Sleep and activity/rest cycle disturbances during aging: an actigraphic and brain imaging study
Sleep and activity/rest cycle disturbances represent risk factors for the development of cognitive decline and dementia in aging. However, the association between these disturbances and cerebral modifications during aging remains to be explored. The aim of this thesis was to determine if sleep and activity/rest cycle disturbances could constitute a cerebral frailty factor for the development of cognitive decline and dementia in older adults (AMImage cohort).
First, we have shown that the discrepancy measured between self-reported sleep questionnaires and actigraphy – used as an objective technique – is influenced by the subject’s mood (Baillet et al., 2016). These results strengthen the use of an objective technique to measure sleep. Thanks to brain imaging, we observed that a reduced 24-h amplitude of the activity/rest cycle is associated with disruption of white matter structural integrity. Our results suggest that cerebral frailty associated with age-related activity/rest cycle dysfunction has a vascular origin (Baillet et al., 2017). Then, we observed that a poor sleep quality is associated with high cerebral amyloid burden, mainly circumscribed to frontal regions. This may be due to a deficit of amyloid-β peptide clearance from the brain during sleep.
To conclude, sleep and activity/rest cycle disturbances in older adults may be associated with two separate physiopathological processes leading to cerebral frailty. As sleep and activity/rest cycle are modifiable risk factors, interventions to improve their quality could offer a potential useful strategy for reducing the burden of cognitive impairment and dementia in old age.
Keywords: sleep, activity/rest cycle, actigraphy, Magnetic Resonance Imaging, Positons Emission Tomography, aging.
Baillet, M., Cosin, C., Schweitzer, P., Pérès, K., Catheline, G., Swendsen, J., Mayo, W., 2016. Mood Influences the Concordance of Subjective and Objective Measures of Sleep Duration in Older Adults. Front. Aging Neurosci. 8. doi:10.3389/fnagi.2016.00181
Baillet, M., Dilharreguy, B., Pérès, K., Dartigues, J.-F., Mayo, W., Catheline, G., 2017. Activity/rest cycle and disturbances of structural backbone of cerebral networks in aging. NeuroImage 146, 814–820. doi:10.1016/j.neuroimage.2016.09.051
Articles in preparation: Baillet, M., Meyer, M., Dilharreguy, B., Barse, E., Pérès, K., Helmer, C., Dartigues, J-F., Allard, M., Fernandez, P., Zanotti-Fregonara, P., Catheline, G., Mayo, W., 2017. Objective sleep quality assessment and cerebral β-amyloid burden in aging.