Long-term changes in time spent walking and subsequent cognitive and structural brain changes in older adults.
ABSTRACT: Previous studies have shown that more active older adults have better cognition and brain health based on a variety of structural neuroimaging measures. Nevertheless, the effects of maintaining physical activity (PA) over an extended period of time on future changes in older adults' cognition and brain structure are unknown. Participants were 141 initially well-functioning community-dwelling older adults (aged 70-79 years at baseline; 60% female; 42% black) studied over a 13-year period. PA (self-reported time spent walking) was assessed annually from years 1 to 10. Magnetic resonance imaging with diffusion tensor was performed at years 10 and 13. Time spent walking decreased on average by 8.4% annually from year 1 to year 10. Independent of initial time spent walking, demographics, and APOE e4 status, better maintenance of time spent walking over the decade predicted less reduction in hippocampal volume (p = 0.03), smaller increases in global gray matter mean diffusivity and white matter axial diffusivity (p < 0.01), and maintenance of general cognitive performance (p < 0.01). Maintenance of cognitive performance was associated with smaller increases in white matter axial diffusivity (p < 0.01). PA at baseline and at year 10, as well as changes in PA over a 5-year period, was less predictive of future changes in brain structure and cognition. Thus, how PA levels change over longer periods of aging may be an important contributor to cognitive and neural protection.
Project description:<h4>Objectives</h4>Physical activity (PA) has been hypothesized to spare gray matter volume in late adulthood, but longitudinal data testing an association has been lacking. Here we tested whether PA would be associated with greater gray matter volume after a 9-year follow-up, a threshold could be identified for the amount of walking necessary to spare gray matter volume, and greater gray matter volume associated with PA would be associated with a reduced risk for cognitive impairment 13 years after the PA evaluation.<h4>Methods</h4>In 299 adults (mean age 78 years) from the Cardiovascular Health Cognition Study, we examined the association between gray matter volume, PA, and cognitive impairment. Physical activity was quantified as the number of blocks walked over 1 week. High-resolution brain scans were acquired 9 years after the PA assessment on cognitively normal adults. White matter hyperintensities, ventricular grade, and other health variables at baseline were used as covariates. Clinical adjudication for cognitive impairment occurred 13 years after baseline.<h4>Results</h4>Walking amounts ranged from 0 to 300 blocks (mean 56.3; SD 69.7). Greater PA predicted greater volumes of frontal, occipital, entorhinal, and hippocampal regions 9 years later. Walking 72 blocks was necessary to detect increased gray matter volume but walking more than 72 blocks did not spare additional volume. Greater gray matter volume with PA reduced the risk for cognitive impairment 2-fold.<h4>Conclusion</h4>Greater amounts of walking are associated with greater gray matter volume, which is in turn associated with a reduced risk of cognitive impairment.
Project description:Emerging evidence suggests physical activity (PA) is associated with cognitive function. To overcome limitations of self-report PA measures, this study investigated the association of accelerometer-measured PA with incident cognitive impairment and longitudinal cognition among older adults.Participants were recruited from the cohort study Reasons for Geographic and Racial Differences in Stroke in the United States. Accelerometers provided PA measures, including the percentage of total accelerometer wearing time spent in moderate-to-vigorous-intensity PA (MVPA%), light-intensity PA, and sedentary time for four to seven consecutive days at baseline. Cognitive impairment was defined by the Six-Item Screener. Letter fluency, animal fluency, word list learning, and Montreal Cognitive Assessment (orientation and recall) were conducted to assess executive function and memory.Participants (N = 6452, 69.7 ± 8.5 yr, 55.3% women, 30.5% Black) with usable accelerometer and cognition measures spent extremely limited time in MVPA (1.5% ± 1.9% of accelerometer wearing time). During an average of 3 yr of follow-up, 346 cases of incident cognitive impairment were observed. After adjustments, participants in higher MVPA% quartiles had a lower risk of cognitive impairment (i.e., quartile 2: odds ratio = 0.64, 95% confidence interval = 0.48-0.84) and better maintenance in executive function (?0.03 z-score units) and memory (?0.12 z-score units) compared with quartile 1 (P < 0.05). Stratified analyses showed the same association among White adults, but higher MVPA% was associated with better maintenance of only memory among Black adults. No significance was found for light-intensity PA or sedentary time.There was a dose-response relationship between MVPA% and cognitive function in older adults, with higher levels associated with a 36% or lower risk of cognitive impairment and better maintenance of memory and executive function over time, particularly in White adults.
