Priebe Marion G, Wachters-Hagedoorn Renate E, Heimweg Janneke A J, Small Alexandra, Preston Tom, Elzinga Henk, Stellaard Frans, Vonk Roel J
Dept of Medical Biomics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Eur J Nutr. 2008 Dec;47(8):417-23. doi: 10.1007/s00394-008-0743-6. Epub 2008 Oct 13.
Based on in vitro measurements, it is assumed that starch in wholemeal bread is rapidly digestible, which is considered to be less desirable for health.
To evaluate the in vitro prediction, we characterized starch digestion of wholemeal wheat bread (WB) and postprandial glucose kinetics in healthy volunteers.
In a crossover study 4 healthy men ingested either intrinsically (13)C-enriched WB (133 g) or glucose (55 g) in water. Plasma glucose and insulin concentrations were monitored during 6 h postprandially. Using a primed continuous infusion of D-[6,6-(2)H(2)] glucose, the rate of systemic appearance of glucose was estimated (reflecting glucose influx) and the endogenous glucose production calculated.
The glucose influx rate after WB was comparable with that after glucose in the early postprandial phase (0-2 h) (P = 0.396) and higher in the late postprandial phase (2-4 h) (P = 0.005). Despite the same initial glucose influx rate the 0-2 h incremental area under the curve (IAUC) of insulin after WB was 41% lower than after glucose (P = 0.037). Paradoxically endogenous glucose production after WB was significantly more suppressed than after glucose (0-2 h IAUC: P = 0.015, 2-4 h IAUC: P = 0.018).
Starch in WB seems to be partly rapidly and partly slowly digestible. Postprandial insulin response and endogenous glucose production after WB ingestion might not solely be determined by the digestive characteristics of starch; other components of WB seem to affect glucose homeostasis. In vitro measurements might not always predict in vivo starch digestion precisely.
基于体外测量，人们认为全麦面包中的淀粉易于快速消化，而这被认为对健康不太有益。
为了评估体外预测结果，我们对全麦小麦面包（WB）的淀粉消化特性以及健康志愿者的餐后葡萄糖动力学进行了表征。
在一项交叉研究中，4名健康男性分别摄入内源性富含¹³C的WB（133克）或水中的葡萄糖（55克）。在餐后6小时内监测血浆葡萄糖和胰岛素浓度。通过一次给予并持续输注D-[6,6-(²)H₂]葡萄糖，估算葡萄糖的全身出现率（反映葡萄糖流入）并计算内源性葡萄糖生成量。
WB摄入后早期（0至2小时）的葡萄糖流入率与葡萄糖摄入后的相当（P = 0.396），而在餐后晚期（2至4小时）则更高（P = 0.005）。尽管初始葡萄糖流入率相同，但WB摄入后胰岛素在0至2小时的曲线下增量面积（IAUC）比葡萄糖摄入后低41%（P = 0.037）。矛盾的是，WB摄入后内源性葡萄糖生成受到的抑制比葡萄糖摄入后更显著（0至2小时IAUC：P = 0.015，2至4小时IAUC：P = 0.018）。
WB中的淀粉似乎部分易于快速消化，部分易于缓慢消化。摄入WB后的餐后胰岛素反应和内源性葡萄糖生成可能不仅仅由淀粉的消化特性决定；WB的其他成分似乎会影响葡萄糖稳态。体外测量可能并不总是能精确预测体内淀粉消化情况。
