New Delhi, Feb. 10 -- India's over-reliance on glycated haemoglobin (HbA1c) test alone for diagnosing and monitoring type-2 diabetes could result in underdiagnosis, delayed treatment and avoidable complications for millions, according to a new study published in The Lancet Regional Health-Southeast Asia on Monday. The study - titled "The limitations and fallacies of relying on glycosylated haemoglobin for diagnosing and monitoring diabetes in Indian populations" - reveals significantly distorted HbA1c readings in populations with high prevalence of anaemia, inherited haemoglobin disorders and glucose-6-phosphate dehydrogenase (G6PD) deficiency. The HbA1c test measures average blood sugar levels over the past 2-3 months by checking the percentage of haemoglobin coated with glucose. A normal range is below 5.7% while a reading of 6.5% or more suggests diabetes. "Relying exclusively on HbA1c can result in misclassification of diabetes status," Professor Anoop Misra, corresponding author of the study and chairman of the Fortis C-DOC Centre of Excellence for Diabetes, Metabolic Diseases and Endocrinology, New Delhi, said. "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 study notes that iron deficiency anaemia - endemic in India, affecting over half of total adults in some regions - can falsely elevate HbA1c levels, while conditions such as haemoglobinopathies and G6PD deficiency may artificially lower them, masking true hyperglycaemia. India also has one of the world's highest burdens of sickle cell disease and G6PD deficiency, particularly among tribal population, the authors note in the study. The study cautions that national diabetes prevalence estimates based primarily on HbA1c may be misleading, potentially leading to over- or under-allocation of health resources. htc...