title: Association between smoking and heart rate variability among individuals with depression.
abstract: BACKGROUND
  Both depression and smoking have been independently associated with lower heart rate variability (HRV), suggesting dysregulation of cardiac autonomic function. However, no studies have systematically explored the effects of smoking on HRV among depressed patients.
  
  
  OBJECTIVE
  This study examined differences in HRV based on smoking status among depressed individuals.
  
  
  METHODS
  Electrophysiological data were examined among 77 adult outpatients without a history of myocardial infarction, who met criteria for major depressive disorder or dysthymia. Frequency domain [low frequency (LF), high frequency (HF), LF/HF ratio, respiratory sinus arrhythmia (RSA)] parameters of HRV, and heart rate and inter-beat interval (IBI) data were compared between depressed smokers (n = 34) and depressed nonsmokers (n = 44).
  
  
  RESULTS
  After controlling for covariates, depressed smokers, compared to depressed nonsmokers, displayed significantly lower LF, HF, and RSA.
  
  
  CONCLUSIONS
  Among depressed patients, smoking is associated with significantly lower HRV, indicating dysregulated autonomic modulation of the heart.
authors: VA Boston Healthcare System, 150 S. Huntington Ave. (116-B4), Boston, MA 02130, USA. christopher.harte@va.gov
authors: Christopher B
authors: CB
authors: Harte
authors: Gabrielle I
authors: GI
authors: Liverant
authors: Denise M
authors: DM
authors: Sloan
authors: Barbara W
authors: BW
authors: Kamholz
authors: Laina E
authors: LE
authors: Rosebrock
authors: Maurizio
authors: M
authors: Fava
authors: Gary B
authors: GB
authors: Kaplan
mesh_terms: D000328:Adult; D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology*; D003866:Depressive Disorder / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000503:physiopathology*