1. Division of Diabetes and Endocrinology, Hyogo Prefectural Kakogawa Medical Center, Kakogawa 675-8555, Japan
2. Division of Diabetes and Endocrinology, Kobe University Hospital, Kobe 650-0017, Japan
3. Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan