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Current Obesity Reports
Published in: Current Obesity Reports 2/2015

01-06-2015 | Obesity Treatment (CM Apovian, Section Editor)

What is the Mechanism Behind Weight Loss Maintenance with Gastric Bypass?

Authors: Saurav Chakravartty, Daniele Tassinari, Angelo Salerno, Emmanouil Giorgakis, Francesco Rubino

Published in: Current Obesity Reports | Issue 2/2015

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Abstract

Obesity is an epidemic on the rise. With the failure of non-surgical strategies, bariatric surgery has emerged as the most effective therapeutic option for the treatment of severe obesity. Among various surgical options, Roux-en-Y gastric bypass (RYGB) results in sustained weight loss and profound metabolic improvements. The traditional view that gastric bypass and bariatric surgery in general works primarily through restriction/malabsorption of nutrients has become obsolete. It is now increasingly recognised that its mechanisms of action are primarily physiologic, not mechanic. In fact, clinical and translational studies over the last decade have shown that a number of gastrointestinal mechanisms, including changes in gut hormones, neural signalling, intestinal flora, bile acid and lipid metabolism can play a significant role in the effects of this procedure on energy homeostasis. The clinical efficacy and mechanisms of action of RYGB provide a compelling evidence for the role of the gastrointestinal tract in the regulation of appetite and satiety, body weight and glucose metabolism. This review discusses the physiologic changes that occur after RYGB and that contribute to its mechanisms of action.
Literature
1.
2.
McPherson K, Marsh T, Brown M. Foresight: tackling obesities: future choices — modelling future trends in obesity and the impact on health. 2nd ed. London: U.K. Government Office for Science; 2007.
3.
Atallah R et al. Long-term effects of 4 popular diets on weight loss and cardiovascular risk factors: a systematic review of randomized controlled trials. Circ Cardiovasc Qual Outcomes. 2014;7(6):815–27.CrossRefPubMed
4.
Leblanc ES et al. Effectiveness of primary care-relevant treatments for obesity in adults: a systematic evidence review for the U.S. Preventive Services Task Force. Ann Intern Med. 2011;155(7):434–47.CrossRefPubMed
5.
Buchwald H et al. Bariatric surgery: a systematic review and meta-analysis. JAMA. 2004;292(14):1724–37.CrossRefPubMed
6.
Sjostrom L. Review of the key results from the Swedish Obese Subjects (SOS) trial—a prospective controlled intervention study of bariatric surgery. J Intern Med. 2013;273(3):219–34.CrossRefPubMed
7.
8.
Angrisani L et al. Laparoscopic adjustable gastric banding versus Roux-en-Y gastric bypass: 10-year results of a prospective, randomized trial. Surg Obes Relat Dis. 2013;9(3):405–13.CrossRefPubMed
9.
Zhang Y, Ju W, Sun X, Cao Z, Xinsheng X, Daquan L, Xiangyang X, Qin M. Laparoscopic sleeve gastrectomy versus laparoscopic Roux-en-Y gastric bypass for morbid obesity and related comorbidities: a meta-analysis of 21 studies. Obes Surg. 2015;25(1):19–26.
10.
Schauer PR et al. Bariatric surgery versus intensive medical therapy for diabetes—3-year outcomes. N Engl J Med. 2014;370(21):2002–13.CrossRefPubMed
11.
Mingrone G et al. Bariatric surgery versus conventional medical therapy for type 2 diabetes. N Engl J Med. 2012;366(17):1577–85.CrossRefPubMed
12.
