title: Inflammation in Schizophrenia: Cytokine Levels and Their Relationships to Demographic and Clinical Variables.
abstract: Inflammation may play a role in the accelerated physical aging reported in schizophrenia, though biomarker findings and associations with demographic and clinical factors are inconsistent.
  
  
  
  In a cross-sectional, case-control design, 95 outpatients with schizophrenia (mean age ± SD: 48.1 ± 10.2 years) and 95 demographically comparable healthy comparison subjects (HCs) (mean age ± SD: 48.1 ± 12.1 years) were studied. Sociodemographic and clinical data were collected, and plasma levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interferon-γ (IFN-γ) were assayed. The authors compared cytokine levels, examined demographic and clinical associations, and adjusted for relevant variables with linear models.
  
  
  
  Individuals with schizophrenia had higher levels of TNF-α and IL-6 but not IFN-γ than HCs. Age was not related to cytokine levels, and age relationships did not differ between diagnostic groups. Women had higher levels of IL-6. TNF-α and IL-6 levels were significantly correlated with depressive symptoms, and adjustment for depression reduced the group effect for both. Within the HCs, TNF-α levels were associated with physical comorbidity and body mass index. IL-6 levels were significantly correlated with body mass index and within schizophrenia patients, with worse mental and physical well-being. Accounting for physical morbidity and mental well-being reduced group differences in TNF-α and IL-6 levels, respectively. Worse positive symptoms were associated with higher IL-6 levels.
  
  
  
  Higher TNF-α and IL-6 levels in schizophrenia patients were associated with depression, physical comorbidity, and mental well-being. Further longitudinal studies are warranted to assess inflammation as a potential treatment target for a subgroup of schizophrenia.
authors.affiliation: Department of Psychiatry, University of California San Diego, La Jolla, CA; Sam and Rose Stein Institute for Research on Aging, University of California San Diego, La Jolla, CA.
authors.forename: Ellen E
authors.initials: EE
authors.lastname: Lee
authors.affiliation: Department of Psychiatry, University of California San Diego, La Jolla, CA; Departments of Family Medicine and Public Health, University of California San Diego, La Jolla, CA.
authors.forename: Suzi
authors.initials: S
authors.lastname: Hong
authors.affiliation: Department of Psychiatry, University of California San Diego, La Jolla, CA; Sam and Rose Stein Institute for Research on Aging, University of California San Diego, La Jolla, CA.
authors.forename: Averria Sirkin
authors.initials: AS
authors.lastname: Martin
authors.affiliation: Department of Psychiatry, University of California San Diego, La Jolla, CA; Desert-Pacific Mental Illness Research Education and Clinical Center, Veterans Affairs San Diego Healthcare System, San Diego, CA.
authors.forename: Lisa T
authors.initials: LT
authors.lastname: Eyler
authors.affiliation: Department of Psychiatry, University of California San Diego, La Jolla, CA; Departments of Neurosciences, University of California San Diego, La Jolla, CA; Sam and Rose Stein Institute for Research on Aging, University of California San Diego, La Jolla, CA; The Center for Healthy Aging, University of California San Diego, La Jolla, CA. Electronic address: djeste@ucsd.edu.
authors.forename: Dilip V
authors.initials: DV
authors.lastname: Jeste
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000097:blood*; D003863:Depression / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D006304:Health Status; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010549:Personal Satisfaction; D012559:Schizophrenia / Q000097:blood* / Q000453:epidemiology
chemical_list: D016207:Cytokines
keywords: IFN-γ; IL-6; TNF-α; cytokines; inflammation; schizophrenia