HbA1c Test Limitations in Indian Diabetics

WHY IN NEWS?

A recent paper in The Lancet Regional Health – Southeast Asia suggests that the widely used HbA1c test may not reliably diagnose or monitor diabetes in Indians. Experts recommend using oral glucose tolerance tests (OGTT) and continuous glucose monitoring (CGM) for better accuracy, emphasizing the need for a comprehensive environmental impact assessment of diabetes diagnostic methods.

Why HbA1c May Be Inaccurate in India:

● Test Principle: HbA1c (glycated haemoglobin) measures the percentage of haemoglobin coated with glucose, reflecting average blood sugar over 2–3 months.

● Haemoglobin Dependence: The test’s accuracy depends on normal haemoglobin levels and red blood cell lifespan.

● Anaemia Burden: India has a high prevalence of iron-deficiency anaemia, which can distort HbA1c readings.

● Genetic Disorders: Conditions like thalassaemia, sickle cell disease, and G6PD deficiency affect red blood cells and alter results.

● Infectious Diseases: Malaria and other illnesses impacting haemoglobin further reduce test reliability in Indian populations.

Study Findings And Expert Recommendations

● Study Variation: Research comparing HbA1c and OGTT found significant diagnostic differences in identifying prediabetes, highlighting the importance of a precautionary principle in diabetes management.

● South India Data: One study found OGTT detected 87.8% prediabetes cases compared to 45.4% by HbA1c.

● Pune Study: Another study showed HbA1c identified higher prediabetes prevalence than OGTT, highlighting inconsistency.

● Alternative Tests: Experts suggest using Oral Glucose Tolerance Test (OGTT) for diagnosis, considering it as part of a broader environmental impact assessment of diabetes testing methods.

● Continuous Monitoring: Regular self-monitoring or Continuous Glucose Monitoring (CGM) provides dynamic glucose patterns without sole reliance on HbA1c, contributing to a more pollution-free environment in diabetes care.

Understanding Diabetes Diagnosis :

● Diabetes Mellitus: A chronic metabolic disorder characterised by high blood glucose levels due to insulin deficiency or resistance.

● HbA1c Thresholds: <5.7% normal, 5.7–6.4% prediabetes, ≥6.5% diabetes.

● OGTT: Measures body’s glucose handling after consuming a glucose solution.

● CGM: Tracks glucose levels continuously through wearable sensors.

● Public Health Concern: India is often termed the “diabetes capital”, with a rapidly rising disease burden, necessitating environmental democracy in health awareness and management strategies. |