Heath Madeleine L, Kow Lilian, Slavotinek John P, Valentine Robin, Toouli Jim, Thompson Campbell H
Department of Medicine, Flinders Medical Centre, Flinders University, Bedford Park 5042, South Australia.
Metabolism. 2009 Jun;58(6):753-8. doi: 10.1016/j.metabol.2008.05.021.
Weight loss after laparoscopic adjustable gastric banding surgery (LAGB) is associated with mobilization of adipose tissue from a variety of depots. We sought to evaluate and relate abdominal and hepatic lipid deposition in an obese female population 3 and 12 months after LAGB. We related changes in these depots to markers of insulin sensitivity. Eighteen female obese subjects underwent magnetic resonance imaging and spectroscopy before and 3 and 12 months after LAGB for the quantification of abdominal subcutaneous (ABSAT) and visceral (VAT) adipose tissue areas and liver fat content (LFAT). Fasting blood free fatty acids (FFA) were analyzed. Insulin sensitivity was assessed by the homeostasis model assessment of insulin resistance index (HOMA-R). Mean weight loss 3 and 12 months after LAGB was 9.8 +/- 1.1 kg and 20.0 +/- 2.2 kg, respectively. Postoperatively, VAT area loss exceeded ABSAT area loss in the cohort as a whole and when divided according to preoperative liver fat stores. Three months after LAGB, reductions had occurred in VAT and ABSAT areas (both P < .01) and in FFA (P < .05). Twelve months after LAGB, further significant reductions (P < .01) occurred in VAT and ABSAT areas but not in FFA. No significant reduction occurred in LFAT at either time point in the group as a whole. In those with preoperative hepatic steatosis (LFAT > approximately 5%, n = 7), LFAT fell by 42% (P = .036) 3 months after LAGB, with a total reduction of 50% (P = .027 cf baseline) occurring by 12 months. There was an improvement in HOMA-R at 12 months (1.9 +/- 0.3 cf 2.9 +/- 0.5 at baseline, P = .04) but not 3 months (2.7 +/- 0.4). Preoperatively, LFAT related significantly to VAT area (r = 0.67, P = .003) and HOMA-R (r = 0.497, P = .04) but not ABSAT area. Postoperatively at both 3 and 12 months, LFAT continued to relate to VAT area (r = 0.63, P < .01 at both time points) but not HOMA-R. The changes in LFAT and VAT area were unrelated postoperatively. Abdominal adipose tissue loss was greater from the visceral than subcutaneous depots, suggesting that insulin sensitivity may not be an important determinant of selective lipid depot loss. The lack of a significant change in liver fat in the group as a whole may relate to low preoperative liver fat stores and to high postoperative dietary fat intakes. Preoperative liver fat stores did not influence insulin sensitivity or abdominal lipid changes during weight loss. Liver fat content and VAT area interrelated more closely than either related to ABSAT area, suggesting differing regulatory pathways for fat mobilization from ABSAT and VAT depots but possibly similar pathways for storage and mobilization of fat in the liver and viscerally.
腹腔镜可调节胃束带手术（LAGB）后的体重减轻与来自各种脂肪储存部位的脂肪组织动员有关。我们试图评估肥胖女性人群在LAGB术后3个月和12个月时腹部和肝脏的脂质沉积情况，并将二者联系起来。我们将这些储存部位的变化与胰岛素敏感性标志物相关联。18名肥胖女性受试者在LAGB术前、术后3个月和12个月接受了磁共振成像和波谱分析，以量化腹部皮下（ABSAT）和内脏（VAT）脂肪组织面积以及肝脏脂肪含量（LFAT）。分析空腹血游离脂肪酸（FFA）。通过胰岛素抵抗指数的稳态模型评估（HOMA-R）来评估胰岛素敏感性。LAGB术后3个月和12个月时的平均体重减轻分别为9.8±1.1 kg和20.0±2.2 kg。术后，在整个队列中以及根据术前肝脏脂肪储存情况进行划分时，VAT面积的减少超过了ABSAT面积的减少。LAGB术后3个月，VAT和ABSAT面积均有所减少（均P<.01），FFA也减少（P<.05）。LAGB术后12个月，VAT和ABSAT面积进一步显著减少（P<.01），但FFA没有变化。在整个组中，两个时间点的LFAT均未出现显著降低。在术前有肝脂肪变性（LFAT>约5%，n = 7）的患者中，LAGB术后3个月LFAT下降了42%（P = .036），到12个月时总共下降了50%（与基线相比P = .027）。12个月时HOMA-R有所改善（1.9±0.3，而基线时为2.9±0.5，P = .04），但3个月时未改善（2.7±0.4）。术前，LFAT与VAT面积显著相关（r = 0.67，P = .003）以及与HOMA-R相关（r = 0.497，P = .04），但与ABSAT面积无关。术后3个月和12个月时，LFAT均继续与VAT面积相关（两个时间点r = 0.63，P<.01），但与HOMA-R无关。术后LFAT和VAT面积的变化不相关。腹部脂肪组织从内脏储存部位的丢失比皮下储存部位更大，这表明胰岛素敏感性可能不是选择性脂质储存部位丢失的重要决定因素。整个组中肝脏脂肪没有显著变化可能与术前肝脏脂肪储存量低以及术后饮食脂肪摄入量高有关。术前肝脏脂肪储存量在体重减轻期间不影响胰岛素敏感性或腹部脂质变化。肝脏脂肪含量与VAT面积的相互关系比二者与ABSAT面积的关系更密切，这表明从ABSAT和VAT储存部位动员脂肪的调节途径不同，但肝脏和内脏中脂肪储存和动员的途径可能相似。
