title: Iron deficiency: Prevalence and relation to cardiovascular biomarkers in heart failure outpatients.
abstract: BACKGROUND
  Both iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked.
  
  
  OBJECTIVE
  To identify the prevalence of ID in a HF clinic and evaluate whether ID is associated with increased plasma concentrations of different cardiovascular biomarkers that carry a poor prognosis.
  
  
  METHODS
  We prospectively included 149 patients with systolic HF referred to an outpatients HF clinic. ID was defined as ferritin<100 μg/L or ferritin 100-300 μg/L and Tranferin-saturation<0.20. Five different cardiovascular biomarkers were analyzed on frozen plasma.
  
  
  RESULTS
  The patients had a median age of 70 (Interquartile range: 64-75) years, 25% were females, 29% were in functional class III-IV and LVEF was 32 (27-39) %. The prevalence of ID was 45% (95%-confidence interval (CI): 37-53%). In multivariate analyses, ID was not associated with plasma concentrations of troponin I, NT-proBNP, MR-proANP, chromogranin A or copeptin (P>0.05 for all) but with plasma concentrations of hs-CRP (odds ratio: 2.03, 95%-CI: 1.02-4.02, P=0.043).
  
  
  CONCLUSIONS
  ID is frequent in an outpatient HF clinic. ID is not associated with cardiovascular biomarkers after adjustment for traditional confounders. Inflammation, but not neurohormonal activation is associated with ID in systolic HF. Further studies are needed to understand iron metabolism in elderly HF patients.
authors.affiliation: Department of Cardiology, Herlev University Hospital, DK-2730 Herlev, Denmark. Electronic address: m.schou@dadlnet.dk.
authors.forename: Morten
authors.initials: M
authors.lastname: Schou
authors.affiliation: Department of Internal Medicine KNEA, North Zealand University Hospital, DK-3400 Hillerod, Denmark.
authors.forename: Helle
authors.initials: H
authors.lastname: Bosselmann
authors.affiliation: Department of Cardiology, Herlev University Hospital, DK-2730 Herlev, Denmark.
authors.forename: Freja
authors.initials: F
authors.lastname: Gaborit
authors.affiliation: Department of Cardiology, Herlev University Hospital, DK-2730 Herlev, Denmark.
authors.forename: Kasper
authors.initials: K
authors.lastname: Iversen
authors.affiliation: Department of Clinical Biochemistry, Rigshospitalet, DK-2100 Copenhagen, Denmark.
authors.forename: Jens P
authors.initials: JP
authors.lastname: Goetze
authors.affiliation: Department of Clinical Biochemistry, North Zealand University Hospital, DK-3400 Hillerod, Denmark.
authors.forename: Georg
authors.initials: G
authors.lastname: Soletomas
authors.affiliation: Department of Endocrinology, Herlev University Hospital, DK-2730 Herlev, Denmark.
authors.forename: Jon
authors.initials: J
authors.lastname: Rasmussen
authors.affiliation: Department of Endocrinology, Herlev University Hospital, DK-2730 Herlev, Denmark.
authors.forename: Caroline
authors.initials: C
authors.lastname: Kistorp
authors.affiliation: Department of Cardiology, Rigshospitalet, DK-2100 Copenhagen, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Kober
authors.affiliation: Department of Cardiology, Rigshospitalet, DK-2100 Copenhagen, Denmark.
authors.forename: Finn
authors.initials: F
authors.lastname: Gustafsson
authors.affiliation: Department of Internal Medicine KNEA, North Zealand University Hospital, DK-3400 Hillerod, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Tonder
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D053379:Chromogranin A / Q000097:blood; D015897:Comorbidity; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005293:Ferritins / Q000097:blood*; D006020:Glycopeptides / Q000097:blood; D054143:Heart Failure, Systolic / Q000097:blood / Q000175:diagnosis / Q000401:mortality; D006801:Humans; D007501:Iron / Q000378:metabolism; D000090463:Iron Deficiencies; D019189:Iron Metabolism Disorders / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010045:Outpatients; D010446:Peptide Fragments / Q000097:blood*; D015995:Prevalence; D011379:Prognosis; D013223:Statistics as Topic; D014168:Transferrin / Q000032:analysis; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D053379:Chromogranin A; D006020:Glycopeptides; D010446:Peptide Fragments; D014168:Transferrin; D019210:Troponin I; C048197:copeptins; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein; D005293:Ferritins; D007501:Iron
keywords: Cardiac biomarkers; Heart failure; Heart failure clinic; Inflammation; Iron deficiency