HRT Speeds Progression of Heart Disease in Diabetics
Study finds these postmenopausal women should avoid hormone therapy
TUESDAY, June 29, 2004 (HealthDayNews) -- Hormone therapy can contribute to the development of cardiovascular disease in postmenopausal women with diabetes or pre-diabetes.
This finding, appearing in the June 28 online issue of Circulation, bolsters previous research that has suggested hormone replacement therapy (HRT) should not be used to reduce the risk of cardiovascular disease among postmenopausal women in general.
Both diabetes and pre-diabetes are already risk factors for cardiovascular disease, especially among women. And the national Women's Health Initiative (WHI) found that estrogen combined with progestin increased the risk of heart disease, stroke and blood clots. However, Yale University researchers reported Monday that the results of that landmark study cannot be applied to all menopausal women because the average age of the participants was 63. Menopause typically occurs between the ages of 50 and 55.
The Circulation study used data from the Women's Angiographic Vitamin and Estrogen (WAVE) study, which randomly gave 423 postmenopausal women either estrogen, estrogen plus progestin or a placebo for three years. Many of the participants had diabetes or glucose intolerance when the study started and all had evidence of atherosclerosis, or hardening of the arteries. The trial is the first to use angiography (X-rays of coronary vessels) to record the progression of atherosclerosis in postmenopausal women with diabetes or impaired glucose tolerance.
At the end of the study period, cholesterol profiles were better among women who had taken HRT, as were their fasting glucose and insulin resistance levels. These are all risk factors for heart disease.
On the other hand, the women in the hormone groups exhibited narrower arteries and worse levels of inflammatory markers such as C-reactive protein and fibrinogen, both of which are associated with cardiovascular disease. C-reactive protein and fibrinogen levels decreased slightly in women taking hormones who had normal glucose tolerance. When the math was done, HRT appeared to speed the progression of atherosclerosis.
"The study showed that in women with diabetes [who were also taking hormone therapy], the artery blockage moves faster than in women without diabetes," said study author Barbara Howard, president of MedStar Research Institute in Hyattsville, Md.
Dr. Alan J. Garber is a professor of medicine and biochemistry and cell biology at Baylor College of Medicine in Houston. He said, "Patients with diabetes have so many concomitant cardiovascular risk factors that they're virtually a seething cauldron of heart disease risk problems, and so what you do is you're just throwing another spice into the brew" with hormone therapy. "This becomes important when you consider that patients with diabetes have a well-known previously described tendency to translate small negatives into large negatives. That is what has happened here."
Using hormones to ease menopausal symptoms -- such as hot flashes or vaginal dryness -- in women with diabetes or prediabetes should be an individualized decision made in close consultation with a woman's physician, the study authors stressed.
"It's always a risk-benefit calculation," Howard said. "For women without diabetes if they're under 50 years old, where their absolute risk for some of these events is not high, we can say use estrogen for a year or so to get them through the [menopausal] symptoms. The problem is that women are at increased risk for cardiovascular disease if they have diabetes, so it might be something you might not want to be eager to do in these women."
Garber added: "Patients with diabetes need to be very careful about each individual risk factor that they have. When present in diabetic patients, it becomes a big deal. You have to balance the severity of the [menopausal] symptoms against the risk posed by trying to treat symptoms with these hormones. There are other ways to treat symptoms. Each menopausal woman should consult their physician."
For more on diabetes and heart disease, visit the American Diabetes Association.