The purpose of this study was to investigate the discrepancies between subjective and objective sleep assessments in middle-aged to elderly adults.
A survey on sleep and physical function by age group was conducted among 138 community-dwelling individuals aged 50 years and older. For objective sleep evaluation, a non-wearable sleep monitor (a sheet-shaped body vibrometer) was used to measure the respiratory event index (REI), which indicates the respiratory state during sleep, and sleep efficiency at home. As an indicator of sleep-related breathing disorders, the REI based on the estimated total sleep time (REI_eTST) was used. For subjective sleep assessment, the Epworth Sleepiness Scale (ESS) and the Athens Insomnia Scale (AIS) were used. Additionally, BMI, skeletal muscle index (SMI), grip strength, and physical activity were measured, and cognitive function was assessed using the HDS-R. One-way ANOVA and Tukey’s test were used to compare differences between age groups for each evaluation item.
The mean age of the participants was 77.1 years, and their mean BMI was 23.3 kg/m². The average sleep efficiency (%) was as follows: 50s: 86.7 ± 13.5, 60s: 88.5 ± 6.4, 70s: 87.4 ± 6.1, 80s: 81.5 ± 11.4, 90s: 77.7 ± 8.5. The respiratory event index (REI_eTST) (events/h) was as follows: 50s: 8.5 ± 3.2, 60s: 10.8 ± 4.2, 70s: 13.1 ± 4.9, 80s: 18.5 ± 9.1, 90s: 21.5 ± 10.9, with significant differences observed in those aged 80 and over compared to those aged 70 and below. The ESS scores were: 50s: 8.9 ± 5.4, 60s: 5.8 ± 3.3, 70s: 4.3 ± 2.9, 80s: 5.7 ± 3.2, 90s: 6.1 ± 2.6. The AIS scores were: 50s: 5.1 ± 4.6, 60s: 3.8 ± 3.4, 70s: 2.9 ± 2.6, 80s: 2.7 ± 2.9, 90s: 2.3 ± 2.1, with no significant differences observed between age groups. Moreover, grip strength, physical activity, and HDS-R scores showed significant declines in those aged 80 and over compared to those aged 70 and below.
In this study, a significant decline in objective sleep assessments was observed in participants aged 80 and older. On the other hand, while objective indicators showed a deterioration in sleep conditions among those in their 80s and 90s, no deterioration was observed in the subjective assessments, suggesting a discrepancy between subjective and objective evaluations. This indicates that elderly individuals may have fewer subjective symptoms related to sleep disturbances.
This study suggests that in the future, when assessing sleep in the very elderly in clinical and research settings, it is preferable to use objective assessments with a sleep monitor.
Sleep assessment
Older people
