Bone Up on Hormone Replacement Therapy
April 13, 2001 -- After menopause, women start to lose bone in
critical areas of the skeleton, placing them at risk for bone fractures. For
years now, experts have said that taking hormone replacement therapy after
menopause is one of the best ways to slow bone loss and prevent these fractures
and the loss of height that occurs as women age. Now a new study says that in
women who don't actually have osteoporosis, hormone replacement may not be
doing the trick.
Bone loss is linked to the sharp decline in a woman's natural
levels of the hormone estrogen that occurs around menopause. Significant bone
loss leads to the brittle-bone disease osteoporosis.
Although studies in women with osteoporosis have indicated that
hormone replacement therapy may substantially reduce fracture risk, results of
studies conducted in women without osteoporosis have been mixed.
And these new findings, published in the April 15 issue of the
American Journal of Medicine, don't help to clarify the situation
The study raises suggests that hormone replacement therapy, or
HRT, may not be effective at preventing fractures among women who don't have
established osteoporosis, says study author Jane Cauley, DrPh, of the
University of Pittsburgh. She says any usefulness of the therapy in preventing
fractures may be restricted to those women who already have the brittle-bone
The four-year study of more than 2,700 women aged 44-79 found
no difference in the incidence of fractures and no difference in height loss
between women taking hormone replacement -- either estrogen alone or estrogen
plus progestin -- and women taking no hormones.
But Robert Recker, MD, disagrees that this new study rules out
HRT or estrogen as an effective way to reduce fractures. He argues this because
of the way the study was conducted. Although the authors collected data on
fractures, the main goal of the study was to study the effect of the hormones
on heart disease -- not the effect on fractures.
And because the women in the study did not have osteoporosis,
he says, there is no way to know that they would be the best candidates for the
"This does not in any way change my mind about the
potential benefits of HRT or estrogen in preventing fractures," says
Recker, who is director of the Osteoporosis Research Center at Creighton
University School of Medicine in Omaha, Neb. He says that many other studies
have shown that HRT increases bone mass and that a few studies have shown that
the therapy also can reduce the risk of fractures.
Recker says in addition to those, other studies suggest that
the estrogenlike drug raloxifene, which is sold as Evista, is very effective at
reducing the risk of spine fractures. Since estrogen and Evista work similarly,
he says there's no reason to believe that estrogen would be any less effective
at reducing fractures when taken for five years or more.