title: Novel cardiovascular risk markers in depression: no association between depressive symptoms and osteoprotegerin or adiponectin in persons at high risk for sleep apnea.
abstract: BACKGROUND
  Inflammation is believed to play a role in the pathogenesis of both cardiovascular disease and depressive disorders. We hypothesized that circulating concentrations of the novel inflammatory and cardiovascular biomarkers osteoprotegerin (OPG) and adiponectin as well as high sensitivity C-reactive protein (hsCRP) are associated with the severity of depressive symptoms and presence of major depressive disorder (MDD).
  
  
  METHODS
  In a cross-sectional population-derived study (Akershus Sleep Apnea Project) 520 persons underwent clinical examination and venous blood sampling. Medical history was obtained and the participants completed the Beck Depression Inventory (BDI). Structured clinical interviews for axis-I disorders including MDD were performed in a subgroup of 288 participants. OPG and adiponectin concentrations were determined by in-house time-resolved immunofluorometric assays.
  
  
  RESULTS
  Despite significant correlation with hsCRP (r=0.162, p<0.001), the sum-score of BDI did not correlate with OPG or adiponectin levels (r=0.011, p=0.811 and r=0.055, p=0.210, respectively). Neither circulating OPG nor adiponectin differed between persons with (n=34) and without (n=246) MDD (median±interquartile range: 1.18 (0.96-1.49) vs. 1.17 (0.93-1.57) ug/l and 7.26 (5.13-9.91) vs. 7.39 (5.23-11.37) mg/l, respectively).
  
  
  CONCLUSIONS
  Causal considerations are not possible, and results in the sub-group of diagnosed participants need careful interpretation due to small sample size.
  
  
  CONCLUSIONS
  hsCRP was independently associated with depressive symptoms, but no association between depression severity or presence of MDD and OPG- or adiponectin concentrations was observed in community-residing persons at high risk for obstructive sleep apnea.
authors.affiliation: Division of Medicine, Akershus University Hospital and Institute of Clinical Medicine, University of Oslo, Norway. gunnar.einvik@medisin.uio.no
authors.forename: Gunnar
authors.initials: G
authors.lastname: Einvik
authors.forename: Allan
authors.initials: A
authors.lastname: Flyvbjerg
authors.forename: Harald
authors.initials: H
authors.lastname: Hrubos-Strøm
authors.forename: Anna
authors.initials: A
authors.lastname: Randby
authors.forename: Jan
authors.initials: J
authors.lastname: Frystyk
authors.forename: Mette
authors.initials: M
authors.lastname: Bjerre
authors.forename: Silje K
authors.initials: SK
authors.lastname: Namtvedt
authors.forename: Håvard A
authors.initials: HA
authors.lastname: Kristiansen
authors.forename: Inger H
authors.initials: IH
authors.lastname: Nordhus
authors.forename: Virend K
authors.initials: VK
authors.lastname: Somers
authors.forename: Toril
authors.initials: T
authors.lastname: Dammen
authors.forename: Torbjørn
authors.initials: T
authors.lastname: Omland
mesh_terms: D052242:Adiponectin / Q000097:blood*; D000328:Adult; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D003430:Cross-Sectional Studies; D003863:Depression / Q000097:blood*; D003865:Major Depressive Disorder / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053244:Osteoprotegerin / Q000097:blood*; D011569:Psychiatric Status Rating Scales; D018570:Risk Assessment; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000097:blood*
chemical_list: D052242:Adiponectin; D015415:Biomarkers; D053244:Osteoprotegerin; D002097:C-Reactive Protein