Association of subjective cognitive complaints with poor sleep quality: A cross-sectional study among Chinese elderly

Subjective cognitive complaints (SCC) are the earliest symptom of Alzheimer's disease (AD) progression. Increasing evidence shows an association between poor sleep quality and SCC, but the current conclusions regarding the association between poor sleep quality and SCC in older adults are contradictory. Here, we aimed to explore the correlation of SCC with poor sleep quality among older adults without dementia living in nursing home and community in China.

A cross-sectional survey on sleep and psychosomatic health of older adults was conducted in Guangdong, China, between November 2020 and March 2021. Socio-demographic, health-related information, psychological factors, sleep quality and SCC of participants were evaluated through a face-to-face interview. A 9-item Subjective Cognitive Decline Questionnaire (SCD-Q9) was used to measure SCC; SCD-Q9 > 3 was defined as SCC. The Chinese version of the Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality; PSQI > 7 was defined as poor sleep quality. The relationship between SCC and sleep quality was evaluated using logistics regression analysis.

The study involved 730 participants (mean age 74.14 ± 8.246 years). The total SCC prevalence was 59.59%. The SCC group had poor sleep quality than the reference group (p < 0.05). Adjusted multiple logistic regression analysis revealed an association of poor sleep quality with SCC (OR = 1.841; 95% CI, 1.267-2.647; p = 0.001) after controlling for age, sex, residence, education level, marital status, income, smoking, alcohol consumption, tea drinking, multimorbidity, waist circumference, napping duration, anxiety symptoms, and depression symptoms. Hierarchical logistics regression analysis showed an association between sleep quality and SCC among community older adults (OR = 2.872; 95% CI: 1.787-4.615; p < 0.001), but not in nursing home residents (OR = 0.845; 95% CI: 0.437-1.637; p = 0.619).

Poor sleep quality is associated with SCC in community older adults. Therefore, medical staff should take measures, such as earlier cognitive intervention, to postpone cognitive decline in older adults, in the meantime, earlier management and treatment of sleep disorders should be taken into consideration.