That's interesting that the UK < 42mmol/mol (6.0%) for pre-diabetes. This is clearly too high isn't it? That's an average of 7mmol/L (126mg/dl). An average of 6.9 certainly isn't normal.
And it wouldn't surprise me if the UK changes it to a lower level in the future. Getting a reading of just under 6% (42) and being told it's normal would mean a lot of people would not have a lot of time to make the changes necessary. Indeed, once you hit 6.0% hitting 6.5% is very common within a year or less.
Personally, I think that 6.0% (42) or 6.2% (44) should be a diabetes diagnosis (although this will never likely happen). Then individuals would make lifestyle changes when it was that much easier to do so. Now, this wouldn't work in the US as it would affect insurance issues but in the UK it would be possible. (I don't live in either).
As an aside, blood pressure normal levels were changed recently and so there is no reason that the same won't happen with T2D.
(Note: in the above I'm talking about HbA1c as a diagnostic tool rather than as a indicator of Diabetes Control. The former being used to diagnose people who are taking no medication and may or may not be diabetic).
There are a lot more factors in play than what is best for the patient.
I have always thought that the lower threshold for identifying pre-D is a double edged sword.
No matter what the threshold, few patients actually make the sustained lifestyle changes needed to avert T2 in those who will develop it.
Where the level is lower (e.g below 42mmol/l) many patients become labelled with a health condition and medication when in fact they won’t go on to develop T2 (not everyone does). Plus, of course, in a healthcare system based on insurance, it is in the interests of pharma and business to get people registered T2 and on lifetime medication regimes as soon as possible.
In contrast, a higher threshold (e.g. above 37mmol/l) for declaring pre-D significantly reduces the number of people diagnosed, simultaneously reducing the burden of cost on the healthcare system, while also giving patients an increased medical monitoring regime and a greater chance of making changes to their lifestyle.
Here in the UK if the criteria were lowered to the American levels the National Health Service would suddenly gain massive numbers of new Pre-Ds, without the staff and resources to cope with them. Diabetes is already presented in the media as a terrible ‘burden’ and at risk of ‘bankrupting’ the NHS in future. Instantly adding millions of new pre-Ds would knock the NHS’s budgets to the core.
I can remember reading a fascinating article by Jenny Ruhl (
www.bloodsugar101.com ) discussing how diagnostic criteria are decided. She made it clear that the decisions are made by committee, informed by selected evidence, on the basis of various cost benefit analyses and resource availability. They look at overall population benefit v cost/implementation. The individual patient’s benefit is not a priority, especially since decisions like this are massively influenced by administrators, budget holders, politicians and industry representatives rather than practicing clinicians.