title: Combined measure of pro- and anti-oxidant exposures in relation to prostate cancer and colorectal adenoma risk: an update.
abstract: OBJECTIVE
  We previously proposed an oxidative balance score (OBS) and illustrated its practical application by using data from previously completed case-control studies of two neoplasms - sporadic colorectal adenoma and prostate cancer. In the present study we extend our analysis by substituting questionnaire-based measures with systemic biomarkers of pro- and anti-oxidant exposures.
  
  
  METHODS
  Low, medium and high pro-oxidant exposures, and high, medium and low antioxidant exposures were assigned 0, 1 and 2 points, respectively and individual points for all exposures were then summed to calculate the overall score. Case and controls were compared using logistic regression analysis after adjusting for covariates.
  
  
  RESULTS
  When OBS was treated as a continuous variable the adjusted odds ratios and 95% confidence intervals (CI) for each additional score point were the same: 0.90 (95% CI: 0.83-0.97) for each study. When the OBS was divided into three approximately equal intervals, a comparison of the lowest to highest category showed similar adjusted ORs (95% CIs) of 0.34 (0.13-0.88) and 0.34 (0.14-0.86) for colorectal adenoma and prostate cancer, respectively.
  
  
  CONCLUSIONS
  Our analyses provide support for the stated hypothesis that combined measures of pro- and anti-oxidant exposures may be associated with oxidative stress-related conditions.
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA. mgoodm2@sph.emory.edu
authors.forename: Michael
authors.initials: M
authors.lastname: Goodman
authors.forename: Roberd M
authors.initials: RM
authors.lastname: Bostick
authors.forename: Myron
authors.initials: M
authors.lastname: Gross
authors.forename: Bharat
authors.initials: B
authors.lastname: Thyagarajan
authors.forename: Chiranjeev
authors.initials: C
authors.lastname: Dash
authors.forename: W Dana
authors.initials: WD
authors.lastname: Flanders
mesh_terms: D000236:Adenoma / Q000473:pathology; D000975:Antioxidants / Q000008:administration & dosage / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000209:etiology* / Q000473:pathology; D006801:Humans; D016015:Logistic Models; D008297:Male; D018384:Oxidative Stress; D011471:Prostatic Neoplasms / Q000209:etiology*; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D011795:Surveys and Questionnaires
chemical_list: D000975:Antioxidants; D015415:Biomarkers