title: Mechanisms of long-term weight regain in patients undergoing sleeve gastrectomy.
abstract: OBJECTIVE
  Weight regain after bariatric surgery may be associated with behavioral, metabolic, or mechanical factors alone or in combination. The aim of this study was to investigate which factors are related to weight regain in the long-term after sleeve gastrectomy (SG).
  
  
  METHODS
  A retrospective case-control study with 40 patients undergoing SG (32 women, 8 men; age 42.9 ± 10.7 y; preoperative body mass index 35 ± 2.8 kg/m(2)), was performed. Patients were grouped according percentile->50% (cases) or <50% (controls)-of weight regain (%WR cutoff: 25% of weight loss). Weight history, anthropometry, glucose, insulin, homeostasis model assessment-estimated insulin resistance (HOMA-IR), thyroid-stimulating hormone, resting energy expenditure, body composition, dietary survey, psychological test, and physical activity were recorded. Residual gastric capacity was estimated using a radiologic method. RESULTS (MEDIAN [P25-P75]): The evaluation was conducted 38.5 mo (34-41 mo) after SG. Percent weight regain ranged from 2.7% to 129.2% (25.4% [13-37.1]). Patients in the higher %WR group had a greater residual gastric volume (252.7 ± 108.4 versus 148.5 ± 25.3; P < 0.05) and the estimated volume was significantly correlated with %WR (r = 0.673; P = 0.023). Significantly higher body mass index (P = 0.001), resting energy expenditure (P = 0.04), fasting insulin (P = 0.01), and HOMA-IR (P = 0.02) were observed in the higher %WR group. A higher fat intake and a trend toward higher total energy intake were observed in the group with greater %WR. Clinical or borderline levels of anxiety were more frequently observed in the higher %WR group (70% versus 30%; P = 0.01).
  
  
  CONCLUSIONS
  Results from the present study demonstrated that the most important factor associated with long-term weight regain after SG was residual gastric volume. Additional prospective studies with larger numbers of patients are necessary to confirm our results.
authors.affiliation: Department of Nutrition, Clinica Las Condes, Santiago, Chile.
authors.forename: Veronica
authors.initials: V
authors.lastname: Alvarez
authors.affiliation: Department of Nutrition, Clinica Las Condes, Santiago, Chile; Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, Chile. Electronic address: fcarrasc@gmail.com.
authors.forename: Fernando
authors.initials: F
authors.lastname: Carrasco
authors.affiliation: Department of Nutrition, Clinica Las Condes, Santiago, Chile.
authors.forename: Ada
authors.initials: A
authors.lastname: Cuevas
authors.affiliation: Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, Chile.
authors.forename: Barbara
authors.initials: B
authors.lastname: Valenzuela
authors.affiliation: Department of Nutrition, Clinica Las Condes, Santiago, Chile.
authors.forename: Giselle
authors.initials: G
authors.lastname: Muñoz
authors.affiliation: Department of Nutrition, Clinica Las Condes, Santiago, Chile.
authors.forename: Daniela
authors.initials: D
authors.lastname: Ghiardo
authors.affiliation: Department of Nutrition, Clinica Las Condes, Santiago, Chile.
authors.forename: Maria
authors.initials: M
authors.lastname: Burr
authors.affiliation: Department of Nutrition, Clinica Las Condes, Santiago, Chile.
authors.forename: Yael
authors.initials: Y
authors.lastname: Lehmann
authors.affiliation: Department of Nutrition, Clinica Las Condes, Santiago, Chile.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Leiva
authors.affiliation: Department of Surgery, Clinica Las Condes, Santiago, Chile.
authors.forename: Marcos
authors.initials: M
authors.lastname: Berry
authors.affiliation: Department of Surgery, Clinica Las Condes, Santiago, Chile.
authors.forename: Fernando
authors.initials: F
authors.lastname: Maluenda
mesh_terms: D050154:Adiposity; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition; D015992:Body Mass Index; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D005743:Gastrectomy; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000601:surgery; D011182:Postoperative Care; D012189:Retrospective Studies; D013972:Thyrotropin / Q000097:blood; D015430:Weight Gain
chemical_list: D001786:Blood Glucose; D007328:Insulin; D013972:Thyrotropin
keywords: Bariatric surgery; Food intake; Gastric volume; Sleeve gastrectomy; Weight regain