Why your HbA1c test could be lying: Experts warn of massive overdiagnosis of diabetes in seniors and women

A Lancet review warns that the HbA1c test, widely used in India, may give misleading results for diabetes diagnosis. Age-related changes and anemia can inflate readings, though the test remains reliable for monitoring blood sugar trends over three months.

Hyderabad: In a major alarm for India’s healthcare system, a recent review published in The Lancet Regional Health: Southeast Asia (February2026) has warned that the HbA1c test, commonly prescribed by doctors as a diagnostic tool, is providing misleading results for people.

While the report acknowledges that HbA1c remains a vital tool for monitoring how patients manage their blood sugar over a 90-day period, it warns that it is a flawed method for initial diagnosis.

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The study points to a massive statistical discrepancy. While the ICMR-INDIAB study used the traditional Oral Glucose Tolerance Test (OGTT) to identify 101 million diabetics in India, international surveys relying solely on HbA1c have projected a staggering 215 million diabetic cases in India.

Renowned diabetologist Dr V Mohan of Mohan Diabetes Centre, Chennai, who led the earlier ICMR study, recently clarified that Hb1Ac test is not intended for standalone diagnosis.

He noted that the test ‘picks-up’ people with very mild abnormalities and labels them as diabetics. Therefore, Hb1Ac for diagnosis of diabetes is not a good test but it remains a ‘gold standard’ for assessing the control of diabetes.

The core of the issue lies in several biological distortions that are particularly prevalent in the Indian population. For instance, research highlights that HbA1c levels naturally rise by approximately 0.08 percent for every decade of life, even in non-diabetic individuals.

This means that a 70-year-old with a Hb1AC reading of 6.6 percent might be perfectly healthy for their age, However, such persons would be labeled as diabetic and potentially placed on unnecessary medication

Furthermore, the high prevalence of iron deficiency anemia in India falsely inflates HbA1c readings because red blood cells live longer in anemic patients, giving them more time to collect sugar.

In a message to the general public and patients, noted public health speaker and top neurologist from Hyderabad, Dr Sudhir Kumar (hyderabaddoctor in X) says “Don’t discard the test, contextualise it. If you have anemia or kidney issues, your HbA1c might not tell the whole story. Don’t panic over a single number, look at the trend. HbA1C remains reliable to track blood sugar over the last 3 months but it is not absolute truth. It is a proxy”.

Important points:

• Traditional fasting blood sugar test is gold standard to diagnose diabetes
• Hb1Ac test should be used only to understand sugar levels in the last 90 days
• Fasting glucose above 12: Person is diabetic
• Fasting glucose between 110 and 125: Per is prediabetic
• Hb1Ac wrongly tags senior citizens as diabetics/prediabetics
• Hb1Ac naturally increases by 0.08 percent every decade as persons age
• Anemic women might show HbA1c of 6.5 although their actual blood sugar is normal, leading to misdiagnosis
• Hb1Ac should not be used to diagnose diabetes