compared the effectiveness of testosterone and estrogen replacement for women with CAIS [1]. The study found that testosterone was well-tolerated and had few adverse effects, but more specifically, that testosterone was superior to estrogen in improving sexual desire. However, it is unknown whether testosterone replacement has the same beneficial effects on cardiovascular and bone health as estrogen replacement, in these women.

Discussion: The patient was started on Oestrogel (0.06%)- 2 pumps/day. At her follow-up appointment, she reported alleviation of her symptoms and normalised libido, so she decided against commencing testosterone. However, the role of testosterone replacement in CAIS remains uncertain and warrants further research.

References: 1. Oestrogen vs androgen in hormone-replacement therapy for complete androgen insensitivity syndrome: a multicentre, randomised, double-dummy, double-blind crossover trial. Birnbaum, Wiebke et al. The Lancet Diabetes & Endocrinology, Volume 6, Issue 10, 771 - 780