Metabolic health

Hemoglobin A1c (HbA1c)

A1C, glycated hemoglobin

Included in every MyHealthspan membership: Focus, Baseline, and Complete.

Your average blood sugar over recent months.

HbA1c measures how much of the hemoglobin in your red blood cells has glucose attached. Because red blood cells live about three months, it reflects your average blood sugar over the past two to three months.

HbA1c gives a longer view than a single glucose reading.

A glucose result shows your blood sugar at one moment, and it can shift with a recent meal, stress, or illness. HbA1c builds up slowly as glucose sticks to hemoglobin, so it changes little from day to day and you don't need to fast for it.

Diabetes Canada's guidelines use HbA1c, along with glucose tests, to define prediabetes and diabetes. In someone without symptoms, a result in the diabetes range is confirmed with a repeat test on another day.

Glucose sticks to hemoglobin, so HbA1c keeps a running record.

Questions

What does a higher HbA1c mean?

A higher HbA1c means your blood sugar has been running higher on average. Depending on the level, it can point to prediabetes or diabetes. Your result is read with your fasting glucose, weight, blood pressure, family history, and other results.

Can anything make HbA1c less accurate?

Yes. Iron deficiency, some types of anemia, inherited hemoglobin variants, and severe kidney or liver disease can make HbA1c read higher or lower than your true average. Age and ethnicity can also affect results. If something looks off, a clinician may compare it with your glucose.

What happens if my result is out of range?

HbA1c often responds over a few months to changes in eating, activity, sleep, and body weight, and some people also need medication. 1:1 longevity coaching can help you decide what to work on, and a clinician can advise on treatment and when to retest.

Sources and references