HbA1c and glucose readings disagree: preparing a useful reassessment

An HbA1c result that seems inconsistent with glucose readings can lead to confusion about whether diabetes control is improving. Before deciding that the laboratory or device is wrong, ask the clinician to compare what each measurement represents. The aim is to understand the discrepancy and choose a reliable basis for care, not to select whichever number looks more reassuring.

Match the time periods

Bring the laboratory report with its date and the glucose records covering the period the clinician requests. Note whether home readings are occasional measurements, a structured diary or a continuous-monitoring report. A few recent readings do not represent the same time span as HbA1c. Mark recent illness or treatment changes so the doctor can interpret the history rather than compare numbers without context.

Preserve the original units and methods

HbA1c may be reported in different units, while glucose readings may also use different units across countries. Keep the original report and device settings visible. Do not compare the numerical values directly or convert them from memory. Ask the clinician to explain which measures are comparable and whether an estimated average from a device is being confused with a laboratory HbA1c result.

Tell the clinician about relevant blood history

NIDDK: The A1C Test & Diabetes explains that HbA1c reflects glucose over a longer period and can be affected by conditions involving red blood cells or haemoglobin. Tell the doctor about known anaemia, recent bleeding, transfusion, kidney disease or a haemoglobin condition. These facts do not prove that the result is wrong; they indicate questions that may need consideration. Bring relevant existing reports rather than ordering an extensive new panel yourself.

Ask how the discrepancy will be checked

The team may decide to repeat a measurement, review a test method or use other information, depending on the situation. Ask what problem the proposed step is expected to resolve and when the answer will be discussed. If the test is being used to establish a new diagnosis, clarify what confirmation is needed. If diabetes is already diagnosed, clarify how the uncertainty affects monitoring and the next review.

Do not adjust treatment from a disputed result alone

Continue the plan agreed with your treating clinician and seek their advice about changes. Do not stop insulin, increase medicines or dismiss symptomatic glucose episodes because another result seems normal. Ask for clear instructions about which readings and symptoms require contacting the team. Urgent symptoms should be assessed promptly rather than waiting for a planned comparison visit.

Make a cross-border review useful

If you are arranging an assessment in Turkey, send both the laboratory result and the relevant glucose record, with a sentence describing the discrepancy. Through the contact page, ask which clinician should review them and whether further testing should wait until the records are assessed. The useful outcome is an explained monitoring plan and a defined next decision, not simply another isolated result.