0455 Role of Interaction Between Anterior Insula Response to Sleep-Related Pictures and Stress Levels on Sleep Disturbance

Abstract Introduction Literature suggests that stress may play an important role in sleep disturbance. Individuals with higher stress levels often showed hyperarousal to stressful events, possibly leading to sleep disturbance. Hyperarousal is also one of features of stress-related sleep disturbance. Here, we examined the extent to which stress levels interact with neural activity in response to sleep-related information to predict sleep disturbance. Methods Forty eight healthy adults (26 females, age = 35.7 ± 10.5) without sleep disorders based on nocturnal polysomnography participated in this study. They were viewing sleep-related pictures (e.g., bedroom and sunset) and non-sleep related, neutral pictures (e.g., kitchen and landscape) during fMRI scanning. They also completed questionnaires assessing stress levels and sleep disturbance using Life Experience Survey (LES) and Pittsburgh Sleep Quality Index (PSQI), respectively. Activity in response to sleep-related pictures compared to neutral pictures was extracted from our region-of-interest (ROI), the anterior insula, and entered into our moderation models. The SPSS macro PROCESS (Hayes, 2013) was used to conduct moderation analyses. Given a significant correlation between age and PSQI scores, age was included as a covariate. Results Our moderation analyses showed that interactions between stress levels and anterior insula response to sleep-related pictures significantly predicted sleep disturbance. Simple slope analyses showed that at higher anterior insula response, higher stress levels were associated with greater sleep disturbance, but at lower anterior insula response, stress was not significantly associated with sleep disturbance. These results indicate that individuals with high levels of stress were more likely to experience sleep disturbance if they showed greater anterior insula response to sleep-related pictures (i.e., hyperarousal in response to sleep-related information). Conclusion The current findings suggest that interactions between stress levels and neural substrates of hyperarousal, particularly the anterior insula, may play a critical role in sleep disturbance. Support Brain Research Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT & Future Planning (Study No.: 2016M3C7A1904338 and NRF-2018R1D1A1B07049704).