Department of Health Statistics, Shaanxi Key Laboratory of Free Radical Biology and Medicine and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Air Force Medical University of PLA, Changle West Road No. 169, Xi'an, 710032, Shaanxi, China. Department of Endocrinology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, No. 136, Jingzhou Street, Xiangyang, 441021, Hubei, China. Department of Endocrinology, 3201 Hospital of Xi'an Jiao tong University Health Science Center, 783 Tianhan Road, Hanzhong, 723000, Shaanxi, China. Department of Clinical Nutrition, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, No. 136, Jingzhou Street, Xiangyang City, 441021, Hubei, China. Department of Endocrinology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, No. 136, Jingzhou Street, Xiangyang, 441021, Hubei, China. linggao048@sina.com. Department of Health Statistics, Shaanxi Key Laboratory of Free Radical Biology and Medicine and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Air Force Medical University of PLA, Changle West Road No. 169, Xi'an, 710032, Shaanxi, China. shanglei@fmmu.edu.cn.