title: Heart rate variability and biomarkers of systemic inflammation in patients with stable coronary heart disease: findings from the Heart and Soul Study.
abstract: BACKGROUND
  Chronic low-grade systemic inflammation is a key component in atherogenesis. Decreased heart rate variability (HRV), a strong predictor of cardiovascular events, has been associated with elevations in circulating levels of C-reactive protein (CRP), interleukin (IL)-6, and fibrinogen in apparently healthy individuals. We investigated whether decreased HRV is associated with inflammatory markers in patients with coronary heart disease (CHD).
  
  
  METHODS
  We studied the relationship between HRV and CRP, IL-6, and fibrinogen in 862 outpatients with CHD. All participants provided fasting blood samples and underwent 24-h ambulatory monitoring to assess time-domain measures of HRV (MeanNN, SDNN, SDANN, and RMSSD). Regression analyses were adjusted for age, sex, ethnicity, body mass index, smoking, diabetes, beta blocker use, and cardiopulmonary history.
  
  
  RESULTS
  MeanNN, SDNN, and SDANN were significantly and inversely associated with CRP and IL-6 levels in age-adjusted models and after adjustment for all covariates (p ≤ 0.02). MeanNN, SDNN, and SDANN were also inversely associated with fibrinogen levels in age-adjusted models (p < 0.03), but not significantly so in multivariable-adjusted models. Reduced vagal modulation of heart rate (RMSSD) was not significantly associated with any inflammatory measures.
  
  
  CONCLUSIONS
  Reduced cardiac autonomic control is associated with increased systemic inflammation in patients with stable CHD. This relationship was largely independent of important covariates.
authors.affiliation: Department of General Internal Medicine, Division of Psychosomatic Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland. roland.vonkaenel@insel.ch
authors.forename: Roland
authors.initials: R
authors.lastname: von Känel
authors.forename: Robert M
authors.initials: RM
authors.lastname: Carney
authors.forename: Shoujun
authors.initials: S
authors.lastname: Zhao
authors.forename: Mary A
authors.initials: MA
authors.lastname: Whooley
mesh_terms: D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis* / Q000378:metabolism; D015331:Cohort Studies; D003327:Coronary Disease / Q000097:blood / Q000503:physiopathology*; D005260:Female; D005340:Fibrinogen / Q000032:analysis* / Q000378:metabolism; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators; D015850:Interleukin-6; D005340:Fibrinogen; D002097:C-Reactive Protein