Serum ferritin levels and endocrinopathy in medically treated patients with β thalassemia major

Abstract

The association between iron overload indices and pathology of the heart and liver in transfusion-dependent patients with β thalassemia major (TM) has been extensively studied. Nonetheless, data on endocrine disease remains limited. This was a cross-sectional study of 382 TM patients treated with regular transfusions and desferrioxamine at the Thalassemia Center in Dubai, UAE. Retrieved data included demographics, splenectomy status, steady-state serum ferritin levels, and the presence of endocrinopathies (diabetes mellitus, hypothyroidism, hypoparathyroidism, and hypogonadism). Multivariate logistic regression analyses were used to determine which variables were independently associated with the occurrence of each endocrinopathy. The mean age of patients was 15.4 ± 7.6years, with an equal sex distribution. The mean serum ferritin level was 2597.2 ± 1976.8μg/l. The frequencies of specific endocrinopathies were diabetes mellitus (10.5%), hypothyroidism (6.3%), hypoparathyroidism (10.5%), and hypogonadism (25.9%). On multivariate logistic regression analysis, patients with a serum ferritin level >2,500μg/l, but not >1,000-2,500μg/l, were 3.53 times (95% CI 1.09-11.40) more likely to have diabetes mellitus, 3.25 times (95% CI 1.07-10.90) more likely to have hypothyroidism, 3.27 times (95% CI 1.27-8.39) more likely to have hypoparathyroidism, and 2.75 times (95% CI 1.38-5.49) more likely to have hypogonadism compared to patients with a serum ferritin level ≤1,000μg/l. However, splenectomized patients with serum ferritin levels ≤2,500μg/l had comparably high rates of all endocrinopathies as patients with serum ferritin levels >2,500μg/l. Endocrinopathy is common in TM patients treated with desferrioxamine therapy, especially in patients with serum ferritin levels >2,500μg/l or those splenectomized.