Yu-Hsiang Chou1, Tun-Jun Tsai2. 1. Renal Division, Department of Internal Medicine, National Taiwan University Hospital, Yun-Lin Branch, Dou Liu City, Yunlin County, Taiwan; Graduate Institute of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan. 2. Renal Division, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: tjtsai@ntuh.gov.tw.