A little more than a decade ago, most physicians considered hormone replacement therapy an important part of treating postmenopausal women because of its ability to help control hot flashes, maintain bone health and lower the risk of colorectal cancer. Their enthusiasm for this treatment came to a halt in July of 2002, when the same physicians took their patients off HRT nearly across the board.
An article in the New York Times explains what happened. “A rigorous study found that the [HRT] drugs, a combination of estrogen and progestin, caused small increases in breast cancer, heart attacks, strokes and blood clots.”
Doctor’s attitudes have mellowed somewhat since that breaking news blew a hole in conventional thought. Now, hormone replacement therapy has been approved by the FDA to treat hot flashes and vaginal dryness related to menopause, but they recommend that it be used for the shortest amount of time possible, preferably no more than two years.
HRT to prevent accelerated aging in ApoE4 Alzheimer gene carriers?
A new wrinkle has just appeared on the HRT front. A recent study found that healthy menopausal women carrying a well-known genetic risk factor for Alzheimer's disease, known as ApoE4, showed measurable signs of accelerated biological aging. The encouraging part of the otherwise distressing study is that in ApoE4 carriers who started hormone therapy at menopause and remained on that therapy, this acceleration was absent. The study found that hormone replacement therapy for non-carriers of ApoE4 had no protective effect on their biological aging.
First author of the study, Emily Jacobs, PhD, is a postdoctoral fellow at Harvard Medical School. In an interview with Science Daily, Jacobs said, "We know from numerous studies that ApoE4 is a major genetic risk factor for cognitive decline, Alzheimer's disease and early mortality. We wanted to see whether an accelerated rate of biological aging explained this risk."
For this study, researchers used telomere shortening as an index of biological aging. A telomere is a region of repetitive nucleotide sequences at each end of a chromatid which protects the end of the chromosome from deterioration, or from fusion with neighboring chromosomes. Telomeres give researchers a glimpse of how we are aging biologically.
The researcher drew blood samples from nearly 70 healthy women, most of them between the ages of 45 and 65, who had been on hormone therapy since menopause. These women were randomly divided into two groups, one of which remained on hormones, while the other group discontinued therapy. Through periodic blood tests, researchers calculated the change in telomere length that had taken place over the two-year period.
According to Jacobs, telomere length is relatively easy to measure in blood cells, and it's an emerging marker of biological aging that predicts the incidence of age-related diseases and mortality.