Sleep Med Psychophysiol.  2000 Jun;7(1):43-50.

Effects of Nasal Continuous Positive Airway Pressure Application on Sympathetic Activation: Power Spectrum Analysis of Electrocardiogram in Obstructive Sleep Apnea Syndrome

• Youn T
• Park HJ
• Kim EJ
• Jeong DU

Abstract

OBJECTIVES
Obstructive sleep apnea syndrome(OSAS) is known to be associated with the changes of autonomic nervous system (ANS). Nasal continuous positive airway pressure (nCPAP) treatment was found to correct abnormal ANS changes in OSAS but it remains to be further clarified. We aimed to assess the effects of nCPAP on ANS manifested on electrocardiogram, using spectrum analysis in the subjects with OSAS.
METHODS
Digital polysomnography was performed in 18 patients with OSAS (mean age 43.7+/-16.6 years ; 17 males, 1 female ; mean respiratory disturbance index (RDI) 48.6+/-20.9) for one baseline and another CPAP nights From each night, 300 continuous beats of ECGs without artifact were chosen from both stage 2 sleep and REM sleep and they were used for power spectrum analysis. We compared between baseline and CPAP nights the heart rate variability including VLF(very low frequency power), LF(low frequency power), HF(high frequency power), R-R means, R-R variance, and LF/HF ratio, using Wilcoxon signed ranks test.
RESULTS
In all patients, nCPAP proved to be effective in relieving apneas and snoring. During nCPAP night compared with baseline night, decreases in VLF (p<0.05), LF (p<0.01), and R-R variance (p<0.05) were found in stage 2 sleep, and decreased LF (p<0.05) was found in REM sleep. No significant differences in each sleep stage were found in other variables between the two nights.
CONCLUSION
Our findings suggest that OSAS increases the activity of sympathetic nervous system and nCPAP application effectively decreases the activity. And nCPAP does not appear to influence the parasympathetic nervous activity in OSAS.

Keyword

Obstructive sleep apnea; Continuous positive airway pressure (CPAP); Autonomic nervous system; Power spectrum analysis; Heart rate variability

MeSH Terms

Apnea
Artifacts
Autonomic Nervous System
Continuous Positive Airway Pressure*
Electrocardiography*
Female
Heart Rate
Humans
Male
Polysomnography
Sleep Apnea, Obstructive*
Sleep Stages
Sleep, REM
Snoring
Spectrum Analysis*
Sympathetic Nervous System