Dixon JB et al. Adjustable gastric banding and conventional therapy for type 2 diabetes: a randomized controlled trial. JAMA. 2008;299(3):316–23.CrossRefPubMed
13.
Dogan K et al. Long-term effects of laparoscopic Roux-en-Y gastric bypass on diabetes mellitus, hypertension and dyslipidaemia in morbidly obese patients. Obes Surg. 2014;24(11):1835–42.CrossRefPubMed
14.
Leahey TM et al. Effects of bariatric surgery on food cravings: do food cravings and the consumption of craved foods “normalize” after surgery? Surg Obes Relat Dis. 2012;8(1):84–91.CrossRefPubMed
15.
Olbers T et al. Body composition, dietary intake, and energy expenditure after laparoscopic Roux-en-Y gastric bypass and laparoscopic vertical banded gastroplasty: a randomized clinical trial. Ann Surg. 2006;244(5):715–22.CrossRefPubMedCentralPubMed
16.
Ernst B et al. Differential changes in dietary habits after gastric bypass versus gastric banding operations. Obes Surg. 2009;19(3):274–80.CrossRefPubMed
17.
Bueter M et al. Alterations of sucrose preference after Roux-en-Y gastric bypass. Physiol Behav. 2011;104(5):709–21.CrossRefPubMed
18.
Pepino MY et al. Changes in taste perception and eating behavior after bariatric surgery-induced weight loss in women. Obesity (Silver Spring). 2014;22(5):E13–20.CrossRef
19.
Ullrich J et al. Roux-en-Y gastric bypass surgery reduces hedonic hunger and improves dietary habits in severely obese subjects. Obes Surg. 2013;23(1):50–5.CrossRefPubMed
20.
Werling M et al. Increased postprandial energy expenditure may explain superior long term weight loss after Roux-en-Y gastric bypass compared to vertical banded gastroplasty. PLoS One. 2013;8(4):e60280.CrossRefPubMedCentralPubMed
21.
Das SK et al. Long-term changes in energy expenditure and body composition after massive weight loss induced by gastric bypass surgery. Am J Clin Nutr. 2003;78(1):22–30.PubMed
22.
Ochner CN et al. Relation between changes in neural responsivity and reductions in desire to eat high-calorie foods following gastric bypass surgery. Neuroscience. 2012;209:128–35.CrossRefPubMedCentralPubMed
23.
Scholtz S et al. Obese patients after gastric bypass surgery have lower brain-hedonic responses to food than after gastric banding. Gut. 2014;63(6):891–902.CrossRefPubMedCentralPubMed
24.
Gautron L, Zechner JF, Aguirre V. Vagal innervation patterns following Roux-en-Y gastric bypass in the mouse. Int J Obes (Lond). 2013;37(12):1603–7.CrossRef
25.
Zagorodnyuk VP, Chen BN, Brookes SJ. Intraganglionic laminar endings are mechano-transduction sites of vagal tension receptors in the guinea-pig stomach. J Physiol. 2001;534(Pt 1):255–68.CrossRefPubMedCentralPubMed
26.
27.
Berthoud HR et al. Vagal sensors in the rat duodenal mucosa: distribution and structure as revealed by in vivo DiI-tracing. Anat Embryol (Berl). 1995;191(3):203–12.CrossRef
28.•
Yousseif A et al. Differential effects of laparoscopic sleeve gastrectomy and laparoscopic gastric bypass on appetite, circulating acyl-ghrelin, peptide YY3-36 and active GLP-1 levels in non-diabetic humans. Obes Surg. 2014;24(2):241–52. This study reports the comparative effects of LRYGBP and LSG on appetite and circulating gut hormones. The two surgical procedures are anatomically distinct causing differential entero-endocrine cell nutrient exposure and thus potentially different gut hormone changes.CrossRefPubMedCentralPubMed
29.
Malin SK et al. Improved acylated ghrelin suppression at 2 years in obese patients with type 2 diabetes: effects of bariatric surgery vs standard medical therapy. Int J Obes (Lond). 2014;38(3):364–70.CrossRef
