WINSTON-SALEM, NC -- Postmenopausal hormone replacement therapy markedly reduces the occurrence of atherosclerosis in the internal carotid artery in monkeys, a Wake Forest University Baptist Medical Center research team reported today at an American Heart Association meeting in Santa Fe, NM.
Blockage of the internal carotid artery is a leading cause of stroke.
The team found that hormone replacement therapy from soy protein with phytoestrogens provided equivalent stroke-prevention benefits to the standard Premarin therapy prepared from mammalian estrogens.
"Phytoestrogens were as robust as Premarin," said Thomas B. Clarkson, D.V.M., professor of comparative medicine at the Wake Forest University School of Medicine.
Clarkson and his colleagues presented their findings at AHA's 38th Annual Conference of Cardiovascular Disease, Epidemiology and Prevention.
Clarkson noted that several recent studies done elsewhere had reached differing conclusions regarding the benefits of hormone replacement therapy in preventing stroke. Stroke ranks third as a cause of death for middle-aged and older women. A 50-year-old white woman has a 20 percent probability of developing a stroke sometime in her remaining lifetime.
He said that one review of seven studies of stroke deaths among postmenopausal users of estrogen replacement therapy found a reduction of risk ranging between 20 and 60 percent compared to women who were not using estrogen replacement therapy. But an English study found no benefit, and a third hinted that estrogen replacement therapy might actually be making strokes more severe.
"Given the uncertainties about the effect of estrogens on stroke and
stroke risk, it seemed to us important to place a major focus on the evaluation
of internal carotid artery atherosclerosis, the lesion site most commonly
associated with cerebrovascular symptoms of human primates," Clarkson said.
Contact: Robert Conn, Mark Wright or Jim Steele
Wake Forest University Baptist Medical Center