BACKGROUND: Noradrenergic function has been linked to posttraumatic stress disorder (PTSD) and might have a role in mediating sleep disturbances of the disorder. Our objective was to relate a peripheral manifestation of noradrenergic function, sympathetic nervous system activity as indexed by heart rate variability during sleep, to the development of PTSD in subjects with recent traumatic injuries. METHODS: Subjects who had recall of life-threatening experiences were recruited from one of two regional trauma centers. Select subjects received a polysomnographic recording within 1 month of the trauma. Digitized electrocardiogram recordings were extracted from early and late rapid-eye-movement (REM) and preceding non-REM sleep periods. Autoregression was applied to R-R interval time series to calculate the ratios of low-frequency to high-frequency spectral densities (LF/HF ratios), which index sympathetic activation. Posttraumatic stress disorder status was determined at 2 months. RESULTS: There was a significant state x group interaction: LF/HF ratios were higher during the REM sleep of the nine subjects who were positive for PTSD symptoms, compared with the 10 subjects who were PTSD negative. CONCLUSIONS: Our findings are consistent with the possibility that increased noradrenergic activity during REM sleep contributes to the development of PTSD.
BACKGROUND: Noradrenergic function has been linked to posttraumatic stress disorder (PTSD) and might have a role in mediating sleep disturbances of the disorder. Our objective was to relate a peripheral manifestation of noradrenergic function, sympathetic nervous system activity as indexed by heart rate variability during sleep, to the development of PTSD in subjects with recent traumatic injuries. METHODS: Subjects who had recall of life-threatening experiences were recruited from one of two regional trauma centers. Select subjects received a polysomnographic recording within 1 month of the trauma. Digitized electrocardiogram recordings were extracted from early and late rapid-eye-movement (REM) and preceding non-REM sleep periods. Autoregression was applied to R-R interval time series to calculate the ratios of low-frequency to high-frequency spectral densities (LF/HF ratios), which index sympathetic activation. Posttraumatic stress disorder status was determined at 2 months. RESULTS: There was a significant state x group interaction: LF/HF ratios were higher during the REM sleep of the nine subjects who were positive for PTSD symptoms, compared with the 10 subjects who were PTSD negative. CONCLUSIONS: Our findings are consistent with the possibility that increased noradrenergic activity during REM sleep contributes to the development of PTSD.
Authors: Michelle B Rissling; Paul A Dennis; Lana L Watkins; Patrick S Calhoun; Michelle F Dennis; Jean C Beckham; Junichiro Hayano; Christi S Ulmer Journal: J Trauma Stress Date: 2016-09-07