ESPE Abstracts (2015) 84 P-1-32

Aetiological Diagnosis of Diabetes in Italian Diabetic Children and Adolescents

Maurizio Delvecchioa, Giuseppina Salzanob, Enza Mozzilloc, Giulio Frontinod, Ippolita Patrizia Paterae, Sonia Tonif, Ivana Rabboneg, Valentino Cherubinih, Stefano Tuminii, Giuseppe D’Annunzioj, Lorenzo Iughettik, Giulio Maltonil, Vittoria Cauvinm, Marco Mariglianon & Fabrizio Barbettio,p

aPediatric Section, Department of Biomedical Sciences and Human Oncology, AOU Consorziale Policlinico Giovanni XXIII, Bari, Italy; bDepartment of Pediatrics, University of Messina, Messina, Italy; cPediatric Section, Department of Translational Medical Sciences, Federico II University, Naples, Italy; dDepartment of Pediatrics, San Raffaele Diabetes Research Institute, Milan, Italy; eEndocrinology and Diabetology Unit, Bambino Gesù Children’s Hospital, Rome, Italy; fTuscany Regional Centre of Pediatric Diabetes, Meyer Children’s Hospital, Florence, Italy; gDepartment of Pediatrics, University of Turin, Turin, Italy; hMaternal-Infantile Department, Division of Pediatric Diabetes in Children and Adolescents, Salesi Hospital, Ancona, Italy; iDepartment of Pediatrics, University of Chieti, Chieti, Italy; jPediatric Clinic, Giannina Gaslini Institute, Genoa, Italy; kDepartment of Medical and Surgical Sciences for Mothers, Children and Adults, Pediatric Unit, University of Modena & Reggio Emilia, Modena, Italy; lPediatric Department, University of Bologna, Sant’Orsola-Malpighi Hospital, Bologna, Italy; mDepartment of Pediatrics, S. Chiara Hospital, Trento, Italy; nRegional Center for Pediatric Diabetes, Clinical Nutrition and Obesity, Department of Life and Reproduction Sciences, University of Verona, Verona, Italy; oDepartment of Experimental Medicine and Surgery, University of Tor Vergata, Rome, Italy; pBambino Gesù Children’s Hospital, Rome, Italy

Background: Type 1 diabetes (T1D) is the most frequent etiology in Italian diabetic children and adolescents. Data on type 2 (T2D) and monogenic diabetes (MD) prevalence are scanty.

Objective and hypotheses: To estimate the prevalence of T1D, T2D, secondary diabetes, and MD in a pediatric population of Italian diabetic patients.

Method: Data on 3,076 patients (diabetes onset January 2007–December 2012, age at diagnosis <18 years) were collected from 13 Italian Tertiary Centers. Genetic testing was performed when required. Diabetes was categorized as T1D, T2D, MD or as syndromes associated with diabetes (if confirmed by genetic testing), and secondary diabetes (i.e. cystic fibrosis).

Results: 2813 patients (51.8% males) were diagnosed with T1D (91.4%), 35 T2D (1.1%), 196 MD 6.4% (180 MODY=5.8%, (2.8% MODY1, 88.3% MODY2, 7.2% MODY3, 1.7% MODY5; neonatal diabetes 0.6%)). Nine cases (0.3%) were diagnosed with other genetic conditions (Wolfram syndrome, mitochondrial diabetes, severe insulin resistance, other), and 23 (0.7%) with secondary diabetes.

Conclusion: Similarly to other countries, T1D is the most frequent diagnosis in Italian diabetic patients <18 years, while a striking disparity, likely due to different lifestyle and genetic background, is observed between the rate of T2D of this study (1.1%, in keeping with European reports of 0.24–1.4%) and the SEARCH data from US (about 11%). At further variance with other Western countries (e.g. Norwegian registry, the DPV-Wiss study, the SEARCH study), the prevalence of MD in Italy is very high. This could depend on the fact that broader attention is devoted to MD in Italy than in the US, and also on the fact that genetic testing is easily accessible and free of charge. The close follow-up of patients with incidental hyperglycemia likely accounts for the very high rate of GCK/MODY2 mutations, the most frequent MODY type in Italy.