HbA1c: Normal Values, Prediabetes and How to Lower It
HbA1c, glycated hemoglobin, is the only test that shows your average blood sugar over the past two to three months rather than at the moment the blood was drawn. It therefore does not depend on what you had for breakfast, does not require fasting, and is used both to diagnose diabetes and to follow treatment. This article covers the cut-offs for prediabetes and diabetes, how HbA1c translates into an average blood sugar, why it is increasingly reported in mmol/mol, what can falsely change it and how it actually comes down.
Normal HbA1c values
| Result | HbA1c (%) | HbA1c IFCC (mmol/mol) | What it means |
|---|---|---|---|
| Normal | below 5.7 | below 39 | An average blood sugar in a range that carries no risk. |
| Prediabetes | 5.7 to 6.4 | 39 to 47 | A raised risk of type 2 diabetes; the state is reversible. |
| Diabetes | 6.5 and above | 48 and above | The diagnosis is confirmed by a repeat result or by fasting glucose. |
| Target in treated diabetes | usually below 7.0 | below 53 | The target is individual: stricter in younger people, gentler in older people and where hypoglycemia is a risk. |
What average blood sugar sits behind your HbA1c
| HbA1c | Average glucose (mmol/L) | Average glucose (mg/dL) |
|---|---|---|
| 5.0 % | 5.4 | 97 |
| 5.5 % | 6.2 | 111 |
| 6.0 % | 7.0 | 126 |
| 6.5 % | 7.8 | 140 |
| 7.0 % | 8.6 | 154 |
| 8.0 % | 10.2 | 183 |
| 9.0 % | 11.8 | 212 |
| 10.0 % | 13.4 | 240 |
This conversion explains a common paradox: fasting sugar is fine, but HbA1c is 6.1. Morning sugar is only one point in the day, while HbA1c also sees what happens after meals. Spikes after eating are most often the first sign of insulin resistance, years before fasting glucose crosses the line.
When HbA1c lies
HbA1c measures how much sugar has bound to the hemoglobin in the red cells over their lifespan of about 120 days. Anything that changes the red cells changes the result too, with no connection to blood sugar:
- Falsely low: recent bleeding or a transfusion, hemolytic anemia, treating anemia with iron or B12 (young cells carry less sugar), pregnancy, advanced kidney or liver disease.
- Falsely high: anemia from iron or B12 deficiency (older cells carry more sugar), a removed spleen.
- Unreliable: inherited hemoglobin variants (thalassemias and similar), where the laboratory chooses a different method.
That is why a diagnosis of diabetes is never made on one number. It is confirmed by a repeat HbA1c or by fasting glucose (7.0 mmol/L and above), and in unclear cases by a glucose tolerance test (OGTT). In anemia, an endocrinologist relies on glucose rather than on HbA1c.
Prediabetes: the one stage that can be reversed
An HbA1c of 5.7 to 6.4 is not diabetes and it is not a verdict. In most people it is a state in which the tissues respond less well to insulin while the pancreas is still compensating. In the large prevention trials, losing 5 to 7 percent of body weight and about 150 minutes of movement a week halved the progression to diabetes, and did so more strongly than the medicine given to the other group. What genuinely lowers HbA1c, in order of strength: weight loss, strength training and a walk after meals, 7 to 8 hours of sleep, and the order and type of carbohydrates on the plate. A detailed plan is in the article on how insulin resistance is treated, and how many calories and what deficit make sense is worked out by the calorie calculator.
The result shows up in the report with a delay: HbA1c follows a three-month average, so a recheck sooner than 8 to 12 weeks shows nothing new. Once diabetes has been diagnosed, HbA1c is checked every 3 months until the target is reached, and every 6 months after that.
What an endocrinology appointment looks like
An endocrinologist reads HbA1c together with glucose, insulin, lipids, blood pressure, weight and waist circumference, because risk is not made of a single number. If the result is in the prediabetes range, you get a plan with a deadline and a recheck in three months; if it is in the diabetes range, confirmation of the diagnosis, an assessment of the kidneys, eyes and feet, and a treatment plan. At the Miren Medic clinic endocrinology appointments are held by Dr Zorana Đuran and Dr Nemanja Nenezić, without a referral, and HbA1c, glucose, insulin and lipids are run in the clinic laboratory. More about the service on the endocrinologist Belgrade page.
Prices
| Service | Price |
|---|---|
| Endocrinology appointment (Dr Zorana Đuran) | 7.000 RSD |
| Endocrinology appointment (Dr Nemanja Nenezić) | 12.000 RSD |
| Follow-up appointment (Dr Nenezić) | 10.000 RSD |
| Internal medicine appointment (Dr Andreja Kovačević) | 6.000 RSD |
Frequently asked questions
What are normal HbA1c values?
Below 5.7 % (39 mmol/mol). Values of 5.7 to 6.4 % (39 to 47 mmol/mol) are prediabetes, and 6.5 % (48 mmol/mol) and above is diabetes, which is confirmed by a repeat result. The target in treated diabetes is usually below 7 %.
What does HbA1c in mmol/mol (IFCC) mean?
The same result expressed in the newer international unit. The conversion is mmol/mol = (% × 10.93) − 23.5, so 5.7 % is the same as 39 mmol/mol, and 6.5 % the same as 48 mmol/mol. Many laboratories print both values.
Does HbA1c have to be taken fasting?
No. HbA1c shows an average over two to three months and does not depend on your last meal. Blood is drawn fasting only if glucose, insulin or lipids are being run from the same sample.
Why is HbA1c raised while fasting sugar is normal?
Because HbA1c also sees the sugar spikes after meals, which a morning measurement does not catch. That is often the first sign of insulin resistance. The finding is checked with the HOMA index and, if needed, with a glucose tolerance test.
How do I lower my HbA1c?
The strongest effects come from losing 5 to 7 percent of body weight, strength training, a walk after meals and enough sleep, along with less free sugar and fewer sugary drinks. The change only shows in the report after 8 to 12 weeks. An endocrinologist starts medication when habits are not enough.
How often is HbA1c checked?
Every 3 to 6 months in prediabetes, and in diabetes every 3 months until the target is reached, then every 6 months. A recheck before 8 weeks have passed makes no sense, because the result follows a three-month average.
Book an appointment
If your HbA1c is 5.7 or above, book an endocrinology appointment at the Miren Medic clinic. The tests, the interpretation and a plan with a deadline come from one place, without a referral, and prediabetes is a state that the right plan can reverse.
