Lower levels of plasma syndecan-4 are associated with loss of body weight and fat-free mass after bariatric surgery.

OBJECTIVE: Bariatric surgery induces a significant loss of both fat mass (FM) and fat-free mass (FFM). The proteoglycan receptor syndecan-4 (SDC4) plays a crucial role in adipose tissue and skeletal muscle functions. Thus, this study was performed (i) to assess plasma SDC4 levels after both Sleeve Gastrectomy (SG) and Roux-en-Y Gastric Bypass (RYGB) surgeries, and (ii) to explore potential associations with changes in body composition variables. RESULTS: Twenty-six patients (17 females) with severe obesity underwent SG (n = 13) or RYGB (n = 13) and were followed up to 1 year (1Y). Body weight, FM, FFM, and SCD4 were measured at baseline (BL), and at week 11 (W11) and 1Y after surgery. Independently of procedure, there was a significant body weight loss at W11, with an average FM and FFM reduction of 13.7 ± 0.6 kg and 5.3 ± 0.5 kg, respectively. Participants continued to lose weight afterwards, with a total weigth loss of 38.2 ± 1.5 kg at 1Y. No associations were found at BL between SDC4 levels and any anthropometric variable; however, SDC4 levels were lower than BL at both W11 and 1Y, independently of type of surgery. Additionally, changes in SDC4 between BL and 1Y were positively correlated with weight and FFM loss during the same period. TRIAL REGISTRATION: ClinicalTrials.gov NCT04051190 on 09/08/2019.

Hedonic hunger, eating behavior, and food reward and preferences 1 year after initial weight loss by diet or bariatric surgery.

OBJECTIVE: The objective of this study was to investigate changes in hedonic hunger, eating behavior, and food reward and preferences at 1-year (1Y) follow-up after an initial weight loss (WL) induced by a 10-week, very low-energy diet alone (controls) or in combination with bariatric surgery. METHODS: Patients scheduled for sleeve gastrectomy or Roux-en-Y gastric bypass and controls were recruited. Body weight/composition, hedonic hunger (Power of Food Scale), eating behavior traits (Dutch Eating Behavior Questionnaire and Three-Factor Eating Questionnaire), and food reward and preferences (computerized behavioral task) were measured at baseline, 11 weeks, and 1Y follow-up. RESULTS: Changes in anthropometric variables were comparable across groups in the initial phase (week 11), and hedonic hunger decreased overall. The bariatric-surgery groups continued to lose body weight and fat mass, whereas weight regain was seen in controls at 1Y follow-up. Decreases in emotional eating, hunger, disinhibition, and food reward and increases in dietary restraint were seen at 1Y follow-up in the bariatric-surgery groups only. CONCLUSIONS: Continued WL with bariatric surgery is paralleled by favorable changes in eating behavior and food reward and preferences. By contrast, controls experienced weight regain at 1Y follow-up and no changes in eating behavior. These striking differences are likely to be important in the long-term WL management of individuals with severe obesity.

Gastrointestinal hormones and appetite ratings after weight loss induced by diet or bariatric surgery.

OBJECTIVE: The aim of this study was to compare changes in gastrointestinal hormones and appetite ratings after a similar weight loss induced by a very low-energy diet alone or in combination with sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB). METHODS: Patients with severe obesity scheduled for SG (n = 15) and RYGB (n = 14) and 15 controls (very low-energy diet alone) were recruited. Body weight/composition, plasma concentrations of ß-hydroxybutyric acid, acylated ghrelin, total glucagon-like peptide-1, total peptide YY, cholecystokinin, and ratings of hunger, fullness, desire to eat, and prospective food consumption were measured pre- and postprandially, before and after 10 weeks of intervention. RESULTS: Changes in body weight/composition and level of ketosis were similar across groups. In SG and RYGB, basal and postprandial acylated ghrelin declined, and postprandial glucagon-like peptide-1 increased, both significantly more compared with controls. Postprandial peptide YY increased in all groups. Overall, postprandial hunger decreased, and postprandial fullness increased. But ratings of desire to eat and prospective food consumption were more favorable after both surgeries compared with controls. CONCLUSIONS: Weight loss with SG and RYGB leads to more favorable changes in gastrointestinal hormones compared with diet alone, although ratings of appetite were reduced across all groups.

