1. Department of Medical Education, Shinshu University, Matsumoto 390-8621, Japan
2. Diabetes Center, Aizawa Hospital, Matsumoto 390-8510, Japan
3. Resident of Internal Medicine, Aizawa Hospital, Matsumoto 390-8510, Japan
4. Diabetes, Endocrinology and Metabolism, Nagano Chuo Hospital, Nagano 380-0814, Japan
5. Department of Diabetes Medicine, Asama Central Hospital, Nagano 385-8558, Japan
6. Diabetes Center, Okaya City Hospital, Okaya 394-0028, Japan
7. Department of Diabetes, Endocrinology and Metabolism, Division of Internal Medicine, Shinshu University Hospital, Matsumoto 390-8621, Japan