Blood glucose monitoring and CGM: a happy marriage

Sometimes when we talk about CGM and blood glucose monitoring, it seems as if we’re offering an either/or. Either you can afford CGM and choose to use it, or you prefer blood glucose monitoring and find it easier to manage. The reality is that blood glucose testing and CGM go hand in hand. Here’s why.

1. You need to test your blood sugar if you feel funny.

CGM (Continuous Glucose Monitoring) is wonderful: nobody argues that. It’s a life-changing device for people with Type 1 diabetes – especially kids. But it’s not meant to be used entirely without a glucometer, completely without blood glucose testing. 

All CGM manufacturers recommend that if the result on your CGM doesn’t match how you’re feeling (if it says your blood sugar is 8mmol/l but you feel like you’re going low, for example), it’s important to test your blood glucose with a glucometer. 

Your glucometer is your source of truth: your measurement of blood glucose.

Having a glucometer in the house is essential, even if you constantly wear CGM, so that you have this back-up when you need it. Don’t need it right now? Don’t worry.

2. You need to test your blood sugar for an immediate reading.

Do you know exactly how CGM works? (We explain it here!) There’s a filament in the sensor that reads the glucose levels in the interstitial fluid, which is a thin layer of fluid that surrounds the cells in the tissue below the skin. Because it’s not testing blood glucose, there’s a 5 to 10-minute delay. Interstitial fluid readings are accurate, but delayed.

So there are a few times when you might want to test your blood sugar with a glucometer for an immediate reading:

• During hypoglycaemia (low blood sugar)
• If your blood sugar is rapidly changing (up or down)
• Postprandially (directly after a meal)
• During or after sport

In general, small fluctuations make for small differences in interstitial vs blood glucose. Big fluctuations (going high or low) make for big differences.

3. You need to test your blood sugar if your CGM isn’t working.

Machines are machines, and sometimes CGM doesn’t work properly. Maybe the sensor is faulty, or damaged, or you knocked it off by walking too close to a doorway. Whatever the case may be, it’s essential to have a glucometer handy so that you can test your blood glucose if your CGM isn’t working.

4. You always need to take a glucometer with you when you travel.

This is probably the number one tip! There’s nothing more scary than being in a foreign place unable to test your blood glucose. Any time you travel, no matter if it’s a night away or an overseas adventure, it’s essential to take a glucometer with you. Think of it as your diabetes safety blanket!

Confused about which glucometer to get?

Now that we’ve convinced you how necessary a glucometer is to have at home – whether or not you use a CGM – you might be wondering which one to get. We like the Contour Plus Elite glucometer. It’s affordable, it has a smart-light feature (that flashes red when your blood sugar is below target, green when you’re within target and yellow/amber when you’re above target) and it allows for Second-Chance sampling. This means that if you didn’t add enough blood to the test strip the first try, you now have a second chance to add more blood to the same test strip. That can save a lot of strips!

Find out more about the Contour Plus Elite glucometer on https://www.diabetes.ascensia.co.za/ or follow them on Facebook.