There is a reason diabetes has earned the label of a silent killer. Often, it shows no symptoms until serious complications develop.
An estimated 77 million adults live with diabetes and nearly 25 million are prediabetic, according to World Health Organisation data.
More than half unaware of their status, increasing risks of heart attacks, strokes and blindness.
India’s diabetes burden is immense. Over 10 crore people have diabetes and another 13.6 crore are prediabetic.
HbA1c has been the global benchmark for diabetes diagnosis. But experts now warn it may fail many South Asian patients. It has prompted calls to rethink its central role in India.
A recent viewpoint in The Lancet Regional Health argues that HbA1c, long considered the “gold standard,” can mislead in populations with high rates of iron-deficiency anaemia, haemoglobinopathies, and G6PD deficiency —conditions common across India and the region.
Researchers note these biological factors change red blood cell lifespan and structure, undermining the assumptions behind HbA1c. This raises concerns about delayed diagnoses, misclassification, and flawed public health data.
What is HbA1c?
For the uninitiated, HbA1c estimates average blood glucose over three months by measuring glucose bound to haemoglobin.
Normally, red blood cells live around 120 days, providing a reliable gauge. But nutritional deficiencies or inherited blood disorders can shorten or prolong red cell life. This reportedly produces falsely low or high readings.
Experts caution that relying solely on HbA1c is clinically risky.
The scale of the problem is vast. Iron-deficiency anaemia remains widespread, particularly among women and children.
It can distort HbA1c, sometimes producing elevated values that do not reflect true glucose control. It may lead to unnecessary or aggressive treatment while leaving anaemia untreated.
Inherited haemoglobin disorders, such as thalassaemia and sickle cell traits, further complicate testing.
Reports claim that many laboratory analysers are calibrated for normal haemoglobin and may misread altered forms.
G6PD deficiency, common in some Indian communities, can cause premature red blood cell breakdown. The review warns that in men with undiagnosed G6PD deficiency, HbA1c alone may delay diabetes diagnosis by up to four years, increasing the risk of heart, kidney, and eye complications.
Even well-equipped urban hospitals are not immune to these limitations. Experts believe red blood cell variations and haemoglobin disorders can affect readings, with rural and tribal areas likely experiencing even greater discrepancies.
India relies on a single biomarker as a “one-size-fits-all” approach. It fails to account for the country’s biological and socio-economic diversity.
Distorted data
Errors in HbA1c readings can reportedly distort national diabetes data, affecting more than individual patients.
Surveys and screening programmes that rely on it risk misrepresenting prevalence, which can misguide policies and divert resources. Failing to account for blood disorders and anaemia may leave significant health issues unaddressed.
The review advocates a comprehensive diagnostic strategy. Combining HbA1c with oral glucose tolerance tests (OGTT), routine self-monitoring of blood glucose, and standard blood assessments gives a more accurate picture of diabetes risk.
A tiered, context-aware approach is recommended. In low-resource areas, priority should go to OGTT, affordable self-monitoring, and basic anaemia screening.
In urban and tertiary centres, HbA1c can be paired with continuous glucose monitoring, while fructosamine testing provides a reliable alternative for short-term glucose measurement independent of red blood cell variations.
Experts emphasise that these strategies improve diagnostic accuracy, reduce misclassification, and better align care with India’s biological and public health realities.
They urge clinicians, policymakers, and researchers to ensure convenience never compromises patient safety or data reliability.
Also Read: Diabetes, Stress Highlight Health Challenge In Latest India Wellness Index Report https://www.vibesofindia.com/diabetes-stress-highlight-health-challenge-in-latest-india-wellness-index-report/
