Hemodynamic, Autonomic, and Vascular Function Changes after Sleep Deprivation for 24, 28, and 32 Hours in Healthy Men

Recovery Sleep After Sleep Restriction Is Insufficient to Return Elevated Daytime Heart Rate and Systolic Blood Pressure to Baseline Levels

OBJECTIVE

Sleep restriction alters daytime cardiac activity, including elevating heart rate (HR) and blood pressure (BP). There is minimal research on the cumulative effects of sleep loss and the response after subsequent recovery sleep on HR and BP. This study examined patterns of HR and BP across baseline, sleep restriction, and recovery conditions using multiple daytime cardiac measurements.

METHODS

Participants (15 healthy men, mean [standard deviation] = 22.3 [2.8] years) completed an 11-day inpatient protocol with three nights of 10 hours/night baseline sleep opportunity, five sleep restriction nights (5-hour/night sleep opportunity), and two recovery nights (10-hour/night sleep opportunity). Resting HR and BP were measured every 2 hours during wake. Multilevel models with random effects for individuals examined daytime HR and BP across study conditions and days into the study.

RESULTS

Mean daytime HR was 1.2 (0.5) beats/min lower during sleep restriction compared with baseline ( p < .001). During recovery, HR was 5.5 (1.0) beats/min higher ( p < .001), and systolic BP (SBP) was 2.9 (1.1) mm Hg higher ( p = .009). When accounting for days into the study (irrespective of condition) and measurement timing across the day, HR increased by 7.6 beats/min and SBP increased by 3.4 mm Hg across the study period ( p < .001).

CONCLUSIONS

Our findings suggest that daytime HR and SBP increase after successive nights of sleep restriction, even after accounting for measurement time of day. HR and SBP did not recover to baseline levels after two recovery nights of sleep, suggesting that longer recovery sleep may be necessary to recover from multiple, consecutive nights of moderate sleep restriction.

The association between sleep disturbances and blood pressure variability: a review of the literature

STUDY OBJECTIVES

Sleep disturbances are an underrecognized public health issue that results in various adverse outcomes and disturbed quality of life. Blood pressure variability (BPV) is an emerging entity in assessing cardiovascular disease risk and accumulating evidence suggests that BPV is closely associated with end-organ damage. This review aims to explore the association between sleep disturbances and BPV.

METHODS

A comprehensive systematic literature search was conducted electronically using Web of Science, Ovid MEDLINE, , and SCOPUS. The electronic search was restricted to relevant English-language studies published between 1985 and August 2020. Most studies were prospective cohorts in design. After applying eligibility criteria, 29 articles were included for synthesis.

RESULTS

This review shows that sleep disturbances are linked to short-term, midterm, and long-term BPV. Restless legs syndrome, shift work, insomnia, short sleep, long sleep, obstructive sleep apnea, and sleep deprivation were all positively associated with systolic blood pressure or diastolic blood pressure fluctuations.

CONCLUSIONS

Given the prognostic implications of BPV and sleep disturbances on cardiovascular mortality, recognizing and treating both disorders is essential. More research is needed to examine the impact of sleep disorder treatment on BPV and cardiovascular mortality.

CITATION

Al Haddad N, Costanian C, Zibara V, et al. The association between sleep disturbances and blood pressure variability: a review of the literature. J Clin Sleep Med. 2023;19(8):1533-1544.

Sleep Loss Influences the Interconnected Brain-Body Regulation of Cardiovascular Function in Humans

OBJECTIVE

Poor sleep is associated with hypertension, a major risk factor for cardiovascular disease. However, the mechanism(s) through which sleep loss affects cardiovascular health remains largely unknown, including the brain and body systems that regulate vascular function.

METHODS

Sixty-six healthy adults participated in a repeated-measures, crossover, experimental study involving assessments of cardiovascular function and brain connectivity after a night of sleep and a night of sleep deprivation.

RESULTS

First, sleep deprivation significantly increased blood pressure-both systolic and diastolic. Interestingly, this change was independent of any increase in heart rate, inferring a vasculature-specific rather than direct cardiac pathway. Second, sleep loss compromised functional brain connectivity within the vascular control network, specifically the insula, anterior cingulate, amygdala, and ventral and medial prefrontal cortices. Third, sleep loss-related changes in brain connectivity and vascular tone were not independent, but significantly interdependent, with changes within the vascular control brain network predicting the sleep-loss shift toward hypertension.

CONCLUSIONS

These findings establish an embodied framework in which sleep loss confers increased risk of cardiovascular disease through an impact upon central brain control of vascular tone, rather than a direct impact on accelerated heart rate itself.

