0390 Cracking the EEG Code on Insomnia: How Odds Ratio Product Architecture Relates to Number of Insomnia Symptoms

Abstract

Abstract Introduction Objective markers of insomnia have remained largely elusive. Odds ratio product (ORP; a marker of objective sleep quality), is currently being investigated for a potential role in assisting in insomnia diagnosis. Recent research has shown how patients with insomnia may present with hyperarousal and may be identified by looking at ORP architecture. In the current study, we aimed to investigate how ORP architecture, and specifically time spent in the lowest two (deep sleep) and last decile (full wakefulness) of ORP, relate to the number of insomnia symptoms. Methods 403 participants (age 46.3±12.3, range 18-79, 172 females) recorded their sleep with in-home PSG using the Cerebra Sleep System and completed sleep questionnaires. Sleep quality was measured using the odds ratio product (ORP) derived from micro-analyzing frontal EEG channels. On the questionnaires, participants reported whether they experienced any of the following insomnia symptoms at least three times a week: trouble falling asleep, trouble staying asleep, and waking up too early. Statistical analyses included number of insomnia symptoms as a dependent variable in a multiple linear regression, time spent in the lowest two deciles of ORP and the highest decile of ORP as independent variables, and age as a covariate in a separate model. Results 60 participants reported 1 symptom of insomnia, 82 reported 2 symptoms, and 68 reported 3 symptoms. The full model was significant (F2,399=4.675, p=0.010, R=0.228, R2 adj=0.052) and indicated that time spent in the highest decile of ORP was the only significant predictor of number of insomnia symptoms (t399=2.321, p=0.021, β=0.131) after controlling for age. Time spent in the lowest two deciles of ORP (deep sleep) was not a significant predictor (p >0.05). Conclusion Time in the highest ORP decile, indicative of full wakefulness, is positively associated with insomnia symptoms after controlling for age. Individuals reporting more insomnia symptoms spent more time in full wakefulness. Time spent in deep sleep was not associated with insomnia symptoms. This may indicate hyperarousal and low sleep drive in participants with subjective insomnia complaints, which is consistent with insomnia etiology. Support (if any)