Menopausal hormone therapy increases risk of incontinence

Estrogen therapy has been touted as an effective treatment for urinary incontinence, but new research shows the treatment may actually raise the risk of incontinence (JAMA 2005; 293:935-48).

Investigators from Wayne State University, Detroit, analyzed data from the Women's Health Initiative, a multicenter, double-blind, placebo-controlled trial of menopausal hormone therapy in 27,347 post-menopausal women. Subjects ranged in age from 50 to 79 years and were enrolled between 1993 and 1998. Urinary incontinence symptoms were known in 23,296 at baseline and at 1 year.

Women in the trial were randomized to receive estrogen alone (0.625 mg/day of conjugated equine estrogen), estrogen plus progestin (2.5 mg/day of medroxyprogesterone acetate), or placebo.

Researchers found that hormone therapy increased the incidence of all types of incontinence at 1 year among women who were continent at baseline. The highest risk was for stress incontinence--a 1.87-fold increased risk with estrogen plus progestin, and a 2.15-fold higher risk with estrogen alone. Mixed incontinence was 1.49-fold more likely to occur with patients taking estrogen and progestin and 1.79-fold more likely if the patient was taking estrogen alone. Estrogen alone increased the risk of urge incontinence by 1.32-fold.

Physicians should likely refrain from prescribing estrogen therapy for the prevention or relief of incontinence, the authors concluded.