1. Department of Diabetes, Endocrine and Metabolic Diseases, Yachiyo Medical Center Tokyo Women's Medical University Yachiyo, Chiba Japan
2. Clinical Research Support Center Asahi General Hospital Asahi, Chiba Japan
3. Department of Diabetes and Metabolic Diseases Asahi General Hospital Asahi, Chiba Japan
4. Department of Clinical Laboratory Asahi General Hospital Asahi, Chiba Japan
5. Preventive Medicine Research Center Asahi General Hospital Asahi, Chiba Japan
6. Department of Internal Medicine Asahi General Hospital Asahi, Chiba Japan
7. Department of Medicine, Diabetes Center, School of Medicine Tokyo Women's Medical University Tokyo Japan