Pathway linking nutritional status to cognitive function in older adults with chronic diseases: Exploring the mediating role of sleep quality

Objective: This study aimed to explore the pathway linking nutritional status to cognitive function in older adults with chronic diseases, and whether sleep quality potentially mediates their association. Methods: A cross-sectional study was conducted among 248 older adults with chronic diseases who were admitted in a district tertiary hospital, Shenzhen, China from January to December 2022. The participants completed the sociodemographic and clinical characteristics questionnaire, the Mini Nutritional Assessment Short Form (MNA-SF), the Montreal Cognitive Assessment (MoCA), and the Pittsburgh Sleep Quality Scale (PSQI). Linear regression and the bootstrap method were employed for data analysis. Results: We observed that older adults with chronic diseases showed notable cognitive decline, as indicated by a MoCA score (mean = 23.60, SD = 4.68). The direct effect analysis indicated that older adults with compromised nutritional status were more likely to experience cognitive decline (β = 1.006, P < 0.001). The mediation analysis revealed that sleep quality partially mediated the relationship between nutrition and cognitive function, accounting for 17.59 % of the overall effect. Specifically, poor sleep quality may increase the risk of subsequent cognitive decline among older adults with compromised nutritional status. Conclusions: This study identified that the impact of nutritional status on cognitive performance was partially mediated by sleep quality in older adults with chronic diseases. Further supporting the importance of high-quality sleep in maintaining brain health during aging. Monitoring and enhancing nutritional status and sleep quality may contribute to mitigating the progression of cognitive decline.