Department of Gerontology and Geriatrics;
the First Affiliated Hospital of China Medical University;
Department of Gerontology and Geriatrics;
Shengjing Hospital of China Medical University;
Department of Tumor Research;
the First Affiliated Hospital of China Medical University;
Department of Kidney;
General Hospital of Chinese People’s Liberation Army;
Helicobacter pylori antibody; Pepsinogen; Gastrin; Gastric ageing;