Pathophysiologic phenotypes of Japanese subjects with varying degrees of glucose tolerance: Using the combination of C-peptide secretion rate and minimal model analysis

We tried to characterize the clinical features associated with glucose meta bolism in the development of diabetes. Study subjects were glucose-tolerant subjects without a family history of diabetes (normal glucose tolerance [N GT]1 group, n = 15) and with a first-degree diabetes relative (NGT2, n = 9) . 12 subjects with impaired glucose tolerance (IGT). and 13 subjects with t ype 2 diabetes mellitus (DM). The first phase C-peptide secretion (CS1), in sulin sensitivity (Si), and glucose effectiveness (Sg) were assessed by the combination of C-peptide 2-compartment model and minimal model analyses. U sing these parameters, each group was characterized: CS1 was decreased in N GT2 and IGT compared with NGT1 and further decreased in DM; Si was not diff erent among NGT1, NGT2, and IGT, whereas Si was decreased in DM; CSI x Si v alue was decreased in NGT2 compared with NGT1 and decreased in IGT, DM, pro gressively; Sg was decreased in IGT and DM compared with NGT1 and NGT2. CS1 x Si and Sg values could segregate each group distinctively, although it h ad a large variety of phenotypes. CS1 x Si value and Sg are assumed to repr esent the contributions of insulin-dependent and independent mechanisms to glucose tolerance, respectively, and thus, both mechanisms should play an i mportant role in the characterization of pathophysiologic phenotypes of the subjects with various degrees of glucose tolerance, Copyright (C) 2001 by W.B. Saunders Company.