What should you know about HbA1c in sickle cell disease?

HbA1c measures glucose attached to haemoglobin and is commonly used to assess average blood glucose over the life of a red blood cell. Sickle cell disease changes red-cell shape and survival, and transfusions can introduce haemoglobin from another person. These factors may make HbA1c appear lower or otherwise fail to match your day-to-day glucose readings. The result should therefore be interpreted alongside your haemoglobin type, treatment history, symptoms, and direct glucose measurements.

An HbA1c result that does not fit home readings, a glucose test, or symptoms needs careful review rather than automatic reassurance. Fatigue, pale skin, thirst, frequent urination, and blurred vision can have different explanations, including anaemia, a sickle cell episode, or high blood glucose. Your clinician may use a blood glucose test or another marker that is less dependent on red-cell lifespan. Recent transfusion, haemolysis, kidney problems, or a haemoglobin variant can all affect the choice of test.

Tell the diabetes or haematology team when your last transfusion occurred and which sickle cell medicines you take. Bring home glucose records, meter details, and a list of symptoms to the appointment. Do not change diabetes treatment from HbA1c alone. If a different test is recommended, ask how to prepare and how its result will guide care. Continue your established sickle cell plan, drink fluids as advised, and seek help early during a pain or fever episode.

Seek urgent help for chest pain, difficulty breathing, sudden weakness, confusion, severe dehydration, or a fever during a sickle cell illness. Arrange prompt review for repeated very high or low glucose readings, vomiting, worsening fatigue, or new pale skin. A mismatch between your symptoms and HbA1c should be reported promptly so it can be assessed with a suitable test.

Is HbA1c dependable with my haemoglobin type and recent transfusions? Which blood glucose or alternative test should we use? How should I record readings during sickle cell pain or illness? Could anaemia or kidney health change the interpretation?