Hypocalcemia due to hypoparathyroidism in beta-thalassemia major patients

Background: This is a retrospective analysis of case records of beta -thala ssemia major patients who developed hypoparathyroidism (HPT). The objective of this study was to assess the prevalence of hypocalcemia and hypoparathy roidism in beta -thalassemia major patients being followed at King Khalid U niversity Hospital (KKUH), Riyadh, Saudi Arabia. Patients and Methods: Diagnosis was based on low serum calcium (S/Ca), high ser-um phosphate (PO4), normal serum magnesium and alkaline phosphatase, a nd low serum parathyroid hormone levels. Other parameters analyzed included age, sex, serum ferritin levels, age of onset of HPT, any symptoms of hypo calcemia, and presence of other complications in these patients. Results: Out of 40 patients, eight (20%) were diagnosed to have HPT. The me an age at diagnosis was 13.6 years (range 11-16 years), mean serum calcium was 1.88 mmol/L (range 1.58-2.04), mean serum ferritin was 7490 mug/L (rang e 2000-23,064) and mean serum phosphate was 1.88 mmol/L (range 1.50-2.73). Serum parathyroid hormone (PTH) levels were low in most of the patients. On ly two patients (25%) had mild symptoms of hypocalcemia. Growth retardation was present in all patients, while four patients had liver dysfunction, tw o had diabetes mellitus and two had cardiac dysfunction. Conclusion: HPT due to iron overload may develop in a significant number of thalassemia major patients, especially when chelation therapy is not optim al, therefore, all thalassemics should be carefully watched for this compli cation from early in their second decade.