title: Ascorbic acid prevents contrast-mediated nephropathy in patients with renal dysfunction undergoing coronary angiography or intervention.
abstract: BACKGROUND
  Contrast agents can cause a reduction in renal function that may be due to the generation of reactive oxygen species. Conflicting evidence suggests that administration of the antioxidant acetylcysteine prevents this renal impairment. The action of other antioxidant agents has not been investigated.
  
  
  RESULTS
  We conducted a randomized, double-blind, placebo-controlled trial of ascorbic acid in 231 patients with a serum creatinine concentration > or =1.2 mg/dL who underwent coronary angiography and/or intervention. Ascorbic acid, 3 g at least 2 hours before the procedure and 2 g in the night and the morning after the procedure, or placebo was administered orally. Contrast-mediated nephropathy was defined by an absolute increase of serum creatinine > or =0.5 mg/dL or a relative increase of > or =25% measured 2 to 5 days after the procedure. Contrast-mediated nephropathy occurred in 11 of the 118 patients (9%) in the ascorbic acid group and in 23 of the 113 patients (20%) in the placebo group (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.17 to 0.85; P=0.02). The mean serum creatinine concentration increased significantly in the placebo group (from 1.36+/-0.50 to 1.50+/-0.54 mg/dL, P<0.001) and nonsignificantly in the ascorbic acid group (from 1.46+/-0.52 to 1.52+/-0.64 mg/dL, P=0.07). The mean increase in serum creatinine concentration was greater in the placebo group than in the ascorbic acid group (difference of 0.09 mg/dL; 95% CI, 0.00 to 0.17; P=0.049).
  
  
  CONCLUSIONS
  Prophylactic oral administration of ascorbic acid may protect against contrast-mediated nephropathy in high-risk patients undergoing a coronary procedure.
authors.affiliation: Department of Cardiology, Onassis Cardiac Surgery Centre, 356 Syngrou Ave, 176 74, Athens, Greece. spargias@ocsc.gr
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Spargias
authors.forename: Elias
authors.initials: E
authors.lastname: Alexopoulos
authors.forename: Stamatis
authors.initials: S
authors.lastname: Kyrzopoulos
authors.forename: Panayiotis
authors.initials: P
authors.lastname: Iokovis
authors.forename: Panayiotis
authors.initials: P
authors.lastname: Iacovis
authors.forename: Darren C
authors.initials: DC
authors.lastname: Greenwood
authors.forename: Athanassios
authors.initials: A
authors.lastname: Manginas
authors.forename: Vassilis
authors.initials: V
authors.lastname: Voudris
authors.forename: Gregory
authors.initials: G
authors.lastname: Pavlides
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Buller
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Kremastinos
authors.forename: Dennis V
authors.initials: DV
authors.lastname: Cokkinos
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood / Q000139:chemically induced / Q000517:prevention & control*; D000284:Administration, Oral; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D000975:Antioxidants / Q000008:administration & dosage / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000627:therapeutic use*; D003287:Contrast Media / Q000009:adverse effects*; D017023:Coronary Angiography; D003404:Creatinine / Q000097:blood; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000097:blood; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D018384:Oxidative Stress; D011292:Premedication; D012306:Risk; D016896:Treatment Outcome; D014508:Urea / Q000097:blood
chemical_list: D000975:Antioxidants; D003287:Contrast Media; D014508:Urea; D003404:Creatinine; D001205:Ascorbic Acid