1Diabetes Center, Tokyo Women's Medical University School of Medicine, 8-1 Kawadacho, Shinjuku-ku, 162-8666 Tokyo, Japan. 2Department of Pediatrics, Teine Keijinkai Hospital, Seitoku University, Matsudo, Japan. 3Department of Pediatrics, Saitama Medical University Moroyama, Saitama, Japan. 4Department of Pediatrics, Nihon University Hospital School of Medicine, Tokyo, Japan. 5Department of Pediatrics, Osaka City University School of Medicine, Osaka, Japan. Department of Pediatrics, Yokohama City Minato Red Cross Hospital, Yokohama, Japan. 7Department of Pediatrics, Tokyo Women's Medical University Medical Center East, Tokyo, Japan.