1. Department of Pediatrics, Institute of Medical Sciences, University of Opole, 45-040 Opole, Poland
2. Department of Pediatrics, University Clinical Hospital in Opole, 46-020 Opole, Poland
3. Pediatric Diabetes and Metabolic Disorders Unit, Regional Center for Pediatric Diabetes, University City Hospital, 37126 Verona, Italy
4. Department of Human Pathology in Adult and Developmental Age “Gaetano Barresi”, University of Messina, 98122 Messina, Italy