Metabolic and Hormonal Changes After Laparoscopic Roux-en-Y Gastric Bypass and Sleeve Gastrectomy: a Randomized, Prospective Trial

Department of Surgery, St Claraspital, 4016 Basel, Switzerland.
Obesity Surgery (Impact Factor: 3.74). 02/2012; 22(5):740-8. DOI: 10.1007/s11695-012-0622-3
Source: PubMed

ABSTRACT The mechanisms of amelioration of glycemic control early after laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) are not fully understood.
In this prospective, randomized 1-year trial, outcomes of LRYGB and LSG patients were compared, focusing on possibly responsible mechanisms. Twelve patients were randomized to LRYGB and 11 to LSG. These non-diabetic patients were investigated before and 1 week, 3 months, and 12 months after surgery. A standard test meal was given after an overnight fast, and blood samples were collected before, during, and after food intake for hormone profiles (cholecystokinin (CCK), ghrelin, glucagon-like peptide 1 (GLP-1), peptide YY (PYY)).
In both groups, body weight and BMI decreased markedly and comparably leading to an identical improvement of abnormal glycemic control (HOMA index). Post-surgery, patients had markedly increased postprandial plasma GLP-1 and PYY levels (p < 0.05) with ensuing improvement in glucose homeostasis. At 12 months, LRYGB ghrelin levels approached preoperative values. The postprandial, physiologic fluctuation returned, however, while LSG ghrelin levels were still markedly attenuated. One year postoperatively, CCK concentrations after test meals increased less in the LRYGB group than they did in the LSG group, with the latter showing significantly higher maximal CCK concentrations (p < 0.012 vs. LRYGB).
Bypassing the foregut is not the only mechanism responsible for improved glucose homeostasis. The balance between foregut (ghrelin, CCK) and hindgut (GLP-1, PYY) hormones is a key to understanding the underlying mechanisms.

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    • "Sleeve gastrectomy , a surgical technique without duodenal exclusion , produced similar results regarding GLP - 1 secretion in comparison to patients submitted to GB ( Nannipieri et al . , 2013 ; Peterli et al . , 2012 , 2009 ; Romero et al . , 2012 ) . In another study in obese diabetic patients submitted to SG , the first phase of insulin secretion after an intravenous glucose tolerance test improved early after surgery and secretion of GLP - 1 and PYY was increased . However , patients with longstanding T2D ( >10 years ) did not experience the same"
    02/2015, Degree: PhD, Supervisor: Francisco Castro e Sousa
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    • "These data cannot exclude the possibility that increases in GLP-1, decreases in ghrelin, and a myriad of other factors are part of a broader set of hormonal changes that work in concert to mediate the potent effects of these procedures. Other factors that have been hypothesized to be altered after one or more of these procedures include prandial secretion of cholecystokinin (Jacobsen et al., 2012; Peterli et al., 2012), glucose inhibitory peptide (Lee et al., 2013; Romero et al., 2012), glucagon (Romero et al., 2012), GLP-2 (Jacobsen et al., 2012; Romero et al., 2012), peptide YY (Dimitriadis et al., 2013; Peterli et al., 2009), and perhaps others (Dimitriadis et al., 2013; Santoro et al., 2008). Determining the relative contribution of these different factors to surgical benefits on glucose tolerance and weight loss remains an important research goal. "
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    ABSTRACT: Bariatric surgical procedures such as vertical sleeve gastrectomy (VSG) and Roux-en-Y gastric bypass (RYGB) are the most potent treatments available to produce sustained reductions in body weight and improvements in glucose regulation. While traditionally these effects are attributed to mechanical aspects of these procedures, such as restriction and malabsorption, a growing body of evidence from mouse models of these procedures points to physiological changes that mediate the potent effects of these surgeries. In particular, there are similar changes in gut hormone secretion, bile acid levels, and composition after both of these procedures. Moreover, loss of function of the nuclear bile acid receptor (FXR) greatly diminishes the effects of VSG. Both VSG and RYGB are linked to profound changes in the gut microbiome that also mediate at least some of these surgical effects. We hypothesize that surgical rearrangement of the gastrointestinal tract results in enteroplasticity caused by the high rate of nutrient presentation and altered pH in the small intestine that contribute to these physiological effects. Identifying the molecular underpinnings of these procedures provides new opportunities to understand the relationship of the gastrointestinal tract to obesity and diabetes as well as new therapeutic strategies to harness the effectiveness of surgery with less-invasive approaches. Copyright © 2015 Elsevier Inc. All rights reserved.
    Cell Metabolism 02/2015; 21(3). DOI:10.1016/j.cmet.2015.01.001 · 16.75 Impact Factor
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    • "Blood glucose (A), insulin (B), and GLP-1 (C) response to liquid meal or oral glucose ingestion in non-surgical healthy controls and those after AGB, SG, and RYGB [29, 46, 51]. Data were adjusted for baseline values "
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    ABSTRACT: To date, weight loss surgeries are the most effective treatment for obesity and glycemic control in patients with type 2 diabetes. Roux-en-Y gastric bypass surgery (RYGB) and sleeve gastrectomy (SG), two widely used bariatric procedures for the treatment of obesity, induce diabetes remission independent of weight loss while glucose improvement after adjustable gastric banding (AGB) is proportional to the amount of weight loss. The immediate, weight-loss independent glycemic effect of gastric bypass has been attributed to postprandial hyperinsulinemia and an enhanced incretin effect. The rapid passage of nutrients into the intestine likely accounts for significantly enhanced glucagon like-peptide 1 (GLP-1) secretion, and postprandial hyperinsulinemia after GB is typically attributed to the combined effects of elevated glucose and GLP-1. For this review we focus on the beneficial effects of the three most commonly performed bariatric procedures, RYGB, SG, and AGB, on glucose metabolism and diabetes remission. Central to this discussion will be the extent to which the effects of surgery are mediated by GLP-1. Better understanding of these mechanisms could provide insight to development of novel therapeutic strategies for treatment of diabetes as well as refinement of surgical techniques.
    Reviews in Endocrine and Metabolic Disorders 06/2014; 15(3). DOI:10.1007/s11154-014-9291-y · 3.81 Impact Factor
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