Monitoring Blood Sugar: a Continuous Challenge

It's not unusual for pharmacists to be asked to recommend a new blood glucose meter. In fact, diabetes affects almost 10% of the population in Canada.

Whether a patient is buying their first meter or needs a replacement, it can be hard to decide on a particular model, especially since the technology is constantly evolving.

Of course, the real challenge isn't choosing the best meter overall, but choosing the best meter for the person being treated. Blood sugar testing can be a chore for many, not only because it hurts to prick your finger, but also because of the mental burden of remembering to test, since regular monitoring is key to controlling blood sugar.

That's where blood glucose meters come in.

A valuable ally

Many new devices and device versions have appeared on the market over the past several years, each promising more benefits for people who need to test their blood sugar every day.

We are all familiar with traditional blood glucose meters, which measure capillary blood glucose levels.

However, a new generation of meters has emerged in recent years, and they may be a game changer for diabetics: These new devices are known as continuous glucose monitors (CGMs).

CGMs measure glucose levels in the fluid around cells (interstitial fluid) via a sensor inserted under the skin. There are 2 kinds of CGM:

• Intermittently-scanned CGM (isCGM)
• Real-time CGM (rtCGM)

 Intermittently-scanned CGMs only record data on demand, when the user scans the device or hovers a smartphone over the sensor.

Real-time CGMs record data continuously, which makes it possible to spot rapid fluctuations in blood sugar. Some devices allow the user to set alerts such as a hypoglycemia alarm, prompting the user to take action to control it.

Benefits

When it comes to equipment

• Fewer components to carry (lancing device, lancets, test strips, control solution, etc.), which is more practical while on the go or at work.
• Fewer finger pricks. Some sensors can last up to 14 days.
• Some sensors can send data directly to a smartphone.
• Automatic injection. Some models are compatible with an insulin pump, or can even be fully integrated to create an artificial pancreas system.

 In terms of prevention

• CGMs make it easier to stay on top of blood sugar readings. It can be all too easy to forget to perform a capillary blood glucose test while enjoying good company or when life gets busy. Frequent finger pricks can also be a deterrent for many.
• Real-time CGMs can reveal fluctuations in blood sugar that might otherwise go unnoticed, such as hypoglycemia, hyperglycemia, and rapid changes in glucose levels.
• The ambulatory glucose profile (AGP) report provides a summary of CGM data. The report overlays data collected over the past 14 days to give an overview of average values in a typical 24-hour day. 
• Blood sugar fluctuations are easier to understand, which can help people make informed decisions to manage their diabetes (physical activity, diet, sleep, treatment).
• Users can make faster decisions about their blood sugar management.
• Users may have less anxiety about hypoglycemic episodes, since data can be shared with loved ones or a health care professional.

Disadvantages

• Capillary blood glucose testing may still be required to verify CGM results in case of malfunction or uncertainty (hypoglycemia, absence of results, results that don’t reflect the user’s symptoms).
• Some devices may show inaccurate values due to illness or dehydration, or when certain medications are taken (e.g., acetaminophen, hydroxyurea).
• The adhesive used to hold the sensor in place can cause skin irritation or redness. Allergic reactions may also occur.
• The sensor may need to be removed before undergoing certain tests (e.g., MRI, X-ray).
• This technology is more expensive, and the sensors must be replaced every few days. 
  

Good news! 

Increasing numbers of private and public insurance plans are covering CGMs. Check with provincial organizations and private insurers to find out more.

Recommendations

The Diabetes Canada Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada were updated in 2021 with respect to blood glucose monitoring. The update includes new recommendations for CGMs, including target populations and reasons for using these devices.

Towards a better quality of life

While continuous glucose monitors are increasingly popular, traditional blood glucose meters and test strips are here to stay, as they are still needed to confirm CGM results in certain cases.

However, there's no harm in eligible patients availing themselves of new technology that improves their quality of life and complements the health service offering.

Expert recommendations are clear: these devices can help improve health, among other things, simply by enhancing quality of life. So, the next time someone asks your advice about a new blood glucose meter, think CGM!

For more information, I encourage you to visit Diabetes Canada online.

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This article was written with support from Annik Beauclair, B.Pharm, Vigilance Santé pharmacist.