Evaluation and management of diabetes in patients with thalassaemia major

Thalassaemia major is an inherited haemoglobinopathy and the commonest genetic disease in Sri Lanka. Around 3500 patients have been identified up to date and Sri Lanka is considered a country with intermediate prevalence of thalassaemia. This disease is characterised by chronic anaemia and iron overload due to transfusion therapy and gastrointestinal absorption. Excessive iron overload and suboptimal chelation result in deposition of iron in various tissues primarily heart and liver and frequently involves endocrine glands. Chronic hypoxia due to anaemia, viral infections and individual susceptibility are other factors which could potentiate the toxicity of iron deposition and contribute to endocrine dysfunction. Detecting the exact prevalence of endocrinopathies in patients with thalassaemia is challenging due to variability in the study population. This partly relates to ages of patients being studied and the adequacy of chelation therapy. Available data show the leading endocrine complications among patients with thalassaemia are delayed puberty or hypogonadism and growth retardation followed by diabetes mellitus, hypothyroidism, hypoparathyroidism, osteoporosis and adrenal insufficiency.