Newswise — Could hormone therapy, when begun near the onset of menopause, prevent or delay the onset of atherosclerosis, more commonly called hardening of the arteries?

That's the question researchers hope to answer as part of the Kronnos Early Estrogen Prevention Study (KEEPS) under way at eight national medical centers, including Mayo Clinic.

The January issue of Mayo Clinic Women's HealthSource includes an overview of this initiative and why the answers will be important for women.

In July 2002, the Women's Health Initiative, a large study focusing on similar questions was halted when the data suggested that hormone therapy may increase the risk of heart attacks and strokes. Researchers now believe that those results were influenced by the older ages of the women in the study. The average age was 63.

"There are reasons to believe that hormone therapy may be beneficial for preventing the early lesions of atherosclerosis in younger women, but ineffective or even harmful once the disease is established, as you find with older women," says Virginia Miller, Ph.D., principal investigator of KEEPS at Mayo Clinic.

The five-year study is focusing on women within six months to three years of their last menstrual cycle. Participants are between ages 42 and 58.

"We know that estrogen reduces blood lipids, and we know that estrogen prevents osteoporosis," says Dr. Miller. "If we can show that it also slows the progression of cardiovascular disease in recently menopausal women, it will really help women sort out the risks and benefits."

Launched by the Kronos Longevity Research Institute, KEEPS includes 720 women. In addition to studying effects of estrogen on the arteries, researchers are studying the differences in safety and effectiveness of estrogen patches and pills.

Mayo Clinic Women's HealthSource is published monthly to help women enjoy healthier, more productive lives. Revenue from subscriptions is used to support medical research at Mayo Clinic. To subscribe, please call 800-876-8633, extension 9PK1or visit www.bookstore.mayoclinic.com.