title: Elevated C-reactive protein and late-onset bipolar disorder in 78 809 individuals from the general population.
abstract: BACKGROUND
  No prospective studies have examined the role of C-reactive protein (CRP) in late-onset bipolar disorder.
  
  
  OBJECTIVE
  We tested the hypothesis that elevated levels of CRP are associated cross-sectionally and prospectively with late-onset bipolar disorder, and that such an association possibly is causal.
  
  
  METHODS
  We performed cross-sectional and prospective analyses with a median follow-up time of 5.9 years (interquartile range: 4.4-7.6) in 78 809 individuals from the general population, and used genetic variants influencing CRP levels to perform a Mendelian randomisation study.
  
  
  RESULTS
  Elevated levels of CRP were associated both cross-sectionally and prospectively with late-onset bipolar disorder. When CRP was on a continuous scale, a doubling in CRP yielded an observational odds ratio for late-onset bipolar disorder of 1.28 (1.08-1.52) with a corresponding causal odds ratio of 4.66 (0.89-24.3).
  
  
  CONCLUSIONS
  Elevated CRP is associated with increased risk of late-onset bipolar disorder in the general population which was supported by the genetic analysis.
authors.affiliation: Marie Kim Wium-Andersen, MD, Department of Clinical Biochemistry, The Copenhagen General Population Study, Herlev Hospital, Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; David Dynnes Ørsted, MD, PhD, Department of Clinical Biochemistry, The Copenhagen General Population Study, Herlev Hospital, Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Børge Grønne Nordestgaard, MD, DMSc, Department of Clinical Biochemistry, The Copenhagen General Population Study, Herlev Hospital, Copenhagen University Hospital, The Copenhagen City Heart Study, Frederiksberg Hospital, Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Marie Kim
authors.initials: MK
authors.lastname: Wium-Andersen
authors.affiliation: Marie Kim Wium-Andersen, MD, Department of Clinical Biochemistry, The Copenhagen General Population Study, Herlev Hospital, Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; David Dynnes Ørsted, MD, PhD, Department of Clinical Biochemistry, The Copenhagen General Population Study, Herlev Hospital, Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Børge Grønne Nordestgaard, MD, DMSc, Department of Clinical Biochemistry, The Copenhagen General Population Study, Herlev Hospital, Copenhagen University Hospital, The Copenhagen City Heart Study, Frederiksberg Hospital, Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: David Dynnes
authors.initials: DD
authors.lastname: Ørsted
authors.affiliation: Marie Kim Wium-Andersen, MD, Department of Clinical Biochemistry, The Copenhagen General Population Study, Herlev Hospital, Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; David Dynnes Ørsted, MD, PhD, Department of Clinical Biochemistry, The Copenhagen General Population Study, Herlev Hospital, Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Børge Grønne Nordestgaard, MD, DMSc, Department of Clinical Biochemistry, The Copenhagen General Population Study, Herlev Hospital, Copenhagen University Hospital, The Copenhagen City Heart Study, Frederiksberg Hospital, Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark Boerge.Nordestgaard@regionh.dk.
authors.forename: Børge Grønne
authors.initials: BG
authors.lastname: Nordestgaard
mesh_terms: D000368:Aged; D001714:Bipolar Disorder / Q000097:blood* / Q000235:genetics; D002097:C-Reactive Protein / Q000032:analysis* / Q000235:genetics*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D000067562:Late Onset Disorders / Q000097:blood* / Q000235:genetics; D016015:Logistic Models; D008297:Male; D057182:Mendelian Randomization Analysis; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D002097:C-Reactive Protein