Diabetes
What is an HbA1c? What’s a good number?
This Is Hemoglobin! Source: WikipedIf you have diabetes, you should be tracking your HbA1c. It’s the best measure that we have of your average blood sugars over the last three months.
But what is an HbA1c?!
Hemoglobin is the stuff that carries oxygen in your blood and gives it that red color. When you have extra sugar in your blood, some of it attaches to the homoglobin and forms a variant called hemoglobin A1c. It’s also called “glycated hemoglobin” – or HbA1c for short.
Hemoglobin and its variations live for about 120 days. By measuring the percentage of HbA1c in your blood, we can tell about how high your blood sugars have been during that lifespan.
How is an HbA1c test performed?
The HbA1c test is done by drawing blood from a vein. You may feel a slight pinch when the needle in inserted. Blood can be sent away to a lab or measured on a machine in your doctor’s office or at a hospital.
There are home HbA1c test kits available that cost about $15 per test. The home tests are less accurate but can give you a strong estimate.
What is a normal HbA1c?
In people without diabetes, the HbA1c is usually between 4% and 6%. From the Wikipedia page onglycated hemoglobin, here’s a chart showing how your HbA1c compares to your estimated average blood glucose during the prior months:
| HbA1c | eAG (estimated average glucose) | ||
|---|---|---|---|
| (%) | (mmol/mol) | (mmol/L) | (mg/dL) |
| 5 | 31 | 5.4 (4.2–6.7) | 97 (76–120) |
| 6 | 42 | 7.0 (5.5–8.5) | 126 (100–152) |
| 7 | 53 | 8.6 (6.8–10.3) | 154 (123–185) |
| 8 | 64 | 10.2 (8.1–12.1) | 183 (147–217) |
| 9 | 75 | 11.8 (9.4–13.9) | 212 (170–249) |
| 10 | 86 | 13.4 (10.7–15.7) | 240 (193–282) |
| 11 | 97 | 14.9 (12.0–17.5) | 269 (217–314) |
| 12 | 108 | 16.5 (13.3–19.3) | 298 (240–347 |
What is a good HbA1c?
Below are the 2011 guidelines for the major American standards bodies:
- American Diabetes Association – recommends an HbA1c under 7%.
- American Association of Clinical Endocrinologists – recommends an HbA1c under 6.5%.
The guidelines are based in part on the two largest studies of people with diabetes, the Diabetes Control and Complications Trial (DCCT) and its follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study. The studies found that there is a dramatic decrease in complications as HbA1cs dropped to 7% and below.
When a higher HbA1c may be recommended
Doctors do not always recommend aiming for an HbA1c below 7%. Intensive diabetes treatments can dramatically increase the risk of low blood sugars, especially if you have certain medical conditions. So if the risk of low blood sugars is very high, your doctor may recommend slightly higher targets. Likewise, if you are diagnosed when older, say in your 80s, your doctor may set higher targets because you are highly unlikely to live long enough to experience substantial complications.
Aiming for a higher HbA1c is not ideal if you will live long enough to experience complications. Because diabetes is progressive, studies have show that even a few years at a lower HbA1c has benefits decades from now.
Lucien's House 