title: Higher serum iron is associated with increased oxidant stress in HIV-infected men.
abstract: BACKGROUND
  F₂-isoprostanes (F₂-IsoP) are oxidant stress biomarkers that are higher in HIV-infected women than men. We explored whether the effect of hemoglobin (Hgb), serum iron, or anemia on F₂-IsoP is different between HIV-infected women and men.
  
  
  METHODS
  Plasma F₂-IsoP were quantified by gas chromatography/mass spectrometry; clinical and laboratory data were collected at enrollment or from the medical record. Multivariable linear regression was used to assess associations between F₂-IsoP and Hgb, anemia as a dichotomous variable, and serum iron with adjustment for age, sex, race, body mass index, CD4 lymphocyte count, self-reported current smoking status, and antiretroviral therapy.
  
  
  RESULTS
  Compared with men, women had lower Hgb [median: 12.7 (interquartile range: 11.8-13.9) vs. 14.9 (13.7-15.8) g/dL, P < 0.001], lower iron levels [75 (47-97) vs. 90 (69-121) µg/dL, P = 0.004], more anemia (29% vs. 10%, P < 0.001), and higher levels of F₂-IsoP [42 (32-62) vs. 36 (25-46) pg/mL, P < 0.001]. The relationship between iron and F₂-IsoP differed significantly between men and women (interaction P = 0.02). Men had a 21% (95% confidence interval: 8 to 36) increase in F₂-IsoP per interquartile increase in iron (P = 0.001), whereas no relationship was seen among women [-4% (-17 to 13, P = 0.65].
  
  
  CONCLUSIONS
  Although women have overall higher F₂-IsoP than men, a relationship between circulating F₂-IsoP and iron levels was observed in men but not in women with HIV infection. The association between female sex and higher F₂-IsoP is not explained by iron or Hgb levels because the association persists when controlling for these factors. The role of iron in oxidant stress and sex-specific differences among HIV-infected individuals require further study.
authors.affiliation: *Department of Medicine, Division of Infectious Diseases; †Department of Biostatistics; ‡Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN; §Departments of Genomic Medicine and Medicine, Cleveland Clinic Foundation/Lerner Research Institute, Cleveland, OH; and ‖Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN (Dr Crist is now with the Acute Disease Epidemiology Section, Georgia Department of Public Health, Atlanta, GA; Dr Melekhin is now with Middle Tennessee Medical Center, Murfreesboro, TN).
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Crist
authors.forename: Vlada V
authors.initials: VV
authors.lastname: Melekhin
authors.forename: Aihua
authors.initials: A
authors.lastname: Bian
authors.forename: Ayumi
authors.initials: A
authors.lastname: Shintani
authors.forename: Ginger L
authors.initials: GL
authors.lastname: Milne
authors.forename: Asha R
authors.initials: AR
authors.lastname: Kallianpur
authors.forename: Leigh A
authors.initials: LA
authors.lastname: Dageforde
authors.forename: David W
authors.initials: DW
authors.lastname: Haas
authors.forename: Todd
authors.initials: T
authors.lastname: Hulgan
mesh_terms: D000328:Adult; D000740:Anemia / Q000209:etiology; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000097:blood* / Q000188:drug therapy*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D012307:Risk Factors
chemical_list: D019380:Anti-HIV Agents; D006454:Hemoglobins; D007501:Iron