Commentary

The report by Hendrix et al is the latest surprising finding to come out of the WHI trials of HT in healthy postmenopausal women. UI is a common problem after menopause and increases steadily with age. Until recently, HT had been among recommended therapies for UI, based on a mixture of small trials, observational studies, and the documented benefits of oestrogen on genital symptoms such as atrophic vaginitis and dyspareunia. The WHI results, however, confirm earlier findings of the HERS trial,¹ which reported that oestrogen and progestin were not only ineffective but actually worsened symptoms of existing UI. WHI extends those findings to unopposed oestrogen and to previously asymptomatic women, in whom HT increased incident UI.

The biological mechanisms remain to be elucidated, but these findings from 2 large, well done randomised controlled trials using validated measures of incontinence probably close the door on HT as a therapy for UI. In retrospect, the increase in UI after menopause seems primarily to be a function of age rather than hormonal changes.² Clinicians should advise women about behavioural therapies such as pelvic exercises and weight loss and target additional therapies to the specific type of incontinence (stress v urge).³

These findings probably don’t affect the primary remaining indication for HT, treating bothersome menopausal symptoms. HT remains an option for younger women with troublesome hot flashes and sleep disturbances, since incontinence was uncommon in this trial and not clearly affected by HT in women closer to menopause. Clinicians should follow recommendations to use the lowest effective dose for the shortest time needed to relieve symptoms and periodically reassess need for therapy.