Part 1 of a 2-Part Series On Cholesterol Risks and Management
When most people hear the word “cholesterol,” they automatically
link it to cardiovascular disease, including heart attacks, strokes and
peripheral vascular disease. Yet it really is not as simple as that.
“People often think that cholesterol is a bad thing, but cholesterol
is actually something our bodies need,” says Dr. Lincy Mathew, an
internal medicine specialist with Washington Township Medical Foundation.
“Cholesterol is a type of fat known as a lipid,” she explains.
“It is an essential building block for cell membranes, hormones
such as testosterone and estrogen, vitamin D, and substances we need to
digest and absorb foods. The body also needs cholesterol to build the
protective sheath that surrounds nerve fibers. Most cholesterol is produced
by the liver, but we also get cholesterol from some of the foods we eat.”
Cholesterol is carried through the blood by molecules called lipoproteins
that are made up of lipids on the inside and proteins on the outside.
There are two kinds of lipoproteins – low-density lipoproteins (LDL)
and high-density lipoproteins (HDL).
“LDL cholesterol is sometimes called the ‘bad’ cholesterol,
because a high level of LDL cholesterol can lead to a buildup of hard
deposits called plaques that can clog the arteries and make the arteries
less flexible,” says Dr. Mathew. “If a plaque ruptures, it
can result in a heart attack or a stroke. In addition, plaque buildup
also can cause peripheral artery disease that restricts the blood supply
to the legs and arms.
“HDL cholesterol is sometimes called the ‘good’ cholesterol,
because it carries cholesterol from other parts of the body back to the
liver, which removes that cholesterol from the body,” she continues.
“So, in general, a high level of LDL cholesterol in your blood increases
your chances of cardiovascular disease, while low levels of HDL cholesterol
have been shown to increase your risks for cardiovascular disease. A higher
level of HDL lowers your chance of developing cardiovascular disease.”
Triglycerides are another type of fat in your blood that the body uses
for energy. The combination of high levels of triglycerides with low HDL
cholesterol or high LDL cholesterol can increase your risk for cardiovascular
disease. To check your cholesterol levels, including triglycerides, your
physician can order a simple blood test called a lipid profile.
“High cholesterol levels usually don’t produce any symptoms,”
Dr. Mathew notes. “That’s why it is important to have cholesterol
screenings, including the level of triglycerides, at regular intervals,
depending upon your risk factors. In general, men should start cholesterol
screenings at age 35, and women should start screenings at age 45. If
there are significant risk factors for cardiovascular disease –
such as a strong family history of cardiovascular disease, or a personal
history of high blood pressure, obesity or smoking – then the screenings
should begin 10 years earlier, at age 25 for men and age 35 for women.”
The National Institutes of Health (NIH) gives the following general guidelines
for evaluating your cholesterol and triglyceride levels, measured in milligrams
(mg) of cholesterol per deciliter (dL) of blood:
Total Cholesterol Levels
Less than 200 mg/dL – desirable
200-239 mg/DL – borderline high
240 mg/dL and above – high
LDL (Bad) Cholesterol Levels
Less than 100 mg/dL – optimal
100-129 mg/dL – near optimal
130-159 mg/dL – borderline high
160-189 mg/dL – high
190 mg/dL and above – very high
HDL (Good) Cholesterol Levels
Less than 40 mg/dL – a major risk factor for cardiovascular disease
40-59 mg/dL – the higher, the better
60 mg/dL and higher – considered protective against cardiovascular disease
Triglyceride Levels
Less than 150 mg/dL – normal
150-199 mg/dL – borderline high
200-499 mg/dL – high
500 mg/dL and above – very high
“You can’t make a blanket statement about how often to screen
for cholesterol,” says Dr. Mathew. “The general recommendation
for screening intervals in the U.S. is every five years for people with
no risk factors. The frequency of screening should be based on each patient’s
risk factors and circumstances, with shorter intervals for persons who
have lipid levels close to those warranting therapy and longer intervals
for those not at increased risk who repeatedly have had normal lipid levels.”
Learn More
Part 2 of this series on cholesterol will discuss ways to manage your
cholesterol levels and lower your risks for cardiovascular disease.
If you need help finding a personal physician,
click here.
For information about cholesterol from the NIH,
click here.
For information about cholesterol from the American Heart Association,
click here.
To calculate your risk for cardiovascular disease using the American Heart
Association’s CV Risk Calculator,
click here.