Affiliation:
1. Department of Neurobiology Weizmann Institute of Science Rehovot Israel
2. Appscent Medical Ra'anana Israel
3. The Sleep and Fatigue Institute, Assuta Medical Center Tel Aviv Israel
4. The Research Institute of Applied Chronobiology, The Academic College of Tel‐Hai Tel Hai Israel
5. Pulmonary Institute, Sha'are Zedek Medical Center Jerusalem Israel
6. The Faculty of Medicine The Hebrew University of Jerusalem Jerusalem Israel
7. Department of Medical Neurobiology, Institute for Medical Research Israel Canada, Faculty of Medicine The Hebrew University Jerusalem Israel
8. Department of Cognitive and Brain Sciences Hebrew University of Jerusalem Jerusalem Israel
Abstract
SummaryObstructive sleep apnea is a prevalent sleep‐disordered breathing condition characterized by repetitive reduction in breathing during sleep. The current care standard for obstructive sleep apnea is continuous positive air pressure devices, often suffering from low tolerance due to limited adherence. Capitalizing on the unique neurocircuitry of olfactory perception and its retained function during sleep, we conducted a pilot study to test transient, respiration‐based olfactory stimulation as a treatment for obstructive sleep apnea markers. Thirty‐two patients with obstructive sleep apnea (apnea–hypopnea index ≥ 15 events per hr) underwent two polysomnography sessions, “Odour” and “Control”, in random order. In “Odour” nights, patients were presented with transient respiratory‐based olfactory stimulation delivered via a computer‐controlled commercial olfactometer (Scentific). The olfactometer, equipped with a wireless monitoring, analysed respiratory patterns and presented odour upon detection of respiratory events. No odours were presented in “Control” nights. Following exclusions, 17 patients entered the analysis (four women, 47.4 (10.5) years, body mass index: 29.4 (6.3) kg m−2). We observed that olfactory stimulation during sleep reduced the apnea–hypopnea index (“Odour”: 17.2 (20.9), “Control”: 28.2 (18.6), z = −3.337, p = 0.000846, BF10 [Bayesian Factor 10]= 57.9), reflecting an average decrease of 31.3% in the number of events. Relatedly, stimulation reduced the oxygen desaturation index by 26.9% (“Odour”: 12.5 (15.8), “Control”: 25.7 (25.9), z = −3.337, p = 0.000846, BF10 = 9.522). This effect was not linked to the severity of baseline obstructive sleep apnea markers (ρ = −0.042, p = 0.87). Olfactory stimulation did not arouse from sleep or affect sleep structure, measured as time per sleep stage (F1,16 = 0.088, p = 0.77). In conclusion, olfactory stimulation during sleep was effective in reducing the severity of obstructive sleep apnea markers without inducing arousals, and may provide a novel treatment for obstructive sleep apnea, prompting continued research.