Robert J Brychta1, Nanna Yr Arnardottir2,3, Erlingur Johannsson4, Elizabeth C Wright1, Gudny Eiriksdottir3, Vilmundur Gudnason3,5, Catherine R Marinac1, Megan Davis1, Annemarie Koster6, Paolo Caserotti7, Thorarinn Sveinsson2, Tamara Harris8, Kong Y Chen1. 1. National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD. 2. Research Center of Movement Science, University of Iceland, Reykjavík, Iceland. 3. Icelandic Heart Association, Kópavogur, Iceland. 4. Center of Sport and health Sciences, School of Education, University of Iceland, Laugarvatn, Iceland. 5. Faculty of Medicine, University of Iceland, Reykjavík, Iceland. 6. Department of Social Medicine, CAPHRI School for Public Health and Primary Care, Maastricht University, Maastricht, The Netherlands. 7. Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark. 8. National Institute on Aging, Bethesda, Maryland.
Abstract
STUDY OBJECTIVES: To identify cross-sectional and seasonal patterns of sleep and physical activity (PA) in community-dwelling, older Icelandic adults using accelerometers. METHODS: A seven-day free-living protocol of 244 (110 female) adults aged 79.7 ± 4.9 years was conducted as part of a larger population-based longitudinal observational-cohort study in the greater Reykjavik area of Iceland. A subpopulation (n = 72) repeated the 7-day measurement during seasonal periods with greater (13.4 ± 1.4 h) and lesser (7.7 ± 1.8 h) daylight. RESULTS: Cross-sectional analyses using multiple linear regression models revealed that day length was a significant independent predictor of sleep duration, mid-sleep, and rise time (all p < 0.05). However, the actual within-individual differences in sleep patterns of the repeaters were rather subtle between periods of longer and shorter day-lengths. Compared to women, men had a shorter sleep duration (462 ± 80 vs. 487 ± 68 minutes, p = 0.008), earlier rise time, and a greater number of awakenings per night (46.5 ± 18.3 vs. 40.2 ± 15.7, p = 0.007), but sleep efficiency and onset latency were similar between the two sexes. Daily PA was also similar between men and women and between periods of longer and shorter day-lengths. BMI, age, gender, and overall PA all contributed to the variations in sleep parameters using multiple regression analysis. CONCLUSIONS: The sleep and PA characteristics of this unique population revealed some gender differences, but there was limited variation in response to significant daylight changes which may be due to long-term adaptation.
STUDY OBJECTIVES: To identify cross-sectional and seasonal patterns of sleep and physical activity (PA) in community-dwelling, older Icelandic adults using accelerometers. METHODS: A seven-day free-living protocol of 244 (110 female) adults aged 79.7 ± 4.9 years was conducted as part of a larger population-based longitudinal observational-cohort study in the greater Reykjavik area of Iceland. A subpopulation (n = 72) repeated the 7-day measurement during seasonal periods with greater (13.4 ± 1.4 h) and lesser (7.7 ± 1.8 h) daylight. RESULTS: Cross-sectional analyses using multiple linear regression models revealed that day length was a significant independent predictor of sleep duration, mid-sleep, and rise time (all p < 0.05). However, the actual within-individual differences in sleep patterns of the repeaters were rather subtle between periods of longer and shorter day-lengths. Compared to women, men had a shorter sleep duration (462 ± 80 vs. 487 ± 68 minutes, p = 0.008), earlier rise time, and a greater number of awakenings per night (46.5 ± 18.3 vs. 40.2 ± 15.7, p = 0.007), but sleep efficiency and onset latency were similar between the two sexes. Daily PA was also similar between men and women and between periods of longer and shorter day-lengths. BMI, age, gender, and overall PA all contributed to the variations in sleep parameters using multiple regression analysis. CONCLUSIONS: The sleep and PA characteristics of this unique population revealed some gender differences, but there was limited variation in response to significant daylight changes which may be due to long-term adaptation.
Authors: Christina S McCrae; Meredeth A Rowe; Candece G Tierney; Natalie D Dautovich; Allison L Definis; Joseph P H McNamara Journal: J Gerontol B Psychol Sci Soc Sci Date: 2005-07 Impact factor: 4.077
Authors: Mark G Davis; Kenneth R Fox; Melvyn Hillsdon; Debbie J Sharp; Jo C Coulson; Janice L Thompson Journal: Med Sci Sports Exerc Date: 2011-04 Impact factor: 5.411
Authors: Henry C Driscoll; Linda Serody; Susan Patrick; Jennifer Maurer; Salem Bensasi; Patricia R Houck; Sati Mazumdar; Eric A Nofzinger; Bethany Bell; Robert D Nebes; Mark D Miller; Charles F Reynolds Journal: Am J Geriatr Psychiatry Date: 2007-12-10 Impact factor: 4.105
Authors: Mary Amanda Dew; Carolyn C Hoch; Daniel J Buysse; Timothy H Monk; Amy E Begley; Patricia R Houck; Martica Hall; David J Kupfer; Charles F Reynolds Journal: Psychosom Med Date: 2003 Jan-Feb Impact factor: 4.312
Authors: Runa Stefansdottir; Vaka Rognvaldsdottir; Sunna Gestsdottir; Sigridur L Gudmundsdottir; Kong Y Chen; Robert J Brychta; Erlingur Johannsson Journal: Sleep Health Date: 2020-06-11
Authors: Yurika Otoki; Marie Hennebelle; Anthony J Levitt; Kiyotaka Nakagawa; Walter Swardfager; Ameer Y Taha Journal: Lipids Date: 2017-04-24 Impact factor: 1.880
Authors: Marissa A Evans; Daniel J Buysse; Anna L Marsland; Aidan G C Wright; Jill Foust; Lucas W Carroll; Naina Kohli; Rishabh Mehra; Adam Jasper; Swathi Srinivasan; Martica H Hall Journal: Sleep Date: 2021-09-13 Impact factor: 5.849
Authors: Taylor B Turrisi; Kelsey M Bittel; Ashley B West; Sarah Hojjatinia; Sahar Hojjatinia; Scherezade K Mama; Constantino M Lagoa; David E Conroy Journal: Int J Behav Nutr Phys Act Date: 2021-02-04 Impact factor: 6.457
Authors: Vaka Rognvaldsdottir; Robert J Brychta; Soffia M Hrafnkelsdottir; Kong Y Chen; Sigurbjorn A Arngrimsson; Erlingur Johannsson; Sigridur L Guðmundsdottir Journal: PLoS One Date: 2020-05-15 Impact factor: 3.240