Progressive rise in gut hormone levels after Roux-en-Y gastric bypass suggests gut adaptation and explains altered satiety

Authors


  • Presented to the Annual Meeting of the Association of Surgeons of Great Britain and Ireland, Glasgow, UK, April 2005, and published in abstract form in Br J Surg 2005; 92(S1): 38

Abstract

Background:

Bariatric surgery is the most effective treatment for achieving long-term weight loss in morbidly obese patients. This study investigated prospective changes in gut hormones and metabolic indices after Roux-en-equation image gastric bypass (RYGB).

Methods:

Six patients were seen before, and at 1, 3 and 6 months after operation. Blood was collected after a 12-h fast and at regular intervals after a mixed 420-kcal meal. Hormonal responses were determined, and comparisons between basal levels and areas under the curve were made. Visual analogue scores were used to assess satiety, hunger and nausea.

Results:

Mean body mass index decreased from 48·3 kg/m2 before surgery to 36·4 kg/m2 6 months after RYGB. This was accompanied by a decrease in fasting leptin (P < 0·001) and insulin (P = 0·021) levels. At 1, 3 and 6 months after operation, progressively increasing peptide YY (P < 0·001), enteroglucagon (P = 0·045) and glucagon-like peptide 1 (P = 0·042) responses were observed. There was no change in fasting ghrelin levels (P = 0·144). Postprandial satiety was significantly increased by 1 month after surgery and this was maintained until the end of the study (P < 0·001).

Conclusion:

RYGB resulted in substantial weight loss with enhanced postprandial satiety, a sustained weight plateau, and proportionate reduction in fasting insulin and leptin levels. Lack of the expected increase in appetite and food intake as components of a counter-regulatory response may be explained by gut adaptation and the consequent graded rise in the levels of gut hormones that promote satiety. Copyright © 2005 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

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