Effects of chronic consumption of sugar-enriched diets on brain metabolism and insulin sensitivity in adult Yucatan Minipigs

Excessive sugar intake might increase the risk to develop eating disorders via an altered reward circuitry, but it remains unknown whether different sugar sources induce different neural effects and whether these effects are dependent from body weight. Therefore, we compared the effects of three high-fat and isocaloric diets varying only in their carbohydrate sources on brain activity of reward-related regions, and assessed whether brain activity is dependent on insulin sensitivity. Twenty-four minipigs underwent 18FDG PET brain imaging following 7-month intake of high-fat diets of which 20% in dry matter weight (36.3% of metabolisable energy) was provided by starch, glucose or fructose (n = 8 per diet). Animals were then subjected to a euglycemic hyperinsulinemic clamp to determine peripheral insulin sensitivity. After a 7-month diet treatment, all groups had substantial increases in body weight (from 36.02±0.85 to 63.33±0.81 kg; P&lt;0.0001), regardless of the diet. All groups present...过量摄入糖分或可通过改变奖赏回路（reward circuitry）增加进食障碍的发病风险，但目前尚不明确不同糖类来源是否会引发不同的神经效应，且此类效应是否依赖于个体体重。为此，本研究比较了仅糖类来源存在差异的三种等热量高脂饮食对奖赏相关脑区神经活动的影响，并评估了脑活动是否与胰岛素敏感性相关。本研究纳入24头迷你猪（minipig），在饲喂为期7个月的高脂饮食后，对其开展18氟脱氧葡萄糖正电子发射断层显像（18FDG PET）脑成像。上述高脂饮食中，干物质重量占比20%、代谢能占比36.3%的碳水化合物分别由淀粉、葡萄糖或果糖提供，每组各8头实验动物。随后，对所有实验动物实施正糖高胰岛素钳夹试验（euglycemic hyperinsulinemic clamp），以测定其外周胰岛素敏感性。经7个月的饮食干预后，无论饲喂何种饮食，各组实验动物的体重均出现显著增长（从36.02±0.85 kg增至63.33±0.81 kg；P<0.0001）。各组实验动物均呈现……