Pre-sleep emotional induction affects REM rate and sympathetic activity during sleep

Abstract

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.