2.50
Hdl Handle:
http://hdl.handle.net/10755/211708
Type:
Research Study
Title:
HEART RATE VARIABILITY AS A BIOMARKER OF AROUSAL in INSOMNIA
Abstract:
Overview:  Insomnia is a major public health problem, affecting an estimated 15% or more of the U.S. population.  In recent years, research has provided growing support for the contribution of physiological factors, in addition to well-understood cognitive and behavioral factors, in the onset and perpetuation of insomnia.  Evidence implicates physiological hyperarousal processes, both in the central nervous system and in the periphery, as contributors to the severity and chronicity of insomnia.  It is also hypothesized that pre-existing, dispositional arousal may contribute to the risk for developing insomnia.  This presentation will review heart rate variability as a biomarker of peripheral arousal in persons with chronic insomnia. HRV as a Biomarker:  Heart rate variability (HRV) refers to various computed outcomes used to quantify the time interval in between heart beats as well as beat-to-beat changes in this interval.  Physiological studies show that high variability of the inter-beat interval (IBI) generally corresponds to parasympathetic nervous system (PSNS) activity and low variability of the IBI generally corresponds to sympathetic nervous system (SNS) activity.  This is attributed to differences in the mechanisms of heart rate modulation; PSNS exerts cardiac effects directly via vagal efferents, resulting in quick changes (high variability).  In particular, respiration causes immediate variability of heart rate (respiratory sinus arrhythmia) via vagal stimulation. The SNS exerts cardiac effects through hormonal mechanisms resulting in slow, persisting changes (low variability).  Although it is accepted that high frequency heart rate changes reflect PSNS activity, low frequency changes do not reflect pure SNS activity but rather the relative balance of SNS and PSNS activity.  Therefore, increased levels of low frequency variability could be related to increased SNS activity, reduced PSNS activity, or some combination of the two. Measurement of HRV:  HRV outcomes are calculated from electrocardiographic data.  Outcomes may characterize the frequency domain or the time domain.  Frequency domain outcomes quantify the relative occurrence of often high-frequency versus low-frequency variation in the IBI and are typically calculated using power spectral density.  Time domain outcomes also quantify overall variability in the IBI, but are based in standard statistical calculations (e.g., standard deviation) versus frequency analysis. HRV and Insomnia: Examination of heart rate data in persons with insomnia has shown higher overall heart rate, along with some evidence of reduced low-frequency and increased high-frequency HRV.  This evidence suggests overactive SNS, but clinical implications remain unclear and more research is needed. Implications: The relationship of peripheral arousal, as evidenced by HRV, to insomnia influences both the theoretical understanding of insomnia and its treatment.  Current models of chronic insomnia strongly emphasize the contributions of maladaptive cognitive and behavioral factors, but physiological influence of arousal may also need to be incorporated into etiologic and treatment models.  Peripheral arousal mechanisms may be related to risk of insomnia, progression from acute to chronic insomnia, and/or risk of negative health consequences from chronic insomnia such as hypertension.  Thus, evidence of peripheral arousal on HRV outcomes may support reduction of arousal (i.e., SNS activity) as an important treatment target in insomnia.
Keywords:
Insomnia; Psychosocial factors; Cognitive factors; Behavioral factors
Repository Posting Date:
20-Feb-2012
Date of Publication:
20-Feb-2012
Other Identifiers:
4939
Sponsors:
Western Institute of Nursing

Full metadata record

DC FieldValue Language
dc.typeResearch Studyen_GB
dc.titleHEART RATE VARIABILITY AS A BIOMARKER OF AROUSAL in INSOMNIAen_GB
dc.identifier.urihttp://hdl.handle.net/10755/211708-
dc.description.abstractOverview:  Insomnia is a major public health problem, affecting an estimated 15% or more of the U.S. population.  In recent years, research has provided growing support for the contribution of physiological factors, in addition to well-understood cognitive and behavioral factors, in the onset and perpetuation of insomnia.  Evidence implicates physiological hyperarousal processes, both in the central nervous system and in the periphery, as contributors to the severity and chronicity of insomnia.  It is also hypothesized that pre-existing, dispositional arousal may contribute to the risk for developing insomnia.  This presentation will review heart rate variability as a biomarker of peripheral arousal in persons with chronic insomnia. HRV as a Biomarker:  Heart rate variability (HRV) refers to various computed outcomes used to quantify the time interval in between heart beats as well as beat-to-beat changes in this interval.  Physiological studies show that high variability of the inter-beat interval (IBI) generally corresponds to parasympathetic nervous system (PSNS) activity and low variability of the IBI generally corresponds to sympathetic nervous system (SNS) activity.  This is attributed to differences in the mechanisms of heart rate modulation; PSNS exerts cardiac effects directly via vagal efferents, resulting in quick changes (high variability).  In particular, respiration causes immediate variability of heart rate (respiratory sinus arrhythmia) via vagal stimulation. The SNS exerts cardiac effects through hormonal mechanisms resulting in slow, persisting changes (low variability).  Although it is accepted that high frequency heart rate changes reflect PSNS activity, low frequency changes do not reflect pure SNS activity but rather the relative balance of SNS and PSNS activity.  Therefore, increased levels of low frequency variability could be related to increased SNS activity, reduced PSNS activity, or some combination of the two. Measurement of HRV:  HRV outcomes are calculated from electrocardiographic data.  Outcomes may characterize the frequency domain or the time domain.  Frequency domain outcomes quantify the relative occurrence of often high-frequency versus low-frequency variation in the IBI and are typically calculated using power spectral density.  Time domain outcomes also quantify overall variability in the IBI, but are based in standard statistical calculations (e.g., standard deviation) versus frequency analysis. HRV and Insomnia: Examination of heart rate data in persons with insomnia has shown higher overall heart rate, along with some evidence of reduced low-frequency and increased high-frequency HRV.  This evidence suggests overactive SNS, but clinical implications remain unclear and more research is needed. Implications: The relationship of peripheral arousal, as evidenced by HRV, to insomnia influences both the theoretical understanding of insomnia and its treatment.  Current models of chronic insomnia strongly emphasize the contributions of maladaptive cognitive and behavioral factors, but physiological influence of arousal may also need to be incorporated into etiologic and treatment models.  Peripheral arousal mechanisms may be related to risk of insomnia, progression from acute to chronic insomnia, and/or risk of negative health consequences from chronic insomnia such as hypertension.  Thus, evidence of peripheral arousal on HRV outcomes may support reduction of arousal (i.e., SNS activity) as an important treatment target in insomnia.en_GB
dc.subjectInsomniaen_GB
dc.subjectPsychosocial factorsen_GB
dc.subjectCognitive factorsen_GB
dc.subjectBehavioral factorsen_GB
dc.date.available2012-02-20T12:09:39Z-
dc.date.issued2012-02-20T12:09:39Z-
dc.date.accessioned2012-02-20T12:09:39Z-
dc.description.sponsorshipWestern Institute of Nursingen_GB
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