Hypoparathyroidism in adult patients with beta-thalassemia major

Objective: To evaluate the prevalence of hypoparathyroidism in adult transfusion-dependent patients with beta-thalassemia major in a teaching referral hospital in Oman. Methods: All adult (>13 years) patients with beta-thalassemia major seen at Royal Hospital in Oman between 2004 and 2006 were studied. Demographic, pharmaceutical, clinical and biochemical data were collected for all the subjects. Analyses were performed using both descriptive and univariate statistics. Results: A total of 31 patients were included into the study with an overall mean age of 19±3 years ranging from 14 to 30 years. Just over half of the subjects were males (n=16; 52%). All the patients were on hypertransfusion and combined chelation therapy with desferrioxamine 40-60 mg/kg 5 days per week and deferiprone 75 mg/kg/day. Three of the patients had low levels of parathyroid hormone (<1.6 pmol/l). A further three patients had normal levels of parathyroid hormone (1.6-9.3 pmol/l) in the presence of low serum calcium levels (<2.1 mmol/l). These patients (with normal hypoparathyroid hormone levels, but lower calcium levels) were also defined to have hypoparathyroidism bringing the total prevalence of hypoparathyroidism in this cohort of adult patients with Beta-thalassemia major to 19% (6 out of 31). The patients with hypoparathyroidism had statistically significantly lower levels of parathyroid hormone (2.7 versus 5.3 pmol/l; p=0.031) and serum calcium (1.7 versus 2.3 pmol/l; p=0.004) compared to those without hypoparathyroidism. Conclusion: The prevalence of hypoparathyroidism in adult beta-thalassemia major patients at this referral center was significantly higher (19%) than those reported elsewhere (2.5 and 10.7%).