Ghrelin and PYY3−36 in gastrectomized and vagotomized patients: relations with appetite, energy intake and resting energy expenditure

Abstract

Background/Objectives: Reduced food intake, appetite loss and alteration of ghrelin and PYY 3À36 secretion have been suggested to have a function in the loss of body weight commonly observed after gastrectomy. The objective of this study was to investigate the circulating concentrations of ghrelin and PYY 3À36 and their relationships with food intake, appetite and resting energy expenditure (REE) after gastrectomy plus vagotomy. Subjects/Methods: Seven patients with total gastrectomy (TG), 14 with partial gastrectomy (PG) and 10 healthy controls were studied. Habitual food intake and REE was assessed; fasting and postprandial plasma total ghrelin, PYY 3À36 concentrations and appetite ratings were determined after ingestion of a liquid test meal. Results: Differently from PG and controls, fasting ghrelin correlated with REE, and a higher energy intake was observed in the TG group. Fasting plasma ghrelin concentrations were lower in TG compared with controls, and no ghrelin response to the meal was observed in either PG or TG. Fasting plasma PYY 3À36 concentrations were not different among the groups. There was an early and exaggerated postprandial rise in PYY 3À36 levels in both PG and TG groups, but not in controls. No effect of ghrelin or PYY 3À36 concentrations was observed on hunger, prospective consumption or fullness ratings. Conclusions: Total ghrelin and PYY 3À36 do not seem to be involved with appetite or energy intake regulation after gastrectomy plus vagotomy. Ghrelin secreted by sources other than stomach is likely to have a function in the long-term regulation of body weight after TG.

Recovery of Food Intake after Gastrectomy for Gastric Cancer: Based on a Large-Scale Gastric Cancer Cohort

“…In the study by Liedman et al [14], food intake was comparable between patients with gastric substitute after TG and those who underwent Roux-en-Y reconstruction. Other studies observed that patients who underwent STG ate less compared to those who underwent TG, and adverse postprandial symptoms were considered a major cause of reduced calorie intake [14,21]. Moreover, in many studies, patients recovered food intake within several months after gastrectomy, and the amount of food intake reached the recommended daily allowances [20,22,23].…”

Effect of vagotomy during Roux-en-Y gastric bypass surgery on weight loss outcomes

“…An increase in %EWL due to vagotomy could be secondary to its neuroendocrine effects, specifically on ghrelin, a hormone that affects both short and long-term regulation of body weight [11][12][13]. Since the vagus nerve may need to be intact for ghrelin to increase appetite and food intake in humans [14], vagotomy might decrease ghrelin's orexigenic effect and completely abolish fasting-induced elevation of plasma ghrelin level [15].…”

Prokinetics stimulate the increase of ghrelin in mice

“…The study by Unger et al (32) pointed out the decrease in ghrelin signaling under this catecholaminergic and dopaminergic overstimulation, whereas it should be also noted that Karasawa et al (33) reported confl icting fi ndings in a similar experimental Parkinsonism model. Interestingly, no change in fasting ghrelin in vagotomized patients (34) suggests that disturbed cholinergic transmission is not a determinant for lowered ghrelin levels in Parkinson's disease. Moreover, an in vitro study by Iwakura et al (18) however, the facts that the ghrelin-producing cells are stimulated by low ambient D-glucose (36), and the intra-gastric infusion of nutrients provoke the increase in dopamine in the brain (37) may confer an indirect evidence for the interaction between dopamine and ghrelin in the gastrointestinal system.…”