1108 Objective-Subjective Discrepancy in Sleep Assessment in Patients Without Significant History: Roles of Insomnia and Depression Symptoms

Abstract Introduction Disparities between objective and subjective sleep measures have been frequently reported in patients with depression and insomnia. Relatively few studies evaluated objective-subjective mismatch in people without medical or psychiatric conditions. This study analyzes the effect of mood and insomnia symptoms on sleep (mis)perception in patients without significant history who were referred for a diagnostic PSG and failed to meet OSA diagnosis. Methods A total of 191 patients without major medical or psychiatric diagnoses were selected from 2001 consecutive PSGs based on AHI 5.0 and PLM index 25.0 (102 women, 70 Caucasian, MAge=42.3±15.2). Using subjective post-PSG estimates of in-lab total sleep time (TST), sleep latency (SL) and time awake after sleep onset (WASO), objective-subjective mismatch indices (MI=objective-subjective/objective) were calculated. MIs were regressed on objective sleep variables (TST, SL, SE, N1%, N3%, REM%, REM latency, WASO, #awakenings, total arousal index, TAI) and ESS, ISI, Center for Epidemiologic Studies Depression Scale-Revised (CESDR) and ISI-by-CESDR interaction, with age, sex and BMI as covariates. Results In this sample, 139 (72.8%) patients had ISI≥8 (suggestive of insomnia), and 66 (34.6%) had CESDR≥16 (suggestive of depression). Above-threshold ISI and CESDR scores were significantly related (chi-square(1df)=22.8, p 0.001). Greater overestimation of SL was significantly predicted by higher TAI (p=0.048), higher objective-SE (p=0.043), higher objective-WASO (p 0.001), higher CESDR (p 0.001) and ISI-by-CESDR interaction (p=0.001). In patients with ISI 8, CESDR predicted SL overestimation (R-square=37.2%); with ISI≥8, CESDR and SL-MI were unrelated (R-square=0.5%). MIs for TST and WASO did not relate to any predictor variables. Conclusion In this sample of patients without significant medical or psychiatric history and without OSA, above-threshold insomnia and depression symptoms were strongly related. Overestimation of SL related to greater objective sleep disturbance on TAI and WASO, but, paradoxically, higher objective SE. Overestimation of SL strongly related to elevated depression symptoms among patients without ISI elevation, but not in patients with elevated ISI, suggesting the role of mood in sleep misperception in normal sleepers. Support (if any) none