1. Department of Clinical Nutrition, The Third Affiliated Hospital of Chongqing Medical University, Chongqing 410020, P.R. China
2. Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing 400042, P.R. China
3. Division of Renal Diseases and Hypertension, Department of Medicine, and Department of Pharmacology/Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052, U.S.A.