021 - Type 1 diabetes mellitus
Autor(s): A. Morandi, G. Contreas, A. Sabbion, S. Costantini, R. Mella, L. Pinelli
Issue: RIMeL - IJLaM, Vol. 3, N. 1, 2007 (MAF Servizi srl ed.)
Page(s): 21-27
The preclinical phase of Type 1 Diabetes Mellitus (T1DM) is described and the tests for the identification of genetic, immunological and metabolic risk factors are highlighted with emphasis on their use in diagnosis. T1DM diagnosis is related to symptoms, fasting glycemia ≥126 mg/dL and OGTT after 2 hours ≥200 mg/dL. The differential diagnosis of type 2 diabetes, which is increasing in frequency among children, is possible by taking into account well defined clinical and analytical parameters. An early diagnosis of T1DM is important in order to avoid the risk of ketoacidosis and to have a better follow-up without complications. Symptoms are clear and a diagnosis can be made in the physician’s office with fast tests. When a patient arrives at a laboratory with a suspected diabetes, the physician who prescribed the analyses needs to be available in order to be informed and to grant to the patient a quick access to a Centre of Pediatric Diabetology. The determination of glycated haemoglobin levels allows a practical glycemia monitoring. Ideal levels are < 7.5 - 8.5 % below the age of 6 years, < 8 % between 6 and 12 years and < 7 - 7.5 % above the age of 12 years. The commonest genetic variants are HbS, HbC and HbE. Among those, some might lead to over or under estimate the HbA1c levels. False elevated levels are measured in case of anemia with iron deficiency or after chronic treatment with salicylates. In case of evident and continuous discrepancy between the glycemic and HbA1c levels in a diabetic patient, the laboratory physician needs to be stimulated by the diabetologist to perform further analyses.