Association of heart rate variability with REM sleep without atonia in idiopathic REM sleep behavior disorder

Jeong Hun Yang; Sang Ho Choi; Mi Hyun Lee; Seong Min Oh; Jae-Won Choi; Jee Eun Park; Kwang Suk Park; Yu Jin Lee

doi:10.5664/jcsm.8934

Association of heart rate variability with REM sleep without atonia in idiopathic REM sleep behavior disorder

J Clin Sleep Med. 2021 Mar 1;17(3):461-469. doi: 10.5664/jcsm.8934.

Authors

Jeong Hun Yang¹, Sang Ho Choi², Mi Hyun Lee³, Seong Min Oh⁴, Jae-Won Choi⁵, Jee Eun Park⁶, Kwang Suk Park^{7

8}, Yu Jin Lee³

Affiliations

¹ Department of Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea.
² Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, Republic of Korea.
³ Department of Psychiatry and Center for Sleep and Chronobiology, Seoul National University College of Medicine and Seoul National University Hospital, Seoul, Republic of Korea.
⁴ Department of Psychiatry, Dongguk University Ilsan Hospital, Gyeonggi-do, Republic of Korea.
⁵ Department of Neuropsychiatry, Eulji University School of Medicine, Eulji General Hospital, Seoul.
⁶ Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea.
⁷ Department of Biomedical Engineering, College of Medicine, Seoul National University, Seoul, Republic of Korea.
⁸ Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University, Seoul, Republic of Korea.

Abstract

Study objectives: Idiopathic rapid eye movement sleep behavior disorder (iRBD), characterized by rapid eye movement sleep without atonia (RSWA) and dream-enactment behavior, has been suggested to be a predictor of α-synucleinopathies. Autonomic instability, represented by heart rate variability, is a common characteristic of both iRBD and α-synucleinopathies. Previous studies reported that RSWA was associated with autonomic dysfunction and was a possible predictor of phenoconversion. Therefore, we sought to compare heart rate variability between iRBD and control groups and explore the relationship between heart rate variability and RSWA in patients with iRBD.

Methods: Nocturnal polysomnographic data on 47 patients (28 men, 19 women) diagnosed with iRBD based on video-polysomnography and 26 age-matched and sex-matched controls were reviewed. The first 5-minute epoch with a stable electrocardiogram lead II on video-polysomnography was selected from stage N2, wake, and rapid eye movement. For quantification of RSWA, tonic activity was analyzed from the submentalis electromyogram and phasic activity from the submentalis and bilateral anterior tibialis electromyogram channels.

Results: Compared to the control group, the iRBD group showed significant reductions in the standard deviation of the R-R intervals, the root mean square of successive R-R interval differences, and high-frequency values. Quantified tonic activity was inversely correlated with normalized low-frequency values and low-frequency/high-frequency ratios and positively correlated with normalized high-frequency values.

Conclusions: This study implied decreased cardiac autonomic function in patients with iRBD, which showed parasympathetic predominance. Heart rate variability of the patients with iRBD in this study was associated with quantified tonic RSWA, which was previously reported to be a possible predictor of phenoconversion.

Keywords: REM sleep behavior disorder; autonomic nervous system; heart rate variability.

MeSH terms

Female
Heart Rate
Humans
Male
Muscle Hypotonia
Polysomnography
REM Sleep Behavior Disorder*
Sleep, REM