Project description:<h4>Objective</h4>To investigate the longitudinal associations between active commuting (walking and cycling to work) and body mass index (BMI).<h4>Method</h4>We used self-reported data on height, weight and active commuting from the Commuting and Health in Cambridge study (2009 to 2012; n=809). We used linear regression to test the associations between: a) maintenance of active commuting over one year and BMI at the end of that year; and b) change in weekly time spent in active commuting and change in BMI over one year.<h4>Results</h4>After adjusting for sociodemographic variables, other physical activity, physical wellbeing and maintenance of walking, those who maintained cycle commuting reported a lower BMI on average at one year follow-up (1.14kg/m(2), 95% CI: 0.30 to 1.98, n=579) than those who never cycled to work. No significant association remained after adjustment for baseline BMI. No significant associations were observed for maintenance of walking. An increase in walking was associated with a reduction in BMI (0.32kg/m(2), 95% CI: 0.03 to 0.62, n=651, after adjustment for co-variates and baseline BMI) only when restricting the analysis to those who did not move. No other significant associations between changes in weekly time spent walking or cycling on the commute and changes in BMI were observed.<h4>Conclusions</h4>This work provides further evidence of the contribution of active commuting, particularly cycling, to preventing weight gain or facilitating weight loss. The findings may be valuable for employees choosing how to commute and engaging employers in the promotion of active travel.
Project description:Physical activity (PA) is crucial for maintaining good health of older adults and owning a dog and walking it can enforce it. The purpose of this study was to evaluate the effect of dog ownership on PA in older adults as well as its positive impact on perceived degree of health, and sleep. There were 44 participants of mean age 68 ± 5.4 years (18 males, 26 females) enrolled in this study (dog owners-DO, n = 26; non-dog owners-NDO, n = 18). Xiaomi Mi Band 2 accelerometer, International Physical Activity Questionnaire- Short form (IPAQ-Short Form) and SF-36 questionnaires were used to measure the level of PA, sleep, and subjective health. A statistically significant difference was observed in favor of dog owners in most of the monitored parameters. All accelerometer PA parameters (step count, activity time, distance, calories) showed a significant difference at a p < 0.01. Sleep parameters were significant in total sleep length (p = 0.05) and light sleep length (p < 0.05). DO reported higher total PA time (min/week), MET/min/week spent in walking, and spent calories/week (p < 0.05). In SF-36 they reported higher score (p < 0.05) in general health, physical functioning, social functioning, pain, vitality, and emotional well-being. Body mass index (BMI) was significantly lower in the DO group (p < 0.01). The results suggest that dog ownership may affect the overall PA and health of older adults.
Project description:<b>Background: </b>Early pathological changes in white matter microstructure can be studied using the diffusion tensor imaging (DTI). It is not only important to study these subtle pathological changes leading to cognitive decline, but also to ascertain how an intervention would impact the white matter microstructure and cognition in persons at-risk of dementia.<br><br><b>Objectives: </b>To study the impact of a multidomain lifestyle intervention on white matter and cognitive changes during the 2-year Finnish Geriatric Intervention Study to prevent Cognitive Impairment and Disability (FINGER), a randomized controlled trial in at-risk older individuals (age 60-77 years) from the general population.<br><br><b>Methods: </b>This exploratory study consisted of a subsample of 60 FINGER participants. Participants were randomized to either a multidomain intervention (diet, exercise, cognitive training, and vascular risk management, n?=?34) or control group (general health advice, n?=?26). All underwent baseline and 2-year brain DTI. Changes in fractional anisotropy (FA), diffusivity along domain (F1) and non-domain (F2) diffusion orientations, mean diffusivity (MD), axial diffusivity (AxD), radial diffusivity (RD), and their correlations with cognitive changes during the 2-year multidomain intervention were analyzed.<br><br><b>Results: </b>FA decreased, and cognition improved more in the intervention group compared to the control group (p?<?0.05), with no significant intergroup differences for changes in F1, F2, MD, AxD, or RD. The cognitive changes were significantly positively related to FA change, and negatively related to RD change in the control group, but not in the intervention group.<br><br><b>Conclusion: </b>The 2-year multidomain FINGER intervention may modulate white matter microstructural alterations.
