Tongue Fur and Metabolites in Diabetes Mellitus

This study is a prospective cross-sectional study. The investigators enroll participants form the department of endocrinology and of metabolism, China Medical University Hospital. In total, 300 participants , composed of 100 of type 2 diabetes , 100 of pre-DM and 100 healthy participants. The investigators apply tongue diagnosis system, pulse wave analysis, body constitution questionnaires, and nailfold capillaroscopy to assess the differences of TCM diagnosis. After collecting the tongue coating and analyzing the metabolite signals with a flying mass spectrometer, The investigators collect the data to establish metabolite pattern and biomarkers. This study aims to identify the clinical symptoms of DM with TCM diagnostic tools and investigate the pattern difference and treatment for DM. Furtherly, the investigators add mass spectrometer to analyze the metabolites of tongue coating, the investigators propose to establish a metabolite pattern and biomarker to identify important biological indicators of DM.