Gretchen Tietjen, a neurology professor at MCO, said that women who appeared to have few risk factors for stroke were found in a recent study to show signs of plaque buildup in the major artery to the brain - a significant risk factor in stroke.
Dr. Tietjen co-wrote an editorial on the subject that was published this month in the journal, Stroke. Her comments were based on research conducted by a team from the University of Pittsburgh School of Medicine.
The Pittsburgh study, published in the same issue, looked at plaque buildup in the main artery in the neck, called the carotid artery. Narrowing of that artery can lead to a stroke, the No. 3 cause of death nationwide, behind heart disease and cancer.
The study found that premenopausal women with normal levels of so-called “bad cholesterol” and normal blood pressure showed signs of plaque buildup after menopause.
“The finding is striking in that this is in the `normal' range that wouldn't make me worry if I saw it in a medical exam,'' Dr. Tietjen said. For instance, premenopausal women with a systolic blood pressure of 112 had significant plaque buildup after menopause. They had a 10 point increase in systolic pressure post–menopause. Systolic blood pressure is the top number in a blood pressure reading.
Women in the high end of the normal cholesterol range saw the same deterioration.
Such data may suggest that the standards of stroke risk may need to be re-evaluated, Dr. Tietjen said.
But while hormone replacement therapy is shown to protect postmenopausal women from the increased risk of heart disease that can come with menopause, “this study doesn't predict how hormone replacement therapy is going to play out'' for stroke, Dr. Tietjen said.
In fact, existing studies suggest that hormone-replacement therapy may slightly increase the risk of stroke in the first six months to two years it is used.
Only a few studies on the subject exist. They show an increase in minor strokes and such stroke warning signs as TIAs - Transient Ischemic Attack - in early hormone replacement therapy. Transient Ischemic Attacks stem from a brief interruption of blood supply to part of the brain. This causes a passing impairment in vision, speech, sensation, or movement, Dr. Tietjen said.
“We're not seeing the beneficial effects because hormones are increasing the tendency for blood clotting. Dr. Tietjen said.
But she said that after prolonged hormone therapy, evidence suggests that the body adjusts to the hormone and stroke risk declines.