Factors analysis of metabolic syndrome using direct measurement of insulin resistance in Chinese with different degrees of glucose tolerance

Background & objectives: With the increasing prevalence of type 2 diabetes and cardiovascular disease in Taiwan, the understanding of metabolic syndrome (MetS) becomes more important. The purpose of this study was to investigate the clustering patterns of the risk variables of the MetS with factor analysis (FacAn). Methods: A total of 564 Chinese individuals with normal glucose tolerance (N, n=345), impaired glucose tolerance (IGT, n=164) or diabetes mellitus (DM, n=55) were enrolled. Insulin resistance was measured by insulin suppression test (IST). The components of MetS such as waist hip ratio (WHR), fasting plasma glucose (FPG), systolic blood pressure (SBP), diastolic blood pressure (DBP), triglyceride (TG), high density lipoprotein cholesterol (HDLC) and steady state plasma glucose (SSPG) from IST were put into the model of exploratory FacAn. Results: In spite of the minor different loading patterns, three dimensions were identified in the three subgroups; a "blood pressure" dimension, loading with mainly SBP and DBP, an "insulin resistance" dimension, loading mainly with SSPG, and an "adiposity/glucose" dimension loading with TG, WHR or FPG. Interpretation & conclusions: Our results were consistent with different ethnic groups in earlier reports that more than two dimensions were identified and that the MetS is not unified by a single underlying aetiology, i.e., insulin resistance. Longitudinal analysis in this and other populations will be required to validate our findings and to test their generalisability.