title: Bile acids synthesis decreases after laparoscopic sleeve gastrectomy.
abstract: BACKGROUND
  Bariatric surgery is the most effective treatment alternative in morbid obesity. The mechanisms contributing to these benefits remain poorly understood. Bile acids (BAs) are mediators of different regulatory functions in glucose and cholesterol homeostasis and energy expenditure. Recent evidence suggests that BAs are critically important for the beneficial effects of sleeve gastrectomy (SG).
  
  
  OBJECTIVE
  The aim of this study was to evaluate the effect of SG on BA synthesis.
  
  
  METHODS
  University Hospital. Santiago, Chile.
  
  
  METHODS
  Obese patients were evaluated before and after SG (1, 3, 6, and 12 months). BA synthesis was evaluated through the serum marker, 7 α-hydroxy-4-cholesten-3-one (C4). Primary and secondary BA and C4 were determined by high performance liquid chromatography coupled with tandem mass spectrometry detection (HPLC-MS/MS).
  
  
  RESULTS
  From June 2013 to January 2014, 19 patients (age 37.6±7.8 years; BMI 35.8±3.5 kg/m(2); 79% female) were included in this study. Mean weight loss at 1, 3, 6, and 12 months was 11.3, 17.5, 23.6, and 25.4 kg, respectively, equivalent to 11.8, 18.6, 24.8, and 26.9 of total body water percentage (%TBW) (P<.0001), respectively and 43.2, 68.2, 91, and 98.8 of percentage of excess weight loss (%EWL), respectively (P<.001). Serum C4 levels at baseline, 1, 3, 6, and 12 months were 23.4±21.1, 4.9±8.2, 8.7±12.1, 13.8±12.9, and 18.8±16.8 ng/mL (P<.0001), respectively. Fibroblast growth factor 19 (FGF19) levels at baseline, 1, 3, 6, and 12 months were 71±33.3, 130.5±66.2, 117.8±57.2, 134.6±91.7, and 124.3±85.9 pg/mL (P = .019), respectively.
  
  
  CONCLUSIONS
  Serum levels of C4 decrease after SG, indicating a reduction in the synthesis of BA. FGF19 may play a role in decreasing BA synthesis. Further studies are necessary to characterize the effect of bariatric surgery on BA homeostasis.
authors.affiliation: Department of Surgery. Faculty of Medicine, Universidad de los Andes, Santiago, Chile. Electronic address: aescalona@clinicauandes.cl.
authors.forename: Alex
authors.initials: A
authors.lastname: Escalona
authors.affiliation: Department of Digestive Surgery, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Muñoz
authors.affiliation: Department of Nutrition, Diabetes and Metabolism, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Veronica
authors.initials: V
authors.lastname: Irribarra
authors.affiliation: Department of Clinical Laboratories, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Sandra
authors.initials: S
authors.lastname: Solari
authors.affiliation: Department of Clinical Laboratories, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Fidel
authors.initials: F
authors.lastname: Allende
authors.affiliation: Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Juan
authors.initials: J
authors.lastname: Francisco Miquel
mesh_terms: D000293:Adolescent; D000328:Adult; D001647:Bile Acids and Salts / Q000096:biosynthesis*; D015415:Biomarkers / Q000378:metabolism; D002783:Cholestenones / Q000378:metabolism; D005260:Female; D005743:Gastrectomy / Q000379:methods*; D015390:Gastric Bypass / Q000379:methods; D015391:Gastroplasty / Q000379:methods*; D006801:Humans; D010535:Laparoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000378:metabolism / Q000601:surgery*; D055815:Young Adult
chemical_list: D001647:Bile Acids and Salts; D015415:Biomarkers; D002783:Cholestenones; C002656:7 alpha-hydroxy-4-cholesten-3-one
keywords: Bariatric surgery; Bile acids; Obesity; Sleeve gastrectomy