1. Department of Endocrinology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450002, P.R. China
2. Department of Nephrology, The Third People's Hospital of Zhengzhou, Zhengzhou, Henan 450000, P.R. China
3. Department of Endocrinology, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110022, P.R. China