1. Graduate School of Public Health, Teikyo University, Japan
2. Division of Nephrology and Hypertension, The Jikei University School of Medicine, Japan
3. Department of Internal Medicine, Nephrology, Teikyo University Chiba Medical Center, Japan
4. Akimoto Occupational Health Consultant Office, Japan
5. Department of Community Medicine, Teikyo University Chiba Medical Center, Japan