肥満耐糖能異常での膵β細胞機能とインスリン感受性

Abstract

Pancreatic beta-cell function and insulin sensitivity were assessed in obese Japanese subjects using fasting and 75g-oral glucose tolerance test measurements of glucose and insulin. One hundred three subjects were classified into three categories according to the status of glucose tolerance: normal glucose tolerance (NGT, n=34), impaired glucose tolerance (IGT, n=47), and diabetes mellitus (DM, n=22). Insulinogenic index, 1st-phase insulin secretion index, and 2nd-phase insulin secretion index declined with worsening glucose tolerance. Homeostasis model assessment of beta-cell function (HOMA-beta) was significantly lower in DM than in IGT. Homeostasis model assessment of insulin resistance (HOMA-IR) increased with worsening glucose tolerance, whereas the insulin sensitivity index (ISI) and the metabolic clearance rate of glucose (MCR) decreased with worsening glucose tolerance. In conclusion, we established the close relationship of glucose-intolerance to pancreatic beta-cell dysfunction as well as impaired insulin sensitivity in obese Japanese subjects.