1. Center for Geriatrics and Gerontology, Taichung Veterans General Hospital, Taichung, Taiwan;
2. Division of Nephrology, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan;
3. Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan;
4. Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, Taiwan