title: Oxidative stress markers in adults 2 years after Roux-en-Y gastric bypass.
abstract: BACKGROUND
  Obesity is a chronic disease associated with oxidative stress. Bariatric surgery for the treatment of obesity may affect biomarkers of oxidative stress.
  
  
  OBJECTIVE
  The aim of the present study was to evaluate the effect of Roux-en-Y gastric bypass (RYGB) on blood markers of oxidative stress, such as vitamins C and E, β-carotene, reduced glutathione (GSH), catalase (CAT), ferric reducing antioxidant potential (FRAP), and thiobarbituric acid-reactive substances (TBARS).
  
  
  METHODS
  A prospective controlled clinical trial was carried out. The participants were distributed into two groups: a control group (n=35), which was evaluated once, and a bariatric group (n=35), which was evaluated at baseline as well as 6, 12, and 24 months after surgery.
  
  
  RESULTS
  After surgery, the BMI decreased from 47.05±1.46 to 30.53±1.14 kg/m (P<0.001), but 25.7% of the participants regained weight after 24 months. In relation to the baseline, postsurgery reductions were found in vitamin C (31.9±4.6%, P<0.001), β-carotene (360.7±368.3%, P<0.001), vitamin E (22.8±4.1%, P<0.001), GSH (6.6±5.2%, P=0.090), CAT (12.7±5.6%, P=0.029), and FRAP (1.2±3.8%, P=0.085) 2 years after RYGB. TBARS levels decreased after 12 months (71.6±2.9%, P<0.001) in relation to the baseline but increased by 195.0±28.2% between the 12th and the 24th month (P<0.001).
  
  
  CONCLUSIONS
  The present findings show that oxidative stress returned 2 years after RYGB. Concentrations of vitamin C, β-carotene, GSH, CAT, and FRAP were decreased, whereas the concentration of TBARS decreased in the first year but increased in the following year, which may be partly explained by the imbalance between antioxidants and pro-oxidants.
authors.affiliation: Postgraduate Programme in Nutrition, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: Carla
authors.initials: C
authors.lastname: Dadalt
authors.forename: Regina L M
authors.initials: RL
authors.lastname: Fagundes
authors.forename: Emilia A M
authors.initials: EA
authors.lastname: Moreira
authors.forename: Danilo
authors.initials: D
authors.lastname: Wilhelm-Filho
authors.forename: Maiara B
authors.initials: MB
authors.lastname: de Freitas
authors.forename: Alceu A
authors.initials: AA
authors.lastname: Jordão Júnior
authors.forename: Fernanda
authors.initials: F
authors.lastname: Biscaro
authors.forename: Rozangela C
authors.initials: RC
authors.lastname: Pedrosa
authors.forename: Hélio
authors.initials: H
authors.lastname: Vannucchi
mesh_terms: D000328:Adult; D000886:Anthropometry / Q000379:methods; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000097:blood; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D002374:Catalase / Q000097:blood; D002149:Energy Intake / Q000502:physiology; D005260:Female; D015390:Gastric Bypass; D005978:Glutathione / Q000097:blood; D006801:Humans; D008297:Male; D009765:Obesity / Q000097:blood / Q000503:physiopathology / Q000601:surgery*; D018384:Oxidative Stress / Q000502:physiology*; D011184:Postoperative Period; D011446:Prospective Studies; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood; D019207:beta Carotene / Q000008:administration & dosage / Q000097:blood
chemical_list: D015415:Biomarkers; D017392:Thiobarbituric Acid Reactive Substances; D019207:beta Carotene; D014810:Vitamin E; D002374:Catalase; D005978:Glutathione; D001205:Ascorbic Acid