Continuous glucose monitoring
FACT SHEET:
Version 7 June 2022. First published April 2018. NDSSFS010
Continuous glucose monitoring (CGM) is a way to check glucose levels throughout the day
and night without pricking your nger.
NDSS Helpline 1800 637 700
ndss.com.au
CGM can help you see the eects of insulin and
other medicines, food, physical activity, and
illness on your glucose levels. It can help you
make decisions to keep your glucose levels in
a healthy range. It can also help nd trends or
changes in your glucose levels. You can use this
information to make day-to-day decisions about
how to manage your diabetes. You can also
share this information with your diabetes health
professionals to help make decisions about your
diabetes management. CGM provides more
information than blood glucose monitoring with
a nger prick check.
CGM devices have three main parts
A. The sensor is a small electrode inserted
just under the skin, usually on the tummy or
arm. It measures the level of glucose in the
uid between your cells. Depending on the
device, you need to insert a new sensor
every 7 to 10 days.
B. The transmitter is attached to the sensor and
sends glucose readings to a wireless receiver,
insulin pump or compatible smartphone or
smart device. Depending on the type, you
need to replace your transmitter every
3–12 months. Transmitters are not reusable.
C. The receiver shows your glucose data.
The receiver can be a standalone device, an
insulin pump or compatible smartphone or
smart device (via an app). The receiver also
stores glucose data. You can upload the
glucose data for you and your diabetes health
professional to review. This can help make
decisions about changes to your insulin doses
or insulin pump settings as well as food
choices and physical activity.
Continuous glucose monitoring
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Version 7 June 2022. First published April 2018. NDSSFS010
How do CGM devices work?
CGM devices are small wearable monitors that
measure and show your glucose levels throughout
the day and night. They can be programmed to
sound alarms and send alerts if your glucose
levels are outside your set target range. CGM
devices also display arrows to show when your
glucose levels are rising or falling, and how
quickly they are changing, or staying steady.
Why use CGM?
Some of the benets of CGM include:
24/7 readings. CGM allows you to see the
changes to your glucose levels across the day
and night instead of just at a single point in time.
The graph on the receiver can show patterns
that may help you and your diabetes health
professionals learn how dierent things, such as
food and physical activity, aect your glucose
levels.
Trend arrows. These show if your glucose levels
are steady, rising or falling and how quickly they
are changing. This allows you to respond to rising
or falling glucose levels before they are out of your
range.
Alarms. You can set the CGM device to sound
an alarm if your glucose levels are rising too high
or if you are at risk of a hypo (also known as
hypoglycaemia or low glucose levels). This allows
you to act before glucose levels rise too high or
drop too low. Alarms can also be very useful if you
cannot always tell when you are having a hypo.
Overnight monitoring. CGM devices measure
glucose levels throughout the night without you
having to wake up to do a nger prick blood
glucose check.
Reduced need for nger prick checks.
CGM does not completely replace nger prick
checks, but it does reduce the number you need
to do. Ask your diabetes health professionals for
advice about when and how often you need to do
nger prick checks.
Peace of mind. Seeing your glucose levels at any
time and getting alerts if your glucose levels go
outside your target range can provide reassurance
and reduce fear of hypos.
Data sharing. Some CGM devices let you share
glucose data with others via an app on their
smartphone or smart device or notify them of
alerts and alarms via SMS messages. This can
be particularly useful for sharing your glucose
levels with others such as friends, family, parents,
or carers. You can also share with your diabetes
health professionals.
Insulin pump integration to prevent hypos.
Some CGM devices work with a compatible
insulin pump. This means they can temporarily
stop insulin delivery from the pump if glucose
levels drop below your target range or if the
sensor predicts that the glucose level will become
too low. This may help reduce the risks of hypos
or make them easier to correct.
Closed loop technology to help you stay
in range. Some CGM devices and compatible
insulin pumps work together to deliver less insulin
when blood glucose levels are predicted to
become too low, and more insulin if glucose levels
are predicted to become too high. This can help
keep your glucose levels in your target range.
Can help with blood glucose management.
Always wearing your CGM device has shown to
reduce average blood glucose levels (HbA1c),
keep your levels in your target range more of the
time and reduce blood glucose variability.
Downsides to CGM
Some of the downsides to CGM include:
It does not replace blood glucose monitoring.
Using CGM can reduce the number of nger
prick checks you need to do. Some devices still
need calibrating at least twice a day by entering
a nger prick check. Finger prick checks may
also be recommended for other situations.
Ask your diabetes health professional for advice
about when you need to do blood glucose level
nger prick check. This could be when glucose
levels are changing rapidly, to conrm a hypo,
when symptoms do not match the sensor
reading or before adjusting or giving an insulin
correction dose.
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Version 7 June 2022. First published April 2018. NDSSFS010
Accuracy. CGM devices measure glucose levels
in the uid between your cells instead of in the
blood. Given glucose travels to the blood rst and
then to the uid between the cells, CGM readings
and blood glucose levels will not usually be the
same. The dierence is because of a time delay
between 6-12 minutes from when glucose moves
from the blood (nger prick check) and into the
uid between your cells (CGM). The readings may
be close when glucose levels are stable. You will
see the greatest dierence between these readings
when your glucose levels change quickly.
