See attached table of values

I don't really know about HbA1C but i do remember there was Michael Patrick Buonocore who survived a blood sugar of 2,656 mg/dL upon admittance to the ER in East Stroudsburg, PA, on March 23, 2008.

So i think his HbA1C should have really peaked.

https://www.healthline.com/diabetesmine/highest-diabetes-A1C-in-history#1

to clarify: Is there a physico-chemical maximum that HbA1c can reach?

I have seen 11’s in ER with a Type 1. The goal should be to achieve a normal level not how high can you go!

See attached table of values

I have seen in our lab a 12 years old girl with Random Blood sugar of 600 mg/dl and Hb A1c of 18%

Lamia Al-Naama , amezing. The human body is so robust that can sustain with such a high blood glucose levels.

I have seen HbA1c of 24 in one subject.

A HbA1c% of 15 is generally needs evaluation especially if not matching the plasma sugar (looking for factors that interfere with red blood cells lifespan leading to a high level).

Hyder Mirghani

Thank you for that comment

So, when we see a very high HbA1c, we should start looking at reticulocyte count and markers of haemolysis and Hb electrophoresis and Bone marrow function, especially if the blood sugars are lower than expected.

Should we also use Fructosamine level as a cross-check? Do people use that still?

Thank you, fructosamine is helpful when the glycated hemoglobin is questionable, but needs standardization and it gives a shorter duration of glycemic status.

HbA1c reflects the average of blood sugar over a period of 6-8 weeks. The higher the sugar the more Hb glycation. I remember a figure of 13%in one of my patients. I am not sure how much is maximum!

Upper limits of any measure in laboratories depend upon technology use and we normally use a term called linearity range

for example my lab's A1c upper linearity range is 14.5 and values above are reported as >14.5

similarly there is another concept dealing with how low a analyte concentration can be measured and that is termed Diagnostic sensitivity, like my kit do not measures < 4.0 so this is the diagnostic range

Finally both linearity range and diagnostic sensitivity can be manipulated if you are having the requisite calibrators where you can target the range you want/think your value is.

if u think your value could be like AIC=20% than u must use a calibration curve targeting that range.

Regards

i guess the patient with a very high HbA1c (not the case here) should simply consult the lab specialists/chemical pathologist and he or she will be better able to clarify the patient's conditions according to this/her relevant medical conditions.

By the way i had few very detailed articles on my personal page here including a presentation which highlight the confounders affecting A1C results.

The technology doing HbA1c is also important and taken into account

Regards

I fully agree and endorse the reply by Sikandar Hayat Khan.

I also endorse the comments of Dr. Sikander Hayat. Lab.Consultant Biochemist be kept in the picture for explaining the requisite observation and its interpretation.

We have observed 13 persent in a patient

What is the HbA1c cutoffs value to determine control or uncontrol In T2DM

I have seen 17 in one of our Type.2DM patient

Having the experience of seeing tens of thousands of diabetic patients, maximum HbA1c I remember to have seen a patient with has been 17.0%, though I have seen hundreds above 13%.

So high levels of HbA1c are possible only in Type 2 diabetic patients as they may remain asymptomatic and remain neglected until they come up to the hospital with a complication. In Type 1 diabetes, symptoms worsen and patients will end up coming to the hospital early with drowsiness, dehydration, or gastrointestinal symptoms, if not in coma due to diabetic ketoacidosis.

A value of >10 needs injectable therapy, we observed a value of 17