Checking blood glucose levels using the traditional finger prick method, can be an uncomfortable and cumbersome part of having diabetes.  Fortunately, the newest continuous glucose monitoring systems allow people to check blood glucose levels quickly, easily and pain-free by wearing a sensor on the body.  These sensors are worn continuously for 10-14 days and contain a very thin probe which measures glucose levels in the interstitial fluid below the skin.  Data is then transmitted to a smartphone or reader via bluetooth every 1-5 minutes.  Alarms can also be set to alert someone that their blood glucose level is going too low or too high.  Finger prick confirmation is then generally only needed when readings are low or when symptoms don’t match the readings.

Who should monitor blood glucose levels?

While the NHS generally only advocate for blood glucose monitoring in people who are on insulin or prone to hypoglycaemia (low glucose levels), there is tremendous value in people with diabetes controlled by diet or oral medication checking their blood glucose levels periodically as well.  Knowledge is power and blood glucose monitoring is one of the rare opportunities for people to get immediate feedback on how their body is responding to (and coping with) the food they are eating.  When someone watches first hand as their blood glucose levels shoot up within 2 hours of eating something high in sugar or carbohydrates, this is far more likely to motivate change compared to listening to someone give generic nutrition advice.  Drops in blood glucose levels can also be closely monitored to see if they are associated with fatigue.  This real-time, client-specific data allows clients to adjust their eating and exercise patterns for optimal control.  Continuous glucose monitoring can also be particularly helpful for those assisting clients who have both a brain injury and diabetes, as it allows the family and support team to monitor what is going on 24 hours a day.

Clients on insulin or prone to hypoglycemia, will usually need to check their glucose level multiple times per day, long-term.  In clients with diabetes controlled by diet or oral diabetes medication, periodic bursts of monitoring (for a few weeks to a few months) is usually sufficient to meet their needs.  The NHS have very specific criteria about who is eligible to receive testing strips and sensors on prescription, so everyone else will need to pay for these items themselves.  Fortunately, both options are readily available at pharmacies and online without a prescription.

The dietitians at Specialist Nutrition Rehab have tested the two most common blood glucose monitoring sensors in the UK.  Here is our analysis:

Abbott Freestyle Libre 2

This is the new-and-improved version of the original Freestyle Libre sensor.  The latest version has improved the accuracy of the readings and the sensor appears to have better adhesion than the previous model.  This sensor is the best choice for people with impaired cognitive function, limited computer skills and/or those who just want basic information about their blood glucose levels.

Advantages:

• Some clients (eg. those prone to hypoglycaemia) may be eligible to get these sensors on prescription through the NHS.  They will need to contact their diabetes team about this.
• There is a 14 day free trial for self-paying customers (compatible smartphone required).
• Slightly less expensive than the Dexcom G6 (£96.58+VAT/month or £133.29+VAT if you need a reader as well).
• Easy to set up.
• Alarms are optional and parents and support workers can get the alarms to ring on their phone as well.

Disadvantages:

• Can only be worn on the back of the arm which makes it slightly more prone to being knocked off.
• You must scan the sensor every 8 hours otherwise you get gaps in the readings.  This can be a challenge overnight.
• The alarms only go off once when you are outside of the target blood glucose range, so are easy to ignore.
• Can only be submerged in water for up to 30 minutes, so not ideal for people engaging in hydrotherapy.
• Sensor readings cannot be calibrated to a finger prick test.
• Clients only receive precise blood glucose readings when the device is scanned, otherwise they have to just observe the general trends on the graph.
• Obtaining and sharing reports with health professionals is quite cumbersome and requires logging in online.

Dexcom G6

The Dexcom G6 is best suited for people with reasonably good computer skills who want precise and detailed information about what their blood glucose levels are doing.

Advantages:

• Can be worn on the belly (which is more discrete) or the back of the arm.  Slightly more adhesive than the Freestyle Libre 2 (but also slightly bigger).
• Alarms for low blood glucose levels are mandatory and parents and support workers can get the alarms to ring on their phone as well.
• Information is continuously transmitted to the person’s smartphone (if kept within 6 meters) – no “scanning” required of the sensor.
• Can see exact blood glucose readings at any time (current or historic).
• Sensor readings can be calibrated to a finger prick test if there are any discrepancies.
• Excellent reports are quickly generated and very easy to share with health professionals via text or email.
• Can be submerged in water for up to 24 hours so perfect for people who swim or engage in hydrotherapy.

Disadvantages:

• Not widely available on the NHS.
• More expensive ( £159+VAT/month).
• Requires reasonably good computer skills to set up initially (eg. scanning various QR codes).
• If the bluetooth signal is interrupted between the sensor and the smartphone app, it can take up to 30 minutes to re-pair to the device (in which case no alarms will sound).
• Alarms will go off every 5 minutes if the person is outside of their target blood glucose range, with no option to turn these off.

Continuous glucose monitoring systems are definitely the future of diabetes care and can help clients carefully manage their blood glucose levels.

To refer a client with diabetes or for more information on monitoring blood glucose levels and interpreting the results, contact Sheri Taylor at 0121 384 7087 or info@specialistnutritionrehab.co.uk.  For more articles like this direct to your inbox, please sign up for our free, monthly e-newsletter below.