Corresponding Author

Health Management Centre, Tianjin Medical University General Hospital, Tianjin, China

Nutritional Epidemiology Institute and School of Public Health, Tianjin Medical University, Tianjin, China

Correspondence: Kaijun Niu, M.D., Ph.D. Nutritional Epidemiology Institute and School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, China.

(e-mail: nkj0809@gmail.com, niukaijun@tmu.edu.cn).

Yuhong Zhao, M.D., Ph.D. Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, No. 36, San Hao Street, Shenyang, Liaoning 110004, China.

(e-mail: zhaoyuhong@sj-hospital.org).