title: The longitudinal association between inflammation and incident depressive symptoms in men: the effects of hs-CRP are independent of abdominal obesity and metabolic disturbances.
abstract: BACKGROUND
  This cohort study evaluates whether the association between low-grade inflammation and incident depressive symptoms is independent of abdominal obesity and metabolic disturbances.
  
  
  METHODS
  A cohort of 1167 non-depressed men aged 35 to 80 years were followed up over 5 years to assess incident depressive symptoms measured by the Centre for Epidemiology Scale-Depression or Beck Depression Inventory-I. Venous tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and high sensitivity C-reactive protein (hsCRP) were quantified at baseline and 5years. Logistic regression determined whether hsCRP, IL-6 and TNF-α were associated with incident depressive symptoms independent of abdominal obesity and metabolic factors. Ancillary analysis utilizing depression z scores stratified participants by waist circumference ≥ 102 cm and ≥2 metabolic disturbances.
  
  
  RESULTS
  Incident depressive symptoms occurred in 95 men at 5 years (8.14% of total). Clinically relevant depressive symptoms were associated with baseline hsCRP (adjusted OR=1.04; 95% CI 1.00-1.07, p=.03) and annualized ΔhsCRP (adjusted OR=1.04; 95% CI 1.01-1.08, p=.02). Ancillary analysis showed that the association between annualized ΔhsCRP and depression z score was only significant in men with waist circumference<102 cm (β=.19, p<.001) and ≤1 metabolic disturbance (β=.18, p<.001). None of the measured cytokines were significantly associated with depression.
  
  
  CONCLUSIONS
  hsCRP and annualized ΔhsCRP were positively associated with depressive symptoms in a cohort of men. Further investigation into the role of abdominal obesity and metabolic disturbances in the inflammation-depression hypothesis is warranted.
authors.affiliation: Freemasons Foundation Centre for Men's Health, Discipline of Medicine, School of Medicine, The University of Adelaide, Adelaide, Australia; Department of Rehabilitation Psychology and Psychotherapy, Institute of Psychology, University of Freiburg, Freiburg, Germany. Electronic address: phillip.tully@adelaide.edu.au.
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Tully
authors.affiliation: Department of Rehabilitation Psychology and Psychotherapy, Institute of Psychology, University of Freiburg, Freiburg, Germany; Medical Psychology and Medical Sociology, Medical Faculty, University of Freiburg, Freiburg, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Baumeister
authors.affiliation: Department of Rehabilitation Psychology and Psychotherapy, Institute of Psychology, University of Freiburg, Freiburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Bengel
authors.affiliation: University of Sydney, NHMRC Clinical Trials Centre, Sydney, NSW, Australia.
authors.forename: Alicia
authors.initials: A
authors.lastname: Jenkins
authors.affiliation: University of Sydney, NHMRC Clinical Trials Centre, Sydney, NSW, Australia.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Januszewski
authors.affiliation: Freemasons Foundation Centre for Men's Health, Discipline of Medicine, School of Medicine, The University of Adelaide, Adelaide, Australia.
authors.forename: Sean
authors.initials: S
authors.lastname: Martin
authors.affiliation: Freemasons Foundation Centre for Men's Health, Discipline of Medicine, School of Medicine, The University of Adelaide, Adelaide, Australia.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Wittert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000378:metabolism; D003863:Depression / Q000453:epidemiology* / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D007249:Inflammation / Q000453:epidemiology* / Q000503:physiopathology; D015850:Interleukin-6 / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D008659:Metabolic Diseases / Q000453:epidemiology* / Q000503:physiopathology; D008875:Middle Aged; D056128:Obesity, Abdominal / Q000453:epidemiology* / Q000503:physiopathology; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D055105:Waist Circumference
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein
keywords: Abdominal adiposity; Body mass index; C-reactive protein; Depression; Inflammation; Interleukin-6; Longitudinal; Metabolic syndrome; Obesity; Tumor necrosis factor-alpha