Introduction: Endocrine complications observed in patients with thalassemia major (TM) are mainly secondary to martial overload. Hypoparathyroidism (HPT) is a late and rare complication, typical of the 2nd decade of life in transfusion-dependent thalassemia patients (TDT). It is usually associated with other iron overload conditions (diabetes, hypogonadism, heart failure, etc.). The incidence of PTH varies from 1.2% to 20% depending on the center. Men are more frequently affected than women (male/female ratio = 1.35).
Patients and methods: Prospective descriptive study conducted at the endocrinology department of the CHU of Constantine over two years concerning polytransfused BTM patients. All our patients underwent a clinical examination, a hormonal assessment (somatotropic, gonadotropic and thyrotropic function) and a haematological evaluation. A phosphocalcic assessment was performed by measuring corrected serum calcium, phosphorus and PTH levels as well as vitamin D.
Results: A total of sixty-four patients were enrolled in the present study; hypoparathyroidism was found in 12 patients (18.75%), the mean age was 21.66 years, male predominance was not present in our series as we have more affected women than men (8 women and 4 men), the male to female ratio was 4:8. The most common endocrinopathy associated with hypoparathyroidism was hypogonadotrophic hypogonadism, followed by growth retardation in our patients.
Discussion:PTH is the consequence of iron deposition in the parathyroid glands and resulting tissue fibrosis or suppression of parathyroid secretion induced by bone reabsorption resulting from increased haematopoiesis secondary to chronic anaemia. PTH is asymptomatic in most beta thalassaemics, but may be diagnosed on the occasion of symptomatic hypocalcaemia contrasting with normal or low PTH levels, sometimes with a relatively severe clinical picture involving tetany and convulsions. Recently, brain CT abnormalities (calcifications) have been reported in TM patients in relation to hypoparathyroidism. The high frequency of PTH in our patients may be partly related to poor compliance with chelation therapy in line with what has been reported in the literature. Vitamin-calcium treatment was started in all our patients with hypoparathyroidism.
Conclusion: Iron overload remains a real problem, even in countries where iron chelation therapy is widely available and properly monitored. Early detection of endocrine complications is mandatory to improve morbidity and quality of life of these patients. Since asymptomatic hypocalcaemia is common in these TM patients, it is wise to recall the importance of checking the phospho-calcium balance from the second decade of life in TM patients.
15 Sep 2022 - 17 Sep 2022