Why HbA1c might be wrong for some people with diabetes
Red Blood Cell Lifespan < 74 Days Can Clinically Reduce Hb1Ac Levels in Type 2 Diabetes
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Some people with diabetes have red blood cells that don’t live as long. Because HbA1c measures sugar stuck to red blood cells over time, shorter-lived cells mean less sugar gets measured—even if blood sugar is high.
Surprising Findings
People with shorter RBC lifespans had higher blood sugar but similar A1c levels compared to others.
Most assume A1c directly reflects average glucose — but here, two people with the same A1c had very different real sugar levels, purely due to RBC lifespan.
Practical Takeaways
If your A1c is normal but your daily glucose readings are high, ask your doctor about factors like RBC lifespan that might be skewing the result.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Some people with diabetes have red blood cells that don’t live as long. Because HbA1c measures sugar stuck to red blood cells over time, shorter-lived cells mean less sugar gets measured—even if blood sugar is high.
Surprising Findings
People with shorter RBC lifespans had higher blood sugar but similar A1c levels compared to others.
Most assume A1c directly reflects average glucose — but here, two people with the same A1c had very different real sugar levels, purely due to RBC lifespan.
Practical Takeaways
If your A1c is normal but your daily glucose readings are high, ask your doctor about factors like RBC lifespan that might be skewing the result.
Publication
Journal
Journal of Personalized Medicine
Year
2022
Authors
Saijun Zhou, Rongna Dong, Junmei Wang, Li Zhang, Babadzhanova G Yu, X. Shao, Pufei Bai, Rui Zhang, Yongjian Ma, P. Yu
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Claims (6)
If you have type 2 diabetes and your red blood cells don’t live as long, your actual blood sugar might be higher than what your A1c test shows — meaning the A1c test could be misleading for some people.
There's a new math formula that fixes HbA1c blood sugar readings for people with type 2 diabetes when their red blood cells don't live as long as usual — this could give a more accurate picture of their blood sugar control.
If you have type 2 diabetes and your red blood cells don’t live as long—less than 75 days—your A1c test might not give a true picture of your blood sugar control, because the test could show lower numbers than reality.
If your red blood cells live longer, they soak up more sugar over time, which can make your HbA1c blood test go up — even if your average blood sugar hasn't actually changed.
People with type 2 diabetes may have red blood cells that don't live as long as those in healthy people—about 95 days compared to 100 days—suggesting their bodies replace blood cells faster.