by Jennifer Douglas
(Spain)
QUESTION: My HbA1c is 6.6%, but my fasting, random, and 2-hour after-meal finger-prick glucose readings are usually normal. I have no classic diabetes symptoms, lost 19 kg, eat low carb, walk daily, and feel well. In one country I am told I have diabetes, while in another I may be called prediabetic. Why can this happen?
An HbA1c of 6.6% is in the diabetes range under current criteria, but one borderline result should be confirmed when you have no clear hyperglycemic symptoms and your glucose tests are otherwise normal. If HbA1c and glucose readings remain substantially different, I would look for missed glucose peaks, laboratory variation, or a condition that makes HbA1c less reliable. Home finger-prick readings are useful, but they cannot by themselves confirm or exclude diabetes.
Answer by Dr. Albana Greca, MD, MMedSc
Hi Jenny,
Your 19 kg weight loss, daily walking, and healthier food choices may have improved your glucose substantially. That progress matters. But feeling well or seeing normal meter readings does not prove diabetes is absent, because type 2 diabetes can be present without symptoms.
For a nonpregnant adult, HbA1c of 6.5% or higher is in the diabetes range. A value of 6.6% corresponds to an estimated average glucose of about 143 mg/dL, but that estimate is useful only when HbA1c accurately reflects your glucose.
See our HbA1c to average glucose calculator and HbA1c guide.
Not in every situation. Without unequivocal hyperglycemia, diagnosis requires confirmation with a second abnormal result. When two different tests disagree, the test above the diagnostic threshold should be repeated.
If HbA1c is 6.6% but fasting plasma glucose is below 126 mg/dL, I would usually repeat a laboratory HbA1c using a standardized method. If the repeat HbA1c is again 6.5% or higher, current ADA criteria support diabetes even if fasting glucose remains below 126 mg/dL.
See blood tests used to diagnose diabetes.
A glucose meter shows only the moment you test. If you mainly test fasting or after low-carbohydrate meals, you may miss rises after other meals, overnight, during illness, or at other times.
A fasting meter reading around 95 mg/dL and a 2-hour reading around 92 mg/dL are reassuring, but laboratory plasma glucose is preferred for diagnosis. Review normal fasting glucose and blood sugar after eating.
HbA1c depends on glucose exposure and red-blood-cell lifespan. I would investigate a persistent mismatch rather than assume either test is correct.
When HbA1c is unreliable, plasma glucose criteria are preferred. A complete blood count and ferritin are useful first checks; B12, folate, kidney, liver, or hemoglobin studies may be added when indicated.
Yes. A 75-gram oral glucose tolerance test measures fasting plasma glucose and the 2-hour response to a standardized glucose drink. A 2-hour value of 200 mg/dL or higher is in the diabetes range; 140–199 mg/dL is in the prediabetes range.
An ordinary 2-hour finger-prick result after a meal is not the same test and should not be compared directly with OGTT thresholds.
Short-term continuous glucose monitoring can sometimes reveal glucose peaks that finger-prick testing misses. However, CGM is not currently a diagnostic test for diabetes. I would use it only as additional pattern information, not instead of repeat HbA1c, fasting plasma glucose, or an OGTT.
Countries may differ in terminology and may update diagnostic thresholds at different times. If one of the countries was New Zealand, there is a specific recent explanation: from 1 July 2026, New Zealand lowered its HbA1c diabetes threshold from 50 mmol/mol to 48 mmol/mol and changed the prediabetes range to 42–47 mmol/mol.
An HbA1c of 6.6% is about 49 mmol/mol. Under the older New Zealand threshold, that could have been called prediabetes; under the new 2026 threshold it is in the diabetes range, aligning with the international 6.5% or 48 mmol/mol threshold.
Losing excess weight can markedly improve insulin resistance and glucose. If the 19 kg loss was intentional and your weight is now healthy and stable, that is encouraging. Continued unexplained weight loss or weakness should be assessed.
If type 2 diabetes was previously confirmed, later improvement does not simply change the diagnosis to “prediabetes.” Diabetes can enter remission, but remission has a specific definition. An HbA1c of 6.6% is not below the usual remission threshold.
Continue a sustainable eating and activity plan rather than trying to force glucose lower. Use our blood sugar chart and blood sugar log to track patterns.
I would not dismiss an HbA1c of 6.6%, but I would not let one borderline result create unnecessary fear. Confirm it properly. If the repeat HbA1c remains at least 6.5%, current criteria support diabetes even with normal fasting glucose. If the mismatch remains large, investigate why HbA1c may not reflect your true glucose exposure.
Arrange prompt review for continued unexplained weight loss, excessive thirst, frequent urination, recurrent infections, blurred vision, or consistently high glucose. Seek urgent care for vomiting with marked hyperglycemia, severe dehydration, confusion, difficult breathing, or loss of consciousness.
Educational safety note: This answer is for general diabetes education only. It does not replace personal diagnosis or treatment. Do not start or stop diabetes medicine, excessively restrict carbohydrate, or change your exercise plan solely because of one HbA1c result.
Last reviewed: July 2026.
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