title: Nocturnal heart rate variability in patients treated with cognitive-behavioral therapy for insomnia.
abstract: Insomnia and reduced heart rate variability (HRV) increase the risk of cardiovascular disease and its precursors; thus, it is important to evaluate whether treatment for insomnia provides cardiovascular safeguards. The present study aimed to evaluate potential cardiovascular benefits of cognitive behavioral therapy for insomnia (CBT-I).
  
  
  
  The present study included 65 patients treated for chronic insomnia (M = 51.8 years, SD = 10.0; 66.2% female) at a university hospital. Patients received CBT-I over a 6-week period, and change scores from pre- to posttreatment derived from the Insomnia Severity Index, sleep diary, and polysomnography (PSG) were used as indices of sleep improvement. HRV variables (i.e., low frequency [LF], high frequency [HF], and the ratio of low to high frequency [LF:HF ratio]) were derived for Stage 2 (S2) and rapid-eye movement (REM) sleep at pre- and posttreatment. High HF (i.e., parasympathetic activity) and/or low LF:HF ratio (i.e., sympathovagal balance) were used as indices of HRV improvement.
  
  
  
  Following therapy, sleep improvements, particularly for sleep onset latency, were related with reduced HF in S2 (r = .30, p < .05) and in REM (r = .36, p < .01). A trend was also observed between reduced insomnia symptoms and increased HF in REM (r = -.21, p < .10).
  
  
  
  Findings suggest that contrary to expectations, sleep improvements following CBT-I were associated with reduced parasympathetic activation and increased sympathovagal balance. Although preliminary, these results raise the question as to whether insomnia treatment might play a role in physiological changes associated with cardiovascular anomalies. Future research is needed to examine the long-term impact of treatment as a preventative tool against insomnia-related morbidity. (PsycINFO Database Record
authors.affiliation: École de psychologie, Université Laval.
authors.forename: Denise C
authors.initials: DC
authors.lastname: Jarrin
authors.affiliation: École de psychologie, Université Laval.
authors.forename: Ivy Y
authors.initials: IY
authors.lastname: Chen
authors.affiliation: École de psychologie, Université Laval.
authors.forename: Hans
authors.initials: H
authors.lastname: Ivers
authors.affiliation: École de psychologie, Université Laval.
authors.forename: Manon
authors.initials: M
authors.lastname: Lamy
authors.affiliation: École de psychologie, Université Laval.
authors.forename: Annie
authors.initials: A
authors.lastname: Vallières
authors.affiliation: École de psychologie, Université Laval.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Morin
mesh_terms: D000328:Adult; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods; D057566:Self Report; D012890:Sleep / Q000502:physiology*; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*