Abstract

1. Diagnosis of Glycemic Abnormalities In Thalassemic Adolescents Continuous versus glucose tolerance and insulin-glucose parameters Soliman AT, Elawwa A, Yassin M.Department of Pediatrics & Endocrinology, Hamad Medical Center, P O Box 3050, Doha, Qatar. ATSOLIMAN@yahoo.com Table 2 Correlations between ferritin and glycemic date in patients with BTM Abstract We assessed OGT and 72 h CGM and calculated HOMA and the QUICKI indices in 16 adolescents with BTM. Using OGTT, 4 cases (25%) had impaired fasting blood glucose (BG) (> 5.6 mmol/L) and two had impaired glucose tolerance (IGT) (BG > 7.8 and < 11.1 mmol/L). Monitoring the maximum (postprandial) BG using CGM system diagnosed 4 adolescents with diabetes (25%) (BG > 11.1 mmol/L) and 9 with IGT (56%). CGM is superior to OGTT for the diagnosis of glycemic abnormalities in adolescents with BTM. F = fasting, BG = blood glucose – OGT= Oral glucose test , CGM = continuous glucose monitoring, * p < 0.05 Fig: Correlation between serum ferritin level and the average BG concentrations Patients and Methods We studied 16 randomly selected thalassemic adolescents. All patients were investigated using a standard 75 gm oral glucose tolerance test (OGTT) and 72-h continuous glucose concentration by CGM system (Medtronic system). Fasting serum insulin and C-peptide concentrations were also measured. HOMA-B, HOMA-IR were calculated . Results Table 1: Glycemic abnormalities diagnosed by OGTT versus CGMS in thalassemic patients. * Only 3 out of the 16 adolescents with BTM showed insulin resistance state (HOMA and QUIKI). . Interpretation Our data suggest that CGMS is a better method for detection of glycemic abnormalities in adolescents with thalassemia than standard OGTT (31 % by OGTT, and 75% by CGMS). Preliminary data suggests that defective β-cell function rather than insulin resistance may be the cause for glycemic abnormalities. • P < 0.01 CGMS versus OGTT, • IFG = impaired fasting glucose, IGT = impaired glucose tolerance, DM = diabetes mellitus