Addition of testosterone to estrogen replacement therapy in oophorectomized women: effects on sexuality and well-being.

OBJECTIVE: To evaluate the effect of adding testosterone undecanoate 40 mg daily to estrogen replacement on sexual function, psychological well-being and self-esteem in surgically postmenopausal women.

METHODS: A letter of invitation to participate in the study was mailed to women who had undergone hysterectomy and bilateral oophorectomy for benign disorders during 1990-98. Fifty women, 45-60 years old, were consecutively recruited and randomly assigned to oral treatment with testosterone undecanoate 40 mg plus estradiol valerate 2 mg daily or placebo plus estradiol valerate 2 mg daily for 24 weeks. A double-blind design was chosen, with cross-over to the other regimen for another 24 weeks of treatment. Forty-four women completed the study. Outcome included scores on McCoy's sex scale questionnaire, the Psychological General Well-Being index and a self-esteem questionnaire, at baseline and after 24 weeks of either treatment. Serum concentrations of total testosterone, sex hormone binding globulin, free testosterone, dihydrotestosterone, androstenedione, estradiol, follicle stimulating hormone and luteinizing hormone were analyzed at baseline and after 24 weeks of both treatment regimens.

RESULTS: After 24 weeks, both treatment regimens had significantly improved some of the sexual variables. The addition of testosterone had a significantly better effect on the sex variables 'enjoyment of sex', 'satisfaction with frequency of sexual activity' and 'interest in sex'. The total McCoy score was significantly increased by both treatments, but there was a stronger effect when testosterone was also given. Although both regimens improved psychological well-being and self-esteem, we found no significant differences between testosterone-estrogen or estrogen alone at 24 weeks. Serum levels of all androgens, with considerable individual variation, increased significantly from baseline after 24 weeks of testosterone-estrogen treatment. Supraphysiological levels were achieved in a significant proportion of the women. Increases in estradiol and sex hormone binding globulin were less marked when testosterone was also given. Both treatments reduced gonadotropin levels.

CONCLUSIONS: The addition of testosterone undecanoate improved specific aspects of sexual function more than treatment with estrogen alone. Improvements in well-being and self-esteem were similar for both treatments. If testosterone undecanoate 40 mg daily should be used for clinical treatment, regular monitoring of androgen serum levels is needed.