1. Department of Endocrinology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Graduate School of Peking Union Medical College, Beijing 100730, China
2. Department of Endocrinology, Pinggu Hospital, Beijing Traditional Chinese Medicine Hospital, Beijing 100006, China
3. Central Laboratory, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
4. Department of Ultrasound, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, China