Remission target - 5.7% or 6.5% Hba1C

[Sax]

I have been taking an interest in the concept of remission recently... I am about to get my 2nd NHS Hba1C reading much earlier than I'd expected, and I know from recent home testing with an AC1now test kit and Libre that - barring significant measurement error on both - it will be below the UK target remission threshold of 6.5% (albeit this is being artificially helped by 500 mg/day metformin).

However when digging into remission values, I found the following contradicting information from 2009:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2768219/

To quote;
Partial remission is sub-diabetic hyperglycemia (A1C not diagnostic of diabetes [<6.5%], fasting glucose 100–125 mg/dl [5.6–6.9 mmol/l]) of at least 1 year's duration in the absence of active pharmacologic therapy or ongoing procedures.

Complete remission is a return to “normal” measures of glucose metabolism (A1C in the normal range, fasting glucose <100 mg/dl [5.6 mmol/l]) of at least 1 year's duration in the absence of active pharmacologic therapy or ongoing procedures.

The threshold for "pre-diabetes" is taken as >5.7%, so remission is taken in the UK as being a return to a pre-diabetic threshold not that of the healthy populace. The question then is, are either of these enough to address health risks and so meaningful as a target. Turns out this has already been looked into by another member, pavlosn:

https://www.diabetes.co.uk/forum/threads/can-hba1c-be-too-low.68973/

The third set of diagrams he pasted shows a morbidity increase for Hba1C which starts to ramp up at around 6%. What I can't find is any clinical data that supports a 6.5 % target as being a meaningful value.

Given above the 5.7% target makes sense to me.

 

[EllieM]

What I can't find is any clinical data that supports a 6.5 % target as being a meaningful value.

I believe that this level was decided on because diabetic retinopathy and blindness is very low for patients with hba1cs less than 6.5% (48mmol/mol), though some people argue that the target should be 7%.
Correlation Between Hba1c And Diabetic Retinopathy | DiabetesTalk.Net

 

[Mbaker]

I think it should be called partial remission for the 6.5 and full remission for 5.7 and below. My rationale is that up to 6.5 is within the pre-diabetic range. HCP's in my view should shoot for the stars.

 

[Sax]

I've today found a study which came up on a new search in google for slightly different terms, dated 2020 (published 2021), which actually answers a lot of my questions and confusion, and confirms EllieM's input (thanks for that). Its a meta-study on whether the 6.5% diagnostic threshold for diabetes is appropriate, but I also think it helps to give clarity on remission thresholds as well. The link is at:

https://link.springer.com/article/10.1007/s00592-020-01606-5

I won't repeat the whole huge thing, but the conclusion was:

In conclusion, based on the strongest data of moderate retinopathy, this systematic review and meta-analysis is in accord that the HbA1c diagnostic cutpoint of 6.5% (48 mmol/mol) is highly specific for diagnosing T2DM, though the increased prevalence of retinopathy in those aged 55 years or greater and in African-Americans may suggest a lower threshold is appropriate for those groups. However, this analysis highlights that diabetic microvascular complications commonly occur at lower HbA1c values, and the sensitivity of diagnosing T2DM may improve with a lower diagnostic cutpoint. There is a need for studies that standardize the definition of minimal diabetic retinopathy with more sensitive measures of nephropathy and neuropathy to determine if a lower threshold is appropriate.

So 6.5% is a meaningful retinopathy threshold for some racial groups (but possibly not all); and some other forms of damage are still at higher risk of occurring over time below this threshold, to an unknown and as yet un-investigated degree.

Yup I'm sticking to 5.7% myself.

 

[Resurgam]

For some people the Hba1c and blood glucose levels are not closely linked.
When I was eating 50 gm of carbs maximum, my Hba1c was at the top end of normal, so I reduced to no more than 40 gm per day and my Hba1c was exactly the same the following year.

 

[KennyA]

I had a look in Bilous' Handbook of Diabetes, which is what the NHS regards as the key textbook for diabetes. It does not mention remission at all, but then again it deals with diet and diabetes in about half a page.

 

[Sax]

I had a look in Bilous' Handbook of Diabetes, which is what the NHS regards as the key textbook for diabetes. It does not mention remission at all, but then again it deals with diet and diabetes in about half a page.

I try to avoid being overly cynical about the NHS, but that did make me grimly amused. How awful yet appropriate.

 

[KennyA]

I try to avoid being overly cynical about the NHS, but that did make me grimly amused. How awful yet appropriate.

Bilous is written from the point of view of the medical professional, so it is exclusively interested in diabetes as a progressive disease, what pharmacological interventions are required, what rare symptoms occur, what happens as the disease progresses, etc. It's really a guide to managing diabetes decline for clinicians, rather than a textbook on reducing or removing harm arising from the complications of diabetes.

The very small section on diet naturally endorses the usual NHS "eatwell" advice - including recommending "high glycemic index" starches, lots of fruit, and limiting the intake of animal-derived products such as red meat and dairy.

It therefore leaves the impression that, if you are a clinician dealing with a diabetic patient 1) decline is inevitable 2) nothing really helps and 3) the only practical interventions are drugs and more drugs. This is why so many of us find clinical staff amazed and disbelieving that blood glucose readings can be quickly brought back to normal through simple dietary changes.

 

[jjne]

6.5% is really quite high (average 7.8mmol/l, UK equivalent 48). I am around that point after just two and a half months of low carbing from an initial 12.6% (17mmol/l, UK 114). The USA uses 7% as a target, which seems crazy high to me (8.6mmol/l, UK 53).

I thought the threshold for remission would be 6% at most, else I'm in remission already (well, I would be if a year had passed) and that's just daft.