c-peptide and Thalassemia

Topics: Adolescent; Adult; Biomarkers; Blood Glucose; C-Peptide; Child; Diabetes Complications; Diabetes Mellitus; Dietary Supplements; Female; Glucose Tolerance Test; Homeostasis; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Iron Chelating Agents; Male; Metformin; Middle Aged; Pilot Projects; Thalassemia; Young Adult; Zinc; Zinc Sulfate

An increased incidence of diabetes mellitus and glucose intolerance has been reported in thalassaemia major treated with a high transfusion programme (HTP). To investigate beta-cell function, serum immunoreactive insulin (IRI), C-peptide (CP) and glucose were measured fasting and at 3, 6 and 10 min after i.v. administration of 1 mg glucagon in 20 thalassaemia patients treated by many transfusions and in nine healthy control subjects. Fasting C-peptide concentrations (mean +/- SEM) were higher in the thalassaemic group (2.15 +/- 0.17 ng/ml) than in the controls (1.41 +/- 0.13 ng/ml). After stimulation with glucagon, C-peptide concentrations were consistently higher (P less than 0.01) by approximately 50% in the thalassaemic than in the control group (5.29 +/- 0.31 vs 3.36 +/- 0.21 ng/ml, at 3 min; 5.22 +/- 0.30 vs 3.53 +/- 0.21 ng/ml at 6 min and 4.69 +/- 0.27 vs 3.30 +/- 0.17 ng/ml after 10 min). Plasma IRI concentrations increased in both groups after glucagon stimulation but were not significantly different. The glucose values were approximately 15% higher at each sampling time in the thalassaemic group than those of the normal subjects. It is concluded that disturbances in carbohydrate metabolism in thalassaemia major treated with HTP are the consequence of hepatic cirrhosis which accompanies secondary haemosiderosis, and possibly iron deposition in the beta-cells of the pancreas.

Topics: Adolescent; Adult; Blood Glucose; Blood Transfusion; C-Peptide; Female; Glucagon; Humans; Insulin; Islets of Langerhans; Male; Thalassemia

In order to investigate the pancreatic function in patients with thalassaemia major, plasma glucose and immunoreactive C-peptide levels were determined in 9 diabetic thalassaemic patients and in 7 controls after arginine infusion. Mean basal and peak values and C-peptide areas in thalassaemic patients did not differ significantly from those of the controls. However, in the thalassaemic group there was a greater variation in values, since pancreatic beta-cell function was found either normal, reduced or increased. These findings could suggest that different factors may lead to diabetes which complicates thalassaemia, i.e. insulin-resistance, probably due to liver damage subsequent to iron deposition and infectious hepatitis, and insulinopenia, probably due to beta-cell lesion following iron storage in the pancreas.

Topics: Adolescent; Adult; Blood Glucose; C-Peptide; Child; Diabetes Mellitus, Type 1; Female; Humans; Islets of Langerhans; Male; Peptides; Radioimmunoassay; Thalassemia