Exercise is associated with reduced risk for incident dementia among Persons 65 years of age and older

University of Washington Seattle, Seattle, Washington, United States
Annals of internal medicine (Impact Factor: 17.81). 02/2006; 144(2):73-81. DOI: 10.1111/j.1600-0838.2006.00572_2.x
Source: PubMed


Alzheimer disease and other dementing disorders are major sources of morbidity and mortality in aging societies. Proven strategies to delay onset or reduce risk for dementing disorders would be greatly beneficial.
To determine whether regular exercise is associated with a reduced risk for dementia and Alzheimer disease.
Prospective cohort study.
Group Health Cooperative, Seattle, Washington.
1740 persons older than age 65 years without cognitive impairment who scored above the 25th percentile on the Cognitive Ability Screening Instrument (CASI) in the Adult Changes in Thought study and who were followed biennially to identify incident dementia.
Baseline measurements, including exercise frequency, cognitive function, physical function, depression, health conditions, lifestyle characteristics, and other potential risk factors for dementia (for example, apolipoprotein E epsilon4); biennial assessment for dementia.
During a mean follow-up of 6.2 years (SD, 2.0), 158 participants developed dementia (107 developed Alzheimer disease). The incidence rate of dementia was 13.0 per 1000 person-years for participants who exercised 3 or more times per week compared with 19.7 per 1000 person-years for those who exercised fewer than 3 times per week. The age- and sex-adjusted hazard ratio of dementia was 0.62 (95% CI, 0.44 to 0.86; P = 0.004). The interaction between exercise and performance-based physical function was statistically significant (P = 0.013). The risk reduction associated with exercise was greater in those with lower performance levels. Similar results were observed in analyses restricted to participants with incident Alzheimer disease.
Exercise was measured by self-reported frequency. The study population had a relatively high proportion of regular exercisers at baseline.
These results suggest that regular exercise is associated with a delay in onset of dementia and Alzheimer disease, further supporting its value for elderly persons.

