Longitudinal changes in sleep behavior and mild cognitive impairment: An 8-year trajectory analysis in a community-based cohort

초록

Background and aims: Sleep disturbances are associated with neurodegenerative diseases. However, the specific sleep characteristics most strongly linked to cognitive decline remain unclear. This study investigates longitudinal changes in sleep behavior over eight years in individuals with and without cognitive impairment. Methods: We analyzed data from 2078 participants in a community-based cohort who underwent cognitive assessment using the Seoul Neuropsychological Screening Battery-II (SNSB-II). Sleep parameters—including duration, latency, efficiency, and chronotype (mid-sleep time on free days corrected for sleep debt, MSFsc)—were derived from the modified Pittsburgh Sleep Quality Index (PSQI). Of the participants, 626 were classified as having mild cognitive impairment (MCI, mean age: 65.63 ± 5.91 years, male: 53.4 %), while 1452 were cognitively unimpaired (mean age: 65.76 ± 5.78 years, male: 47.0 %). Results: At the time of SNSB-II assessment, the MCI group exhibited a significantly earlier chronotype compared to the cognitively unimpaired group (MSFsc: 2.33 ± 1.2 vs. 2.48 ± 1.16, P = 0.0107). This phase advance was also observed eight years before MCI diagnosis (MSFsc: 2.61 ± 1.17 vs. 2.77 ± 1.14, P = 0.00982). In contrast, the other sleep parameters related to sleep quantity - duration, latency, and efficiency in addition to the overall PSQI score showed no significant differences between groups. Conclusions: Earlier chronotype may be an early marker of cognitive decline. Longitudinal monitoring of sleep phase shifts could provide insights into neurodegenerative risk and facilitate early interventions. Acknowledgement: This study was supported by grants from the NRF funded by MSIT (RS-2024-00359247 to HJ Kim), and KDCA (2011-E71004–00–2021-E0602–01 to C Shin).