Emergence of type 2 diabetes in an hospital based cohort of children with diabetes mellitus

Objectives: Increasing awareness of the heterogeneity of diabetes mellitus (DM) at presentation is changing our approach to this disease. We used the 1999 American Diabetes Association (ADA) criteria to determine the distribution of DM patterns in a large pediatric cohort with the aim of documenting the emergence of type 2 diabetes mellitus. Material and methods: Charts of diabetic children aged 1 to 16 years and admitted to our center between 1993 and 1998 were reviewed for data needed to achieve classification of the type of diabetes mellitus. Results: Of the 382 study patients, 327 (85.6%) had autoimmune type 1 DM (clinical insulin-treated type 1 DM with immunologic and/or genetic evidence of autoimmunity) and 6 (1.6%) had idiopathic type 1 DM (clinical insulin-treated type 1 DM without evidence of autoimmunity). Four (1.0%) patients met all the criteria for type 2 DM; all were obese and three had acanthosis nigricans; in one the diagnosis was changed from type 1 to type 2 DM during follow-up. Four patients could be classified as lean patients with type 2 DM. In keeping with recent reports of a rise in the incidence of type 2 DM,6 of these type 2 cases were diagnosed in the last year of the study. Conclusion: The ADA classification helps to understand the pathophysiology of pediatric DM, thus providing useful therapeutic guidance. At presentation, most cases of pediatric DM are type 1, but we show here that type 2 DM becomes now a diagnosis to consider although in children. Our study, from a one large study center is not an epidemiological one but is consistent with population studies. Systematic or targeted screening for type 2 in children should be discussed.