title: The Ala55Val and -866G>A polymorphisms of the UCP2 gene could be biomarkers for weight loss in patients who had Roux-en-Y gastric bypass.
abstract: OBJECTIVE
  The aim of this study was to investigate whether the Ala55Val and -866G>A polymorphisms of the UCP2 gene are related to weight loss and changes in body composition after bariatric surgery performed by Roux-en-Y gastric bypass (RYGB).
  
  
  METHODS
  This longitudinal study enrolled obese patients submitted to RYGB. Data regarding weight (kg), body mass index (kg/m2), fat-free mass (FFM; kg), fat mass (kg), weight loss (kg and %), and percent excess weight loss were collected from both preoperative and 1-y postoperative medical records. Polymorphisms were genotyped by allelic discrimination using real-time polymerase chain reaction and TaqMan-predesigned single nucleotide polymorphism Genotyping Assay kits (Applied Biosystems, Foster City, CA, USA). The t test was used to compare variables between genotypes of each polymorphism to analyze the dominant and recessive models. Linear regression models were used to adjust the effects of initial weight, age, and sex on the variation of weight and body composition (P < 0.05).
  
  
  RESULTS
  We analyzed 150 severely obese individuals (age 47.2 ± 10.5 y; 80% women). Genotype analysis showed a greater prevalence of heterozygous GA (41.3%) for -866G>A polymorphism and CT (39.3%) for Ala55Val polymorphism. Individuals who carried the T (CT+TT) and A (GA+AA) mutated alleles for Ala55Val and -866G>A, respectively, showed a higher weight and FFM loss.
  
  
  CONCLUSIONS
  The mutated alleles T for Ala55Val and A for -866G>A polymorphism could be biomarkers of weight loss 1 y after RYGB.
authors.affiliation: Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Carolina F
authors.initials: CF
authors.lastname: Nicoletti
authors.affiliation: Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Ana Paula R P
authors.initials: AP
authors.lastname: de Oliveira
authors.affiliation: Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Maria José F
authors.initials: MJ
authors.lastname: Brochado
authors.affiliation: Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Marcela A S
authors.initials: MA
authors.lastname: Pinhel
authors.affiliation: Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Bruno A P
authors.initials: BA
authors.lastname: de Oliveira
authors.affiliation: Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Julio S
authors.initials: JS
authors.lastname: Marchini
authors.affiliation: Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: José E
authors.initials: JE
authors.lastname: Dos Santos
authors.affiliation: Department of Surgery and Anatomy, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Wilson
authors.initials: W
authors.lastname: Salgado
authors.affiliation: Department of Genetics, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Nathalia Moreno
authors.initials: NM
authors.lastname: Cury
authors.affiliation: Department of Genetics, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Luiza Ferreira
authors.initials: LF
authors.lastname: de Araújo
authors.affiliation: Department of Genetics, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Wilson A
authors.initials: WA
authors.lastname: Silva
authors.affiliation: Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. Electronic address: Carla@fmrp.usp.br.
authors.forename: Carla B
authors.initials: CB
authors.lastname: Nonino
mesh_terms: D000328:Adult; D000483:Alleles; D019943:Amino Acid Substitution; D015415:Biomarkers; D001823:Body Composition; D015992:Body Mass Index; D001938:Brazil; D003131:Combined Modality Therapy; D005260:Female; D015390:Gastric Bypass; D005787:Gene Frequency; D056726:Genetic Association Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D009767:Obesity, Morbid / Q000235:genetics / Q000378:metabolism / Q000601:surgery* / Q000628:therapy; D020641:Polymorphism, Single Nucleotide; D000071246:Uncoupling Protein 2 / Q000235:genetics* / Q000378:metabolism; D015431:Weight Loss
chemical_list: D015415:Biomarkers; C000604389:UCP2 protein, human; D000071246:Uncoupling Protein 2
keywords: Bariatric surgery; Biomarker; Obesity; UCP2 polymorphism; Weight loss