The Utility of HbA1c and Fructosamine in Evaluating the Glucose Tolerance in Adult Patients with Transfusion-Dependent Beta-Thalassemia

Q: Why is HbA1c considered unreliable in transfusion-dependent beta-thalassemia (TDT)?

TDT alters red blood cell dynamics through factors like haemolysis and ineffective erythropoiesis, which can distort HbA1c’s reflection of average glycaemia.

Q: How was glucose tolerance assessed in the study?

Glucose tolerance was evaluated using fasting plasma glucose and a 2-hour oral glucose tolerance test (2Hr-OGTT), both treated as gold standards.

Q: What did the study find about HbA1c and fructosamine for diagnosing glucose intolerance?

HbA1c showed higher sensitivity but low specificity, while fructosamine had lower sensitivity and higher specificity; overall, diagnostic reliability of both markers remained limited compared with fasting glucose and 2Hr-OGTT.

Sep 29, 2026

Uploaded by MrHarris58

Transfusion-dependent beta-thalassemia (TDT) promotes iron overload and contributes to glucose intolerance via insulin resistance and pancreatic beta-cell dysfunction, making HbA1c reliability in this setting uncertain. Fructosamine, which reflects short-term glycaemia, is evaluated as an alternative marker. In a cross-sectional study of 61 adult TDT patients, glucose tolerance was assessed using fasting plasma glucose and 2-hour oral glucose tolerance testing as gold standards, with diagnostic performance and correlations analyzed.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages8

Reading Time20 min

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Abstract

Introduction

Methods

Results

Conclusion

Introduction

Background on beta-thalassemia and glucose intolerance

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| Diabetes/Lipids/Obesity | | --- | | Original Article | The Utility of HbA1c and Fructosamine in Evaluating the Glucose Tolerance in Adult Patients with Transfusion‑Dependent Beta‑Thalassemia Durairaj Arjunan1, Jayaditya Ghosh2, Vaishali Kaur2, Arshiya Dutta3, Pinaki Dutta2 ¹Department of Endocrinology, KMCH Institute of Health Sciences and Research, Coimbatore, 2Department of Endocrinology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 3Intern, Atal University, Himachal Pradesh, India Abstract Introduction: Transfusion‑dependent beta‑thalassemia (TDT) leads to iron overload, contributing to glucose intolerance through insulin resistance and pancreatic beta‑cell dysfunction. The reliability of HbA1c in diagnosing diabetes mellitus in TDT is questionable due to altered red blood cell dynamics. Fructosamine, reflecting short‑term glycaemia, offers a potential alternative. This study assesses the utility of HbA1c and fructosamine in evaluating glucose tolerance in adult TDT patients. Methods: In this cross‑sectional study, 61 adult TDT patients were recruited from a tertiary care centre in North India. Glucose tolerance was assessed using fasting plasma glucose (FPG) and a 2‑hour oral glucose tolerance test (2Hr‑OGTT) as gold standards. HbA1c and serum fructosamine levels were measured. Sensitivity, specificity, and diagnostic accuracy of these two tests and their correlation with FPG and 2Hr‑OGTT were analysed. Results: Among the 61 patients of TDT (median age: 27 years), 63.9% had normal glucose tolerance (NGT), while 36.1% exhibited glucose intolerance (24.6% prediabetes, 11.5% diabetes) . HbA1c and fructosamine were significantly elevated in glucose‑intolerant patients compared to those with NGT. HbA1c significantly correlated with FPG (rho = 0.42, P < 0.001) and 2Hr‑OGTT (rho = 0.319, P = 0.012), whereas fructosamine did not show any correlation with either FPG or 2Hr‑OGTT. Using standard cut‑offs, HbA1c demonstrated higher sensitivity (86%) but lower specificity (31%) compared to fructosamine (46% sensitivity, 74% specificity) . Conclusion: While both markers were elevated in glucose‑intolerant TDT patients, their diagnostic reliability remains limited. FPG and 2Hr‑OGTT remain the gold standard for diagnosing glucose intolerance in TDT. Keywords: Fructosamine, Glucose intolerance, HbA1c, Transfusion‑dependent beta‑thalassemia IntroductIon Beta‑thalassemia is a genetic disease where the production of the beta‑globin chain of haemoglobin is either reduced or absent, leading to ineffective erythropoiesis and resulting in haemolytic anaemia. [1] Beta‑thalassemia is the second most common hemoglobinopathy after sickle cell disease. [1] This condition typically manifests in patients between the ages of 6 and 12 months, making the individual dependent on blood transfusions for life (transfusion‑dependent thalassemia (TDT)) . [2] As a result, excess iron accumulatesin various organs, including beta‑cells of the pancreas, leading to impaired glucose tolerance. Despite patients being treated with iron‑chelating agents, many still experience iron overload. Supplementary material available online: [https://journals.lww.com/indjem/](https://journals.lww.com/indjem/) | Access this article online | | | --- | --- | | Quick Response Code:
| Website:
[https://journals.lww.com/indjem/](https://journals.lww.com/indjem/) | | | DOI:
10.4103/ijem.ijem_265_25 | Studies show that the prevalence of impaired fasting glucose, impaired glucose tolerance, and diabetes mellitus in TDT is 17. 21%, 12.46%, and 6. 54%, respectively. [3] The development of glucose intolerance in thalassemia is attributed to both insulin resistance and the toxic effects of iron on pancreatic beta‑cells, leading to secretory dysfunction. [4] Address for Correspondence: Prof. Pinaki Dutta, Department of Endocrinology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh-160 012, Ind

FAQs

Why is HbA1c considered unreliable in transfusion-dependent beta-thalassemia (TDT)?

TDT alters red blood cell dynamics through factors like haemolysis and ineffective erythropoiesis, which can distort HbA1c’s reflection of average glycaemia.

How was glucose tolerance assessed in the study?

Glucose tolerance was evaluated using fasting plasma glucose and a 2-hour oral glucose tolerance test (2Hr-OGTT), both treated as gold standards.

What did the study find about HbA1c and fructosamine for diagnosing glucose intolerance?

HbA1c showed higher sensitivity but low specificity, while fructosamine had lower sensitivity and higher specificity; overall, diagnostic reliability of both markers remained limited compared with fasting glucose and 2Hr-OGTT.

Sep 29, 2026

Uploaded by MrHarris58