Probable PTSD status was not significantly associated with heart rate variability (-11.6% change in geometric mean RMSSD), whereas increased emotional numbing severity was associated with reduced RMSSD.
Cohort (n=860)
Yes
Are PTSD symptom clusters associated with reduced heart rate variability in male military personnel?
Emotional numbing in PTSD is specifically associated with lower heart rate variability, suggesting unique cardiovascular profiles for different PTSD symptom clusters.
Effect estimate: -11.6% change in geometric mean (95% CI -22.2, 4.1)
Absolute Event Rate: 36% vs 43%
BACKGROUND: Heart rate variability (HRV) is governed by sympathetic and parasympathetic regulatory systems. Post-Traumatic Stress Disorder (PTSD) may influence these systems and consequently affect cardiovascular functioning. METHODS: The sample consisted of 860 UK male military personnel approximately half of whom had sustained physical combat injuries in Afghanistan. HRV was measured via Root-Mean Square of Successive Differences (RMSSD) in normal heart beats and PTSD using a self-report questionnaire (Posttraumatic Checklist-Civilian version (PCL)). Associations between probable PTSD status (PCL score ≥ 50) and symptom clusters (avoidance behaviours, emotional numbing, hyperarousal and intrusive thoughts) with HRV were examined. Bootstrap inclusion frequencies and model averaging were employed prior to regression modelling to identify the most important symptom clusters associated with RMSSD. RESULTS: Probable PTSD status was not associated with log RMSSD [-11.6 % (95 % Confidence Interval (CI) -22.2 %, 4.1 %). Increases in severity of emotional numbing were associated with reductions in RMSSD, with a - 1.1 % (95%CI -2.1 %, -0.2 %) decrease in the geometric mean of RMSSD per point increase on the emotional numbing subscale. LIMITATIONS: High levels of comorbidity with depression/anxiety; possible endogeneity/bidirectionality due to PCL including both psychological and physiological symptoms. CONCLUSIONS: Emotional numbing, the symptom cluster including symptoms such as anhedonia, cognitive dysregulation and feeling distant from other people, was associated with lower HRV whilst overall PTSD status was not. These results lend support to the hypothesis that different PTSD symptom clusters may have unique effects on the cardiovascular system, and that particular symptom clusters of PTSD or combinations thereof may be associated with distinctive cardiovascular profiles.
Dyball et al. (Mon,) conducted a cohort in Post-traumatic stress disorder (PTSD) (n=860). Probable PTSD status vs. No probable PTSD was evaluated on Heart rate variability (log RMSSD) (-11.6% change in geometric mean, 95% CI -22.2, 4.1). Probable PTSD status was not significantly associated with heart rate variability (-11.6% change in geometric mean RMSSD), whereas increased emotional numbing severity was associated with reduced RMSSD.