Chicago, IL - New observational data from the Danish Nurse Study show an increased risk of stroke with hormone replacement therapy (HRT), but the risk appeared to be limited to hypertensive women. Normotensive subjects showed no such increase in risk.

The new report appears in the October 2003 issue of the Archives of Neurology.

HRT in this study consisted mostly of 17 estradiol, either alone or combined with norethisterone acetate, a common choice among Scandinavian women, the authors say. Stroke risk was most pronounced among women on combination therapy.

"The results need further confirmation but may potentially have great clinical relevance in guiding practitioners when prescribing HRT," the authors, led by Dr Ellen Løkkegaard (Hvidovre Hospital, University of Copenhagen, Denmark) conclude. "The present study would suggest that HRT should be avoided in hypertensive women."

Safety of HRT regimens

Unlike observational results for other cardiovascular outcomes, data on the relationship between HRT and stroke risk have been conflicting, the researchers write. Results from the Women's Health Initiative showed an increased risk of stroke, particularly ischemic stroke, with the combination of conjugated equine estrogen and medroxyprogesterone acetate.[2] The risks associated with the "traditional" Scandinavian HRT regimen based on 17 estradiol and norethisterone acetate have not been examined, Løkkegaard et al note.

The Danish Nurse Study was begun 1993, and, similar to the American Nurses' Health Study, participants filled out baseline questionnaires on various lifestyle factors and the use of hormone therapy. For this analysis, data on 13 122 women free of major cardiovascular and cerebrovascular disease and breast cancer at study outset were available through December 1998. At that time, 144 strokes were identified from national registries of hospital discharges and causes of death.

At baseline, 28.0% of the original 13 122 women were current users of HRT, 14.3% were past users, and 57.7% were never users. In the overall analysis, HRT exposure was not consistently associated with stroke, but when the women were subdivided based on the presence or absence of hypertension, there was a significantly increased risk among those with hypertension.

Complete informations and data are available on the original website TheHeart.org