Glycated albumin as a diagnostic tool for diabetes mellitus in transfusion-dependent β-thalassemia patients

β-thalassemia is an inherited hemoglobinopathy which, in severe cases, requires lifelong transfusions, leading to iron overload and increases risk of metabolic complications, including diabetes mellitus. The standard glycemic marker, glycated hemoglobin, is unreliable in transfusion-dependent patients due to altered erythrocyte turnover. This study investigates the possible utility of glycated albumin as an alternative biomarker for diagnosing glucose metabolism disorders in transfusion-dependent patients. A cross-sectional analysis was conducted on 254 transfusion-dependent patients followed at the Center for Hemoglobinopathies and Thalassemia at Ferrara Hospital, evaluating Glycated Albumin levels, fasting plasma glucose, oral glucose tolerance test results, and iron overload assessed by Magnetic Resonance Imaging. Glycated Albumin levels significantly correlated with Fasting Plasma Glucose (r = 0.710, p < 0.01), Oral Glucose Tolerance Test glucose levels at 60 and 120 min, and the area under the glycemic curve (p < 0.01). ROC curve analysis identified a Glycated Albumin cutoff of 14.95% for Diabetes Mellitus diagnosis, with a sensitivity of 93.1% and specificity of 89.1%. Glycated Albumin correlated with hepatic and heart iron accumulation but not with pancreatic iron overload. These findings indicate Glycated Albumin as a promising marker for glycemic assessment in transfusion-dependent patients, warranting further validation in multicenter studies.