Choroid plexus volume and its association with cognitive performance across the lifespan: Links to sleep quality and healthy brain aging

The choroid plexus (ChP) is implicated in inflammation and supports the clearance of waste byproducts, particularly those related to the pathogenesis of Alzheimer's disease. Increases in ChP volume have been associated with older age and cognitive decline in both clinical and healthy cohorts. However, the clearance of waste products in the brain is also related to sleep, and sleep quality may contribute to ChP dysfunction and cognitive decline. In the present work, it was therefore hypothesized that the association between age and cognitive performance is mediated by ChP volume, however this is conditional on sleep quality. A moderated-mediation model was tested on a sample (N = 590) of healthy adults aged 18–87 years from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN). Results showed that the relationship between increasing age and decreased cognitive performance was partially mediated by ChP volume, however, this was not conditional on sleep quality. A moderation analysis indicated that the relationship between ChP volume and cognitive performance was moderated by age, with ChP enlargement associated with worse cognitive performance in participants older than 62 years. In participants younger than 62 years, sleep duration was associated with cognitive performance, but ChP volume was not. These findings provide support for the sensitivity of ChP volume to cognitive performance in older adults.