Correlation of Pancreatic Iron Overload Measured by T2*-Weighted Magnetic Resonance Imaging in Diabetic Patients with β-Thalassemia Major

Abstract

Diabetes mellitus (DM) is one of the potential complications in patients with transfusion-dependent β-thalassemia major (β-TM). In this case-controlled study, we examined the pancreatic iron levels in outpatients with β-TM. In this study, cases of patients with β-TM and DM were gender- and age-matched with control subjects, who were non-diabetic and had normal blood glucose on standard oral glucose tolerance (OGTT) tests. One of four diagnoses [normal, pre-diabetes, impaired glucose tolerance (IGT), DM] was made according to the American Diabetes Association (ADA) criteria. The T2*-weighted magnetic resonance imaging (T2*-weighted MRI) of the heart, liver, and pancreas was performed using a 1.5 Tesla scanner. The study enrolled 26 diabetic cases, 17 non-diabetic cases, and eight cases of IGT or pre-diabetes cases. The severity of pancreatic and cardiac iron siderosis was significantly different between the groups. We found a statistically significant difference at 5.6 ms in the T2*-weighted MRI values for the pancreas between patients with normal vs. abnormal glucose metabolism [p < 0.009; odds ratio (OR): 11.2; 95% confidence interval (95% CI): 1.32-94.4)]. The receiver operating characteristic (ROC) curve for the 5.6 ms cutoff led to an area under the curve (AUC) of 0.69 (95% CI: 55.0-84.0; p < 0.02), with sensitivity and specificity of 94.0 and 42.0%, respectively. There was a moderate positive correlation between pancreatic and cardiac T2*-weighted MRI (r = 0.4; p < 0.001), and a weak correlation between the pancreas and the liver (r = 0.38; p < 0.005). To conclude, we have introduced a cutoff of 5.6 ms on T2*-weighted MRI of the pancreas for prediction of abnormal glucose metabolism in β-TM patients.

Keywords:

• β-Thalassemia major (β-TM)
• diabetes mellitus (DM)
• iron overload
• pancreas
• T2*-weighted magnetic resonance imaging (T2*-weighted MRI)

Acknowledgments

The authors sincerely thank the patients for their cooperation. Neda Gholizadeh, Ph.D. in medical radiation engineering, is an employee of Noor Medical Imaging Center, Tehran, Iran; however, she reported the results and edited the materials and methods part of the study and received no financial gain from participating in this research.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Funding

This study was the result of a pediatrics specialty degree thesis. We appreciate the deputy of research of Mazandaran University of Medical Sciences, Sari, Iran, and also the Ethics Committee for accepting the proposal.