1. Department of Pediatrics , Hokkaido University School of Medicine, Kita-ku , Sapporo , Japan
2. Sapporo Children’s Endocrine Clinic, Chuo-ku , Sapporo , Japan
3. Department of Pediatrics , NTT East Sapporo Hospital, Chuo-ku , Sapporo, Hokkaido , Japan
4. Department of Pediatrics , Jichi Children’s Medical Center, Yakishiji , Shimotsuke, Tochigi , Japan