1. Department of Cardiology, The Affiliated Hospital of Qingdao University, Qingdao 266100, P. R. China
2. Department of Endocrinology, The People’s Hospital of Pingdu, Qingdao 266700, P. R. China
3. Department of General Medicine, The People's Hospital of Shinan, Qingdao 266002, P. R. China
4. Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao 266003, P. R. China
5. Department of Urology Surgery, The Affiliated Hospital of Qingdao University, Qingdao 266003, P. R. China
6. Department of Geriatrics, The Affiliated Hospital of Qingdao University, Qingdao 266003, P. R. China