1. Diabetes Center, Tokyo Women’s Medical University School of Medicine, Shinjuku-ku, Tokyo, Japan
2. Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
3. Department of Internal Medicine, Niigata University Faculty of Medicine, Chuo-ku, Niigata, Japan
4. Jikei University School of Medicine, Minato-ku, Tokyo, Japan