Header

UZH-Logo

Maintenance Infos

Effects of Roux-en-Y gastric bypass surgery on energy expenditure and bone metabolism in rats


Abegg, Kathrin. Effects of Roux-en-Y gastric bypass surgery on energy expenditure and bone metabolism in rats. 2014, University of Zurich, Faculty of Science.

Abstract

Bariatric surgery, including the Roux-en-Y gastric bypass (RYGB), is currently the only effective long-term treatment for morbid obesity. Contrary to the traditional classification of RYGB as a restrictive and malabsorptive procedure, these factors seem to play a minor role. Increasing evidence suggests that changes in gut hormone levels, such as glucagon-like peptide-1 (GLP-1), may account for the majority of the effects.
One major side effect of RYGB surgery is a decrease in bone density. In a
longitudinal study in rats, we showed that bone mineral density decreased early after RYGB surgery and coincided with intestinal calcium malabsorption. Although intestinal calcium absorption normalized between two and seven weeks after surgery, there was no restoration of bone mass; this was potentially caused by chronic lactic acidosis. The RYGB-induced changes in bone metabolism occurred independent of weight loss.
Previous studies have shown that the compensatory decrease in energy expenditure in response to body weight loss is attenuated in RYGB rats. Since increased GLP-1 levels contribute to the reduced caloric intake after RYGB surgery, we hypothesized that they may also be involved in the reported alterations in energy expenditure; however, we did not find any effect of acute GLP-1 agonism or antagonism on energy expenditure. We were further able to show that the altered energy expenditure in RYGB rats was not caused by differences in body composition or by a shift in the thermoneutral zone.

Abstract

Bariatric surgery, including the Roux-en-Y gastric bypass (RYGB), is currently the only effective long-term treatment for morbid obesity. Contrary to the traditional classification of RYGB as a restrictive and malabsorptive procedure, these factors seem to play a minor role. Increasing evidence suggests that changes in gut hormone levels, such as glucagon-like peptide-1 (GLP-1), may account for the majority of the effects.
One major side effect of RYGB surgery is a decrease in bone density. In a
longitudinal study in rats, we showed that bone mineral density decreased early after RYGB surgery and coincided with intestinal calcium malabsorption. Although intestinal calcium absorption normalized between two and seven weeks after surgery, there was no restoration of bone mass; this was potentially caused by chronic lactic acidosis. The RYGB-induced changes in bone metabolism occurred independent of weight loss.
Previous studies have shown that the compensatory decrease in energy expenditure in response to body weight loss is attenuated in RYGB rats. Since increased GLP-1 levels contribute to the reduced caloric intake after RYGB surgery, we hypothesized that they may also be involved in the reported alterations in energy expenditure; however, we did not find any effect of acute GLP-1 agonism or antagonism on energy expenditure. We were further able to show that the altered energy expenditure in RYGB rats was not caused by differences in body composition or by a shift in the thermoneutral zone.

Statistics

Downloads

112 downloads since deposited on 15 Jan 2015
52 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Dissertation
Referees:Lutz Thomas A, Langhans W, Gassmann M, le Roux Carel W
Communities & Collections:05 Vetsuisse Faculty > Institute of Veterinary Physiology
Dewey Decimal Classification:570 Life sciences; biology
Language:English
Date:2014
Deposited On:15 Jan 2015 09:43
Last Modified:05 Apr 2016 18:48
Number of Pages:120

Download

Preview Icon on Download
Preview
Filetype: PDF
Size: 8MB

TrendTerms

TrendTerms displays relevant terms of the abstract of this publication and related documents on a map. The terms and their relations were extracted from ZORA using word statistics. Their timelines are taken from ZORA as well. The bubble size of a term is proportional to the number of documents where the term occurs. Red, orange, yellow and green colors are used for terms that occur in the current document; red indicates high interlinkedness of a term with other terms, orange, yellow and green decreasing interlinkedness. Blue is used for terms that have a relation with the terms in this document, but occur in other documents.
You can navigate and zoom the map. Mouse-hovering a term displays its timeline, clicking it yields the associated documents.

Author Collaborations