Division of Sports and Rehabilitation Medicine, Department of Medicine II, Ulm University, Ulm, Germany. Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Dingjiaqiao Str.87, Nanjing, 210009, China. Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Dingjiaqiao Str.87, Nanjing, 210009, China. zimuzhanglao@126.com.