Cholesterol: The Good, The Bad, And The Triglycerides
Why is it Important For Me To Know-and To Control-My Cholesterol Levels?
- Elevated cholesterol levels can lead to atherosclerosis, which in turn
often leads to coronary heart disease, simply defined as the narrowing of
one or more of the blood vessels that supply blood to the heart. This is the
major cause of death in the United States. Despite substantial success in
reducing deaths from coronary heart disease in the past two decades, it still
causes more than 480,000 deaths annually. While we think about heart disease
as a condition affecting the elderly, nearly four in ten people discharged
from hospitals for coronary heart disease are under age 65.
- For every 1% drop in cholesterol level, an adult lowers their risk
of having a heart attack by 2%!
- It is important for all adults to know their cholesterol levels to know
if you have this risk factor for heart disease that you can change. But it
is really important for anyone who already has another one (or more)
of the cardiac risk factors.
- It is important to know the breakdown of your total cholesterol into HDL
and LDL as well. In fact, one in 10 Americans with elevated LDL also have
reduced levels of HDL.
- There are several risk factors for heart disease. Some you simply can't
change: your family history, age, race or gender. Diabetes is a risk factor
that can't be changed completely, but it certainly can be managed. There
are four major, modifiable risk facts for coronary heart disease:
- Smoking: if you smoke, STOP. If you don't smoke, don't start. Make sure
your children never smoke.
- High Cholesterol: keep it within the range your doctor recommends for you.
- Inactive lifestyle: increase physical activity; develop a regular exercise
routine and stick to it.
- High Blood Pressure: keep it within the range your doctor recommends for
- In addition, in women, being postmenopausal is also a major risk factor;
this can be modified by taking estrogen replacement therapy.
- In women, low levels of HDL are a stronger risk factor for heart disease
than for men, in whom elevated LDL is a bigger problem. Interestingly, one
of the actions of estrogen (your own or taken as estrogen replacement) is
that it can boost HDL levels while lowering LDL. It may also decrease the
plaque formation in the artery and act on the arterial walls in a protective
manner. Estrogen may increase triglyceride levels somewhat, however. When progesterone is given in conjunction with estrogen it may mitigate some of the benefit of estrogen,
however most studies show that the overall benefit--in terms of affecting
cholesterol profiles-- is still significant. These findings were one of the
reasons many physicians and researchers presumed that hormone replacement
therapy (HRT) would have a preventive benefit against heart disease. The recent
NIH-sponsored Women's Health Initiative (JAMA, 7/02) did not support this
benefit in women taking a combined estrogen/progestin product (Prempro).
The arm of the Women's Health Initiative evaluating whether an estrogen (Premarin™) will have an overall preventive benefit against cardiovascular disease concluded that there was no significant cardiovascular benefit. However, many physicians have questioned whether those data apply to newly menopausal women, since the study focused on women who on average had been in menopause for more than 10 years before beginning estrogen therapy.
- For women using birth control pills, the information is a little less clear.
Certain progesterone components, for example, are known to decrease HDL, whereas
estrogen generally increases HDL. The net effect of an oral contraceptive
on cholesterol, therefore, depends on the balance between the hormones in
that particular pill.
If you smoke, STOP. If you don’t smoke, don’t start. Make sure your children never smoke.