Share
Written by Dr Katie Stephens, GP
Dr Katie graduated from the University of Manchester in 2007 (MBChB) and completed her GP training in the West Midlands in 2012 (MRCGP).
How to monitor your blood glucose levels
This blog looks at monitoring aims and options for someone with type 1 diabetes. If you would like to learn about monitoring in type 2 diabetes, please see our type 2 diabetes blog.
Once someone is diagnosed with type 1 diabetes, aside from discussing the above important aspects of lifestyle advice, insulin therapy, and risk of complications2, there is usually a plan put in place for monitoring. The main areas of monitoring are:
Monitoring current blood glucose levels
Sugar levels carry an obvious immediate importance, especially with the considerable risk of emergencies from a too-high or too-low level inherent in both having type 1 diabetes and in using insulin. It is important that anyone with type 1 diabetes, or caring for someone with type 1 diabetes, is aware of the signs and symptoms of these emergencies, and knows how to manage them, including when to get help. For information about diabetic emergencies, please visit here3. There are a few different ways to monitor current blood sugar levels:
Finger prick tests. Using a home blood glucose monitor, or ‘glucometer’, a lancet, and a blood glucose test strip. The finger is pricked with a lancet and the sugar level in the small collection of blood is measured by the device.
Continuous glucose monitoring. A small electrode is inserted under the skin and communicates with a phone or other device using Bluetooth, giving constant feedback on what the blood sugar level is without a finger prick test being needed. It can trigger an alarm if levels get too high or low, alerting the user to potential danger.
It is possible to have a ‘closed-loop system’4 where the continuous glucose monitor communicates with an insulin pump. An insulin pump is a second device that is attached to the body and continuously releases small amounts of insulin. It can be programmed to release larger amounts at mealtimes. In a closed-loop system, the continuous glucose monitor tells the pump if sugar levels are starting to get too high or low, and the pump can then automatically adjust the dose of insulin given in response, without the need for manual action by the user.
Flash glucose monitoring. Similar to the above, an electrode is worn under the skin. The difference here is that the results do not automatically transfer constantly, but only when the device is scanned over the sensor. Flash glucose monitors can’t be built into closed-loop systems, as they can’t continuously talk to an insulin pump. They do, however, have an advantage over the classic finger prick tests as the user only needs to scan their phone over the device to check their blood sugar level, instead of needing to prick the skin on the finger each time.
Diabetes UK has a helpful article explaining if you might be eligible for a free Continuous or Flash glucose monitor on the NHS here5.
NICE recommends the following optimal targets for adults with type 1 diabetes6:
- Fasting plasma glucose level of 5–7 mmol/L on waking.
- Plasma glucose level of 4–7 mmol/L before meals at other times of the day.
- For adults who choose to test after meals, plasma glucose level of 5–9 mmol/L at least 90 minutes after eating.
They also recommend that a bedtime target should be agreed, taking into account when the last meal is.
Monitoring HbA1c
As well as monitoring the daily sugar levels multiple times, there is added benefit from regularly checking the HbA1c. As you may recall from earlier , this This is a blood test that gives an average sugar level from the previous three months. The HbA1c can provide a helpful overview to general blood sugar trends and give insight as to how well controlled the condition is. As many of the complications of Diabetes are more likely with higher sugar levels, it is sensible to agree a target HbA1c to aim towards, in order to reduce the chance of these complications occurring.
NICE recommends a standard target HbA1c of 48 mmol/mol for both young people and adults with type 1 diabetes6,7. If an adult has chronic kidney disease but does not require dialysis, it suggests a target range of 48 – 64 mmol/mol. However, NICE also recognises that setting an individual target is ideal. This is important as some people may be prone to having more hypoglycaemic attacks when aiming for a target that is too low for them. We know that having too many hypo’s can put a strain on the heart and lead to other complications, so an ideal individual target will strike a balance between having a low enough target to effectively reduce the risk of complications from Diabetes, while avoiding damage from excessive hypoglycaemia.
NICE also recommends checking the HbA1c every 3 – 6 months to start with for adults. In children and young people, it advises checking this at least 4 times per year.
Monitoring for complications of Diabetes
This includes regular eye checks, foot checks and kidney health checks, all done through the NHS. These are so important, as they can pick up and treat issues before they get worse. Some complications, such as eye damage, may only be treatable if they are detected early enough. If you are overdue an NHS health check or eye screening, please contact your GP (or eye screening clinic).
Monitoring other risk factors for complications
Diabetes is not the only condition that can lead to some of the above complications. High blood pressure, raised cholesterol and smoking can all be linked with the Macrovascular Complications (e.g., heart attacks, strokes), as well as damage to the kidneys and sexual dysfunction. Hypertension can also cause eye damage.
This is why, at annual diabetes checks, the blood pressure, cholesterol level and smoking status are all assessed and optimised. Anyone who has Diabetes and smokes is advised to consider quitting as soon as possible.
If someone with Diabetes is found to also have high blood pressure, because of the significant damage that can occur with both conditions, usually more aggressive treatment is used to try to get the blood pressure lower than in someone without Diabetes.
To learn more about Type 1 Diabetes, please read our full guide here2.
References
- https://www.kinetikwellbeing.com/definitive-guide-for-type-2-diabetes/
- https://www.kinetikwellbeing.com/definitive-guide-for-type-1-diabetes/
- https://www.kinetikwellbeing.com/diabetic-emergency-advice-from-st-john-ambulance/
- https://www.diabetes.org.uk/guide-to-diabetes/diabetes-technology/closed-loop-systems
- https://www.diabetes.org.uk/guide-to-diabetes/diabetes-technology/cgm-flash-pump-who-qualifies-on-nhs
- https://cks.nice.org.uk/topics/diabetes-type-1/management/management-adults
- https://cks.nice.org.uk/topics/diabetes-type-1/management/management-adults
