1. Department of Nephrology, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300381, P.R. China
2. Department of Endocrinology, Fuyang Fourth People's Hospital, Fuyang, Anhui 236000, P.R. China
3. Department of Internal Medicine and Nephrology, King Abdulaziz University, Jeddah 21589, Saudi Arabia