Effects of 24-h acute total sleep deprivation on physiological coupling in healthy young adults

Sleep deprivation is associated with dysregulation of the autonomic nervous system, adverse cardiovascular events, cognitive and complex motor performance impairment. Less is known about the effects of acute total sleep deprivation (ATSD) on physiological coupling. We aimed to determine the effects of 24-h ATSD on the physiological coupling between complex subsystems by evaluating the cardiorespiratory, cardiovascular and cortico-cardiac interactions. This study enrolled 38 young healthy participants aged 23.2 ± 2.4 years. Multiple synchronous physiological signals including electrocardiography, photoplethysmography, bio-electrical impedance, electroencephalography, and continuous hemodynamic data, were performed over a baseline night after regular sleep and after a night with 24-h ATSD in the supine position. The magnitude squared coherence, phase synchronization index, and heartbeat evoked potential amplitudes, were obtained from 10-min synchronous physiological recordings to estimate the coupling strength between two time series. Parameters of hemodynamic characteristics and heart rate variability were also calculated to quantify autonomic regulation. Results indicated that the magnitude squared coherence (0.38 ± 0.17 vs. 0.29 ± 0.12, p = 0.015) between respiration and heart rate variability along with the magnitude squared coherence (0.36 ± 0.18 vs. 0.27 ± 0.13, p = 0.012) between respiration and pulse transit time were significantly decreased after 24-h ATSD. There were no significant differences (all p > 0.05) in phase synchronization indices, heartbeat evoked potential amplitudes as well as other analyzed measurements between baseline and 24-h ATSD states. We conclude that exposure to 24-h ATSD appears to weaken the cardiorespiratory and respiratory-cardiovascular coupling strength of young healthy adults. These findings suggest that physiological coupling analysis may serve as a complementary approach for characterizing and understanding the complex effects of sleep deprivation.

Sleep deprivation reduces vagal tone during an inspiratory endurance task in humans

STUDY OBJECTIVES

Sleep deprivation alters inspiratory endurance by reducing inspiratory motor output. Vagal tone is involved in exercise endurance. This study aimed to investigate the effect of sleep deprivation on vagal tone adaptation in healthy subjects performing an inspiratory effort.

METHODS

Vagal tone was assessed using Heart Rate Variability normalized units of frequency domain component HF (high frequency) before, at the start, and the end of an inspiratory loading trial performed until exhaustion by 16 volunteers after one night of sleep deprivation and one night of normal sleep, where sleep deprivation reduced the inspiratory endurance by half compared to the normal sleep condition (30 min vs 60 min).

RESULTS

At rest, heart rate was similar in sleep deprivation and normal sleep conditions. In normal sleep condition, heart rate increased during inspiratory loading task; this increase was greater in sleep deprivation condition. In normal sleep condition, vagal tone increased at the beginning of the trial. This vagal tone increase was absent in sleep deprivation condition.

CONCLUSIONS

Sleep deprivation abolished vagal tone response to inspiratory load, possibly contributing to a higher heart rate during the trial and to a reduced inspiratory endurance.

CLINICAL TRIAL REGISTRATION

NCT02725190.

Effects of sleep deprivation on endothelial function in adult humans: a systematic review

Sleep deprivation is highly prevalent and is associated with increased cardiovascular disease (CVD) morbidity and mortality. Age-related alterations in sleep and chronobiology may exaggerate CVD susceptibility in older individuals. The mechanisms responsible for the association between sleep deprivation and CVD are not fully understood, but endothelial dysfunction may play a central role. Our objective was to conduct a systematic literature review to evaluate the evidence on the effects of sleep deprivation on endothelial function (EF). This review adhered to the PRISMA guidelines and was pre-registered with PROSPERO (#CRD42020192485, 07/24/2020). We searched PubMed, Web of Science, Embase, and Cochrane Library for articles published through May 1, 2020. Eligibility criteria included publication in English and use of well-established EF methodologies in adult humans. Two investigators independently performed the literature search, study selection, data extraction, risk-of-bias assessment, and qualitative data synthesis. Out of 3571 articles identified, 24 articles were included in the systematic review. Main findings include the following: (1) shorter sleep duration is associated with lower macrovascular EF; (2) not sleeping 7-9 h/night is linked with impaired microvascular EF; (3) sleep restriction impairs micro- and macrovascular EF; (4) acute total sleep deprivation impairs micro- and macrovascular EF but data on macrovascular EF are less consistent; and (5) shift work impairs macrovascular EF. In conclusion, sleep deprivation impairs EF, which may explain the link between insufficient sleep and CVD. Future investigations should fully elucidate the underlying mechanisms and develop strategies to combat the adverse endothelial effects of sleep deprivation across the lifespan.

Sleep deprivation and endothelial function: reconciling seminal evidence with recent perspectives

Sleep is critical for the maintenance of physiological homeostasis and, as such, inadequate sleep beckons a myriad of pathologies. Sleep deprivation is a growing health concern in contemporary society since short sleep durations are associated with increased cardiovascular disease risk and atherosclerotic plaque development. Vascular endothelial dysfunction is an antecedent to atherosclerosis and cardiovascular disease. Herein, we review seminal literature indicating that short sleep durations attenuate endothelial function and explore more recent evidence indicating that sleep deprivation perturbs autonomic balance and the circadian rhythmicity of peripheral vascular clock components. We further examine literature that indicates a mechanistic link between short sleep duration and endothelial dysfunction and subsequent morbidity. Understanding the mechanisms that regulate endothelial function in the context of sleep deprivation facilitates the development and optimization of interventions, such as exercise, that mitigate the ramifications of inadequate sleep on vascular function and cardiovascular health.Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/sleep-deprivation-and-endothelial-function/.