Engström B E, Ohrvall M, Sundbom M, Lind L, Karlsson F A
Department of Medical Sciences, Internal Medicine, University Hospital, Uppsala, Sweden.
Int J Obes (Lond). 2007 Mar;31(3):476-80. doi: 10.1038/sj.ijo.0803440. Epub 2006 Aug 22.
It has been proposed that the success of maintained weight loss in morbidly obese subjects following Roux-en-Y gastric bypass (RYGBP) surgery depends on inappropriately low circulating concentrations of the appetite-stimulating peptide ghrelin, being unresponsive to food intake. In this study, this hypothesis was examined.
Cross-sectional study with repeated blood samples in 40 subjects after 14 h of prolonged overnight fasting followed by a standardized mixed meal (770 kcal).
Twenty men and 20 women were included: 10 middle-aged morbidly obese (body mass index (BMI) 43.9+/-3.3 kg/m(2)), 10 middle-aged subjects who had undergone RYGBP at the Uppsala University Hospital (BMI 34.7+/-5.8 kg/m(2)), 10 middle-aged non-obese (BMI 23.5+/-2.2 kg/m(2)) and 10 young non-obese (BMI 22.7+/-1.8 kg/m(2)).
Ghrelin, glucose and insulin levels were analysed pre- and postprandially.
In the morbidly obese, ghrelin concentrations were lower in the morning than in the RYGBP group and did not change following the meal. In the RYGBP group, fasting ghrelin levels fell after meal intake and showed similar suppression as both age-matched and young non-obese controls. The RYGBP surgery resulted in an increased meal-induced insulin secretion, which was related to the degree of postprandial ghrelin suppression.
The present study demonstrates low circulating concentrations of ghrelin and blunted responses to fast and feeding in morbidly obese subjects. Marked weight reduction after RYGBP at our hospital is followed by a normalization of ghrelin secretion, illustrated by increased fasting levels compared to the preoperative obese state and regain of meal-induced ghrelin suppression.
有人提出，病态肥胖受试者在接受 Roux-en-Y 胃旁路术（RYGBP）后维持体重减轻的成功与否取决于食欲刺激肽胃饥饿素的循环浓度异常低，且对食物摄入无反应。在本研究中，对这一假设进行了检验。
横断面研究，对 40 名受试者在延长的夜间禁食 14 小时后采集重复血样，随后给予标准化混合餐（770 千卡）。
纳入 20 名男性和 20 名女性：10 名中年病态肥胖者（体重指数（BMI）43.9±3.3kg/m²），10 名在乌普萨拉大学医院接受过 RYGBP 的中年受试者（BMI 34.7±5.8kg/m²），10 名中年非肥胖者（BMI 23.5±2.2kg/m²）和 10 名年轻非肥胖者（BMI 22.7±1.8kg/m²）。
在餐前和餐后分析胃饥饿素、葡萄糖和胰岛素水平。
在病态肥胖者中，早晨胃饥饿素浓度低于 RYGBP 组，且餐后无变化。在 RYGBP 组中，进食后空腹胃饥饿素水平下降，与年龄匹配的和年轻的非肥胖对照组表现出相似的抑制情况。RYGBP 手术导致餐后胰岛素分泌增加，这与餐后胃饥饿素抑制程度有关。
本研究表明病态肥胖受试者中胃饥饿素的循环浓度较低，对禁食和进食的反应减弱。在我院，RYGBP 术后显著体重减轻后，胃饥饿素分泌恢复正常，表现为与术前肥胖状态相比空腹水平升高，且恢复了餐后胃饥饿素抑制。
