title: Effect of surgical weight loss on free radical and antioxidant balance: a preliminary report.
abstract: BACKGROUND
  This study observes the effect of surgical weight loss on free radical and antioxidant vitamin balance.
  
  
  METHODS
  22 consecutive morbidly obese patients undergoing vertical banded gastroplasty (VBG) were chosen for the study. Postoperative studies were done at 12 and 24 weeks. Plasma antioxidant and vitamin determinations were performed by HPLC method.
  
  
  RESULTS
  Subjects lost a significant amount of weight (P < 0.01). Compared to preoperative measurements, postoperative measurements of plasma beta-carotene were not statististically different both at 12 and 24 weeks (13.86 +/- 1.26 microg/dl, 12.35 +/- 1.2, P = 0.44; 14.33 +/- 2.03, P = 0.77; preoperatively, 12 and 24 weeks respectively). Alpha-tocopherol increased slightly at the 12th week; the difference was not significant (8.50 +/- 0.77; 9.56 +/- 0.82, P = 0.37; preoperatively and 12th week respectively). The levels of alpha-tocopherol rose at 24th week significantly (10.89 +/- 0.55, P = 0.028). The indicator of lipid peroxidation (malondialdehyde) decreased with weight loss (1.505 +/- 0.11 micromol/L preoperatively; 0.75 +/- 0.062 at 12th week, P = 0.01; 0.712 +/- 0.05 at 24th week, P < 0.01).
  
  
  CONCLUSIONS
  Our data show that free radical generation falls markedly in association with weight loss after VBG. Surgical weight loss leads to significant decrease in oxidant production and also leads to increase in some antioxidant vitamins. The demonstration of decreased free radical generation and correction of balance between free radicals and antioxidant vitamins has important implications for oxidative mechanisms underlying obesity-associated disorders.
authors.affiliation: Department of Internal Medicine, Section of Endocrinology, Meram Medical Faculty of Selcuk University, Meram/Konya, Turkey. gurcank@hotmail.com
authors.forename: Gurcan
authors.initials: G
authors.lastname: Kisakol
authors.forename: Engin
authors.initials: E
authors.lastname: Guney
authors.forename: Firat
authors.initials: F
authors.lastname: Bayraktar
authors.forename: Candeger
authors.initials: C
authors.lastname: Yilmaz
authors.forename: Taylan
authors.initials: T
authors.lastname: Kabalak
authors.forename: Dilek
authors.initials: D
authors.lastname: Ozmen
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000032:analysis*; D005260:Female; D005609:Free Radicals / Q000032:analysis*; D015391:Gastroplasty; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D009752:Nutritional Status; D011184:Postoperative Period; D015431:Weight Loss / Q000502:physiology*; D024502:alpha-Tocopherol / Q000097:blood; D019207:beta Carotene / Q000097:blood
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D019207:beta Carotene; D008315:Malondialdehyde; D024502:alpha-Tocopherol