title: Sex differences in cardiac autonomic function of depressed young adults.
abstract: BACKGROUND
  Cardiac autonomic dysfunction has been proposed as an important contributing factor to the increased cardiovascular risk observed in major depression (MDD). However, the evidence regarding alterations in heart rate variability (HRV) in otherwise healthy depressed subjects has been inconclusive.
  
  
  METHODS
  A case-control study in 50 treatment-naïve young adults with a first MDD episode without comorbid psychiatric disorders and 50 healthy control subjects was conducted. Time- and frequency-domain indexes of HRV were determined at baseline supine and after 5-min of orthostatic stress at 60°.
  
  
  RESULTS
  There were no significant differences in the time- or frequency-domain variables of HRV between depressed patients and controls. However, a random-effect ANOVA model showed that during orthostatic stress depressed men had a reduced HRV and decreased parasympathetic activity compared to control subjects, while no differences were found between depressed women and controls.
  
  
  CONCLUSIONS
  These results suggest a sex-dependent relationship between major depression and cardiac autonomic dysfunction and provide one potential explanation for sex differences in the association of depressive symptoms with cardiovascular morbidity.
authors.affiliation: Research Institute, Fundación Cardiovascular de Colombia, Floridablanca, Colombia.
authors.forename: R G
authors.initials: RG
authors.lastname: Garcia
authors.forename: J G
authors.initials: JG
authors.lastname: Zarruk
authors.forename: J C
authors.initials: JC
authors.lastname: Guzman
authors.forename: C
authors.initials: C
authors.lastname: Barrera
authors.forename: A
authors.initials: A
authors.lastname: Pinzon
authors.forename: E
authors.initials: E
authors.lastname: Trillos
authors.forename: P
authors.initials: P
authors.lastname: Lopez-Jaramillo
authors.forename: C A
authors.initials: CA
authors.lastname: Morillo
authors.forename: R S
authors.initials: RS
authors.lastname: Maior
authors.forename: F A
authors.initials: FA
authors.lastname: Diaz-Quijano
authors.forename: C
authors.initials: C
authors.lastname: Tomaz
mesh_terms: D000704:Analysis of Variance; D001341:Autonomic Nervous System / Q000503:physiopathology*; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000503:physiopathology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000294:innervation / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006630:Hispanic or Latino; D006801:Humans; D007024:Hypotension, Orthostatic / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D010808:Physical Examination; D011569:Psychiatric Status Rating Scales; D012727:Sex Characteristics; D016683:Supine Position / Q000502:physiology; D055815:Young Adult