Background: In patients with short bowel syndrome, an elevated pre-resection Body Mass Index may be protective of post-resection body composition. We hypothesized that rats with diet-induced obesity would lose less lean body mass after undergoing massive small bowel resection compared to non-obese rats. Methods: Rats (CD® IGS; age = 2 mo; N = 80) were randomly assigned to either a high-fat (obese rats) or a low-fat diet (non-obese rats), and fed ad lib for six months. Each diet group then was randomized to either underwent a 75% distal small bowel resection (massive resection) or small bowel transection with re-anastomosis (sham resection). All rats then were fed ad lib with an intermediate-fat diet (25% of total calories) for two months. Body weight and quantitative magnetic resonance-determined body composition were monitored. Results: Preoperative body weight was 884 ± 95 vs. 741 ± 75 g, and preoperative percent body fat was 35.8 ± 3.9 vs. 24.9 ± 4.6%; high-fat vs. low fat diet, respectively (p < 0.0001); preoperative diet type had no effect on lean mass. Regarding total body weight, massive resection produced an 18% vs. 5% decrease in high-fat vs. low-fat rats respectively, while sham resection produced a 2% decrease vs. a 7% increase, respectively (p < 0.0001, preoperative vs. necropsy data). Sham resection had no effect on lean mass; after massive resection, both high-fat and low-fat rats lost lean mass, but these changes were not different between the latter two rat groups. Conclusion: The high-fat diet and low-fat diet induced obesity and marginal obesity, respectively. The massive resection produced greater weight loss in high-fat rats compared to low-fat rats. The type of dietary preconditioning had no effect on lean mass loss after massive resection. A protective effect of pre-existing obesity on lean mass after massive intestinal resection was not demonstrated.

中文翻译：

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75％小肠切除术后肥胖对肥胖者肥胖的影响

背景：患有短肠综合征的患者，切除前的身体质量指数升高可能对切除后的身体成分起到保护作用。我们假设与非肥胖的大鼠相比，饮食引起的肥胖的大鼠在进行大范围小肠切除术后将损失更少的瘦体重。方法：将大鼠（CD®IGS；年龄= 2 mo； N = 80）随机分配为高脂饮食（肥胖大鼠）或低脂饮食（非肥胖大鼠），并随意喂养六个月。然后将每个饮食组随机分为75％的远端小肠切除术（大规模切除）或小肠横断再吻合术（假手术）。然后所有大鼠均接受中等脂肪饮食（占总卡路里的25％）随意喂养两个月。监测体重和定量磁共振确定的身体组成。结果：术前体重为884±95 vs. 741±75 g，术前体脂百分比为35.8±3.9 vs. 24.9±4.6％；高脂饮食与低脂饮食（p <0.0001）；术前饮食类型对瘦体重无影响。关于总体重，高脂组和低脂组的大面积切除术分别减少了18％和5％，而假手术则分别减少了2％和7％（P <0.0001，术前与尸检数据）。假手术切除对瘦肉无影响。大块切除后，高脂和低脂大鼠均失去了瘦体重，但后两组大鼠的这些变化没有差异。结论：高脂饮食和低脂饮食分别导致肥胖和边缘性肥胖。与低脂大鼠相比，大规模切除术在高脂大鼠中产生了更大的体重减轻。饮食预处理的类型对大面积切除后的瘦体重没有影响。未证明肥胖对大肠切除术后肥胖的保护作用。