1. Department of Urology, Shengjing Hospital of China Medical University, 36 Sanhao Street, Shenyang, Liaoning, 110004, P.R. China
2. Department of Urology, The First Hospital of China Medical University, Shenyang, China
3. Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China
4. Nutritional Epidemiology Institute and School of Public Health, Tianjin Medical University, Tianjin, China
5. Health Management Centre, Tianjin Medical University General Hospital, Tianjin, China