Arousal burden is highest in supine sleeping position and during light sleep

Minna Pitkänen; Juho Huovinen; Marika Rissanen; Henna Pitkänen; Samu Kainulainen; Thomas Penzel; Francesco Fanfulla; Ulla Anttalainen; Tarja Saaresranta; Ludger Grote; Jan Hedner; Richard Staats; Brett Duce; Juha Töyräs; Arie Oksenberg; Timo Leppänen

doi:10.5664/jcsm.11398

Arousal burden is highest in supine sleeping position and during light sleep

J Clin Sleep Med. 2024 Oct 4. doi: 10.5664/jcsm.11398. Online ahead of print.

Authors

Minna Pitkänen^{1

2}, Juho Huovinen¹, Marika Rissanen^{1

2}, Henna Pitkänen^{1

2}, Samu Kainulainen^{1

2}, Thomas Penzel³, Francesco Fanfulla⁴, Ulla Anttalainen^{5

6}, Tarja Saaresranta^{5

6}, Ludger Grote⁷, Jan Hedner⁷, Richard Staats⁸, Brett Duce^{9

10}, Juha Töyräs^{1

11

12}, Arie Oksenberg¹³, Timo Leppänen^{1

2

12}

Affiliations

¹ Department of Technical Physics, University of Eastern Finland, Kuopio, Finland.
² Diagnostic Imaging Centre, Kuopio University Hospital, Kuopio, Finland.
³ Center of Sleep Medicine, University Hospital Charité Berlin, Berlin, Germany.
⁴ Respiratory Function and Sleep Unit, Clinical Scientific Institutes Maugeri IRCCS, Pavia, Italy.
⁵ Division of Medicine, Department of Pulmonary Diseases and Clinical Allergology, Turku University Central Hospital, Turku, Finland.
⁶ Sleep Research Centre, University of Turku, Turku, Finland.
⁷ Center for Sleep and Wake Disorders, Institute of Medicine, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden.
⁸ University of Lisbon, Lisbon, Portugal.
⁹ Sleep Disorders Centre, Department of Respiratory & Sleep Medicine, Princess Alexandra Hospital, Australia.
¹⁰ Institute for Health and Biomedical Innovation, Queensland University of Technology, Australia.
¹¹ Science Service Center, Kuopio University Hospital, Kuopio, Finland.
¹² School of Electrical Engineering and Computer Science, The University of Queensland, Brisbane, Australia.
¹³ Sleep Disorders Unit, Loewenstein Hospital-Rehabilitation Center, Raanana, Israel.

PMID: 39364956
DOI: 10.5664/jcsm.11398

Abstract

Study objectives: Arousal burden (AB) is defined as the cumulative duration of arousals during sleep divided by the total sleep time. However, in-depth analysis of AB related to sleep characteristics is lacking. Based on previous studies addressing the arousal index (ArI), we hypothesized that the AB would peak in the supine sleeping position and during non-rapid eye movement stage 1 (N1) and show high variability between scorers.

Methods: Nine expert scorers analyzed polysomnography recordings of 50 participants, the majority with an increased risk for obstructive sleep apnea. AB was calculated in different sleeping positions and sleep stages. A generalized estimating equation was utilized to test the association between AB and sleeping positions, sleep stages, and scorers. The correlation between AB and ArI was tested with Spearman's rank-order correlation.

Results: AB significantly differed between sleeping positions (p<0.001). The median AB in the supine sleeping position was 47-62% higher than in the left and right position. The AB significantly differed between the sleep stages (p<0.001); the median AB was more than 200% higher during N1 than during other sleep stages. In addition, the AB differed significantly between scorers (p<0.001) and correlated strongly with ArI (r=0.935, p<0.001).

Conclusions: AB depends on the sleeping position, sleep stage, and scorer as hypothesized. AB behaved similarly as the ArI, but the high variability in the ABs between scorers indicates a potential limitation caused by subjective manual scoring. Thus, the development of more accurate techniques for scoring arousals is required before AB can be reliably utilized.

Keywords: arousal burden; arousal index; polysomnography; sleep stage; sleeping position.