Following are the observations out of the
Women's Health Initiative study:
Before stopping its eight-year study at the five-year mark, the WHI
came to the following conclusions:
Each year 30 out of 10,000 postmenopausal women taking
notherapy
fall ill to heart disease. For every year women took HRT, they increased
their risk of heart disease by seven per 10,000. This means that for
every 10,000 women taking HRT, 37 could expect to fall ill to heart
disease the first year, 44 the next year, 51 the following year, and so
forth. While the absolute risks are small, the increases were viewed as
significant, and women's heart risks escalated the longer they stayed on
the drugs.
For stroke, risk rose from 21 per 10,000 (for post-menopausal
women not taking HRT) to 29 per 10,000 among those taking HRT,
increasing eight per 10,000 per year.
For pulmonary
embolism, risk increased from eight per 10,000 in
the post-menopausal women not taking HRT to 16 per 10,000 among HRT
users, increasing eight per 10,000 per year.
For invasive
breast cancer, risk rose from 30 per 10,000 among
post-menopausal women not taking HRT to 38 per 10,000 among those taking
HRT, increasing eight per 10,000 per year.
For colorectal
cancer, risk decreased after taking HRT,
from 16 per 10,000 in non-HRT users to 10 per 10,000 HRT users.
For hip fractures,
risk decreased too, from 15 per 10,000 for non-HRT
users to 10 per 10,000 HRT users.
There was no difference in death rates
between the two groups. However, women on the hormone treatment had a 26
percent higher incidence of breast cancer, a 29 percent higher incidence
of heart attacks, a 41 percent higher incidence of strokes and twice as
many blood clots in the lungs and leg veins as those taking the placebo.
In contrast, the hormone-treated women had 37 percent fewer hip
fractures and a 34 percent lower rate of colon cancer.
The study found that the frequency of
these effects in hormone users did not differ by age, ethnic group or
prior health status.