Differences in gastrointestinal hormones and appetite ratings between individuals with and without obesity-A systematic review and meta-analysis.

Determining if gastrointestinal (GI) hormone response to food intake differs between individuals with, and without, obesity may improve our understanding of obesity pathophysiology. A systematic review and meta-analysis of studies assessing the concentrations of GI hormones, as well as appetite ratings, following a test meal, in individuals with and without obesity was undertaken. Systematic searches were conducted in the databases MEDLINE, Embase, Cochrane Library, PsycINFO, Web of Science, and ClinicalTrials.gov. A total of 7514 unique articles were retrieved, 115 included in the systematic review, and 70 in the meta-analysis. The meta-analysis compared estimated standardized mean difference in GI hormones' concentration, as well as appetite ratings, between individuals with and without obesity. Basal and postprandial total ghrelin concentrations were lower in individuals with obesity compared with controls, and this was reflected by lower postprandial hunger ratings in the former. Individuals with obesity had a lower postprandial concentration of total peptide YY compared with controls, but no significant differences were found for glucagon-like peptide 1, cholecystokinin, or other appetite ratings. A large methodological and statistical heterogeneity among studies was found. More comprehensive studies are needed to understand if the differences observed are a cause or a consequence of obesity.

Changes in hedonic hunger and food reward after a similar weight loss induced by a very low-energy diet or bariatric surgery.

OBJECTIVE: The aim of this study was to compare changes in hedonic hunger and food reward in individuals with severe obesity achieving 10% to 15% weight loss with a very low-energy diet (VLED) alone or VLED and bariatric surgery. METHODS: Patients scheduled for sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) initiated a VLED 2 weeks prior to surgery and continued the diet for 8 weeks postoperatively. BMI-matched controls underwent a VLED for 10 weeks. Hedonic hunger was assessed with the Power of Food Scale, and food reward with the Leeds Food Preference Questionnaire, pre and post intervention. RESULTS: A total of 44 participants completed the study: 15 SG, 14 RYGB, and 15 controls (61%, 79% and 69% females, respectively; BMI: 40.5 ± 0.5 kg/m2 ; age: 43.9 ± 1.4 years). Average weight loss was 18.3 ± 0.6 kg (16%), comprising 13.5 ± 0.5 kg fat mass, with no significant differences between groups. Similar reductions in hedonic hunger were observed in all groups. Overall, food reward was similarly reduced in SG and RYGB groups, whereas controls showed little or no change. CONCLUSIONS: Independent of modality, weight loss seems to reduce hedonic hunger, but bariatric surgery leads to several additional favorable changes in food reward and preferences.

Differences in gastrointestinal hormones and appetite ratings among obesity classes.

The aim of this study was to compare gastrointestinal (GI) hormones and subjective ratings of appetite among obesity classes, and between classes of obesity and controls. Ninety-eight adult individuals with obesity, divided into class I (n = 35), II (n = 44) and III (n = 19), together with 45 controls without obesity were included in this cross-sectional analysis. Body weight/composition, and basal and postprandial (after a 600 kcal fixed breakfast) plasma concentrations of acylated ghrelin, active glucagon-like peptide 1 (GLP-1), total peptide YY (PYY), cholecystokinin (CCK) and insulin, as well as subjective ratings of hunger, fullness, desire to eat (DTE) and prospective food consumption (PFC) were measured. There were no differences in the plasma concentration of GI hormones (either basal or postprandial) among obesity classes, except for insulin. In general, obesity was associated with impaired secretion of GI hormones. Ghrelin secretion did not decline postprandially in class-III obesity. GLP-1 peak for obesity class I and II was early and lower, while class III showed no postprandial GLP-1 response. Postprandial PYY response for obesity class II and III was absent, and class III showed a delayed and shortened postprandial CCK response. Obesity class II and III had greater basal insulin concentration compared to controls and postprandial insulin was greater in obesity class III versus class II, class I and controls. No differences were found for appetite ratings among obesity classes. In conclusion, obesity is characterized by impaired secretion of GI hormones, with reduced postprandial satiety, particularly in individuals with obesity class III. This abnormal pattern may lead to overeating.