30.
Lee WJ et al. Changes in postprandial gut hormones after metabolic surgery: a comparison of gastric bypass and sleeve gastrectomy. Surg Obes Relat Dis. 2011;7(6):683–90.CrossRefPubMed
31.
Barazzoni R et al. Gastric bypass does not normalize obesity-related changes in ghrelin profile and leads to higher acylated ghrelin fraction. Obesity (Silver Spring). 2013;21(4):718–22.CrossRef
32.•
Martins C et al. Impact of sustained weight loss achieved through Roux-en-Y gastric bypass or a lifestyle intervention on ghrelin, obestatin, and ghrelin/obestatin ratio in morbidly obese patients. Obes Surg. 2011;21(6):751–8. This manuscript assumes that sustained weight loss maintenance seems to be associated with increased fasting levels of ghrelin and obestatin after RYGB surgery; therefore, ghrelin is unlikely to contribute to weight loss maintenance after RYGB.CrossRefPubMed
33.••
Tamboli RA et al. Early weight regain after gastric bypass does not affect insulin sensitivity but is associated with elevated ghrelin. Obesity (Silver Spring). 2014;22(7):1617–22. This study suggests that higher preoperative ghrelin levels might identify patients who are more susceptible to weight regain after RYGB that could be important to indentified patients who need a closer follow-up.CrossRef
34.
35.
Rasmussen BA et al. Jejunal leptin-PI3K signaling lowers glucose production. Cell Metab. 2014;19(1):155–61.CrossRefPubMed
36.
Rubino F et al. The early effect of the Roux-en-Y gastric bypass on hormones involved in body weight regulation and glucose metabolism. Ann Surg. 2004;240(2):236–42.CrossRefPubMedCentralPubMed
37.
Terra X et al. Long-term changes in leptin, chemerin and ghrelin levels following different bariatric surgery procedures: Roux-en-Y gastric bypass and sleeve gastrectomy. Obes Surg. 2013;23(11):1790–8.CrossRefPubMed
38.
Hao Z, Münzberg H, Rezai-Zadeh K, Keenan M, Coulon D, Lu H, Berthoud HR, Ye J. Leptin deficient ob/ob mice and diet-induced obese mice responded differently to Roux-en-Y bypass surgery. Int J Obes (Lond). 2014. doi:10.​1038/​ijo.​2014.​189.
39.
De Carvalho CP et al. GLP-1 and adiponectin: effect of weight loss after dietary restriction and gastric bypass in morbidly obese patients with normal and abnormal glucose metabolism. Obes Surg. 2009;19(3):313–20.CrossRefPubMed
40.
Le Roux CW et al. Gut hormone profiles following bariatric surgery favor an anorectic state, facilitate weight loss, and improve metabolic parameters. Ann Surg. 2006;243(1):108–14.CrossRefPubMedCentralPubMed
41.
Korner J et al. Prospective study of gut hormone and metabolic changes after adjustable gastric banding and Roux-en-Y gastric bypass. Int J Obes (Lond). 2009;33(7):786–95.CrossRef
42.
Karamanakos SN et al. Weight loss, appetite suppression, and changes in fasting and postprandial ghrelin and peptide-YY levels after Roux-en-Y gastric bypass and sleeve gastrectomy: a prospective, double blind study. Ann Surg. 2008;247(3):401–7.CrossRefPubMed
43.•
Peterli R et al. Metabolic and hormonal changes after laparoscopic Roux-en-Y gastric bypass and sleeve gastrectomy: a randomized, prospective trial. Obes Surg. 2012;22(5):740–8. This manuscript shows that bypassing the foregut is not the only mechanism responsible for improved glucose homeostasis and that the balance between foregut (ghrelin, CCK) and hindgut (GLP-1, PYY) hormones is a key to understanding the underlying mechanisms.CrossRefPubMedCentralPubMed
44.
