Continuous Glucose Monitoring (CGM) devices are becoming an increasingly popular method of monitoring glucose levels for those living with type 1 and type 2 diabetes. I don't have either (yet?) , like many other women, I have had diabetes during my pregnancies. So I am familiar with the ritual of checking my blood glucose with my trust Accu-Chek finger-prick monitor on waking and before and after meals. During my pregnancies, I was advised on how to control it through diet and told it was an excellent way for pretty much everyone to eat for life (whoops!), and I must admit, I never felt so well!
So, recently, I decided to take advantage of some of the new technology on the market and learn more about how my body was reacting to certain foods from the perspective of glucose. I plumped for a Freestyle Libre 2 Sensor through a company called Veri* The subscription also buys you access to their application, which provides feedback on your meals, whilst algorithmically factoring in other lifestyle factors such as sleep and exercise. You can also note other events of note, such as stressful events.
The device, which stays in place for 14 days, is installed by the user. In an almost painless procedure, a needle pierces the skin and retracts, leaving a tiny filament that measures the glucose in the interstitial fluid.
Once in place, it stores data for up to 8 hours and this can be downloaded to the app by holding the phone (NFC) to the sensor.
It's reasonably early days for me, but what have I seen so far?
Food Combining
When I saw a dietician at the hospital, I was advised of the benefits of combining certain foods to slow the absorption of sugar. The CGM allowed me to see this process in action. My breakfast was almost always an apple, a piece of wholemeal toast and a small cholesterol-lowering yoghurt drink. My glucose response wasn't bad (7/10 according to the software) but not the best. Slapping an egg on top of my toast practically flat-lined it (now scoring 10/10). Intellectually, I might have understood this advice, but when I was diabetic, my glucose levels had recovered by the time I checked my blood sugars two hours later. This time, the CGM allowed me to see it in the data throughout those couple of hours rather than a snapshot recording at the end of the postprandial period. I could see the benefits of this in action.
Napping or Sleeping After Food
I generally don't nap. I'm pretty hopeless at it, in fact, but one day, I took a one-hour nap after my lunch. It took much longer for my postprandial measurements to drop. I'm guessing this is why it's a good idea to go for a short walk after food. Similarly, eating late at night is not ideal as it seems glucose levels can be higher for a good duration of the night. Sleep, generally, also helps. The app encouraged me to try not to eat my dinner so late and extend the fasting period to 14 hours, if at all possible.
Data Tracking
Let's face it, with the paper-based food diaries, Slimming World books or MyFitnessPal, it's easy to forget to log stuff you're consuming, accidentally or on purpose. With CGM, that biscuit with a cup of tea - it's in the data somewhere. I forgot to log one meal and then got a notification asking me what happened at 5:30 p.m. to cause my spike. Now, this is OK, but such technology might not be appropriate if there's any history of eating disorders*.
Broadly speaking.....
I've really enjoyed using the CGM and how it has helped me reconnect with the advice we all hear in the media and that I received in the hospital. The use of CGMs for those who have diabetes or who are at risk of developing the condition can be numerous - not least, fewer finger pricks! The benefits of maintaining a good diet are often hidden in the short term. The data made available by this technology means the benefits of good dietary choices are manifested almost immediately on a smartphone. The addition of a scoring system can also help gamify the experience providing encouragement to make good choices. Educationally, this could be worth a lot, particularly with growing concern about the prevalence of type-2 diabetes (13.6 million people in the UK are at risk of developing type 2 diabetes).
There is some controversy over the usefulness of such devices for non-diabetics, however, and there are points of caution to consider. The use of such technology without medical supervision has not been extensively researched (Shmerling, 2021). I suspect it would not be a good idea to make significant decisions about our health by interpreting this data without the guidance of a qualified healthcare professional. Glucose levels are just one metric in a complex picture that makes up human biology.
Nevertheless, as we see an increasing move to distributed healthcare models, the use of such devices and other mHealth solutions may well become more prevalent in all of our lives.
* It should be noted that Veri company is not set up for medical management of diagnosed cases of diabetes. They advise that it is not suitable for those who have or have had eating disorders or are pregnant. Nor do I endorse their products.
References
Diabetes UK (2022) Living with Diabetes, Diabetes UK, Available at: https://www.diabetes.org.uk/guide-to-diabetes (Accessed on: 19 April 2022)
Schmerling, R (2021) Is blood sugar monitoring without diabetes worthwhile?, Harvard Health Publishing, Available at: https://www.health.harvard.edu/blog/is-blood-sugar-monitoring-without-diabetes-worthwhile-202106112473 (Accessed 19 April 2022)
Veri (2022) About Veri https://www.veri.co/about (Accessed 19 April 2022)
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