Cyclical Hormones, But Not Prempro, May Be Protective Against Heart Disease
Many people will recall that in July 2002 women were told to talk to their doctor about perhaps stopping their hormone replacement therapy (HRT) after the Women's Health Initiative (WHI) said a trial of Wyeth's Prempro showed that the drug raised the risk of heart attack, stroke, and breast cancer.
A recent study, which was published on December 16, 2005 in the medical journal Fertility and Sterility, now suggests that the broad-brush notion that hormone replacement therapy raises the risk of heart disease and breast cancer -- causing many women to stop using the HRT drugs -- was fundamentally flawed.
Accordingly, Dr. Edward Klaiber, a Worcester, Massachusetts endocrinologist and lead author of the new study, asserts "Women are now being told not to take hormones for heart disease prevention, and that may be totally wrong".
Prior to the 2002 WHI study results, hormone replacement therapy was routinely prescribed to women as they reached menopause for the purpose of not only relieving unpleasant symptoms like hot flashes but, also, because it was thought to protect against heart disease and osteoporosis.
Based on the alleged problems he found with the WHI study, Dr. Klaiber believes that earlier medical research which showed that cyclical hormones are protective against heart disease is probably still valid, today.
According to Dr. Klaiber, the first problem with the WHI study results is that when the WHI trial was initially designed, hormone replacement therapy usually involved cyclical progesterone, meaning that it was taken just 10 or 12 days a month. Then came Prempro, which combined estrogen and progestin in a daily pill -- a regimen that had never been associated with heart protection, Klaiber said.
Given this difference between the earlier approach to HRT and Prempro, Dr. Klaiber maintains: "The [WHI study] results might have been different if they had used a different form of estrogen that resembled a normal cycle."
Dr. Klaiber states that the WHI study's other major flaw was that the clinical trial participants were older, with a mean age of 62.7 years. This population was already at a greater risk of cardiovascular problems. "The incidence of heart disease is 12 times higher for women in their 80s than it is in the 50s," Dr. Klaiber said. Put otherwise, the WHI study began HRT for the first time in women who might have had pre-existing heart disease.
To determine the strength of his theory, Dr. Klaiber will be following a multi-center trial launched last year by the Phoenix-based Kronos Longevity Research Institute. In the Kronos study women aged 40 to 55 with be treated with hormone pills, hormones delivered through a skin patch, or a placebo. Dr. Klaiber anticipates that the Kronos study will eventually show that hormone replacement therapy is not risky in women who are just beginning to go through menopause. The Kronos study results, however, will not be available until 2010, according to Dr. Klaiber.
Dr. Klaiber does allow that, regardless of its alleged flaws, the WHI study made a very significant contribution to the medical world because it showed that "Prempro was a mistake".
(Posted by: Tom Lamb)