Abstracts / Autonomic Neuroscience: Basic and Clinical 192 (2015) 56–141
showed that LF and HF were similar among different sleep stages; these results were confirmed by SA, which showed no differences of 0 V%, 2LV% and 2UV% between W, N2, N3 and REM. Conclusions. In patients with AIS, CAC seems to be stable during different sleep stages. Therefore, the physiological autonomic modulation during sleep, characterized by a sympathetic predominance during REM and a vagal dominance during NREM sleep, may be lost in acute phase of AIS.
doi:10.1016/j.autneu.2015.07.174
P13.7 Experimental Sleep Restriction Blunts Baroreflex Sensitivity in Healthy Individuals W.W. Holbein, J.K. Limberg, N. Covassin, M.J. Joyner, V.K. Somers Department of Anesthesia Research, Mayo Clinic, Rochester, MN, USA Background: Insufficient sleep is linked to enhanced risk of developing hypertension; however, the mechanism by which this occurs is currently unknown. In this study we sought to evaluate the effects of experimental sleep restriction on spontaneous baroreflex sensitivity. Methods: Five healthy subjects (4 female; age 23 ± 1 years) underwent a 4-day period of acclimation followed by 9 days of experimental sleep restriction (4 hours of sleep per night – from 12:30 AM to 4:30 AM). Beat-by-beat heart rate (HR, ECG) and blood pressure (BP, Finometer) were measured during 15 minutes of quiet rest. Spontaneous cardiac baroreflex (BRS) sensitivity was determined using spectrum analysis. Subjects were studied on Day 2 (Acclimation) and Day 13 (Restriction). Results: Resting BP and HR were not different between acclimation and experimental sleep restriction (SBP: 127 ± 5 vs 133 ±3 mmHg, p = 0.13; DBP: 79 ± 2 vs 80 ± 4 mmHg, p = 0.21; HR: 68 ±3 vs 73 ± 4 BPM, p = 0.8). BRS gain was significantly blunted during sleep restriction when compared to the acclimation period (18 ± 2 vs 13 ± 2%, p b 0.01). Conclusion: Acute experimental sleep restriction in young healthy adults results in a reduction of cardiac baroreflex sensitivity prior to obvious/overt changes in resting BP. These data suggest that impaired baroreflex function may be an early contributing factor to the high prevalence of hypertension and cardiovascular diseases in the sleep deprived general population.
doi:10.1016/j.autneu.2015.07.175
P13.8 Pre-sleep emotional induction affects REM rate and sympathetic activity during sleep J. Delannoya, O. Mandaib, J. Honoréa, T. Kobayashib, H. Sequeiraa a SCALab, CNRS UMR 9193, University of Lille, France b Sleep Research Center, Ashikaga Institute of Technology, Japan Diurnal emotional experience seems to affect sleep stages distribution, notably Rapid Eyes Movement (REM) and NREM3 sleep. However, this incidence remains unclear, especially for positive emotions. In addition, electrodermal activity (EDA), a marker of sympathetic activity, linked to emotional arousal, differs according to sleep stages, the frequency of electrodermal responses (EDRf) being consistently higher during NREM3 sleep. The aim was here to explore the effects of pre-sleep induced emotional states, on sleep stage distribution and EDRf, as potential markers of emotional processing during sleep. Twelve volunteers (20.1 ± 1yo.) slept a
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total of 9 nights at laboratory, divided in 3 sessions, one per week. The first night of each session allowed baseline recordings. Before the second night sleep, each participant saw a negative, neutral, or positive film (20 min; counterbalanced order), then the efficiency of this emotional induction was evaluated with the Positive and Negative Affect Schedule (PANAS). Standard polysomnography and EDA were recorded during all nights. Results showed that the presleep emotional visualisations: 1/ induced congruent negative or positive pre-sleep states; 2/ increased the REM sleep rate for both emotional conditions (p = 0.041); impacted EDRf during NREM3 (p = 0.049), through increases after the negative induction and decreases after the positive one. In conclusion: 1/ we validated a standard method to induce pre-sleep emotional states; 2/ the REM sleep rate appeared to depend on arousal caused by pre-sleep emotional induction; 3/ such induction also modulates the sympathetic activity that could be interpreted as a potential output of emotional processes during sleep. doi:10.1016/j.autneu.2015.07.176
P13.9 Preserved cardiac autonomic dynamics during sleep after partial sleep restriction E. Tobaldinia,b, N. Covassinb, P. Singhb, J. Bukartykb, S. Wangb, N. Montanoa, V.K. Somersb a Dept of Internal Medicine, Fondazione IRCSS Ca' Granda, Ospedale Maggiore Policlinico, Milano and Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Italy b Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN, USA Background. Acute sleep loss alters cardiovascular autonomic control in healthy subjects. However, the effects of Partial Sleep Restriction (PSR) on autonomic regulation are still debated and no data are available during sleep. The aim of this study was to assess the effects of 8 days/8 nights of sleep restriction on autonomic cardiac regulation. Methods. Seven subjects underwent an experimental protocol based on two-thirds of normal sleep time for 8 days/ 8 nights in a hospital-based clinical research unit (Mayo Clinic, MN, USA). During D3 (baseline), D5 (first night after PSR), D11 (after 8 nights of PSR) and D14 (recovery night), complete polysomnographic recordings were performed. ECG and respiration were then extracted, divided according to sleep stages (wake, W, non-REM 2 and 3, N2 and N3, REM), and analyzed using linear spectral (SpA) and non linear symbolic analysis (SA) of heart rate variability. SpA identifies two main components, low frequency (LF), marker of sympathetic modulation and high frequency (HF), marker of vagal modulation. SA identifies three main families of patterns, 0 V%, marker of sympathetic modulation, and 2LV and 2UV%, markers of vagal modulation. A two way ANOVA for repeated measures was used. Results. Analyses showed that the markers of sympathetic modulation, i.e. LFnu, LF/HF and 0 V%, were significantly lower in N2 and N3 compared to W and REM at D3, D5, D11 and D14. On the contrary, HFnu, 2LV% and 2UV% significantly increased as sleep became deeper, being higher in N2 and N3 compared to W and REM on all days. Conclusions. These preliminary results suggest that physiological cardiac autonomic dynamics, characterized by a decreased sympathetic and an increased parasympathetic modulation during N2 and N3 compared to W and REM, are preserved during sleep after 8 nights of PSR in healthy subjects.
doi:10.1016/j.autneu.2015.07.177