0700 Apoe ε4 Allele Is Associated With Long Sleep Duration Among Elderly With And Without Cognitive Impairment

Abstract Introduction Apolipoprotein E gene (APOE) ε4 allele increases the risk for Alzheimer’s Disease (AD). We have previously shown that among cognitively non-impaired elderly and patients with cognitive impairment, longer sleep duration is associated with worse cognitive performance. To date, only two pilot studies have examined the associations between APOEε4 allele and objective sleep in healthy and cognitively impaired elderly and the findings were inconsistent. Our aim was to assess the association between APOEε4 and objective sleep, among healthy controls and patients with Mild Cognitive Impairment (MCI) and AD. Methods A sub-sample of 161 elderly with MCI (n=38), AD (n=48) and non-impaired controls (n=75) were recruited from a large, population-based cohort of 3,140 older adults (>60yrs) residing on the island of Crete, Greece. All participants underwent medical history/physical examination, extensive neuropsychiatric and neuropsychological evaluation, 3-day 24-h actigraphy and APOEε4 allele. Comparisons of sleep variables between APOEε4 allele carriers and non-carriers were assessed, using ANCOVA, controlling for gender, age, BMI, depression, and Sleep Apnea symptoms. Results Our sample included 21 APOE ε4 carriers and 140 non-carriers, aged 77.6 ± 7.1 and 76.1 ± 7.4 years, respectively. Across the three groups, APOEε4 carriers compared to non-carriers had significantly longer nighttime Total Sleep Time (467.8 ± 75.7min vs. 420.9 ± 77.5min, respectively, p= .014), nighttime Total Time in Bed (587.8 ± 79.7min vs. 521.5 ± 86.5min, respectively, p= .001), 24-h Total Sleep Time (513.8 ± 89.3min vs. 456.8 ± 90.6min, respectively, p= .01), and 24-h Total Time in Bed (662.9 ± 109.3min vs. 578.7 ± 118.6min, respectively, p= .002). Other sleep variables examined did not differ between the two groups. Conclusion This is the first study to demonstrate that among non-impaired elderly and patients with MCI and AD, APOEε4 carriers have longer objective 24-h sleep duration compared to non-carriers. These findings further support that objective long sleep duration is a genetically driven biologic marker of worse prognosis in elderly with or without cognitive impairment. Support (If Any) National Strategic Reference Framework (NSRF) - Research Funding Program: THALES entitled “UOC-Multidisciplinary network for the study of Alzheimer’s Disease” Grant Cod:MIS 377299.