Davidson M B, Forsythe A B
Int J Obes. 1978;2(3):309-20.
Six normal-weight subjects were fed five separate diets [isocaloric--20, 40 and 80 per cent carbohydrate (CHO) and hypercaloric 20 and 40 per cent CHO] for 5 days each. Intravenous glucose-tolerance tests were performed on on Day 6. Insulin responses were positively related to caloric and CHO content of the diets, both of which affected insulin secretion independently of each other. Glucose disappearance rates were highly correlated (r = 0.80) with the acute insulin response to glucose. Fasting plasma-glucose levels (FPG) were also affected by both calories and CHO content, but in a more complex manner. Raising CHO content in isocaloric diets or increasing calories in diets of normal CHO content increased FPG. However, if either calories or CHO content were high, increasing the other had no further effect on FPG. Thus, there was an interaction between calories and CHO on FPG. In 18 instances, the diet was continued on Day 6 and another intravenous glucose tolerance test was performed the following morning, 90--120 minutes after 30mg of propantheline bromide by mouth. Glucose disappearance rates were increased in 16 of the 18 paired tests (P less than 0.005) after the anticholinergic agent. There was no effect on FPG or the insulin response to glucose.
both calories and CHO content are positively related to insulin secretion after 5 days of dietary manipulation. Glucose disappearance rates are also influenced, probably via the effect on insulin secretion. Both increased calories and CHO content will raise FPG; but each will have this effect only in the presence of a normal intake of the other. Thus, unless possible interactions between calories and CHO are taken into consideration in the design and interpretation of future dietary studies, erroneous conclusions may be reached. Finally, cholinergic blockade will enhance the disposal of intravenous glucose in the absence of any effect on peripheral insulin levels.
六名体重正常的受试者分别采用五种不同的饮食方案（等热量——碳水化合物（CHO）含量分别为20%、40%和80%，高热量——碳水化合物含量分别为20%和40%），每种饮食方案持续5天。在第6天进行静脉葡萄糖耐量试验。胰岛素反应与饮食的热量和碳水化合物含量呈正相关，二者相互独立地影响胰岛素分泌。葡萄糖清除率与对葡萄糖的急性胰岛素反应高度相关（r = 0.80）。空腹血糖水平（FPG）也受热量和碳水化合物含量的影响，但方式更为复杂。在等热量饮食中提高碳水化合物含量或在正常碳水化合物含量饮食中增加热量会使空腹血糖升高。然而，如果热量或碳水化合物含量较高，增加另一种成分对空腹血糖没有进一步影响。因此，热量和碳水化合物在空腹血糖方面存在相互作用。在18例中，第6天继续该饮食方案，并于次日早晨口服30毫克溴丙胺太林90 - 120分钟后进行另一次静脉葡萄糖耐量试验。在18次配对试验中的16次（P < 0.005），抗胆碱能药物使用后葡萄糖清除率增加。对空腹血糖或对葡萄糖的胰岛素反应没有影响。
经过5天的饮食控制后，热量和碳水化合物含量均与胰岛素分泌呈正相关。葡萄糖清除率可能也受到影响，这可能是通过对胰岛素分泌的作用实现的。热量和碳水化合物含量的增加都会使空腹血糖升高；但只有在另一种成分摄入量正常的情况下，每种成分才会产生这种影响。因此，除非在未来饮食研究的设计和解释中考虑热量和碳水化合物之间可能的相互作用，否则可能会得出错误的结论。最后，胆碱能阻断在不影响外周胰岛素水平的情况下会增强静脉注射葡萄糖的处置。
