Biochemical markers of glucose metabolism may be used to estimate the degree and progression of iron overload in the liver and pancreas of patients with β-thalassemia major

The use of cardiac and hepatic T2* MRI measurements to predict the amount of iron accumulation in these organs has been studied extensively and was suggested to be used reliably. However, it may not be practical to screen other organs with MRI related to economical issues and also the prolonged imaging durations. Herein, we aimed to test the use of fasting glucose, fasting, and postprandial insulin, homeostasis model assessment-insulin resistance (HOMA-IR) (calculated as insulin (mu IU/ml) x glucose (mg/dl)/22.5), and homeostasis model assessment B score (HOMA-B) (calculated as insulin (mu IU/ml) x 20/glucose (mg/dl) -aEuro parts per thousand 3.5) to estimate the tissue iron measured with MRI. A total of 37 patients with beta-thalassemia major (BTM), age 20.8 +/- 6.3 years (7.1-36.8), were enrolled. MRI measurements were done concomitantly to the biochemical tests for glucose metabolism. A positive correlation between HOMA-IR and hepatic iron loading and a negative correlation between pancreatic T2* and fasting blood glucose were found. A positive correlation was found between fasting insulin levels and pancreatic R2* measures. Additionally, a correlation was detected between cardiac and pancreatic iron accumulations. In centers where T2*/R2* MRI facilities are unavailable, fasting insulin, fasting glucose, and HOMA-IR measurements may be used to predict iron overload and may urge the physician for MRI assessment in case of a deterioration in these biochemical tests. Since hepatic iron loading correlated with insulin resistance development, the insulin resistance among patients with BTM may partially be explained with decreased hepatic insulin clearance from heavily iron-loaded liver.