In people with a blood disorder called thalassemia who need regular blood transfusions, their long-term blood sugar marker (HbA1c) goes up when their daily fasting sugar goes up — so even though...

People with a serious blood disorder called thalassemia who need regular blood transfusions have about the same fasting blood sugar as healthy people, even though their long-term blood sugar marker (HbA1c) is high.

People with a blood disorder called thalassemia who need regular blood transfusions often show high blood sugar on HbA1c tests, but their actual blood sugar is normal—so the test might be giving false alarms in these patients.

Older people with a blood condition called thalassemia who need regular blood transfusions tend to have higher HbA1c levels — a number often linked to blood sugar — even if their actual blood sugar isn't high.

In people with a blood disorder who need regular transfusions, the common blood sugar test (HbA1c) often says they have high blood sugar, but their fasting blood sugar test says it's normal — so the two tests don’t match up well.

In pregnant women without diabetes, having more hemoglobin in the blood is linked to slightly higher HbA1c levels — a marker usually tied to blood sugar — suggesting that blood cell levels might affect this test even if sugar isn't high.