HbA1c alone might not reliably indicate India's diabetes prevalence

HbA 1c alone might not reliably indicate India's diabetes prevalenceWe read with concern the paper by T V Sekher and colleagues (September, 2025). 1 The authors themselves concede, albeit briefly, that HbA 1c -only diagnosis is flawed.Multiple factors-anaemia, recent transfusion, pregnancy, advanced age, haemoglobinopathies, haemolytic anaemia, and chronic kidney or liver disease-systematically distort HbA 1c , leading to marked underestimation of prevalence. 2 In South Asia, one important factor for proper interpretation of HbA 1c -anaemia-is endemic: pooled analyses show a prevalence of 45%, rising to 48% in females, older adults (aged 50 years), and those with type 2 diabetes. 3Ignoring such a pervasive confounder makes HbA 1c interpretation unsound.Accurate prevalence assessment requires, at minimum, haemoglobin measurement; ideally iron and ferritin concentrations. 4 recent UK study 5 reinforces our concerns, showing that undiagnosed G6PD deficiency-common in South Asians-produces falsely low HbA 1c values and delays type 2 diabetes diagnosis by more than 4 years.Affected individuals face higher microvascular risks despite similar glucose levels. Te authors highlight major health inequities and question the global reliability of HbA 1c -based diagnosis.This new evidence further undermines the validity of HbA 1c -only prevalence estimates in South Asians.Basing national prevalence estimates on HbA 1c alone is not just methodologically weak-it risks generating misleading data that could derail policy and resource allocation.By failing to adjust for confounding conditions so prevalent in the Indian population, the study's conclusions are rendered questionable, and their potential to guide public health action is severely compromised.Diabetes prevalence in India cannot be validly inferred from HbA 1c alone.