Pancreatic Iron and Bone Health in Thalassemia Major

Background. It has been shown that serum ferritin and heart iron content are good indicators of bone mineral density (BMD) in patients with beta thalassemia major (TM). In the present study we explored for the first time the relationship between pancreatic iron and BMD and bone markers in TM.

Methods. We considered 135 TM patients (68 M, mean age 37.79±7.74 years) enrolled in the MIOT (Myocardial Iron Overload in Thalassemia) Network. BMDs of the lumbar vertebrae (L1-L4) and femoral neck were measured by dual X-ray absorptiometry (DEXA) and were expressed as T-scores. Pancreatic iron overload was quantified by the T2* Magnetic Resonance Imaging (MRI) technique. Blood samples were collected for the measurement of bone formation markers (procollagen 1 amino-terminal propeptide-P1NP, osteocalcin and bone-specific-BAP alkaline phosphatise), bone resorption marker (carboxy-terminal telopeptide of type I collagen-CTX), calcium, and vitamin D.

Results. Pancreatic T2* values were significantly associated to lumbar T-scores (R=0.207, P=0.017) as well as to femoral T-scores (R=0.242, P=0.005). The correlations remained significant also in patients without diabetes. Pancreatic iron (global pancreas T2*<26 ms) was detected in 8 patients. Patients with pancreatic iron showed significant lower lumbar T-scores (-2.61±0.89 vs -1.60±0.89; P=0.031) as well as femoral T-scores (-2.12±1.17 vs -1.03±0.97; P=0.009) and 7 of them (87.6%) had lumbar and femoral T-scores indicating osteopathy (osteopenia or osteoporosis).

As regards as the markers, pancreatic T2* values were negatively correlated to BAP (R=-0.196 P=0.031) and positively correlated to vitamin D (R=0.220, P=0.014).

Conclusion. A significant correlation, although not strong, was detected between pancreatic iron overload and bone disease. From a different point of view, our results support the role of endocrinopathies in thalassemic osteopathy and underline the critical role of a multi-disciplinary intervention in preventing bone complications.