Sleep Efficiency Irregularity Links PTSD with Early Cardiovascular Dysfunction in Young Adults

Purpose: Post-traumatic stress disorder (PTSD) is associated with elevated cardiovascular disease (CVD) risk, with sleep disturbances representing a potential mechanistic link. While prior research has focused on sleep duration and quality, the role of sleep regularity, particularly night-to-night variability in sleep patterns, remains unclear in PTSD as it relates to elevated CVD risk. Thus, this study examined whether sleep regularity is associated with key CVD precursors in young adults with PTSD. Methods: Twenty-eight individuals with a clinical diagnosis of PTSD and twenty-eight non-PTSD (CTRL) individuals (matched for age and sex) completed 7 days of wrist-worn actigraphy to assess sleep efficiency (SE) and total sleep time (TST), including their respective regularity (standard deviation). Oxidative stress (whole blood superoxide) and acute blood pressure control (cardiovagal baroreflex sensitivity (cBRS); Phase IV) were measured as indices of CVD risk. Results: Greater SE irregularity was significantly associated with higher oxidative stress and reduced cBRS in the PTSD group, indicating increased physiological stress and impaired acute blood pressure control. These relationships were not observed in CTRL. In contrast, TST regularity, as well as overall sleep duration and quality, were not associated with either CVD precursor in any group. Conclusion: These findings identify sleep efficiency regularity as an important correlate of early cardiovascular dysfunction in young adults with PTSD and extend previous observations linking sleep irregularity to cardiovascular risk in individuals experiencing chronic anxiety. Collectively, these findings highlight the potential importance of sleep regularity as a behavioral correlate of cardiovascular health across populations experiencing chronic psychological stress.