le Roux C W, Patterson M, Vincent R P, Hunt C, Ghatei M A, Bloom S R
Department of Metabolic Medicine, Imperial College London, Hammersmith Hospital, London W12 0NN, UK.
J Clin Endocrinol Metab. 2005 Feb;90(2):1068-71. doi: 10.1210/jc.2004-1216. Epub 2004 Nov 2.
Circulating levels of the gastric hormone ghrelin rise before and decrease after a meal. In normal-weight subjects, postprandial suppression of ghrelin is proportional to calories consumed. Obese individuals have lower fasting ghrelin levels; however, it is unclear whether the obese show normal postprandial suppression. This study aimed to compare postprandial ghrelin responses in normal-weight and obese subjects, using mixed macronutrient meals with varied fat and calorie content. Postprandial ghrelin response was measured in normal-weight insulin-sensitive subjects and obese insulin-resistant subjects, after six test meals with different fat and calorie content (250-3000 kcal). Increasing the calorie content of meals in normal-weight subjects progressively lowered nadir levels of ghrelin. The obese had lower fasting ghrelin levels, and the reduction after the consumption of all test meals was less than the normal-weight subjects. The lowest postprandial levels in the obese were no different to the nadir in normal-weight volunteers after 1000-, 2000-, and 3000-kcal meals. Thus, circulating ghrelin levels decreased in normal-weight subjects after mixed meals. Obese subjects demonstrated a much reduced ghrelin postprandial suppression. This reduced suppression may influence satiety, thus reinforcing obesity.
胃激素胃饥饿素的循环水平在进食前升高，进食后降低。在体重正常的受试者中，餐后胃饥饿素的抑制与摄入的热量成正比。肥胖个体的空腹胃饥饿素水平较低；然而，尚不清楚肥胖者是否表现出正常的餐后抑制。本研究旨在使用脂肪和热量含量不同的混合宏量营养素餐，比较体重正常和肥胖受试者的餐后胃饥饿素反应。在体重正常的胰岛素敏感受试者和肥胖的胰岛素抵抗受试者中，在食用六种脂肪和热量含量不同（250 - 3000千卡）的测试餐后，测量餐后胃饥饿素反应。增加体重正常受试者餐食的热量含量会逐渐降低胃饥饿素的最低点水平。肥胖者的空腹胃饥饿素水平较低，并且食用所有测试餐后的降低幅度小于体重正常的受试者。在食用1000千卡、2000千卡和3000千卡餐食后，肥胖者的最低餐后水平与体重正常志愿者的最低点没有差异。因此，混合餐后体重正常受试者的循环胃饥饿素水平降低。肥胖受试者的餐后胃饥饿素抑制明显减弱。这种减弱的抑制可能会影响饱腹感，从而加重肥胖。
