Postmenopausal hormone therapy and risk of developing urinary incontinence.

OBJECTIVE

To better understand associations between post-menopausal hormone therapy and the development of urinary incontinence.

METHODS

Postmenopausal hormone use was assessed via biennial mailed questionnaires beginning in 1976 among Nurses' Health Study participants. In 1996, 39,436 post-menopausal women aged 50-75 years reported no leaking of urine and were followed-up for 4 years to identify incident cases of incontinence. We used logistic regression to estimate multivariable-adjusted relative risks (RRs) and 95% confidence intervals (CIs) for the relation of postmenopausal hormone use from 1976 to 1996 to the development of incontinence from 1996 to 2000.

RESULTS

We identified 5,060 incident cases of occasional (leaking urine 1-3 times/month) and 2,495 cases of frequent incontinence (leaking at least weekly) for average yearly incidence rates of 3.2% and 1.6%, respectively. The risk of incontinence was elevated among women taking postmenopausal hormones compared with women who had never taken hormones (oral estrogen: RR 1.54, 95% CI 1.44, 1.65; transdermal estrogen: RR 1.68, 95% CI 1.41, 2.00; oral estrogen with progestin: RR 1.34, 95% CI 1.24, 1.44; transdermal estrogen with progestin: RR 1.46, 95% CI 1.16, 1.84). There was little risk after the cessation of hormones (RR 1.14, 95% CI 1.06, 1.23) and a decreasing risk of incontinence with increasing time since last hormone use; 10 years after stopping hormones, the risk was identical in women who had and had never taken hormone therapy (RR 1.02, 95% CI 0.91, 1.14).

CONCLUSION

Postmenopausal hormone therapy appears to increase risk of developing urinary incontinence. This risk does not vary by route of administration, type of hormones, or dose taken, but is diminished upon cessation of use.

LEVEL OF EVIDENCE

II-2