Regularity of heart rate fluctuations analysis in obstructive sleep apnea patients using information-based similarity

Abstract

Obstructive sleep apnea (OSA) is a common respiratory disorder that is associated with autonomic dysfunction. The low-frequency power to high-frequency power ratio (LF/HF) shows a significant difference between the normal group and OSA group. In fact, only severe sleep apnea events result in obvious clinical signs. However, the difference between the severe OSA (OSA-s) group and mild-moderate (OSA-m) group is often overlooked. The present study included 60 electrocardiogram (ECG) recordings (20 healthy recordings, 14 mild-moderate OSA recordings and 26 severe OSA recordings) from the PhysioNet database. These recordings included 6 h of sleep and were divided into 1-minute segments. Information-based similarity (IBS) was used to analyze heart rate (HR) fluctuations in patients with severe OSA. Compared with LF/HF, the IBS of HR fluctuations shows significant differences between the OSA-m group and the OSA-s group (p < 0.001). The accuracy of IBS in severe OSA detection was 76.7%, while LF/HF exhibited an accuracy of 70%. The study found that the similarity of the regularity of HR fluctuations between adjacent RR segments decreased significantly only in the severe OSA group. This finding may be the reason that severe OSA has a significant effect on sleep quality, while mild-to-moderate OSA tends to be overlooked. Therefore, this IBS method has certain clinical significance, and could be used to detect severe OSA.