Evidence of association between sleep quality and APOE ε4 in healthy older adults A pilot study

Background: It has been estimated that the prevalence of Alzheimer disease (AD) and related dementias will triple by 2035, unless effective interventions or treatments are found for the neurodegenerative disease. Understanding sleep changes as a marker for both AD risk and progression is a burgeoning area of investigation. Specifically, there is emerging evidence that both sleep disturbances and the APOE epsilon 4 allele are associated with increased dementia risk. Previous research has suggested that in AD, individuals carrying the APOE epsilon 4 allele have decreased sleep quality compared to individuals without the APOE epsilon 4 allele. This observational trial aimed to determine if healthy older adults with the risk allele (APOE epsilon 4+) have more sleep complaints or evidence of objective sleep disruption compared to healthy older adults without the risk allele (APOE epsilon 4-). Methods: Within the larger Brain in Motion study, a subset of participants completed at-home polysomnography (PSG) and actigraphy sleep assessment. Subjective sleep complaints were determined using the Pittsburgh Sleep Quality Index. Results: This investigation found a significant relationship between presence of APOE epsilon 4 allele and objective sleep disturbances measured by both actigraphy and PSG, but not subjective sleep complaints in a healthy population screened for dementia. Conclusions: These data suggest that the influence of APOE epsilon 4 allele on objective sleep quality may precede subjective sleep complaints in individuals at increased risk for dementia.