title: Differential association of cognitive and somatic depressive symptoms with heart rate variability in patients with stable coronary heart disease: findings from the Heart and Soul Study.
abstract: OBJECTIVE
  To determine if depression associated with low heart rate variability (HRV) in patients post myocardial infarction (MI), but not in patients with stable coronary heart disease (CHD), may be the result of differential associations of somatic and cognitive depressive symptoms with HRV.
  
  
  METHODS
  To examine the association of somatic and cognitive depressive symptoms with 24-hour HRV, we performed a cross-sectional study of 863 outpatients with stable CHD. The severity of somatic and cognitive depressive symptoms was determined using factor analysis of items of the Patient Health Questionnaire (PHQ-9). Time-domain (SDNN, SDANN) and frequency-domain (VLF, LF, HF, WBF) indices of HRV were derived using ambulatory monitoring.
  
  
  RESULTS
  Unadjusted analyses revealed that somatic symptom scores were significantly associated with HRV (r = -.09 for SDNN; r = -.08 for SDANN; r = -.08 for LnVLF; r = -.08 for LnLF; r = -.10 for LnHF; r = -.08 for LnWBF). After adjustment for demographic variables, comorbidities, and lifestyle factors, somatic symptom scores were no longer associated with lower HRV, with the possible exception of LnWBF (r = -.06). Cognitive depressive symptom scores were not associated with HRV using either unadjusted or adjusted analyses.
  
  
  CONCLUSIONS
  We found that somatic depressive symptoms were associated with lower HRV, although cognitive depressive symptoms were not. The inverse association of somatic symptoms with HRV was largely explained by differences in comorbidities and lifestyle factors. These results suggest that individual symptoms of depression may have differential associations with HRV.
authors.affiliation: Department of Internal Medicine, University Medical Center Groningen, University of Groningen, The Netherlands. p.de.jonge@med.umcg.nl
authors.forename: Peter
authors.initials: P
authors.lastname: de Jonge
authors.forename: Dennis
authors.initials: D
authors.lastname: Mangano
authors.forename: Mary A
authors.initials: MA
authors.lastname: Whooley
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000453:epidemiology; D015331:Cohort Studies; D003327:Coronary Disease / Q000503:physiopathology / Q000523:psychology*; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000453:epidemiology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology / Q000523:psychology*