title: Heart rate variability characteristics in a large group of active-duty marines and relationship to posttraumatic stress.
abstract: OBJECTIVE
  Heart rate variability (HRV), thought to reflect autonomic nervous system function, is lowered under conditions such as posttraumatic stress disorder (PTSD). The potential confounding effects of traumatic brain injury (TBI) and depression in the relationship between HRV and PTSD have not been elucidated in a large cohort of military service members. Here we describe HRV associations with stress disorder symptoms in a large study of Marines while accounting for well-known covariates of HRV and PTSD including TBI and depression.
  
  
  METHODS
  Four battalions of male active-duty Marines (n = 2430) were assessed 1 to 2 months before a combat deployment. HRV was measured during a 5-minute rest. Depression and PTSD were assessed using the Beck Depression Inventory and Clinician-Administered PTSD Scale, respectively.
  
  
  RESULTS
  When adjusting for covariates, including TBI, regression analyses showed that lower levels of high-frequency HRV were associated with a diagnosis of PTSD (β = -0.20, p = .035). Depression and PTSD severity were correlated (r = 0.49, p < .001); however, participants with PTSD but relatively low depression scores exhibited reduced high frequency compared with controls (p = .012). Marines with deployment experience (n = 1254) had lower HRV than did those with no experience (p = .033).
  
  
  CONCLUSIONS
  This cross-sectional analysis of a large cohort supports associations between PTSD and reduced HRV when accounting for TBI and depression symptoms. Future postdeployment assessments will be used to determine whether predeployment HRV can predict vulnerability and resilience to the serious psychological and physiological consequences of combat exposure.
authors.affiliation: From the Center of Excellence for Stress and Mental Health (A.M., M.A.G., D.G.B., C.M.N., V.B.R.), Veteran's Administration, San Diego, California; Departments of Psychiatry (A.M., M.A.G., D.G.B., C.M.N., V.B.R.) and Medicine (D.T.O.), University of California San Diego, La Jolla, California; and VA San Diego Healthcare System (M.A.G., D.G.B., C.M.N., V.B.R.), San Diego, California.
authors.forename: Arpi
authors.initials: A
authors.lastname: Minassian
authors.forename: Mark A
authors.initials: MA
authors.lastname: Geyer
authors.forename: Dewleen G
authors.initials: DG
authors.lastname: Baker
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Nievergelt
authors.forename: Daniel T
authors.initials: DT
authors.lastname: O'Connor
authors.forename: Victoria B
authors.initials: VB
authors.lastname: Risbrough
mesh_terms: D000704:Analysis of Variance; D001341:Autonomic Nervous System / Q000503:physiopathology; D001930:Brain Injuries / Q000453:epidemiology* / Q000503:physiopathology; D002110:Caffeine / Q000008:administration & dosage; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000453:epidemiology* / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008889:Military Personnel / Q000523:psychology / Q000706:statistics & numerical data*; D009538:Nicotine / Q000008:administration & dosage; D017156:Photoplethysmography / Q000379:methods; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D012720:Severity of Illness Index; D013313:Stress Disorders, Post-Traumatic / Q000453:epidemiology* / Q000503:physiopathology; D055815:Young Adult
chemical_list: D002110:Caffeine; D009538:Nicotine