Objective Sleep Effciency Is Negatively Associated with Resting Heart Rate in Young Trauma-Exposed Women with Poor Sleep

Introduction: Women are twice as likely as men to develop post-traumatic stress disorder (PTSD), a debilitating mental health disorder caused by a traumatic event that can lead to a higher risk of developing cardiovascular disease (CVD). Sleep is currently recognized as an essential component of cardiovascular health by the American Heart Association. Further, a large epidemiological study empirically set the cut-off point for normal sleep effciency (SE) at 83%, differentiating good sleep from poor sleep. Trauma-provoked sleep disturbances such as disruptive nocturnal behaviors and nightmares are a hallmark of PTSD. Yet, the impact of sleep disturbances on cardiovascular biomarkers such as blood pressure (BP) and heart rate (HR) in young trauma-exposed women is unknown. Therefore, the aim of our study was to investigate how objectively recorded sleep measures are associated with HR and BP in these young trauma-exposed women. We hypothesized that sleep quality will predict HR and/or BP, independently of the severity of trauma symptoms. Methods: We recruited 93 trauma-exposed young women (18-40 years). During the in-person visit, we measured BP and HR using an automated vital signs monitor. Additionally, we assessed trauma symptom severity using the PTSD checklist for DSM-5 (PCL5). After the laboratory visit, we sent participants home with a sleep watch (Philips Respironics) for 7 consecutive days, to quantify the percentage of time spent asleep while in bed. Given that a minimum of 83% SE is considered effcient sleep, we separated our data into two groups based on SE [good effciency (SE >83%, n= 42) and poor effciency (SE 83% group. Therefore, we conducted further analysis in the SE >83% group only. We observed a negative correlation between HR and the trauma symptoms subcluster of hyperarousal (r= -0.285, p= 0.045) in this poor SE group. Next, we ran a multiple linear regression predicting HR with SE, age, and the subclusters of hyperarousal and intrusion (affected by disruptive nocturnal behaviors and nightmares) as predictors. The model predicting HR was significant (R 2 = 0.366, p< 0.001) and SE remained the strongest predictor (β= -0.458, p= 0.001) even when controlling for age, and trauma symptom subclusters, followed by age (β= -0.263, p= 0.037). Conclusion: Our analyses reveal that sleep effciency in trauma-exposed women is a strong predictor of resting HR, even when controlling for age and trauma symptoms subclusters of intrusion and hyperarousal. These findings suggest that in the context of trauma, it is the reduction in sleep effciency that has the greatest impact on resting heart rate, and ultimately mental health-associated CVD. K01HL161027 and UMN CTSI UL1TR002494 No Disclosure. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.