HbA1c in non-diabetics: what a normal value says about your metabolic health

HbA1c is not only a diabetes marker. Even if you do not have diabetes, your HbA1c reflects your average blood sugar over the past weeks, and with it a part of your metabolic health. Within the normal range there is still a difference between normal and optimal.

With HbA1c I prefer to look at where you sit in the band rather than whether you just fall inside it. Just inside the range is not the same as healthy.

What exactly does HbA1c measure?

HbA1c reflects the percentage of your haemoglobin to which glucose is attached, built up over the lifespan of your red blood cells. That makes it an average over roughly eight to twelve weeks, not a snapshot like fasting glucose. A single sweet meal therefore does not change your HbA1c.

That makes it a stable marker for following your sugar handling over time.

What is a good HbA1c if you do not have diabetes?

Within the non-diabetic range, a higher HbA1c is associated with higher future risk. In a large study of people without diabetes, HbA1c was more strongly linked with later cardiovascular risk than fasting glucose, especially at values above 6.0% (Selvin, 2010). Lower within the range is therefore more favourable than high-normal.

HbA1c, glucose or insulin?

The three complement each other and each tells a different part of the story. Fasting glucose is a snapshot, fasting insulin shows early resistance, and HbA1c gives the average. Insulin can move years before HbA1c (Matthews, 1985).

For the earliest signals, read fasting insulin and HOMA-IR.

What do you do with a high-normal HbA1c?

A high-normal value is mainly a prompt for lifestyle, not a diagnosis. Prediabetes is not a one-way street, because a sizeable share returns to normal values with lifestyle (Tabak, 2012). Movement, strength training and fewer fast sugars help.

To track your HbA1c alongside your other metabolic markers, compose a panel through our custom blood test. See also the overview measuring metabolic health.

My advice: read your HbA1c as a direction sign, not a stamp. If it climbs toward the diabetic range, discuss it with your GP.

References

1. Selvin E, Steffes MW, Zhu H, et al. Glycated hemoglobin, diabetes, and cardiovascular risk in nondiabetic adults. New England Journal of Medicine. 2010. PMID: 20200384.
2. Tabak AG, Herder C, Rathmann W, et al. Prediabetes: a high-risk state for diabetes development. The Lancet. 2012. PMID: 22683128.
3. Matthews DR, Hosker JP, Rudenski AS, et al. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985. PMID: 3899825.

Disclaimer

Every blood test result includes a professional assessment by a BIG-registered doctor. This article gives general information and is not a substitute for medical advice. A blood test is a tool to walk into the conversation with your GP better informed, not a diagnosis in itself. For treatment decisions, discuss your results with your GP.