Lancet study flags flaws in HbA1c test, says anemia distorts diabetes diagnosis in India
The problem is higher in regions with high prevalence of anemia, hemoglobinopathies and red blood cell enzyme (G6PD) deficiency, according to the study.
“Relying exclusively on HbA1c can result in misclassification of diabetes status,” said professor Anoop Misra, corresponding author and chairman of Fortis C-DOC Centre of
Excellence for Diabetes. “Some individuals may be diagnosed later than appropriate, while others could be misdiagnosed, which may affect timely diagnosis and management. Similarly, monitoring of blood sugar status may be compromised.”
The review is based on extensive data and questions the reliance on HbA1c as a sole diagnostic or monitoring tool for type-2 diabetes in South Asia.
HbA1c measurements primarily reflect the glycation of hemoglobin.
“Any condition that affects the quantity, structure or lifespan of hemoglobin—such as anemia, hemoglobinopathies, or other red blood cell disorders—can distort HbA1c values and lead to misleading estimates of average blood glucose,” it said.Shashank Joshi, co-author from Joshi Clinic, Mumbai, said, “Even in well-resourced urban hospitals, HbA1c readings can be influenced by red blood cell variations and inherited hemoglobin disorders. In rural and tribal areas, where anemia and red cell abnormalities are common, the discrepancies may be greater.”
According to the Lancet, in some regions of India–more than 50% of the population in some regions, as per data from 2025–people are nutritionally challenged with widespread iron deficiency anemia, which can distort HbA1c readings.
“This would affect both diagnosis and monitoring, thus misleading clinicians,” said the study, adding that reliance on HbA1c alone could delay diagnosis by up to four years in men with undetected G6PD deficiency, potentially increasing risk of complications.
It also said that inconsistent quality control across laboratories can further affect HbA1c accuracy, making correct diagnosis challenging.
“Public health surveys based solely on HbA1c may misrepresent India’s diabetes burden,” said the Lancet study.
The authors have outlined a resource-adapted framework for India. According to them, in low-resource settings, oral glucose tolerance test (2 glucose values, one fasting and another two hours after ingesting 75 gm of glucose) is recommended for diagnosis, and for self-monitoring of blood glucose (SMBG, using glucose metres) two-three times weekly combined with basic hematologic screening (hemoglobin, blood smear) is recommended, they said in the report.
In tertiary care settings, the study suggests combination of HbA1C (done with standard equipment) with OGTT for diagnosis, while for monitoring, it recommends continuous glucose monitoring (CGM) with alternative markers like fructosamine.
First Appeared on
Source link
