Growth differentiating factor 15 (GDF15) is expressed in the intestine and is one of the most recently identified satiety peptides. The mechanisms controlling its secretion are unclear. The present study investigated whether plasma GDF15 concentrations are meal-related and if potential responses depend on macronutrient type or are affected by previous bariatric surgery. The study included: (1) volunteers ingesting rapidly vs. slowly digested carbohydrates (sucrose vs. isomaltose) (n=10), (2) volunteers who had undergone Roux-en-Y Gastric bypass (RYGB) or sleeve gastrectomy (SG) surgery and unoperated matched controls ingesting a liquid mixed meal (n=9-10 in each group), and (3) individuals with previous RYGB compared with unoperated controls ingesting isocaloric glucose, fat or protein (n=6 in each group). Plasma was collected after an overnight fast and up to 6 h after ingestion (≥12 timepoints). In cohort 1, fasting GDF15 concentrations were ~480 pg/ml. Concentrations after sucrose or isomaltose intake did not differ from baseline (P=0.26-P>0.99) and total area-under-the-curves (tAUCs were similar between groups (P=0.77). In cohort 2, fasting GDF15 concentrations were (pg/ml): RYGB=540±41.4, SG=477±36.4, and controls=590±41.8, with no between-group differences (P=0.73). Concentrations did not increase at any postprandial time point (over all time factor: P=0.10) and tAUCs were similar between groups (P=0.73). In cohort 3, fasting plasma GDF15 was similar among the groups (P>0.99) and neither glucose, fat or protein intake consistently increased the concentrations. In conclusion, we find that plasma GDF15 was not stimulated by meal intake, and that fasting concentrations did not differ between RYGB, SG and BMI-matched controls when investigated during the weight stable phase after RYGB and SG.

中文翻译：

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减肥手术后的受试者和匹配的对照组之间的血浆 GDF15 水平相似，并且不受进餐的影响

生长分化因子 15 (GDF15) 在肠道中表达，是最近发现的饱腹感肽之一。控制其分泌的机制尚不清楚。本研究调查了血浆 GDF15 浓度是否与膳食相关，以及潜在反应是否取决于常量营养素类型或是否受先前减肥手术的影响。该研究包括：(1) 摄入快速与缓慢消化的碳水化合物（蔗糖与异麦芽糖）（n = 10）的志愿者，（2）接受过 Roux-en-Y 胃绕道术 (RYGB) 或袖状胃切除术 (SG) 的志愿者手术和未手术的匹配对照摄入液体混合餐（每组 n = 9-10），以及 (3) 与未手术对照摄入等热量葡萄糖、脂肪或蛋白质（每组 n = 6）的先前 RYGB 的个体相比。在禁食过夜后和摄入后最多 6 小时（≥12 个时间点）收集血浆。在队列 1 中，空腹 GDF15 浓度为 ~480 pg/ml。摄入蔗糖或异麦芽糖后的浓度与基线无差异（P=0.26-P>0.99）和总曲线下面积（tAUCs 组间相似（P=0.77）。在队列 2 中，空腹 GDF15 浓度为（ pg/ml): RYGB=540±41.4, SG=477±36.4, and control=590±41.8, 没有组间差异 (P=0.73). 浓度在任何餐后时间点都没有增加（在所有时间因素: P=0.10) 和 tAUCs 组间相似 (P=0.73). 在队列 3 中，空腹血浆 GDF15 组间相似 (P>0.99) 并且葡萄糖、脂肪或蛋白质摄入量均未持续增加浓度。总而言之，我们发现血浆 GDF15 不受膳食摄入的刺激，