1. Department of Gastroenterology, Xiangya Hospital, Central South University, Changsha, Hunan, China
2. Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, China
3. National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China