title: An intragastric balloon produces large weight losses in the absence of a change in ghrelin or peptide YY.
abstract: WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT?: The development of obesity is a multi-factorial process that results in an alteration in the neuroendocrine hormones that help regulate appetite and body weight. Weight loss has been shown to alter this neuroendocrine balance so as to promote weight regain. An intragastric balloon is an effective method to achieve significant weight loss in obese patients and is well suited for those patients who are looking for an alternative to lifestyle modification alone, and those who are not ready or suitable for surgical intervention. Limited research has shown that the weight loss achieved with an intragastric balloon is mediated by altered secretion of the hormones that regulate appetite and weight. WHAT DOES THIS STUDY ADD?: There are currently limited data on the effects of intragastric balloons on appetite and weight-related hormones. In the current study, we have investigated a broad range of gut hormones and adipokines and their response to weight loss induced by differing methods, and the subsequent effect this may have on weight regain. This is an important research area as novel therapies and long-term strategies are needed to counteract the unfavourable changes to the neuroendocrine control of appetite and satiety associated with diet-induced weight loss. This study aims to determine the effect of weight loss achieved with different methods on fasting levels of appetite hormones. Sixty-six obese adults with metabolic syndrome were randomized to intragastric balloon (IGB) for 6 months, with a 12-month behavioural modification programme (IGB group, 'IGBG') or a 12-month behavioural modification programme alone (control group, 'CG'). Anthropometric assessments and blood samples were taken every 3 months and total ghrelin, peptide YY (PYY), adiponectin and leptin were measured. Significant weight-loss differences favouring the IGBG were evident between groups at all time points. Ghrelin increased when the IGB was in situ (+39.3 pmol L(-1) vs. baseline) and returned to baseline after its removal (-34.7 pmol L(-1) ). Adiponectin and PYY levels remained stable in the IGBG, with transient increases noted in the CG. There were no significant between-group differences for ghrelin, PYY or adiponectin. In the IGBG, despite a decrease in leptin at 6 months (-11.7 ng mL(-1) ), levels increased to baseline after IGB removal (-3.7 ng mL(-1) ). In summary, weight loss associated with the IGB did not alter fasting levels of PYY or adiponectin. There was a return of ghrelin and leptin levels to baseline values after IGB removal. No compensatory rise in ghrelin was evident in either group 12 months after initial weight reduction, suggesting that such treatment strategies may lead to better long-term sustainable weight loss.
authors.affiliation: The Boden Institute, The University of Sydney, Sydney, Australia.
authors.forename: N R
authors.initials: NR
authors.lastname: Fuller
authors.forename: N S
authors.initials: NS
authors.lastname: Lau
authors.forename: G
authors.initials: G
authors.lastname: Denyer
authors.forename: I D
authors.initials: ID
authors.lastname: Caterson
keywords: Adipokines; gut hormones; obesity; weight loss