German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany.
German Center for Diabetes Research (DZD), Muenchen-Neuherberg, Germany.
Am J Clin Nutr. 2018 Aug 1;108(2):279-291. doi: 10.1093/ajcn/nqy100.
Meal composition regulates the postprandial response of pancreatic and gastrointestinal hormones and plays an important role in patients with type 2 diabetes (T2D). Proteins have glucagon and insulinotropic effects, which may differ depending on amino acid composition, form of intake, and rate of digestibility and absorption.
The aim of this study was to test effects of isolated pea protein-based (PP) compared with casein protein-based (CP) meals differing in amino acid compositions on endocrine responses to meal tolerance tests (MTTs) in patients with T2D.
Thirty-seven individuals with T2D [mean ± SD age: 64 ± 6 y; mean ± SD body mass index (kg/m2): 30.2 ± 3.6; mean ± SD glycated hemoglobin: 7.0% ± 0.6%] were randomly assigned to receive either high-animal-protein (∼80% of total protein) or high-plant-protein (∼72% of total protein) diets (30% of energy from protein, 40% of energy from carbohydrate, 30% of energy from fat) for 6 wk. MTTs were performed at study onset and after 6 wk. Participants received standardized high-protein (30% of energy) meals 2 times/d containing either CP-rich (∼85% wt:wt) or PP-rich (∼95% wt:wt) foods.
The CP and PP meals produced differences in insulin, C-peptide, glucagon, and glucose-dependent insulinotropic peptide (GIP) release. Total areas under the curve after CP were significantly lower than after the PP lunch by 40% for insulin and 23% for glucagon. Indexes of insulin sensitivity and secretion were significantly improved for the second CP MTT. This was accompanied by differential rates of appearance of amino acids. The ingestion of PP resulted in significant increases in amino acids after both meals, with a decline between meals. By contrast, CP intake resulted in increases in most amino acids after breakfast, which remained elevated but did not increase further after lunch.
PP elicits greater postprandial increases in glucagon than does CP and consequently requires higher insulin to control glucose metabolism, which appears to be related to the rate of amino acid appearance. The metabolic impact of protein quality could be used as a strategy to lower insulin needs in patients with T2D. This trial was registered at www.clinicaltrials.gov as NCT02402985.
膳食组成调节胰腺和胃肠激素的餐后反应，在 2 型糖尿病（T2D）患者中起着重要作用。蛋白质具有胰高血糖素和胰岛素刺激作用，其作用可能因氨基酸组成、摄入形式以及消化吸收速度而有所不同。
本研究旨在测试基于分离豌豆蛋白（PP）的膳食与基于酪蛋白的膳食（CP）对 T2D 患者餐后耐量试验（MTT）的内分泌反应的影响，这两种膳食的氨基酸组成不同。
37 名 T2D 患者[平均（±SD）年龄：64±6 岁；平均（±SD）体重指数（kg/m2）：30.2±3.6；平均（±SD）糖化血红蛋白：7.0%±0.6%]被随机分配接受高动物蛋白（约 80%的总蛋白）或高植物蛋白（约 72%的总蛋白）饮食（蛋白质提供 30%的能量，碳水化合物提供 40%的能量，脂肪提供 30%的能量）6 周。在研究开始和 6 周后进行 MTT。参与者每天接受 2 次标准化高蛋白（30%的能量）餐，其中含有富含 CP（约 85%wt:wt）或富含 PP（约 95%wt:wt）的食物。
CP 和 PP 膳食在胰岛素、C 肽、胰高血糖素和葡萄糖依赖性胰岛素释放肽（GIP）的释放方面存在差异。CP 后的总曲线下面积比 PP 午餐低 40%，胰高血糖素低 23%。第二次 CP MTT 的胰岛素敏感性和分泌指数显著改善。这伴随着氨基酸出现率的差异。PP 的摄入导致两餐餐后氨基酸显著增加，两餐之间氨基酸水平下降。相比之下，CP 摄入导致早餐后大多数氨基酸增加，这些氨基酸水平升高，但午餐后不再进一步升高。
PP 引起的餐后胰高血糖素增加大于 CP，因此需要更高的胰岛素来控制葡萄糖代谢，这似乎与氨基酸出现率有关。蛋白质质量的代谢影响可作为降低 T2D 患者胰岛素需求的策略。本试验在 www.clinicaltrials.gov 上注册为 NCT02402985。
