1. Department of Endocrinology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
2. Shanxi Provincial Research Center for The Project of Prevention and Treatment of Respiratory Diseases, Xi'an, Shaanxi 710061, P.R. China
3. Department of Endocrinology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China