Keeping it safe in the cell walls
Cholesterol is a fat-like substance that is carried around the body in the blood.
It is found naturally in our body’s cells and is essential for many metabolic
processes, including the creation of hormones, bile and vitamin D. It is so vital
to our health that the liver makes as much cholesterol as needed to be healthy;
it can also be found in some animal-based foods.
Cholesterol is transported to and from our cells by
little ‘couriers’ called lipoproteins. Lipoproteins are
like tiny ‘taxi cabs’ that travel around the blood
stream acting as transporters.
There are three types of lipoproteins; low-density
lipoprotein, or LDL, high-density lipoprotein, or
HDL and another blood fat called ‘triglycerides’.
All three are important to our overall health, but
when levels are too high, it can greatly affect our
heart health. Our genes partly determine what our
blood cholesterol levels are, along with lifestyle
factors such as nutrition, physical activity, obesity,
smoking and alcohol intake.
Diabetes can upset the balance between the
'healthy' (HDL) and 'lousy' (LDL) cholesterol. On
average people with diabetes have higher levels
of 'lousy' (LDL) cholesterol and higher levels of
triglycerides than people without diabetes.
Using a blood sample after a period of fasting, a
lipoprotein profile measured in millimoles per litre
(mmol/L) reveals whether or not the body is over,
or under producing cholesterol.
Low-Density-Lipoprotein (LDL) Cholesterol =
"Lousy" Cholesterol
LDL cholesterol carries most of the ‘freshly
made’ cholesterol from the liver to the cells of
the body. A high LDL level is linked with a higher
risk for cardiovascular disease.
Too much can
slowly build up on the inner walls of the arteries
and form plaque, a thick, hard deposit that
can narrow the arteries (a condition known as
atherosclerosis).
LDL is essential for the body and
is usually healthy as long as it is kept in balance
by a sufficient level of HDL. The goal for LDL-C is:
2.0mmol/L or below.
High-Density-Lipoprotein (HDL) Cholesterol =
“Healthy" Cholesterol
HDL is the carrier of recycled cholesterol and
helps remove the LDL-C from the arteries and
carries it back to the liver where it is broken down
and removed from the body.
A higher level of
HDL cholesterol is associated with a lower risk
of heart attack and stroke as it can also slow
the build-up of arterial plaque. A healthy level of
HDL cholesterol may also protect against heart
attack and stroke, while low levels of this healthy
cholesterol have been shown to increase the
risk of heart disease.
The aim for our HDL is 1.0
mmol/L or greater.
Non HDL-C
Non-HDL cholesterol is your total cholesterol
minus your HDL (healthy) cholesterol. This
provides a more reliable indicator of heart health
than looking at the total cholesterol or LDL
figures.
In other words; a measure of cholesterol
carried within all the 'Lousy' lipoproteins but not
the 'Healthy' ones (which is only HDL). The aim for
non-HDL-C is 2.5 mmol/L or below.
Triglycerides
Triglycerides are a separate type of 'lipid’ to
cholesterol. Rather than being used to build and
maintain cells, triglycerides store excess energy
as well as provide the body with energy.
Food
is one source of triglycerides and your liver also
makes them. Once food is digested, triglycerides
circulate in the bloodstream to be used as energy
by the cells or they are stored in fat cells for later
use.
Lifestyle, diet and exercise all play a role in
triglyceride levels and high levels are associated
with atherosclerosis. Healthy lifestyle choices
can keep triglyceride levels stable. The aim for
triglycerides is 2.0 mmol/L or below.
Total cholesterol
Total cholesterol is the figure of all the different blood fats added
together. The aim is for a total cholesterol less than 4.0 mmol/L.
High cholesterol does not usually present any symptoms itself,
but having high or unbalanced cholesterol levels over a number
of years can lead to the development of cardiovascular disease.
The balance of these cholesterol levels together is a better
indicator of heart health rather than one in particular. This
information is used in combination with a person’s overall
‘cardiovascular risk’ to determine the risk of an individual getting
cardiovascular disease; this includes all heart, stroke and blood
vessel diseases (cvdcheck.org.au). Many factors can determine
a person’s risk; such as age, sex, smoking status, blood
pressure and family history. Cholesterol levels are only one of
these factors.
Your doctor will help determine your cardiovascular risk. If
your risk is low, your lipid profile may be performed every three
years. If you are considered to be at a medium or high risk your
Doctor would likely check your lipid panel every year, or more
often as necessary.
Goals
- LDL-C = 2.0mmol/L or below
- HDL =1.0 mmol/L or greater
- Non-HDL-C = 2.5 mmol/L or below
- Triglycerides = 2.0 mmol/L or below
- Total cholesterol = 4.0 mmol/L or below
Treatment
If your cholesterol levels are found to be unbalanced, discuss
with your doctor about the best approach to manage it.
The
most meaningful thing you can do to reduce your cholesterol
level is to maintain a healthy lifestyle.
This includes eating
healthily and regular movement. In some cases, cholesterollowering
statin medications may also provide benefit, but even
if this happens, it is still worth making lifestyle changes at the
same time as they can improve the effect of the medication. If
you need help with lifestyle modifications, consider arranging an
appointment with your Doctor, Diabetes Educator, Dietitian or
Exercise Physiologist.