title: An inverse correlation between TNF alpha serum levels and heart rate variability in patients with heart failure.
abstract: BACKGROUND
  Recent evidence indicates that chronic heart failure (CHF) is accompanied by both activation of the immune system and autonomic imbalance. There is a growing body of evidence that increased levels of proinflammatory cytokines and other inflammatory markers have important roles as mediators of disease progression and markers of mortality in patients with CHF.
  
  
  OBJECTIVE
  The aim of this study was to investigate connection between autonomic imbalance [obtained by analysis of heart rate variability (HRV)] and activation of the immune system [as measured by serum levels of tumor necrosis factor (TNF)-α] in patients with chronic heart failure.
  
  
  METHODS
  This cross-sectional study included 21 patients with CHF and 8 age- and gender-matched healthy control subjects. We assessed HRV by 24-hour electrocardiographic Holter monitoring and measured serum levels of TNF-α using an enzyme-linked immunosorbent assay. Clinical assessment and echocardiography were also performed.
  
  
  RESULTS
  There was an inverse correlation between serum level of TNF-α and a time-domain parameter of HRV - SDNN (r=-0.542, p<0.05). A similar result was found for HRV triangular index, a geometric measure of HRV (r=-0.556; p<0.05). The correlation was stronger for subjects with a diabetes mellitus, females, and TNFA2 allele carriers (an "A" at position -308A). The pNN50, indirect marker of cardiac vagal activity, was not significantly associated with serum concentration of TNF-α.
  
  
  CONCLUSIONS
  In conclusion, the results of the present study indicate that increased serum TNF-α level is significantly associated with reduced HRV indices, suggesting that activation of the immune system in patients with CHF is closely related to autonomic imbalance.
authors.affiliation: Department of Pharmacology, University of Nis Faculty of Medicine, Nis, Serbia. valentina@medfak.ni.ac.rs
authors.forename: Valentina N
authors.initials: VN
authors.lastname: Nikolic
authors.forename: Tatjana
authors.initials: T
authors.lastname: Jevtovic-Stoimenov
authors.forename: Dragana
authors.initials: D
authors.lastname: Stokanovic
authors.forename: Milena
authors.initials: M
authors.lastname: Milovanovic
authors.forename: Radmila
authors.initials: R
authors.lastname: Velickovic-Radovanovic
authors.forename: Srdjan
authors.initials: S
authors.lastname: Pesic
authors.forename: Milan
authors.initials: M
authors.lastname: Stoiljkovic
authors.forename: Gordana
authors.initials: G
authors.lastname: Pesic
authors.forename: Stevan
authors.initials: S
authors.lastname: Ilic
authors.forename: Marina
authors.initials: M
authors.lastname: Deljanin-Ilic
authors.forename: Dragan
authors.initials: D
authors.lastname: Marinkovic
authors.forename: Nikola
authors.initials: N
authors.lastname: Stefanovic
authors.forename: Slobodan M
authors.initials: SM
authors.lastname: Jankovic
mesh_terms: D000483:Alleles; D001341:Autonomic Nervous System / Q000503:physiopathology; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D004452:Echocardiography; D015716:Electrocardiography, Ambulatory; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000276:immunology / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
chemical_list: D014409:Tumor Necrosis Factor-alpha
keywords: Autonomous nervous system; Chronic heart failure; Heart rate variability; Immune system; Tumor necrosis factor-α