A Tsapanou1, Y Gu2, D M O'Shea3, M Yannakoulia4, M Kosmidis5, E Dardiotis6, G Hadjigeorgiou6, P Sakka7, Y Stern2, N Scarmeas8. 1. Department of Social Medicine, Psychiatry and Neurology, National and Kapodistrian University of Athens, Athens, Greece; Cognitive Neuroscience Division, Department of Neurology and The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA. Electronic address: at2859@cumc.columbia.edu. 2. Cognitive Neuroscience Division, Department of Neurology and The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA. 3. Department of Clinical and Health Psychology, University of Florida, FL, USA. 4. Department of Nutrition and Diabetics, Harokopio University, Athens, Greece. 5. Department of Psychology, Aristotle University of Thessaloniki, Greece. 6. Department of Neurology, Faculty of Medicine, University of Thessaly, Larissa, Greece. 7. Athens Association of Alzheimer's Disease and Related Disorders, Athens, Greece. 8. Department of Social Medicine, Psychiatry and Neurology, National and Kapodistrian University of Athens, Athens, Greece; Cognitive Neuroscience Division, Department of Neurology and The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA.
Abstract
BACKGROUND: Sleep is crucial for cognition, particularly for memory, given its complex association with neurodegenerative processes. The aim of the present study was to examine the association between sleep quality as well as sleep duration and memory performance in a Greek elderly population. SETTING: Cross-sectional design in the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD), a population representative study of Greek elderly (65years or older). METHODS: Data from 1589 participants free of sleep medication were included. Sleep quality was estimated by using the Sleep Scale from the Medical Outcomes Study. An extensive neuropsychological assessment examining memory was administered to each participant. Linear regression analyses were used to examine whether sleep quality (higher score, poor quality) and/or sleep duration were associated with memory expressed in the form of a z-score. Age, sex, education, and body mass index were included as covariates. The main analyses were conducted first on the total sample, then with the exclusion of demented participants, and finally with the exclusion of both demented and participants with Mild Cognitive Impairment (MCI). We then conducted further analyses on the non-demented, non-MCI group, initially stratified by Apolipoprotein E-ε4 gene. We further examined the role of co-morbidities, as well as the association between sleep duration groups and memory. We also explored any interaction effect between sex and sleep quality/duration on memory. We then examined the associations between components of sleep measures and memory scores. Lastly, we examined the associations between sleep quality/duration and verbal/non-verbal memory separately. RESULTS: In the total sample, we noted significant associations between sleep duration and memory (B=-0.001, p≤0.0001), but not for sleep quality and memory (B=-0.038, p=0.121). After excluding the demented participants, the associations were significant for: sleep quality and memory (B=-0.054, p=0.023), and sleep duration and memory (B=-0.001, p≤0.0001). After excluding both the MCI and the demented subjects, the associations between sleep quality and memory (B=-0.065, p=0.006), and sleep duration and memory (B=-0.001, p=0.003) were still significant. The association between the sleep duration groups and memory function was also significant, such that poor memory performance was associated with the longer sleep duration group. The results remained significant even after controlling for the co-morbidities, as well as after adding in the model anxiety and depression as covariates. Associations between sleep quality and memory, and sleep duration and memory were present in the ApoE-ε4 non-carriers. The individual sleep questions that were probably shown to be driving the associations between sleep and memory were: time to fall asleep, sleep not quiet, getting enough sleep to feel rested upon waking in the morning, and getting the amount of sleep needed. Sleep duration was associated with both verbal and non-verbal memory, while sleep quality was only associated with verbal memory. CONCLUSION: Poor sleep quality and longer sleep duration were linked to low memory performance, independent of demographic and clinical factors, in a large sample of cognitively healthy older Greek adults. Other parameters than sleep and memory measurements could play an important role on the association. Levels of melatonin, or circadian rhythms dysregulation might play a crucial role in the above associations.
