title: Oxidative stress and lowered total antioxidant status are associated with a history of suicide attempts.
abstract: BACKGROUND
  There is evidence that depression is accompanied by inflammation, oxidative and nitrosative stress (O&NS) and metabolic disorders. However links between oxidative stress and suicide attempts in depressed patients are poorly understood. This study examines whether a history of suicide attempts is associated with inflammation, O&NS and metabolic disorders.
  
  
  METHODS
  Blood specimens were collected from study participants aged 18-60 (N=342) recruited at the State University of Londrina, Brazil, and measured for oxidative stress biomarkers: nitric oxide metabolites (NOx), lipid hydroperoxides, malondialdehyde, advanced oxidation protein products and plasma total antioxidant potential (TRAP); inflammatory biomarkers: fibrinogen, high-sensitivity C-reactive protein, erythrocyte sedimentation rate, interleukin-6 and tumor necrosis factor-α; and metabolic variables. Subjects were divided into those with (n=141) and without (n=201) a history of suicidal attempts.
  
  
  RESULTS
  Individuals with a history of suicide attempts had significantly higher levels of NOx and lipid hydroperoxides and lowered TRAP as compared to individuals without suicide attempts. There were no significant associations between a history of suicide attempts and inflammatory and metabolic biomarkers and metabolic syndrome. Logistic regression showed that both unipolar and bipolar disorder, female gender, smoking behavior and lipid hydroperoxides were significantly associated with a history of suicide attempts. The combined effects of oxidative stress, smoking, depression, female gender were independent from classical risk factors, including marital status, years of education and anxiety.
  
  
  CONCLUSIONS
  O&NS as well as lowered antioxidant levels may play a role in the pathophysiology of suicidal behavior independently from the effects of depression and smoking, both of which are associated with increased O&NS, and classical suicide predictors, such as years of education and marital status.
authors.affiliation: Department of Clinical Medicine, Psychiatry Unit, Londrina State University, Brazil. hebervargas@sercomtel.com.br
authors.forename: Heber Odebrecht
authors.initials: HO
authors.lastname: Vargas
authors.forename: Sandra Odebrecht Vargas
authors.initials: SO
authors.lastname: Nunes
authors.forename: Marcia
authors.initials: M
authors.lastname: Pizzo de Castro
authors.forename: Chiara Cristina
authors.initials: CC
authors.lastname: Bortolasci
authors.forename: Décio
authors.initials: D
authors.lastname: Sabbatini Barbosa
authors.forename: Helena
authors.initials: H
authors.lastname: Kaminami Morimoto
authors.forename: Kamalesh
authors.initials: K
authors.lastname: Venugopal
authors.forename: Seetal
authors.initials: S
authors.lastname: Dodd
authors.forename: Michael
authors.initials: M
authors.lastname: Maes
authors.forename: Michael
authors.initials: M
authors.lastname: Berk
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001938:Brazil / Q000453:epidemiology; D002097:C-Reactive Protein / Q000032:analysis; D003863:Depression / Q000097:blood; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D016015:Logistic Models; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood; D008875:Middle Aged; D017942:Nitric Acid / Q000097:blood; D018384:Oxidative Stress; D012307:Risk Factors; D057566:Self Report; D012907:Smoking / Q000097:blood; D013406:Suicide, Attempted; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D055815:Young Adult
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D017942:Nitric Acid; D002097:C-Reactive Protein
keywords: Depressive disorders; Inflammation; Metabolism; Nicotine dependence; Oxidative stress; Suicide