P059 Respiratory control stability in posttraumatic stress disorder

RATIONALE: A recent meta-analysis indicated that 75.7% of individuals with posttraumatic stress disorder (PTSD) also suffer from obstructive sleep apnoea (OSA). The reason for the high prevalence of OSA in PTSD is currently unknown. This study investigated whether respiratory control stability (which is known to contribute to OSA in the general population) varies with PTSD symptoms. METHODS: First year University students were recruited and completed an online questionnaire battery including: Life Events Checklist (LEC), PTSD checklist for DSM-5 (PCL-5), Shortness of Breath Questionnaire (SOBQ) and Berlin Sleep Questionnaire. 1/3 of participants timed their maximum breath hold (performed at functional residual capacity) at home on 3 occasions using a stopwatch as per Messieno et al (2018). RESULTS: 313 complete survey responses were obtained. The mean age of participants was 19.9 years and 214 respondents were women. 19 participants were at high risk of OSA based (Berlin Questionnaire) and 80 had probable PTSD (LEC items 1-16 “happened to me” or “witnessed it” plus PCL-5>33). In the whole sample, there was a significant relationship between PTSD symptoms and Shortness of Breath (Pearson p<0.001, r2=0.2). There was no relationship between PTSD symptoms and at-home measured maximum breath-hold duration (n=107, p=0.44, r2=0.006). CONCLUSIONS: In an unselected University student population, posttraumatic stress disorder symptoms are associated with self-reported shortness of breath during everyday activities. However, there was no evidence of a relationship between a surrogate of respiratory control stability (maximum breath-hold duration) and PTSD symptoms.