Women At Risk
Heart disease is often regarded as a “male”
disease. Statistics, however, belie this perception.
Cardiovascular disease is the largest single cause of
female mortality and accounts for one-third of all deaths
among women worldwide, killing more than eight million
women annually. A similar trend can be seen in Singapore,
where cardiovascular disease is likewise the leading cause
of death for women. Three categories of women –
namely, menopausal women, women taking oral contraceptives,
and pregnant women – are particularly vulnerable
in this respect.
Women who have reached menopause have a markedly higher
risk of coronary heart disease and heart attack than their
pre-menopausal counterparts. This is because of the drop
in the female sex hormone oestrogen following menopause.
Oestrogen is thought to have a protective effect on women’s
hearts by causing women to have, relative to men, a lower
systolic blood pressure, a lower level of LDL (“bad”)
cholesterol, and a higher level of HDL (“good”)
cholesterol. Consequently, less cholesterol deposits build
up in the arteries of women, thereby reducing their risk
of developing cardiovascular disease. As a woman nears
the age of menopause however, her ovaries produce less
and less oestrogen. This leads to a corresponding increase
in her “bad” cholesterol level and blood pressure,
coupled with a decrease in her “good” cholesterol
level. In the years following menopause, a woman’s
blood lipid levels and risk of heart disease rise significantly
and become similar to those of a man.
Until recently, it was thought that hormone replacement
therapy (HRT) consisting of either oestrogen alone or
oestrogen combined with progestin would protect post-menopausal
women against heart disease in the same way as natural
oestrogen does before the onset of menopause. Recent studies
conducted by the United States’ Women’s Health
Initiative in 2002 and 2003 have, however, cast doubt
on this belief. These studies suggest that HRT in the
form of oestrogen alone has no impact either way on heart
disease in menopausal women. More alarmingly, the research
indicates that taking oestrogen alone appears to increase
the risk of stroke and uterine cancer, while combination
HRT consisting of oestrogen plus progestin may lead to
an increased risk of breast cancer. In light of these
findings, post-menopausal women who already have heart
disease should avoid HRT altogether and should instead
try to protect their hearts by addressing modifiable risk
factors such as hypertension, high levels of “bad”
cholesterol, smoking, and lack of exercise.
Another group of women who face a slightly higher than
average risk of cardiovascular disease are those who take
oral contraceptives. These women may find their blood
lipid levels detrimentally affected by the hormones contained
in these pills. They are also more likely to have blood
clots forming in vital blood vessels. If a woman taking
oral contraceptives is also a smoker, her risk of developing
cardiac complications would all the more rise, especially
once she reaches the age of 35.
As for pregnant women, they face a greater likelihood
of developing palpitations, hypertension, and congestive
heart failure because the metabolic work of the heart
increases by about 30-50% in the course of pregnancy.
Pregnancy-related palpitations are rarely dangerous. Hypertension
and congestive heart failure, in contrast, are potentially
more serious and require close monitoring. As such, women
with existing heart problems should consult their cardiologists
before they become pregnant so that their conditions can
be evaluated and stabilized before the changes of pregnancy
occur. |
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