Are continuous glucose monitors worth it?

The NHS is continuing to roll out access to Continuous Glucose Monitors (CMGs) to patients with type 1 diabetes, and now over 200,000 patients are using the device.

It is particularly valuable for type 1 diabetes patients who experience large fluctuations, both highs and lows, in blood sugar levels and patients with hypoglycaemia unawareness, which means they don’t experience symptoms when their blood sugar is low.

The use of CMGs by non-diabetics also continues to grow in popularity in the UK, but what is their value? A review published in June and led by researchers at UCL and Birmingham Children’s Hospital found there is a lack of evidence to demonstrate the effective use of continuous glucose monitors (CGMs) in people not living with diabetes (PNLD).

What are CMGs?

Continuous glucose monitors (CMG) are wearable technology that tracks glucose levels under your skin for 24 hours a day while you wear it. The CMG takes measurements throughout the day and night, which you can view on a device such as a smartphone.

One dispute against using CGMs in non-diabetics is that because glucose fluctuations are so small in these people, a CGM does not provide any meaningful information.

Furthermore, there are concerns that they could cause non-diabetics to become anxious if they see a spike or a drop. Occasional fluctuations are normal, and your body can usually handle them.

Benefits of tracking glucose levels

Diabetes is usually assessed using a single-time measurement of blood glucose rather than considering how blood glucose fluctuates over time. So, one argument for using CGMs in non-diabetics is that even if someone’s fasting glucose levels are considered normal, it doesn’t rule out that they are experiencing extreme highs and lows, which can be tracked by a CGM.

A 2018 study found that many individuals considered non-diabetic by standard measures experienced frequent elevations in blood glucose levels into the diabetic range.

It is also claimed that a CGM can help you make better nutritional and lifestyle choices. Even if someone does not have diabetes, they may have a degree of insulin resistance, and certain foods can push their blood sugar to unhealthy levels. A CGM should, therefore, help you recognise which foods to avoid.

However, glycaemic response is not straightforward, and there is a myriad of factors that can influence it:

• Lack of sleep: your body fails to use insulin effectively when sleep deprived.
• Stress: the body releases hormones that can cause blood glucose levels to increase when under stress.
• Your daily cup of coffee: blood sugar levels can be particularly sensitive to caffeine in some people.
• Exercise: depending on the type of activity you’re doing, your blood sugar levels can either go up or down.
• Dehydration: this can cause blood sugar levels to rise, as the ratio of water to sugar changes and glucose becomes more concentrated.
• Skipping meals: this can result in dangerously low or high blood sugar levels. A recent study found that compared to forgoing dinner, skipping breakfast resulted in higher insulin resistance later in the day.

If you want more advice on using a continuous glucose monitor or wish to have your risk of diabetes or pre-diabetes assessed, call +44 (0)20 4580 1152 or email [email protected] to arrange a GP appointment.