Elevated serum parathormone levels are associated with myocardial iron overload in patients with beta-thalassaemia major.

摘要

OBJECTIVES: Despite advances in conventional treatment, iron-induced cardiomyopathy is still the most frequent cause of death among patients with beta-thalassaemia major. Recent studies have correlated increased myocardial iron content to decreased levels of vitamin D in thalassaemic patients. The aim of this study was to measure parathormone (PTH) and metabolites of vitamin D and consequently to investigate whether these parameters predispose to myocardial iron overload in patients with beta-thalassaemia major. METHODS: In 62 patients (29 M and 33 F, mean age: 22.79 +/- 6.18 yr) with beta-thalassaemia major levels of intact parathormone (iPTH) and vitamin D metabolites [25(OmicronH)D(3) and 1,25(OmicronH)(2)D(3)] were measured in serum. Additionally, estimation of myocardial iron content was performed by magnetic resonance imaging, whereas mean serum ferritin concentrations were calculated for 1 yr prior to the study. RESULTS: Results showed markedly decreased levels of serum 25(OH)D(3) in 37 patients (60%), whereas 7 patients (11%) had borderline 25(OH)D(3) levels (between 50 and 75 nmol/L). Serum iPTH levels were significantly higher in patients having increased myocardial iron compared to those having normal myocardial iron (44.04 +/- 22.09 pg/mL vs. 31.39 +/- 14.30 pg/mL, P = 0.017). Multivariant regression analysis identified PTH levels as the major predictor of increased myocardial iron.