title: Association of change in brain structure to objectively measured physical activity and sedentary behavior in older adults: Age, Gene/Environment Susceptibility-Reykjavik Study.
abstract: Many studies have examined the hypothesis that greater participation in physical activity (PA) is associated with less brain atrophy. Here we examine, in a sub-sample (n=352, mean age 79.1 years) of the Age, Gene/Environment Susceptibility-Reykjavik Study cohort, the association of the baseline and 5-year change in magnetic resonance imaging (MRI)-derived volumes of gray matter (GM) and white matter (WM) to active and sedentary behavior (SB) measured at the end of the 5-year period by a hip-worn accelerometer for seven consecutive days. More GM (β=0.11; p=0.044) and WM (β=0.11; p=0.030) at baseline was associated with more total physical activity (TPA). Also, when adjusting for baseline values, the 5-year change in GM (β=0.14; p=0.0037) and WM (β=0.11; p=0.030) was associated with TPA. The 5-year change in WM was associated with SB (β=-0.11; p=0.0007). These data suggest that objectively measured PA and SB late in life are associated with current and prior cross-sectional measures of brain atrophy, and that change over time is associated with PA and SB in expected directions.
authors.affiliation: Research Centre of Movement Science, University of Iceland, Stapi at Hringbraut, Reykjavik, Iceland; Icelandic Heart Association, Kopavogur, Iceland. Electronic address: nya@hi.is.
authors.forename: Nanna Yr
authors.initials: NY
authors.lastname: Arnardottir
authors.affiliation: CAPHRI School for Public Health and Primary Care, Department of Social Medicine, Maastricht University, Maastricht, The Netherlands.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Koster
authors.affiliation: Department of Biostatistics and Bioinformatics, The Rollins School of Public Health, Emory University, Atlanta, GA, United States.
authors.forename: Dane R Van
authors.initials: DRV
authors.lastname: Domelen
authors.affiliation: National Institute of Diabetes and Digestive and Kidney Diseases, Diabetes, Endocrinology and Obesity Branch, Bethesda, MD, United States.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Brychta
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern, Denmark.
authors.forename: Paolo
authors.initials: P
authors.lastname: Caserotti
authors.affiliation: Icelandic Heart Association, Kopavogur, Iceland.
authors.forename: Gudny
authors.initials: G
authors.lastname: Eiriksdottir
authors.affiliation: Icelandic Heart Association, Kopavogur, Iceland.
authors.forename: Johanna E
authors.initials: JE
authors.lastname: Sverrisdottir
authors.affiliation: Icelandic Heart Association, Kopavogur, Iceland.
authors.forename: Sigurdur
authors.initials: S
authors.lastname: Sigurdsson
authors.affiliation: Center for Sport and Health Sciences, Iceland University, Laugarvatn, Iceland.
authors.forename: Erlingur
authors.initials: E
authors.lastname: Johannsson
authors.affiliation: National Institute of Diabetes and Digestive and Kidney Diseases, Diabetes, Endocrinology and Obesity Branch, Bethesda, MD, United States.
authors.forename: Kong Y
authors.initials: KY
authors.lastname: Chen
authors.affiliation: Icelandic Heart Association, Kopavogur, Iceland; University of Iceland, Saemundargata 2, 101 Reykjavik, Iceland.
authors.forename: Vilmundur
authors.initials: V
authors.lastname: Gudnason
authors.affiliation: National Institute on Aging, Laboratory of Epidemiology and Population Sciences, Bethesda, MD, United States.
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Harris
authors.affiliation: National Institute on Aging, Laboratory of Epidemiology and Population Sciences, Bethesda, MD, United States.
authors.forename: Lenore J
authors.initials: LJ
authors.lastname: Launer
authors.affiliation: Research Centre of Movement Science, University of Iceland, Stapi at Hringbraut, Reykjavik, Iceland.
authors.forename: Thorarinn
authors.initials: T
authors.lastname: Sveinsson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology* / Q000502:physiology; D001284:Atrophy / Q000473:pathology; D004198:Disease Susceptibility; D005260:Female; D005500:Follow-Up Studies; D059647:Gene-Environment Interaction; D066128:Gray Matter / Q000473:pathology*; D006801:Humans; D007055:Iceland; D008279:Magnetic Resonance Imaging; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D057185:Sedentary Behavior; D066127:White Matter / Q000473:pathology*
keywords: Brain atrophy; Elderly; MRI; Physical activity; Sedentary behavior