The Effect of Lavender Essential Oil on Sleep Quality and Obstructive Sleep Apnea Syndrome
Date Issued
2015
Date
2015
Author(s)
Wu, Yan-Lin
Abstract
The importance of night time sleep quality is emerging as the pace of everyday life speeds up. Among sleep disorder diseases, Obstructive Sleep Apnea (OSA) affects the patient’s sleep quality most seriously. It may even induce mental or cardiovascular problems. The research studies the influence of lavender essential oil on sleep, with the hope that lavender essential oil can improve SAS and sleep quality. In order to analyze the effect of lavender essential oil on sleep, whole night polysomnography was performed on 32 subjects (13 normal, 10 with mild OSA, and 9 with moderate-severe OSA). The polysomnography constituted of two sessions. The first session lasted for 4 hours in which lavender essential oil was vaporized. The second session started from the 5th hour until the subject wakes up. In this session, only distilled water was vaporized. This study adopts two approaches to evaluate the effect of lavender essential oil on sleep. One is by comparing the sleep events in the two sessions; the other is by analyzing electrocardiography (ECG) signals. Comparison of sleep events shows that for normal subjects, the wake time after sleep onset (WASO) in the first session is significantly shorter than in the second session (p=0.04); the duration of stage N3 in the first session is significantly longer than in the second session (p=0.018). For OSA patients, the duration of stage N2 in the first session is significantly longer than in the second session (p=0.028). It indicates that lavender essential oil may improve the sleep quality of subjects. In the ECG analysis, the single-lead ECG of subjects were used to determine the heart rate variability (HRV). Then, HRV was analyzed using the Poincaré plot and Lomb-Scargle periodogram. In order to construct a baseline for comparison, 43 polysomnograms obtained in regular polysomnography were used in this study. No essential oil was applied in these tests. The subjects comprised 20 normal persons, 9 mild OSA patients, and 14 moderate-severe OSA patients. The Poincaré plot of the ECG recordings show that for normal and mild OSA subjects, the SD1’s and SSR’s of the first sessions are higher in the aromatherapy trials but lower in the baseline trials. Computing the difference of SD1 in the first and second sessions, denoted ΔSD1, one can see that ΔSD1 is significantly lower in the baseline trials than in the aromatherapy trials (p<0.05). This is also true for ΔSSR. The above results suggest that aromatherapy may enhance parasympathetic activity and reduce the heart rate and respiration rate. This implies that the subjects are more relaxed while in sleep. The Lomb-Scargle periodogram results show that for normal subjects, The ratio of LF power to HF power (LHR) of the first sessions is lower in the aromatherapy trials but higher in the baseline trials. Computing the difference of LHR in the first and second sessions, denoted ΔLHR, one can see that ΔLHR is significantly higher in the baseline trials than in the aromatherapy trials (p<0.05). This suggests that aromatherapy may adjust the autonomic nervous system balance of the subjects to relieve the heart stress. In conclusion, vaporization of lavender essential oil seems to be able to improve the sleep quality of normal persons and mild OSA patients and to decrease the parasympathetic nervous system activity. However, its influence on moderate-severe OSA patients is not significant and needs to be studied further.
Subjects
Lavender Essential Oil
Sleep Apnea Syndrome
Heart Rate Variability
Poincar? plot
Lomb-Scargle periodogram
Type
thesis