Hormones boost bone in first 3 years, not after

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Hormones boost bone in first 3 years, not after

By Suzanne Rostler

NEW YORK, Mar 26 (Reuters Health) - While hormone replacement therapy

(HRT) initially strengthens bones in postmenopausal women, taking the

drugs for more than 3 years does not make bones even stronger,

researchers report.

What's more, women who stop taking hormones do lose bone density, but no

more rapidly than women who never took hormones, according to the report

in the March 25th issue of the Archives of Internal Medicine.

The findings contradict the belief that long-term use of HRT will

continue to build bone indefinitely into postmenopausal years.

It was also feared that women who stopped HRT might have an accelerated

rate of bone loss compared with never-users, possibly leading to

increased risk of hip fractures, the researchers explain. Yet, studies

have shown that women who take HRT for a long time--even up to 10

years--and then stop the drugs are no less likely to break a hip than

women who have never taken the drugs.

The research findings are good news for women who want to benefit from

HRT's ability to reduce the risk of osteoporosis but not raise their

risk of breast cancer, Dr. Mark Espeland, a study author, told Reuters

Health. Some previous studies have suggested that long-term use of HRT

might increase the risk of breast cancer, the authors note, but those

studies have been inconclusive.

In the current study, the researchers followed up on a group of women

who took part in a 3-year study of HRT. The investigators found that the

rate of bone loss was equal among a group of nearly 500 postmenopausal

women who stopped HRT before or after the 3-year study, and a group of

women who did not use HRT. Women in all groups lost about 1% of their

bone mineral density in the first year and about half that much annually

in the following years.

Bone density was not found to increase in women who continued HRT after

the study. Those who took HRT gained about 3% bone mineral density in

the spine and 1.5% in the hip in the first year, and continued to gain

slightly in the following 2 years. However, no further gain or loss was

seen in women who continued to take the hormones after the trial ended,

the report indicates.

" In summary, HRT for approximately 7 years did not provide further bone

mineral density benefit beyond that accrued at 3 years, " according to

Dr. Gail A. Greendale from the University of California, Los Angeles,

and colleagues. " Our results suggest that women who stop HRT may resume

bone loss, but that it will not be at a very rapid rate. "

The investigators measured bone mineral density in the hip and spine in

495 women aged 45 to 64 years over the 3-year study period, and again

about 4 years after the study had ended.

The findings may help women to decide whether to use HRT during

menopause, when a natural decline in estrogen can cause hot flashes and

other symptoms, as well as an increase in risk of osteoporosis and other

chronic disorders. While HRT, which contains synthetic forms of estrogen

and progesterone, may lower the risk of these diseases, the health

effects of long-term use are less clear.

" The concern about cumulative risk as a function of long-term HRT has

fueled efforts to maximize potential benefits and minimize possible

risks, " the study authors write.

" Understanding what happens to bone when women stop HRT would provide

part of the answer to this complex problem, " they explain.

Although pharmaceutical companies donated the medication used in the

trial, the study was funded by grants from the National Heart, Lung and

Blood Institute and other federal agencies.

SOURCE: Archives of Internal Medicine 2002;162:665-672.