Poor Sleep Quality Linked With Alzheimer Pathology in Cognitively Healthy Adults

Self-reported poor sleep quality is associated with greater Alzheimer disease biomarkers in adults older than 50 years without cognitive impairment, according to study findings published online in Brain Communications.

Moreover, poor sleep quality at baseline predicted a steeper decrease in amyloid-beta 42 (Aβ42) in cerebrospinal fluid over time, researchers reported.

“Our results further strengthen the hypothesis that sleep disruption may represent a risk factor for Alzheimer disease,” said study coauthor Laura Stankeviciute, MSc, of the Barcelona βeta Brain Research Center in Spain.

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The study included 1168 adults older than 50 years with no identifiable symptoms of Alzheimer disease at baseline from the European Prevention of Alzheimer’s Dementia Longitudinal Cohort Study. Researchers looked for links among core Alzheimer disease biomarkers (total tau [t-tau], phosphorylated tau [p-tau], and amyloid-beta) in cerebrospinal fluid, cognitive performance, and sleep quality as gauged by the Pittsburgh Sleep Quality Index questionnaire.

Cross-sectional analysis showed that a Pittsburgh Sleep Quality Index total score above 5 was significantly associated with increased t-tau. Sleeping less than 7 hours a night, meanwhile, was linked with higher p-tau and t-tau. Finally, higher degrees of sleep disturbance were associated with decreased Aβ42, according to the study.

A longitudinal analysis involving 332 participants who had cerebrospinal fluid taken both at baseline and an average 1.5 years later found that greater sleep disturbances at baseline were associated with a reduction of Aβ42 over time.

“This study demonstrates that self-reported poor sleep quality is associated with greater Alzheimer disease-related pathology in cognitively unimpaired individuals, with longitudinal results further strengthening the hypothesis that disrupted sleep may represent a risk factor for Alzheimer disease,” researchers advised. “This highlights the need for future work to test the efficacy of preventive practices, designed to improve sleep at presymptomatic stages of disease, on reducing Alzheimer disease pathology.”

References

Blackman J, Stankeviciute L, Arenaza-Urquijo EM, et al. Cross-sectional and longitudinal association of sleep and Alzheimer biomarkers in cognitively unimpaired adults. Brain Commun. 2022;4(6):fcac257. doi:10.1093/braincomms/fcac257.

Association between poor sleep quality and an increased risk of developing Alzheimer’s, new study finds. News release. University of Bristol; November 3, 2022. Accessed November 18, 2022.