Information from Industry
NEW YORK (Reuters Health) Mar 26 – The timing of estrogen therapy after menopause appears to play a key role in determining whether this intervention will protect against or facilitate damage from a stroke, findings from an animal study suggest. This may help explain seemingly discordant findings from previous studies.
Recent data from the Women’s Health Initiative (WHI) and other studies suggested that estrogen therapy offered no benefit against stroke or even increased the risk in postmenopausal women. However, years before these studies even began, there were numerous reports describing a neuroprotective effect for estrogen therapy.
In the present study, Dr. Phyllis M. Wise, from the University of Washington in Seattle, and colleagues assessed the impact that the timing of estrogen therapy has on stroke damage in ovariectomized mice. The mice were treated with estrogen therapy either immediately after ovariectomy or 10 weeks later. At 20 weeks of age, ischemic stroke was experimentally induced.
The investigators’ findings appear in the March 26th Early Edition of the Proceedings of the National Academy of Sciences.
The researchers found that animals treated with immediate estrogen therapy experienced much less brain damage than did those who received delayed estrogen therapy.
“These results demonstrate that a prolonged period of hypoestrogenicity disrupts both neuroprotective and antiinflammatory actions of 17beta-estradiol. Our findings may help to explain the results of the WHI that reported no beneficial effect of estrogen therapy against stroke because the majority of the subjects initiated estrogen therapy after an extended period of hypoestrogenicity,” the authors conclude.
Proc Natl Acad Sci USA 2007.