1. Department of Public Health, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
2. Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shinbashi Minato-ku, Tokyo 105-8461, Japan
3. Jikei University School of Medicine, 3-25-8 Nishi-Shinbashi Minato-ku, Tokyo 105-8461, Japan