Center for Medical Biomics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
Am J Clin Nutr. 2012 Nov;96(5):1017-24. doi: 10.3945/ajcn.112.041947. Epub 2012 Sep 18.
Previously we observed that the consumption of pasta and bread resulted in a similar glycemic response, despite a slower intestinal influx rate of glucose from the pasta. Underlying mechanisms of this effect were not clear.
The objective was to investigate the differences in glucose kinetics and hormonal response after consumption of products with slow and rapid in vivo starch digestibility but with a similar glycemic response.
Ten healthy male volunteers participated in a crossover study and consumed (13)C-enriched wheat bread or pasta while receiving a primed-continuous D-[6,6-(2)H(2)]glucose infusion. The dual-isotope technique enabled calculation of the following glucose kinetics: rate of appearance of exogenous glucose (RaE), endogenous glucose production, and glucose clearance rate (GCR). In addition, postprandial plasma concentrations of glucose, insulin, glucagon, and glucose-dependent insulinotropic polypeptide (GIP) were analyzed.
GIP concentrations after pasta consumption were lower than after bread consumption and strongly correlated with the RaE (r = 0.82, P < 0.01). The insulin response was also lower after pasta consumption (P < 0.01). In accordance with the low insulin response, the GCR was lower after pasta consumption, which explained the high glycemic response despite a low RaE.
Slower intestinal uptake of glucose from a starchy food product can result in lower postprandial insulin and GIP concentrations, but not necessarily in a lower glycemic response, because of a slower GCR. Even without being able to reduce postprandial glycemia, products with slowly digestible starch can have beneficial long-term effects. These types of starchy products cannot be identified by using the glycemic index and therefore another classification system may be necessary. This trial was registered at controlled-trials.com as ISRCTN42106325.
此前我们观察到，尽管面食的葡萄糖肠内流入率较慢，但面食和面包的消耗会导致类似的血糖反应。这种效应的潜在机制尚不清楚。
本研究旨在探讨摄入体内消化速度不同但血糖反应相似的产品后，葡萄糖动力学和激素反应的差异。
10 名健康男性志愿者参加了一项交叉研究，在接受持续输注[6,6-(2)H2]葡萄糖的同时，摄入（13）C 标记的小麦面包或意大利面。双同位素技术可计算以下葡萄糖动力学：外源性葡萄糖出现率（RaE）、内源性葡萄糖生成率和葡萄糖清除率（GCR）。此外，还分析了餐后血浆葡萄糖、胰岛素、胰高血糖素和葡萄糖依赖性胰岛素释放肽（GIP）的浓度。
食用意大利面后 GIP 浓度低于食用面包后，且与 RaE 呈强相关（r = 0.82，P < 0.01）。食用意大利面后胰岛素反应也较低（P < 0.01）。与低胰岛素反应一致，食用意大利面后 GCR 较低，这解释了尽管 RaE 较低但血糖反应较高的原因。
淀粉类食物的葡萄糖肠内吸收速度较慢可能导致餐后胰岛素和 GIP 浓度降低，但由于 GCR 较慢，血糖反应不一定降低。即使不能降低餐后血糖，消化速度较慢的淀粉类产品也可能具有有益的长期影响。这些类型的淀粉产品不能通过血糖指数来识别，因此可能需要另一种分类系统。该试验在 controlled-trials.com 上注册为 ISRCTN42106325。
