MONDAY, July 28, 2014 (HealthDay News) -- Healthy women at low risk of cardiovascular disease may be able to take hormone replacement therapy soon after menopause for a short time without harming their hearts, according to a new study.
Previous studies, including the large-scale Women's Health Initiative, found that hormone replacement therapy had harmful effects on the heart. But, many of those women were older when they began the hormone treatments, and much further past menopause.
In this new study, researchers wanted to look at how markers of heart disease, such as the thickness of artery walls, might be affected if healthy women began hormone therapy soon after menopause.
"We were expecting it to slow down the progress of arterial disease," said study researcher Dr. S. Mitchell Harman, chief of the endocrine division and interim chief of medicine at the Phoenix VA Healthcare System. That, in turn, would reduce the risk of heart attack and stroke.
The results, however, did not turn out that way. "We cannot recommend estrogen for the prevention of cardiovascular disease, even in this younger healthier group," he said.
The good news? "It doesn't hurt either," Harman said. "It looks like a wash." So, for women who are affected by the common menopausal symptoms of hot flashes and night sweats, taking hormone replacement therapy for a few years doesn't appear to jeopardize heart health, he said, at least in this healthy group of women.
Findings from the study were published July 29 in the Annals of Internal Medicine.
The study was funded primarily by Kronos Longevity Research Institute, which is supported by the not-for-profit Aurora Foundation. The foundation has no pharmaceutical company ties.
The study, known as the Kronos Early Estrogen Prevention Study (KEEPS), was a four-year clinical trial to compare the effects of three regimens in more than 700 women. The participants were randomly assigned to one of three groups: low-dose oral hormone replacement therapy with estrogen and progesterone; a skin patch of estrogen and oral progesterone; or placebo treatment, with no hormones given.
The women's average age was nearly 53 but ranged from 42 to 58. Their last menstrual period was within 36 months before the study start. The average time since the start of menopause was 1.4 years, according to the study.
Over the course of the study period, Harman's team evaluated markers of heart disease risk. They looked at changes in the thickness of the wall of the common carotid artery in the neck, using ultrasound. This can predict heart attack and stroke risk. They looked at the appearance of new calcium deposits in the heart arteries. They looked also at blood pressure, cholesterol and blood sugar levels.
The investigators found few differences among groups for build-up of plaque and other markers of heart disease risk. The oral dose group had decreased levels of LDL ("bad") cholesterol and increased HDL ("good") cholesterol. But they also had increased triglycerides, another type of blood fat that may increase the risk of heart disease.
The patch group seemed to have better blood sugar levels, the study authors noted.
Hormone replacement therapy has also been linked with increased breast cancer risk, but this study only looked at its effect on heart health.
"Mostly they are confirming what we already know," said Dr. Kellie Flood-Shaffer, division director of obstetrics and gynecology at University of Cincinnati College of Medicine.
The research ''seems to have taken more measurements reflecting cardiovascular disease risk than other studies," she said.
"I think they are showing, at least from a vascular standpoint, we can at least keep [heart disease] at bay," she said, at least in the younger, healthy women.
The study findings point to the need to individualize decisions on hormone replacement therapy based on each person's risk factors, she said. For instance, if a woman has a family history of heart disease, high LDL and bothersome symptoms, she might prescribe hormone therapy.
To learn more about hormone replacement therapy recommendations, visit the U.S. Preventive Services Task Force.