Ying Zheng1,2,3, Zhen Wang4,2. 1. Department of Metabolism and Endocrinology, Second Xiangya Hospital and Institute of Metabolism and Endocrinology, Central South University, Changsha, China. 2. Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Changsha, China. 3. The Center for Medical Research, Second Xiangya Hospital, Central South University, Changsha, China. 4. Department of Metabolism and Endocrinology, Second Xiangya Hospital and Institute of Metabolism and Endocrinology, Central South University, Changsha, China wangzhencs@csu.edu.cn.