1. Department of Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
2. Second Department of Medicine, Asahikawa Medical College, Asahikawa, Hokkaido, Japan
3. Division of Endocrinology and Metabolism, Department of Medicine, Kanazawa Medical School, Kahoku-gun, Ishikawa, Japan
4. Medical and Health Care Center, SANYO Electric Group Health Insurance Association, Moriguchi, Osaka, Japan