Goldstone Anthony P, Prechtl Christina G, Scholtz Samantha, Miras Alexander D, Chhina Navpreet, Durighel Giuliana, Deliran Seyedeh S, Beckmann Christian, Ghatei Mohammad A, Ashby Damien R, Waldman Adam D, Gaylinn Bruce D, Thorner Michael O, Frost Gary S, Bloom Stephen R, Bell Jimmy D
From the Metabolic and Molecular Imaging Group (APG, CGP, SS, ADM, NC, SSD, and JDB) and Robert Steiner MRI Unit (GD), Medical Research Council Clinical Sciences Centre, the Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences (CB), the Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism (MAG, DRA, GSF, and SRB), and the Division of Brain Sciences (ADW), Imperial College London, Hammersmith Hospital, London, United Kingdom, and the Department of Endocrinology, University of Virginia, Charlottesville, VA (BDG and MOT).
Am J Clin Nutr. 2014 Jun;99(6):1319-30. doi: 10.3945/ajcn.113.075291. Epub 2014 Apr 23.
Ghrelin, which is a stomach-derived hormone, increases with fasting and energy restriction and may influence eating behaviors through brain hedonic reward-cognitive systems. Therefore, changes in plasma ghrelin might mediate counter-regulatory responses to a negative energy balance through changes in food hedonics.
We investigated whether ghrelin administration (exogenous hyperghrelinemia) mimics effects of fasting (endogenous hyperghrelinemia) on the hedonic response and activation of brain-reward systems to food.
In a crossover design, 22 healthy, nonobese adults (17 men) underwent a functional magnetic resonance imaging (fMRI) food-picture evaluation task after a 16-h overnight fast (Fasted-Saline) or after eating breakfast 95 min before scanning (730 kcal, 14% protein, 31% fat, and 55% carbohydrate) and receiving a saline (Fed-Saline) or acyl ghrelin (Fed-Ghrelin) subcutaneous injection before scanning. One male subject was excluded from the fMRI analysis because of excess head motion, which left 21 subjects with brain-activation data.
Compared with the Fed-Saline visit, both ghrelin administration to fed subjects (Fed-Ghrelin) and fasting (Fasted-Saline) significantly increased the appeal of high-energy foods and associated orbitofrontal cortex activation. Both fasting and ghrelin administration also increased hippocampus activation to high-energy- and low-energy-food pictures. These similar effects of endogenous and exogenous hyperghrelinemia were not explicable by consistent changes in glucose, insulin, peptide YY, and glucagon-like peptide-1. Neither ghrelin administration nor fasting had any significant effect on nucleus accumbens, caudate, anterior insula, or amygdala activation during the food-evaluation task or on auditory, motor, or visual cortex activation during a control task.
Ghrelin administration and fasting have similar acute stimulatory effects on hedonic responses and the activation of corticolimbic reward-cognitive systems during food evaluations. Similar effects of recurrent or chronic hyperghrelinemia on an anticipatory food reward may contribute to the negative impact of skipping breakfast on dietary habits and body weight and the long-term failure of energy restriction for weight loss.
胃饥饿素是一种由胃产生的激素，其水平会随着禁食和能量限制而升高，并可能通过大脑享乐奖赏 - 认知系统影响饮食行为。因此，血浆胃饥饿素的变化可能通过食物享乐感的改变介导对负能量平衡的反调节反应。
我们研究了给予胃饥饿素（外源性高胃饥饿素血症）是否会模拟禁食（内源性高胃饥饿素血症）对食物享乐反应及大脑奖赏系统激活的影响。
采用交叉设计，22名健康、非肥胖成年人（17名男性）在禁食16小时过夜后（禁食 - 生理盐水组）或在扫描前95分钟进食早餐（730千卡，14%蛋白质，31%脂肪，55%碳水化合物）并在扫描前接受生理盐水（进食 - 生理盐水组）或酰基胃饥饿素（进食 - 胃饥饿素组）皮下注射后，进行功能磁共振成像（fMRI）食物图片评估任务。一名男性受试者因头部运动过多被排除在fMRI分析之外，最终有21名受试者拥有大脑激活数据。
与进食 - 生理盐水组相比，给进食受试者注射胃饥饿素（进食 - 胃饥饿素组）和禁食（禁食 - 生理盐水组）均显著增加了高能食物的吸引力以及眶额皮质的激活。禁食和给予胃饥饿素还增加了海马体对高能和低能食物图片的激活。内源性和外源性高胃饥饿素血症的这些相似作用无法通过葡萄糖、胰岛素、肽YY和胰高血糖素样肽 - 1的持续变化来解释。在食物评估任务期间，给予胃饥饿素和禁食对伏隔核、尾状核、前岛叶或杏仁核的激活均无显著影响，在对照任务期间对听觉、运动或视觉皮层的激活也无显著影响。
在食物评估期间，给予胃饥饿素和禁食对享乐反应以及皮质边缘奖赏 - 认知系统的激活具有相似的急性刺激作用。反复或慢性高胃饥饿素血症对预期食物奖赏的类似作用可能导致不吃早餐对饮食习惯和体重产生负面影响，以及能量限制减肥的长期失败。
