1. Division of Nephrology, Endocrinology and Metabolism, Department of Internal Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
2. Center for Preventive Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
3. Department of Pathology, Keio University School of Medicine, Tokyo 160-8582, Japan
4. Department of Pathology, Saitama Medical University, Saitama 350-0495, Japan