Van Vugt Dean A, Krzemien Alicja, Alsaadi Hanin, Frank Tamar C, Reid Robert L
Department of Obstetrics & Gynaecology, Queen׳s University, Kingston, Canada; Department of Biomedical and Molecular Sciences, Queen׳s University, Kingston, Canada.
Department of Obstetrics & Gynaecology, Queen׳s University, Kingston, Canada.
Brain Res. 2014 Apr 16;1558:44-56. doi: 10.1016/j.brainres.2014.02.037. Epub 2014 Feb 26.
We postulate that insulin regulation of food intake is compromised when insulin resistance is present. In order to investigate the effect of insulin sensitivity on appetitive brain responses, we conducted functional magnetic resonance imaging studies in a group of women diagnosed with polycystic ovary syndrome (PCOS) in which insulin sensitivity ranged from normal to resistant. Subjects (n=19) were imaged while viewing pictures of high calorie (HC) foods and low calorie (LC) foods after ingesting either 75 g glucose or an equivalent volume of water. The insulin sensitive group showed reduced blood oxygen level dependent (BOLD) signal in response to food pictures following glucose ingestion in numerous corticolimbic brain regions, whereas the insulin resistant group did not. There was a significant interaction between insulin sensitivity (sensitive vs resistant) and condition (water vs glucose). The largest clusters identified included the left insula, bilateral limbic/parahippocampal gyrus/culmen/midbrain, bilateral limbic lobe/precuneus, and left superior/mid temporal gyrus/parietal for HC and LC stimuli combined, the left parahippocampal gyrus/fusiform/pulvinar/midbrain for HC pictures, and the left superior/mid temporal gyrus/parietal and middle/inferior frontal gyrus/orbitofrontal cortex for LC pictures. Furthermore, BOLD signal in the anterior cingulate, medial frontal gyrus, posterior cingulate/precuneus, and parietal cortex during a glucose challenge correlated negatively with insulin sensitivity. We conclude the PCOS women with insulin resistance have an impaired brain response to a glucose challenge. The inability of postprandial hyperinsulinemia to inhibit brain responsiveness to food cues in insulin resistant subjects may lead to greater non-homeostatic eating.
我们推测，当存在胰岛素抵抗时，胰岛素对食物摄入的调节会受到损害。为了研究胰岛素敏感性对食欲相关脑反应的影响，我们对一组被诊断为多囊卵巢综合征（PCOS）的女性进行了功能磁共振成像研究，这些女性的胰岛素敏感性范围从正常到抵抗。受试者（n = 19）在摄入75 g葡萄糖或等量体积的水后，观看高热量（HC）食物和低热量（LC）食物的图片时接受成像。胰岛素敏感组在摄入葡萄糖后，对众多皮质边缘脑区的食物图片反应时，血氧水平依赖（BOLD）信号降低，而胰岛素抵抗组则没有。胰岛素敏感性（敏感与抵抗）和条件（水与葡萄糖）之间存在显著交互作用。识别出的最大簇包括左侧脑岛、双侧边缘/海马旁回/山顶/中脑、双侧边缘叶/楔前叶，以及HC和LC刺激合并时的左侧颞上回/颞中回/顶叶，HC图片对应的左侧海马旁回/梭状回/丘脑枕/中脑，以及LC图片对应的左侧颞上回/颞中回/顶叶和额中回/额下回/眶额皮质。此外，在葡萄糖激发试验期间，前扣带回、额内侧回、后扣带回/楔前叶和顶叶皮质的BOLD信号与胰岛素敏感性呈负相关。我们得出结论，患有胰岛素抵抗的PCOS女性对葡萄糖激发试验的脑反应受损。在胰岛素抵抗的受试者中，餐后高胰岛素血症无法抑制大脑对食物线索的反应性，这可能导致更多的非稳态进食。