Discomfort. You may have some mild pain or
discomfort when inserting your CGM. Ask your
diabetes health professional for advice on reducing
the risk of these problems and managing them if
they do occur.
Being attached. Some people do not like
wearing the sensor and transmitter. For example,
if they already use an insulin pump, they will have
two dierent devices attached to their body. For
young children, lean adults, and older people, it can
also be challenging to nd suitable sites to insert
the sensor because they do not have much body
fat. Ask your diabetes health professional to help
you work out the best sites for wearing the sensor.
Staying attached. It can be challenging for some
people to keep the sensor attached, particularly
if they spend a lot of time in water and/or sweat a
lot during physical activity. The sensor might also
get knocked o while playing or during sport. If the
sensor falls out, it cannot be reused.
Skin reactions. Some people may have allergic
reactions, skin rashes, itching, bleeding, or bruising
in the area where the sensor is inserted.
Information overload. It can be overwhelming to
see what your glucose levels are doing all the time.
It can also be overwhelming for carers if you have
chosen to share your readings with them.
Alarm fatigue. CGM alarms can be very helpful,
but if they happen often some people can nd
them annoying and disruptive. Your diabetes health
professional can help you set up the alarms to best
suit your needs.
Data sharing. It is important to rst consider your
privacy and security before sharing your glucose
data. Sharing your glucose data is a personal
choice and should not put you o using CGM.
Continuous glucose monitoring
Government-subsidised CGM
The Australian Government provides access to
subsidised CGM products through the NDSS.
People in the following groups are eligible to
access subsidised CGM products:
Type 1 diabetes. People with type 1 diabetes
Type 1 diabetes; Pre-Pregnancy/Pregnancy/
Post-Pregnancy. Women with type 1 diabetes
who are actively planning pregnancy, pregnant or
immediately post-pregnancy
Conditions similar to type 1 diabetes; Age
Under 21 Years. Children and young people aged
under 21 years with conditions very similar to
type 1 diabetes who require insulin
Accessing subsidised CGM products
You need to be registered with the NDSS and
meet the eligibility criteria to access products.
Go to ndss.com.au/cgm to nd out more about
how to access subsidised CGM products.
Your diabetes health professional will need to ll
out ans sign the Continuous and Flash Glucose
Monitoring Access Form for your eligibility group.
These forms include a list of the health professionals
who can conrm eligibility in each group.
•
Go to ndss.com.au/forms#cgm to download
the form and to nd out how to submit it.
•
Once your application has been approved,
you will receive an email or a letter from the
NDSS explaining how to start accessing your
subsided CGM products.
•
If you are new to CGM, a Starter Kit will be
sent to the diabetes health professional
nominated on your Continuous and Flash
Glucose Monitoring Access Form. The diabetes
health professional nominated on your form
will work with you to set up and start using
your CGM device. After this, you can start to
order CGM products through your community
pharmacy (also known as an NDSS Access
Point), just like you can order blood glucose
monitoring strips, insulin pen needles and/or
insulin pump consumables.
•
If you are already using CGM, you can order
your products through your community
pharmacy, once you have been notied that
your application has been approved.
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Version 7 June 2022. First published April 2018. NDSSFS010
Continuous glucose monitoring
Non-subsidised CGM
•
CGM devices and supplies are considerably
more expensive than nger prick blood
glucose monitoring supplies.
•
If you are not eligible to access subsidised
products through the NDSS, the cost of
CGM is around $4,000–$5,000 per year.
Most private health insurance companies
do not cover CGM devices however you
can make a request.
More information
and support
•
Go to ndss.com.au/cgm-device-chart
for an up-to-date list of subsidised CGM
products and their compatibility with
insulin pumps and smartphones.
•
Go to ndss.com.au/cgm or email
[email protected] to nd out more
about access to CGM products. You
can also call the NDSS Helpline on
1800 637 700 for more information or to
speak to a diabetes health professional.
•
For more information about AMSL
Diabetes (Dexcom) CGM devices, go to
amsl.com.au.
•
For more information about
Medtronic CGM devices, go to
medtronic.com.au.
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A. Sensor
C. Receiver
B. Transmitter
CGM
sensor + transmitter
sensor + transmitter
CGM
CGM
sensor + transmitter
sensor + transmitter
CGM
Top tips
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Version 7 June 2022. First published April 2018. NDSSFS010
Notes
•
Discuss all the pros and cons with your
diabetes health professional before
deciding if CGM may be right for you.
•
Your choice of CGM device will depend
on many factors. Your diabetes health
professional can help you to choose the
right CGM device for you.
•
Work with your diabetes health
professionals to get the most out of
CGM. They can help you learn how to
use and interpret the information you
get, so that you can use it to make
decision about how to manage your
diabetes.
•
CGM provides more information than
blood glucose monitoring with a nger
prick check. It can help you keep your
glucose levels in a healthy range.
Continuous glucose monitoring
The NDSS and you
Whether you have just been diagnosed with diabetes, or have been living with diabetes for a
while, the NDSS provides a range of support services, information, and subsidised products
to help you manage your diabetes, stay healthy and live well. For access to more resources
(including translated versions), or to nd out more about support services, go to ndss.com.au
or call the NDSS Helpline on 1800 637 700.
This information is intended as a guide only. It should not replace individual medical advice and if you
have any concer
ns about your health or further questions, you should contact your health professional.
