Resting-state functional connectivity changes in older adults with sleep disturbance and the role of amyloid burden

Sleep and related disorders could lead to changes in various brain networks, but little is known about the role of amyloid & beta; (A & beta;) burden-a key Alzheimer's disease (AD) biomarker-in the relationship between sleep disturbance and altered resting state functional connectivity (rsFC) in older adults. This cross-sectional study examined the association between sleep disturbance, A & beta; burden, and rsFC using a large-scale dataset from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Sample included 489 individuals (53.6% cognitively normal, 32.5% mild cognitive impairment, and 13.9% AD) who had completed sleep measures (Neuropsychiatric Inventory), PET A & beta; data, and resting-state fMRI scans at baseline. Within and between rsFC of the Salience (SN), the Default Mode (DMN) and the Frontal Parietal network (FPN) were compared between participants with sleep disturbance versus without sleep disturbance. The interaction between A & beta; positivity and sleep disturbance was evaluated using the linear regressions, controlling for age, diagnosis status, gender, sedatives and hypnotics use, and hypertension. Although no significant main effect of sleep disturbance was found on rsFC, a significant interaction term emerged between sleep disturbance and A & beta; burden on rsFC of SN (& beta; = 0.11, P = 0.006). Specifically, sleep disturbance was associated with SN hyperconnectivity, only with the presence of A & beta; burden. Sleep disturbance may lead to altered connectivity in the SN when A & beta; is accumulated in the brain. Individuals with AD pathology may be at increased risk for sleep-related aberrant rsFC; therefore, identifying and treating sleep problems in these individuals may help prevent further disease progression.

Automated summary

There is an interaction between sleep disturbance and Aβ burden in the altered resting state functional connectivity (rsFC) in older adults. Sleep disturbance is associated with hyperconnectivity in the Salience Network (SN) only in the presence of Aβ burden. Identifying and treating sleep problems in individuals with AD pathology may help prevent further disease progression.