BACKGROUND: Sleep is crucial for cognition, particularly for memory, given its complex association with neurodegenerative processes. The aim of the present study was to examine the association between sleep quality as well as sleep duration and memory performance in a Greek elderly population. SETTING: Cross-sectional design in the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD), a population representative study of Greek elderly (65years or older). METHODS: Data from 1589 participants free of sleep medication were included. Sleep quality was estimated by using the Sleep Scale from the Medical Outcomes Study. An extensive neuropsychological assessment examining memory was administered to each participant. Linear regression analyses were used to examine whether sleep quality (higher score, poor quality) and/or sleep duration were associated with memory expressed in the form of a z-score. Age, sex, education, and body mass index were included as covariates. The main analyses were conducted first on the total sample, then with the exclusion of demented participants, and finally with the exclusion of both demented and participants with Mild Cognitive Impairment (MCI). We then conducted further analyses on the non-demented, non-MCI group, initially stratified by Apolipoprotein E-ε4 gene. We further examined the role of co-morbidities, as well as the association between sleep duration groups and memory. We also explored any interaction effect between sex and sleep quality/duration on memory. We then examined the associations between components of sleep measures and memory scores. Lastly, we examined the associations between sleep quality/duration and verbal/non-verbal memory separately. RESULTS: In the total sample, we noted significant associations between sleep duration and memory (B=-0.001, p≤0.0001), but not for sleep quality and memory (B=-0.038, p=0.121). After excluding the demented participants, the associations were significant for: sleep quality and memory (B=-0.054, p=0.023), and sleep duration and memory (B=-0.001, p≤0.0001). After excluding both the MCI and the demented subjects, the associations between sleep quality and memory (B=-0.065, p=0.006), and sleep duration and memory (B=-0.001, p=0.003) were still significant. The association between the sleep duration groups and memory function was also significant, such that poor memory performance was associated with the longer sleep duration group. The results remained significant even after controlling for the co-morbidities, as well as after adding in the model anxiety and depression as covariates. Associations between sleep quality and memory, and sleep duration and memory were present in the ApoE-ε4 non-carriers. The individual sleep questions that were probably shown to be driving the associations between sleep and memory were: time to fall asleep, sleep not quiet, getting enough sleep to feel rested upon waking in the morning, and getting the amount of sleep needed. Sleep duration was associated with both verbal and non-verbal memory, while sleep quality was only associated with verbal memory. CONCLUSION: Poor sleep quality and longer sleep duration were linked to low memory performance, independent of demographic and clinical factors, in a large sample of cognitively healthy older Greek adults. Other parameters than sleep and memory measurements could play an important role on the association. Levels of melatonin, or circadian rhythms dysregulation might play a crucial role in the above associations.
Authors: Krista Specketer; Cyrus P Zabetian; Karen L Edwards; Lu Tian; Joseph F Quinn; Amie L Peterson-Hiller; Kathryn A Chung; Shu-Ching Hu; Thomas J Montine; Brenna A Cholerton Journal: J Clin Exp Neuropsychol Date: 2019-06-10 Impact factor: 2.475
Authors: A Tsapanou; Y Gu; D M O'Shea; M Yannakoulia; M H Kosmidis; E Dardiotis; G Hadjigeorgiou; P Sakka; Y Stern; N Scarmeas Journal: Data Brief Date: 2017-09-01
Authors: Angeliki Tsapanou; Georgios S Vlachos; Stephanie Cosentino; Yian Gu; Jennifer J Manly; Adam M Brickman; Nicole Schupf; Molly E Zimmerman; Mary Yannakoulia; Mary H Kosmidis; Efthimios Dardiotis; Georgios Hadjigeorgiou; Paraskevi Sakka; Yaakov Stern; Nikolaos Scarmeas; Richard Mayeux Journal: J Sleep Res Date: 2018-09-25 Impact factor: 3.981
Authors: Prabha Siddarth; Kitikan Thana-Udom; Rashi Ojha; David Merrill; Joseph M Dzierzewski; Karen Miller; Gary W Small; Linda Ercoli Journal: Int Psychogeriatr Date: 2020-09-28 Impact factor: 7.191