August 22, 2010

Hormone Supplement Benefit Does Not Last After Menopause

A new study suggests that a hormone supplement benefit does not last, despite some earlier evidence that hormone replacement therapy after menopause can help maintain women's muscle mass.

The fact that muscle mass of a woman declines after menopause has been long known, and researchers have assumed that warning estrogen levels may be part of that.

A new study has found that women who used hormones for three years maintained more muscle mass than those who had been given a placebo for comparison.

Researchers from the Women's Health Initiative (WHI), a large U.S. clinical trial looking at a variety of health effects of HRT, found no muscle-mass advantage from HRT after six year.

The findings coincide with another analysis from the WHI that found no evidence HRT preserved women's muscle strength or walking speed over six years.

The new results, which were published in the journal Menopause, add to a larger picture of disappointing findings on the expected benefits of HRT.  

The study was a government-sponsored clinical trial that started in 1993, in which postmenopausal women were randomly assigned to either take HRT or placebo pills.

The trial stopped in 2002 when researchers discovered that women on HRT were not only protected from heart disease, but also showed higher rates of heart attacks, stroke, breast cancer and blood clots.

Experts now say that although HRT is effective at relieving menopausal symptoms, women should take it at low doses and for the shortest time possible.

The scientists still analyze data from the WHI study in order to tease out the health effects.

Dr. Jennifer W. Be a, of the Arizona Cancer Center in Tucson, analyzed data for the study from a group of 1,941 women that took part in the WHI study.  About half were randomly selected to take the placebo.

The study found that the proportion of muscle and fat in each woman's body was measured by DXA scans, which is a type of X-ray used in everyday medical practice to determine bone density.

Bea's team found no evidence that HRT used contributed to greater muscle mass during the sixth year.

Preserving muscle mass and strength with age is considered important due to it helping elderly adults maintain their ability to perform routine tasks and possibly reducing their risk of falls and bone breaks.

Bea's team found that women on HRT had a lower number of falls than those in the placebo group.  However, the association was based on a small number of falls.

The team also discovered that no evidence connected the rate of falls in the different study groups to differences in muscle mass.

According to Bea and her colleagues, future studies should continue to look at the relationship between HRT and the risk of falls and bone fractures.

The researchers also said that their study had limitations.

They said that their findings suggest that while HRT might help delay muscle loss, the benefit does not last long term.


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