Sleep and Psychosocial Factors Linked to Cognition in Alzheimer's Disease

Background According to the 2022 Alzheimer's Association Facts and Figures report, older Black/African American individuals are twice as likely and Hispanic/Latino individuals are about one and one-half times as likely to develop dementia as older white individuals. In addition, Black and Latino adults are at greater risk of experiencing poor quality sleep compared to White adults. Recent studies reveal that sleep disruption may impact the risk for Alzheimer's and other brain diseases. More than 50% of individuals with dementia experience sleep disruptions or poor sleep patterns that precede cognitive impairment by several years. Short sleep duration and poor sleep quality have been linked with Alzheimer's-related brain changes, including two the build up of beta-amyloid and tau in the brain. Studies have also linked poor sleep quality and sleep duration that is either too long or too short with poorer cognitive performance. Yet these prior studies have been predominantly composed of White participants, making the generalizability of the association between sleep and Alzheimer's in Black and Latino populations unknown. Dr. Emily Hokett and colleagues have shown that Black/African American adults may be particularly sensitive to sleep disturbances, and this sensitivity may be partially due to greater experiences of discrimination. However, there is no research investigating the association among sleep, cognition, and Alzheimer's in relation risk factors such as discrimination and protective factors such as level of education and social cohesion in Black/African American,Hispanic/ Latino, and White adults. Research Plan In a diverse sample of older adults, Dr. Hokett and team will identify factors that are positively and negatively associated with sleep quality and duration. They will also study the connection between sleep quality and duration and cognitive function. Finally, they will examine the link between sleep quality and duration and biomarkers of Alzheimer's. The researchers will leverage data from the Offspring Study of Mechanisms for Racial Disparities in Alzheimer's Disease study, which is an ongoing study following individuals over time on cognitive aging and Alzheimer's at the Columbia University Medical Center. The participants of this study are 16% Black/African American, 68% Hispanic/Latino, and 13% White. The researchers will evaluate the participants for level of education attained, sleep duration and quality, social cohesion (e.g., levels of social support or loneliness), discrimination, and childhood socioeconomic status. They will also administer cognitive tests and measure biological markers related to Alzheimer's from participants' blood samples. Finally, a subset of participants will complete brain scans (magnetic resonance imaging, MRI) to assess other biological brain changes associated with Alzheimer's. Impact This project may contribute to a better understanding of modifiable risk factors for Alzheimer's, such as poor sleep and psychosocial factors. If successful, the findings may inform preventive strategies for Alzheimer's, especially for Black and Latino older adults.