322 Comparisons of clinical and polysomnographic characteristics between negative and positive sleep state misperception in insomnia

Abstract

\n \n \n Most of insomnia patients tend to underestimate their sleep duration and quality. In current study, we classified insomnia patients into negative sleep state misperception (NSSM) group and positive sleep state misperception (PSSM) group according to difference between subjective and objective sleep duration. We compared clinical and polysomnographic characteristics between two groups.\n \n \n \n Objective sleep measures using nocturnal polysomnography (nPSG) and subjective measures including Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory (BDI) and subjective questionnaire at the morning after overnight nPSG of 150 insomnia patients were reviewed. The questionnaire included subjective total sleep time (subjective TST), subjective sleep latency (subjective SL). Additionally, TST/SL discrepancy was calculated by subtracting objective variables of nPSG from the morning subjective questionnaire. We calculated misperception index (MI) using the following method; MI=(objective TST-subjective TST)/objective TST. According to MI value, insomnia patients were classified into NSSM (MI>0, n=115), and PSSM (MI<0, n=35) groups.\n \n \n \n There were no significant differences in nPSG parameters, except N3 sleep (%); the PSSM group had significantly higher N3 sleep than NSSM group (p=0.002). On the subjective measures, the NSSM group had significantly higher PSQI score (p<0.001), longer subjective SL (p=0.001) and higher SL discrepancy (p=0.001). In the NSSM group, MI showed positive correlations with N1 sleep proportion (r=0.250, p=0.011), PSQI (r=0.250, p=0.011), BDI (r=0.211, p=0.032), subjective SL (r=0.441, p<0.001) and SL discrepancy (r=0.453, p<0.001). Meanwhile, there were no significant correlations of MI with subjective measures in PSSM group. In the multiple regression analysis, MI was related with SL discrepancy and BDI (R2=0.216, p=0.004) in NSSM group. For belonging the PSSM group, associated factors were N3 sleep (OR=1.075, p=0.001), PSQI (OR=0.813, p=0.002) and SL discrepancy (OR=0.956, p<0.001) on binary logistic regression analysis.\n \n \n \n In the NSSM group, MI was related with high SL discrepancy and depressive mood. High N3 sleep, low PSQI score, and low SL discrepancy were associated factors in the PSSM group. Perception of sleep should be properly evaluated and managed, since they vary with different characteristics of sleep state misperception.\n \n \n \n This study was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF-2018R1D1A1B07049704).\n