O'Donovan Deirdre, Feinle-Bisset Christine, Chong Chilton, Cameron Alexander, Tonkin Anne, Wishart Judith, Horowitz Michael, Jones Karen Louise
Department of Medicine, University of Adelaide, Royal Adelaide Hospital, North Terrace, Adelaide, SA, 5000, Australia.
J Gerontol A Biol Sci Med Sci. 2005 Jul;60(7):940-6. doi: 10.1093/gerona/60.7.940.
Postprandial hypotension occurs frequently in older people and may result in syncope and falls. It has recently been established that the magnitude of the fall in blood pressure is related to the rate at which glucose enters the small intestine. We addressed the hypothesis that the fall in blood pressure induced by an intraduodenal glucose infusion is influenced by the interaction of glucose with the small intestinal absorptive epithelium.
Eight healthy older participants (four male, four female, age 70.3 +/- 3.4 years) were studied on two separate occasions, in single-blind, randomized order. Participants received an intraduodenal glucose infusion (3 kcal/min) with or without guar gum (4 g) for 60 minutes (0-60 minutes), followed by 0.9% saline intraduodenally for a further 60 minutes (60-120 minutes). Blood pressure and heart rate were measured every 3 minutes. Levels of blood glucose, plasma insulin, glucagon-like peptide-1 (GLP-1), and glucose-dependant insulinotropic-polypeptide (GIP) were also determined.
Between t = 0 and t = 30 minutes, the magnitude of the fall in systolic blood pressure (p =.03) and increase in heart rate (p =.027) were lower after guar. The blood glucose (p =.009), plasma insulin (p =.027), plasma GLP-1 (p =.018), and GIP (p <.001) responses to intraduodenal glucose were attenuated by guar.
In healthy older participants, the magnitude of the fall in systolic blood pressure and increase in heart rate induced by intraduodenal glucose are attenuated when the exposure of glucose to the small intestinal mucosa and subsequent glucose absorption is slowed by guar.
餐后低血压在老年人中频繁发生，可能导致晕厥和跌倒。最近已经证实，血压下降的幅度与葡萄糖进入小肠的速率有关。我们探讨了十二指肠内输注葡萄糖引起的血压下降受葡萄糖与小肠吸收上皮相互作用影响这一假说。
八名健康老年参与者（四名男性，四名女性，年龄70.3±3.4岁）在两个不同的场合接受研究，采用单盲、随机顺序。参与者接受十二指肠内葡萄糖输注（3千卡/分钟），输注60分钟（0至60分钟），期间有或没有瓜尔胶（4克），随后再十二指肠内输注0.9%生理盐水60分钟（60至120分钟）。每3分钟测量一次血压和心率。还测定了血糖、血浆胰岛素、胰高血糖素样肽-1（GLP-1）和葡萄糖依赖性促胰岛素多肽（GIP）的水平。
在t = 0至t = 30分钟之间，服用瓜尔胶后收缩压下降幅度（p = 0.03）和心率增加幅度（p = 0.027）较低。瓜尔胶减弱了十二指肠内葡萄糖引起的血糖（p = 0.009）、血浆胰岛素（p = 0.027）、血浆GLP-1（p = 0.018）和GIP（p < 0.001）反应。
在健康老年参与者中，当瓜尔胶减缓葡萄糖与小肠黏膜的接触及随后的葡萄糖吸收时，十二指肠内葡萄糖引起的收缩压下降幅度和心率增加幅度会减弱。