Korner J et al. Effects of Roux-en-Y gastric bypass surgery on fasting and postprandial concentrations of plasma ghrelin, peptide YY, and insulin. J Clin Endocrinol Metab. 2005;90(1):359–65.CrossRefPubMed
45.
Vidal J et al. Long-term effects of Roux-en-Y gastric bypass surgery on plasma glucagon-like peptide-1 and islet function in morbidly obese subjects. J Clin Endocrinol Metab. 2009;94(3):884–91.CrossRefPubMed
46.
Tang-Christensen M, Vrang N, Larsen PJ. Glucagon-like peptide containing pathways in the regulation of feeding behaviour. Int J Obes Relat Metab Disord. 2001;25 Suppl 5:S42–7.CrossRefPubMed
47.
Verdich C et al. The role of postprandial releases of insulin and incretin hormones in meal-induced satiety-effect of obesity and weight reduction. Int J Obes Relat Metab Disord. 2001;25(8):1206–14.CrossRefPubMed
48.
49.
Cohen RV et al. Duodenal-jejunal bypass for the treatment of type 2 diabetes in patients with body mass index of 22–34 kg/m2: a report of 2 cases. Surg Obes Relat Dis. 2007;3(2):195–7.CrossRefPubMed
50.•
Patel RT et al. Surgical control of obesity and diabetes: the role of intestinal vs. gastric mechanisms in the regulation of body weight and glucose homeostasis. Obesity (Silver Spring). 2014;22(1):159–69. This study elucidates the specific role of gastric vs. intestinal manipulations in the regulation of body weight and glucose homeostasis.CrossRef
51.
Mokadem M et al. Effects of Roux-en-Y gastric bypass on energy and glucose homeostasis are preserved in two mouse models of functional glucagon-like peptide-1 deficiency. Mol Metab. 2014;3(2):191–201.CrossRefPubMedCentralPubMed
52.
Jimenez A et al. GLP-1 action and glucose tolerance in subjects with remission of type 2 diabetes after gastric bypass surgery. Diabetes Care. 2013;36(7):2062–9.CrossRefPubMedCentralPubMed
53.
54.
Furet JP et al. Differential adaptation of human gut microbiota to bariatric surgery-induced weight loss: links with metabolic and low-grade inflammation markers. Diabetes. 2010;59(12):3049–57.CrossRefPubMedCentralPubMed
55.
56.
Kohli R et al. Weight loss induced by Roux-en-Y gastric bypass but not laparoscopic adjustable gastric banding increases circulating bile acids. J Clin Endocrinol Metab. 2013;98(4):E708–12.CrossRefPubMedCentralPubMed
57.
Pournaras DJ et al. The role of bile after Roux-en-Y gastric bypass in promoting weight loss and improving glycaemic control. Endocrinology. 2012;153(8):3613–9.CrossRefPubMedCentralPubMed
58.
59.
Zhang Y et al. Activation of the nuclear receptor FXR improves hyperglycemia and hyperlipidemia in diabetic mice. Proc Natl Acad Sci U S A. 2006;103(4):1006–11.CrossRefPubMedCentralPubMed
60.
Watanabe M et al. Bile acids induce energy expenditure by promoting intracellular thyroid hormone activation. Nature. 2006;439(7075):484–9.CrossRefPubMed
61.
De Giorgi S, Campos V, Egli L, Toepel U, Carrel G, Cariou B, Rainteau D, Schneiter P, Tappy L, Giusti V. Long-term effects of Roux-en-Y gastric bypass on postprandial plasma lipid and bile acids kinetics in female nondiabetic subjects: a cross-sectional pilot study. Clin Nutr. 2014. doi:10.​1016/​j.​clnu.​2014.​09.​018.
Metadata
Title
What is the Mechanism Behind Weight Loss Maintenance with Gastric Bypass?
Authors
Saurav Chakravartty
Daniele Tassinari
Angelo Salerno
Emmanouil Giorgakis
Francesco Rubino
Publication date
01-06-2015
Publisher
Springer US
Published in
Current Obesity Reports / Issue 2/2015
Electronic ISSN: 2162-4968
DOI
https://doi.org/10.1007/s13679-015-0158-7

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