In older adults at risk for dementia, lower inter-daily stability of rest-activity rhythms was associated with lower cortical thickness in frontal, temporal, and parietal regions (CWP < 0.001).
Cross-Sectional (n=143)
Are rest-activity rhythms associated with cortical thickness in older adults at risk for dementia?
In older adults at risk for dementia, variability and stability of rest-activity rhythms are associated with reduced cortical thickness in multiple brain regions.
p-value: p=<0.001
STUDY OBJECTIVES: While alterations in rest-activity rhythms are common in older adults "at risk" for dementia, it is unclear how rest-activity rhythms relate to underlying brain integrity. METHODS: Older adults aged ≥50 years (n = 143, mean age = 67) with subjective and/or objective cognitive impairment underwent magnetic resonance imaging scanning and 14 days of actigraphy. The following nonparametric measures were computed: intra-daily variability (IV), inter-daily stability (IS), relative amplitude (RA), and average activity during the least active 5-h period (L5). A vertex-wise analysis correcting for age, sex, and clinical variables examined the association between nonparametric actigraphy measures and cortical thickness. RESULTS: When controlling for age, sex, and body mass index (BMI), lower IV was associated with greater cortical thickness in the right cuneus (cluster-wise p-values CWP < 0.001), left middle frontal gyrus (CWP < 0.001), and lateral orbital frontal cortex (CWP = 0.004). When controlling for age, sex, medical burden (CIRS-G), BMI, and antidepressant use, lower IS was associated with lower cortical thickness in the left (CWP = 0.002) and right superior frontal gyrus (CWP < 0.001), left superior temporal gyrus (CWP = 0.043), and left post-central gyrus (CWP = 0.033). There were no significant associations between RA or L5 and cortical thickness. CONCLUSIONS: In older adults "at risk" for dementia, variability and stability of rest-activity rhythms were associated with reduced cortical thickness in frontal, temporal, parietal, and occipital regions. Further studies could focus on determining the prognostic utility of such markers longitudinally.
Espinosa et al. (Fri,) conducted a cross-sectional in At risk for dementia (subjective and/or objective cognitive impairment) (n=143). Rest-activity rhythm fragmentation and synchronization was evaluated on Cortical thickness (p=<0.001). In older adults at risk for dementia, lower inter-daily stability of rest-activity rhythms was associated with lower cortical thickness in frontal, temporal, and parietal regions (CWP < 0.001).