Glossary · Biology
HbA1c (long-term blood sugar)
In short
HbA1c indicates what proportion of the red blood pigment is bound to sugar. Because red blood cells live for about three months, it reflects the average blood sugar of the past eight to twelve weeks.
It is the standard value for diagnosing and monitoring diabetes and is given in percent or in millimoles per mole. Unlike a single blood sugar reading, it does not fluctuate with the last meal.
In studies, HbA1c is a classic surrogate marker: it is closely linked to the complications of diabetes, but not every reduction brings the same benefit for heart, kidneys or lifespan. In anaemia, iron deficiency or certain haemoglobin variants it can also come out too high or too low.
HbA1c is the memory of blood sugar — over about three months.
Where this comes up in the fact checks
- Berberine – Pooled across more than 30 studies, it lowers HbA1c in type 2 diabetes by 0.19 percentage points.
- CGM (blood glucose sensor) – The studies in healthy people work with surrogate markers such as HbA1c, not with disease outcomes.
Sources
Related terms: Surrogate marker · Biomarker · Meta-analysis
Information only, not medical advice. The BK-Score is a subjective assessment according to disclosed rules – not a scientific evaluation. Scoring rules