CGMs for all

Are we pathologising normal glucose homeostasis?

I have written before about the poor science behind personalised nutrition apps which claim to have finally found the secret to health you’ve been looking for.

Photo by Julius Drost on Unsplash

What most of these apps have in common is the use of continuous glucose monitoring (CGM) technology to monitor a person’s blood glucose to see how they respond to meals. These devices can be life-saving for people with type 1 diabetes and even people with type 2 diabetes who take insulin or medications which increase the risk of hypoglycaemia. I also see some patients with diet- or metformin-controlled type 2 diabetes and even pre- and monogenic diabetes who find these devices can be useful at getting insight into their glucose management. To be clear, the use of CGMs - even in diabetes - is not without its potential downsides. However, wherever there is clear benefit, it’s worth considering their use on a patient-to-patient basis.

In contrast, the benefits of using a CGM in people with normal glucose tolerance (I will expand on this, but if your A1c is under 6.0%/42mmol/mol this is probably you.) are so minuscule and the risks potentially significant that I worry about the growing use of these products across the population.

These risks range from nutritional, to mental health, even to good old quality of life. The latter two are the ones that upset me the most in my practice. I have become so frustrated with seeing poor patients who have been duped by podcasters and the scienc-ey sounding sales patter which accompanies these devices, that I wanted to put together a series of articles which cover “glucose” as in depth as I can.

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My aim with this series of articles is to spell out the same facts and advice that I give to my patients so hopefully anyone reading it who is worried about “glucose spikes” can hopefully get some clarity (or even reassurance!), or at least know where to turn to and what to do for genuinely appropriate dietary advice.

I have focussed a lot on glucose and CVD in this series (because I know this data the most), but I’ll add further thoughts if I can on other diseases like Alzheimer’s in the future if I feel like I can interpret the literature well enough).

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You can hop between the sections below (and I may add more in the future which will be indexed here!):

What is type 2 diabetes and why do we care about glucose being high?

What is prediabetes and why do we care about glucose being high?

Keeping my post-prandial glucose low protects me from type 2 diabetes and CVD doesn't it?

My CGM says my glucose got to 7.0mmol/L - is this diabetes?

I’ve got a CGM, what kind of values are normal?

“Glucose spikes” and “crashes”

I ate some raspberries and my glucose went up - what’s going on?

Surely there are no downsides to trying to keep my glucose excursions low?

I think my CGM readings are too high - what I should I do?”

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