Secondary diabetes in children with thalassaemia major (homozygous thalassaemia).

Life expectancy of patients suffering from homozygous beta-thalassaemia has been improved due to the modern treatment of this disease. This has allowed development of late hemosiderosis-related complications and disturbances of the endocrine and exocrine functions of the pancreas. Carbohydrate metabolism of 16 patients with thalassaemia major was studied. Three of them presented with a pronounced clinical picture and biochemical constellations of a severe diabetes mellitus. The remainder had no clinical symptoms of carbohydrate metabolism disorders. The pancreatic beta-cell function of the patients was assessed by measuring the serum concentrations of immunoreactive insulin and by a glucose tolerance test. Most patients showed very low basal insulin levels while glucose tolerance was reduced in only one of them. In this patient we also established delayed insulin response after an intravenous glucose load. We concluded that the disturbed insulin secretion found in the children studied is most likely the earliest manifestation of the pancreatic beta-cell insufficiency which precedes the changes in the glucose tolerance.