This site is intended for health professionals only

What is pre-diabetes?

When I was young it was quite hard to be diagnosed diabetic. You had to present in a coma and wake up on the Expensive Care Unit, mainlining insulin, or in the A&E rumpus room after slugging the medical SHO in an apparently drunken rage.

No one had ever heard of the term ‘pre-diabetes’. If you had a little trouble controlling your blood sugar and ballooned beyond 18 stone or so, you were asked to cut down on the carbs and you’d get labelled ‘mildly diabetic’.

Now if you so much as eat a Mars bar and have a blood test on the same day, you get a new diagnosis, a prescription for metformin and spend the rest of your life batting away questions about the firmness of your erections.

But what exactly is ‘pre-diabetes’? Apart from this year’s diagnostic fad, that is. (Vitamin D deficiency? Honey, that’s so 2013). 

The now-laughably-outdated terms ‘impaired glucose tolerance’ and ‘impaired fasting glycaemia’ at least made sense in that I could explain them to patients: ‘IGT means that you can’t handle large glucose loads, so lay off the fizzy drinks’; ‘IFG means that your blood sugar is high even when you haven’t eaten, so lay off the fizzy drinks’. Life seemed somehow simpler then

Putting pre- in front of a diagnosis just renders it meaningless. Pre-diabetes? Well, it’s a bit like pre-dead. Except you really will get dead one day.

If you have pre-diabetes, it sounds like you are definitely going to go on to develop the real thing. Except that you probably aren’t. (At least not anytime soon).

Anyone who’s read anything about blood and sugar in the last few decades will be familiar with the name Professor John Yudkin, whose book Pure, White and Deadly became a bestseller. His probably entirely unbiased take on the pre-diabetes thing? ‘An artificial category with virtually zero clinical relevance.’ 

Suppose for a moment that medicalising and monitoring 16 million adults in the UK was actually achievable, bearing in mind that GPs as a whole aren’t terribly busy. What purpose would it serve? Millions of patients on metformin would mean a hike in the share prices of the pharmaceutical companies that make it.

It would also pep up the biological washing powder manufacturers, who were just resigning themselves to the news that the bottom was falling out of the orlistat market and that skidmarks would soon be a thing of the past.

Explain it to patients this way: ‘If you take these tablets after every meal the extra days at the end of your life, the ones you’ll spend enjoying the view out of your nursing home window over the graveyard next door, will just about pay back the extra time you’ll spend on the crapper or shopping for bulk buy deals on toilet paper at LIDL. I’m guessing it’s time that that you’d rather have spent doing something more interesting.’

‘Like shopping for Belgian chocolate, Doc?’

Well, you can’t win ‘em all.  

Dr Tony Copperfield is a GP in Essex. You can follow him on Twitter @DocCopperfield