School of Medicine, Shandong University, No. 44 Wenhua West Road, Jinan, Shandong, 250012, China; Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China; Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong First Medical University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China. Electronic address: jiangqiangjinan@sina.com. School of Medicine, Shandong University, No. 44 Wenhua West Road, Jinan, Shandong, 250012, China; Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China; Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong First Medical University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China. Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China. Central Laboratory, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China. UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia. Department of Clinical Nutrition and Dietetics, Student Research Committee, Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China; Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong First Medical University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China. Electronic address: shuguangpang@163.com.