Download full-text


Available from: Walter A Kukull
  • Source
    • "Several prospective surveys have shown a lower incidence of dementia and Alzheimer's disease (AD) in people who carry out PA (Buchman et al., 2012; Larson et al., 2014; see Hamer & Chida, 2009, and Sofi et al., 2010, for a review and metaanalysis ). However, some prospective randomized trials have shown contradictory results (Denkinger, Nikolaus, Denkinger, & Lukas, 2012; Snowden et al., 2011; Wang, Xu, & Pei, 2012). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to analyze whether physical activity (PA) is a protective factor for the incidence of dementia after 3 years of follow-up. The Neurological Disorders in Central Spain (NEDICES) is a prospective population-based survey of older adults (age 65 years and older) that comprised 5278 census-based participants at baseline (1994-1995). A broad questionnaire was used to assess participants' sociodemographic characteristics, health status, and lifestyle. Subsequently, a modified version of Rosow-Breslau questionnaire was applied to classify individuals' baseline PA into groups (i.e., sedentary, light, moderate, and high). Cox regression models adjusted for several covariates (age, sex, education, previous stroke, alcohol consumption, hypertension, health related variables) were carried out to estimate the association between the PA groups and risk of dementia at the 3-year follow-up (1997-1998). A total of 134 incident dementia cases were identified among 3105 individuals (56.6% female; mean age=73.15±6.26) after 3 years. Hazard ratios (HRs) of the light, moderate, and high PA groups (vs. sedentary group) were 0.40 (95% confidence interval {CI} [0.26, 0.62]; p<.001), 0.32 (95% CI [0.20, 0.54]; p<.001) and 0.23 (95% CI [0.13, 0.40]; p<.001), respectively. Even after controlling for covariates and the exclusion of doubtful dementia cases, HRs remained significant. However, a supplementary analysis showed that the dose-effect hypothesis did not reach statistical significance. PA is a protective factor of incident dementia in this population-based cohort. (JINS, 2015, 21, 861-867).
    Full-text · Article · Nov 2015 · Journal of the International Neuropsychological Society
    • "However, it remains to be determined whether the relationship between white matter structure and cognitive decline can be attributed to typical processes that occur with increasing age or represent the emergence of subclinical pathological processes that result from modifiable cardiovascular risk factors. Differentiating between these alternatives is important as it can inform medical or lifestyle approaches to reduce the proliferation of white matter damage and reverse, limit, or delay the onset of cognitive impairment in older adults (Alagiakrishnan, McCracken, & Feldman, 2006; Larson et al., 2006; Laurin, Verreault, Lindsay, MacPherson, & Rockwood, 2001). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Although the relationship between aging and cognitive decline is well established, there is substantial individual variability in the degree of cognitive decline in older adults. The present study investigates whether variability in cognitive performance in community-dwelling older adults is related to the presence of whole brain or tract-specific changes in white matter microstructure. Specifically, we examine whether age-related decline in performance on the Montreal Cognitive Assessment (MoCA), a cognitive screening tool, is mediated by the white matter microstructural decline. We also examine if this relationship is driven by the presence of cardiovascular risk factors or variability in cerebral arterial pulsatility, an index of cardiovascular risk. Sixty-nine participants (aged 43-87) completed behavioral and MRI testing including T1 structural, T2-weighted FLAIR, and diffusion-weighted imaging (DWI) sequences. Measures of white matter microstructure were calculated using diffusion tensor imaging analyses on the DWI sequence. Multiple linear regression revealed that MoCA scores were predicted by radial diffusivity (RaD) of white matter beyond age or other cerebral measures. While increasing age and arterial pulsatility were associated with increasing RaD, these factors did not mediate the relationship between total white matter RaD and MoCA. Further, the relationship between MoCA and RaD was specific to participants who reported at least one cardiovascular risk factor. These findings highlight the importance of cardiovascular risk factors in the presentation of cognitive decline in old age. Further work is needed to establish whether medical or lifestyle management of these risk factors can prevent or reverse cognitive decline in old age.
    No preview · Article · Oct 2015 · Psychophysiology
  • Source
    • "Previous studies have indicated that physical exercise is beneficial to cognitive functions in older adults (Colcombe et al., 2004; Kramer et al., 2006; Larson et al., 2006; Hillman et al., 2008; Deary et al., 2009; Smith et al., 2010). Among the many kinds of cognitive function, executive function has most firmly been shown to improve through "
    [Show abstract] [Hide abstract]
    ABSTRACT: Functional mobility and cognitive function often decline with age. We previously found that functional mobility as measured by the Timed Up and Go Test (TUG) was associated with cognitive performance for visually-encoded (i.e. for location and face) working memory (WM) in older adults. This suggests a common neural basis between TUG and visual WM. To elucidate this relationship further, the present study aimed to examine the neural basis for the WM-mobility association. In accordance with the well-known neural compensation model in aging, we hypothesized that “attentional” brain activation for easy WM would increase in participants with lower mobility. The data from 32 healthy older adults were analyzed, including brain activation during easy WM tasks via functional Magnetic Resonance Imaging and mobility performance via both TUG and a simple walking test. WM performance was significantly correlated with TUG but not with simple walking. Some prefrontal brain activations during WM were negatively correlated with TUG performance, while positive correlations were found in subcortical structures including the thalamus, putamen and cerebellum. Moreover, activation of the subcortical regions was significantly correlated with WM performance, with less activation for lower WM performers. These results indicate that older adults with lower mobility used more cortical (frontal) and fewer subcortical resources for easy WM tasks. To date, the frontal compensation has been proposed separately in the motor and cognitive domains, which have been assumed to compensate for dysfunction of the other brain areas; however, such dysfunction was less clear in previous studies.The present study observed such dysfunction as degraded activation associated with lower performance, which was found in the subcortical regions. We conclude that a common dysfunction -compensation activation pattern is likely the neural basis for the association between visual WM and functional mobility.
    Full-text · Article · Sep 2015 · Frontiers in Aging Neuroscience
Show more