0651 Longitudinal Effects of CPAP Adherence on Changes in PTSD Symptoms and Subscales: The Importance of Hyperarousal on Adherence and Outcomes

Abstract

Abstract Introduction Comorbidity of posttraumatic stress disorder (PTSD) and obstructive sleep apnea (OSA) is staggeringly high, with rates of 75.7% when using criteria of apnea/hyponea index (AHI) > 5. Continuous positive airway pressure (CPAP) therapy can decrease PTSD symptoms, however, no study has used advanced mixed-modeling to examine which cluster of PTSD CPAP therapy effects. Methods Participants were 59 veterans with PTSD and undiagnosed OSA. Apnea/Hypopnea index (AHI) was scored according to AASM criteria. Auto-titration CPAP devices were prescribed with pressures empirically selected by the sleep physician based on BMI, overall AHI, and dominant event type; maximum pressures was set at 20cm H2O. Analyses used hierarchical linear modeling to examine changes in PTSD symptoms clusters as a function of CPAP use over 6-months. Measures include PTSD checklist (PCL) and clusters (reexperiencing, avoidance, and hyperarousal), percentage of nights CPAP used, weight, and BMI. Results Baseline scores were high: PCL (M=60.02; SD=15.03) and AHI (M=28.18 per hour; SD=20.35). Average number of nights CPAP use in the last 6-months was 59.3%, with 3.5 hours each night with clear adherent and non-adherent groups emerging. The adherent group showed a 15-point drop in PCL scores and the non-adherent group had a 3-point drop. More days of CPAP use in the last 6-months predicted larger decreases in hyperarousal (d=0.56) and re-experiencing (d=0.47) clusters, but not avoidance. The intercept was significant in the hyperarousal analyses suggesting individuals with higher hyperarousal at baseline had less CPAP adherence. Conclusion The need for PTSD clinicians to screen and refer for OSA is necessary, but may not be sufficient, in treating PTSD. Change in hyperarousal symptoms accounted for most of the effects from CPAP use. Higher hyperarousal symptoms at baseline predict lower CPAP adherence, suggesting a higher clinical need to address these individuals as they will get the most positive effects from CPAP. Support This work is supported by a VA RR&D CDA (1lK2Rx002120-01) to Peter Colvonen.