1. Shanxi Medical University, 56 Xinjian South Road, Taiyuan, Shanxi Province 030001, China
2. Department of Nephrology, The First Hospital of Shanxi Medical University, 85 Jiefang South Road, Taiyuan, Shanxi Province 030001, China
3. Department of Geriatrics, The First Hospital of Shanxi Medical University, 85 Jiefang South Road, Taiyuan, Shanxi Province 030001, China