People are always told they should have
regular cholesterol test, as high cholesterol levels could have an impact on
your heart health and your stroke risk.
But how do you make sense of the test
results once you have received them?
Your total cholesterol level is the
simplest chemical test of the liquid part of the blood - serum or plasma. This
is also the sum of the cholesterol in all the different particles
(lipoproteins) carrying cholesterol. The most important particles are LDL (low-density lipoprotein – the bad cholesterol), HDL
(high-density lipoprotein – the good cholesterol) and the triglyceride-rich
particles carry some cholesterol as well.
What are triglycerides? In short, this
is the major form of fat stored by your body, and it is made up of three fatty
acids and the fairly simple small molecule, glycerol.
The body produces cholesterol, and you
also get it from the food you eat. Digestion of food makes the cholesterol and
triglyceride available for absorption and transport in lipoproteins from the
gut (chylomicrons) which are present in the blood for a few hours after a
meal. The liver is responsible for most
of the other lipoproteins. The LDL is the ‘bad’ cholesterol as it is associated
with disease. HDL helps to remove cholesterol from tissues and transports it
through your bloodstream, making it the ‘good’ cholesterol as higher
concentrations are associated with lower risk.
The screening test used to measure
cholesterol levels is called a ‘lipid profile’ and is usually done after a 9 –
12 hour fast. The National Institutes of Health recommend that everyone over
the age of 20 should have his or her cholesterol levels checked at least once
every five years, and more frequently if your cholesterol levels turn out to be
High cholesterol levels increase your
chances of a heart attack or stroke as a result of a build-up of plaque inside
In persons without serious inherited
disorders, the risk is simply assessed by looking at the cholesterol and HDL
cholesterol concentrations. Studies indicate that the ideal is a ratio of total
cholesterol to HDL cholesterol of 4:1.
does the term mg/dL mean, which is used to describe cholesterol levels?
It stands for milligrams of cholesterol
per decilitre, which is one tenth of a litre or 100mL. This measurement is used
in the United States and some other countries, but in South Africa and many
other countries, we use millimoles per liter which is expressed as mmol/L. The mg refers to the mass of cholesterol while
the mmol/L refers to the numbers of particles and simple calculations can
convert the one system to the other. To convert mg/dL to mmol/L, divide the
figure by 38.7.
Here’s what your numbers mean, and
whether you need treatment and/or lifestyle changes.
It has to be stressed that the tables
below are merely an indication, and are not meant for self-diagnosis. All
lifestyle changes and medication should be discussed with your doctor.
These numbers are also not absolute and
there are many other factors your doctor will consider before deciding on
treatment and lifestyle changes. Note that considering LDL and HDL separately
improves the insight into risk.