Glycemic index and glucose utilization of rice vermicelli in healthy subjects.

Glycemic index (GI) is an indicator of glucose absorption into the systemic circulation after ingestion of foods. However, the plasma glucose level is determined by not only the absorption of glucose, but also the disappearance of glucose which is regulated by the insulin response. The aim of this study was to estimate the values of GI and glucose utilization including the absorption and the disappearance of glucose (U(GLU)) in the rice vermicelli (RV) using the resulting glucose clearance (CL(GLU)). Fifteen healthy subjects participated in this study. Alterations in plasma glucose and insulin levels were determined after ingestion of a reference food (12.5, 25, 50, 75 g glucose) and the test foods (white rice, long grain rice and six RV products; 50 g available carbohydrate). Time-course changes in plasma glucose levels were analyzed using a simple kinetic model. The values of CL(GLU) were calculated using the resulting kinetic parameters. A standard curve in which the incremental area under the curve of plasma insulin levels (AUC(INS(ref))) was plotted against the resulting CL(GLU(ref)) was generated using the reference food. The values of GI and U(GLU) in the RV products were calculated from the observed clearances (CL(GLU)), and the predicted clearances (CL(GLU(predict))) respectively, which were estimated using the standard curve of AUC(INS(ref)) vs. CL(GLU(ref)). It was clarified that the values of U(GLU) in the RV products (20-57%) were lower than those of GI (35-62%).