Feng Deng, Karen Ritchie, Graciela Muniz-Terrera, Suzanne Hutchinson, Paresh Malhotra, Craig W Ritchie, Brian Lawlor, Lorina Naci.

Neurobiology of Ageing (2024)

DOI: https://doi.org/10.1016/j.neurobiolaging.2024.09.00610.1016/j.neurobiolaging.2024.09.006

Summary

This study examined whether Alzheimer’s Disease (AD) risk factors were associated with cognition and functional connectivity (FC) between two key brain structures involved with the development of AD, the Locus Coeruleus (LC) and the hippocampus.

The study found evidence that in midlife, the role of functional connectivity between the LC and the hippocampus in supporting cognition is disrupted, in individuals with a high dementia risk score. When genetic risk (APOE ε4) or family history were considered on their own, no alterations of brain–behaviour relationships were found. It was only when a risk score (CAIDE) incorporating genetic risk in combination with lifestyle factors, sex and age was considered, that such alterations were unraveled.

These results provide evidence that brain–behaviour changes in individuals with higher dementia risk scores may be driven by lifestyle factors included in the CAIDE score (i.e., blood pressure, cholesterol, physical activity, body mass index, years of education). These findings highlight the importance of modifying cardiovascular factors for the early prevention of dementia.