Project description:BACKGROUND:There is evidence of brain recovery on brain magnetic resonance imaging (MRI) early postliver transplant (LT), but the longer-term impact is unclear. The aim of this study was to determine the change in brain MRI parameters, cognition, and health-related quality of life (HRQOL) between 6 and 12 months post-LT. METHODS:Listed cirrhotics underwent cognitive, HRQOL and brain MRI pre-LT, 6 months (post-LT1), and 1-year (post-LT2) post-LT. Assessment of MRI changes between visits was performed for ammonia-associated metabolite changes using magnetic resonance spectroscopy, white matter changes using tract-based spatial statistics analysis on diffusion tensor imaging data and grey matter changes using voxel-based morphometry analysis on 3D high resolution T1-weighted images. RESULTS:Forty-five patients were included, of which 23 were tested at all visits. Cognitive and HRQOL scores improved between all visits compared with pre-LT values. This trend continued on magnetic resonance spectroscopy with reduced glutamine + glutamate and higher myoinositol, choline between pre-LT/post-LT1 but lower degrees of improvement between post-LT1/post-LT2. On diffusion tensor imaging, mean diffusivity, linear diffusivity and mode of anisotropy continued to increase in the posterior internal capsule at both post-LT visits. On voxel-based morphometry, a continued increase was seen in basal ganglia grey matter between both post-LT visits was seen. CONCLUSIONS:HRQOL and cognition continue to improve compared with pre-LT values up to 1 year post-LT, although the rate of improvement slows down after 6 months. Grey matter increase is steady over time at 1 year although changes in ammonia-related metabolites and white matter integrity improve at a slower pace at 1 year post-LT.
Project description:Short-term adherence to physical activity (PA) in older adults improves psychomotor processing abilities and is associated with greater brain activation. It is not known whether these associations are also significant for longer-term adherence to moderate-intensity activities.We measured the cross-sectional association of regular walking with brain activation while performing the digit symbol substitution test (DSST). Participants of the lifestyle interventions and independence for elders-pilot study were examined 2 years after completing a 1-year treatment, consisting of either PA or education in successful aging (SA). Data were obtained from 20 PA participants who reported having remained active for 2 years after the end of the treatment and from 10 SA participants who reported having remained sedentary during the same period (mean age: 81.5 and 80.8 years). Complete brain activation and behavioral data were available for 17 PA and 10 SA participants.Two years after the formal intervention had ended, the PA group engaged in more minutes of moderate activity and had significantly greater DSST score and higher brain activation within regions important for processing speed (left dorsolateral prefrontal, posterior parietal, and anterior cingulate cortices). Associations were independent of self-reported health, blood pressure, cognition, medication records, gray matter atrophy, and white matter hyperintensities.Persistent engagement in PA may have beneficial effects on psychomotor processing speed and brain activation, even for moderate levels and even when started late in life. Future studies are warranted to assess whether these beneficial effects are explained by delayed neuronal degeneration and/or new neurogenesis.
Project description:Participation in classroom physical activity (PA) may improve time-on-task (TOT); however, the influence of sustained moderate-to-vigorous PA (MVPA) on TOT is unknown. PURPOSE:To explore the influence of classroom PA delivered with academic lessons on TOT, determine if the relationship between classroom PA and TOT differs by age, sex, race/ethnicity, weight or baseline fitness, and identify the influence of MVPA on TOT when controlling for demographic variables. METHODS:Teachers in intervention schools were asked to deliver two 10-min PA lessons per day, 5 d·wk. PA was observed in both intervention and control schools to determine the amount and intensity of PA. Time-on-task was observed before and immediately after PA. Anthropometrics and fitness were assessed at baseline and end of the school year for 3 yr. Multilevel modeling was used to estimate overall group difference, change over the study, and group difference in change while accounting for covariates. RESULTS:Students who participated in PA lessons engaged in significantly more MVPA than those in the control schools in all 3 yr (all P < 0.001). There was a significant linear increase in the percent of TOT before PA lessons for both control and intervention groups over the 3-yr period (P < 0.001), with no group difference. The intervention group spent significantly more TOT (P = 0.01) after PA than the control group. The percent of time spent in MVPA was significantly associated with the percent of TOT (P < 0.01). CONCLUSIONS:Results indicate that children who received PA lessons participated in significantly more MVPA than those who did not and that PA was significantly associated with more TOT. These findings provide support for classroom PA as a means of increasing TOT in elementary age children.
Project description:Although the beneficial effects of physical activity (PA) on memory and executive function are well established in older adults, little is known about the relationship between PA and brain microstructure and the contributions of physical functional limitations and chronic diseases. This study examined whether higher PA would be longitudinally associated with greater microstructural integrity in memory- and executive function-related networks and whether these associations would be independent of physical function and chronic diseases.Diffusion tensor imaging was obtained in 2006-2008 in 276 participants (mean age = 83.0 years, 58.7% female, 41.3% black) with PA (sedentary, lifestyle active, and exercise active) measured in 1997-1998. Gait speed, cognition, depressive symptoms, cardiovascular and pulmonary diseases, hypertension, stroke, and diabetes were measured at both time points. Mean diffusivity and fractional anisotropy were computed from normal-appearing gray and white matter in frontoparietal and subcortical networks. Moderating effects of physical function and chronic diseases were tested using hierarchical regression models.Compared with the sedentary, the exercise active group had lower mean diffusivity in the medial temporal lobe and the cingulate cortex (?, p values: -.405, .023 and -.497, .006, respectively), independent of age, sex, and race. Associations remained independent of other variables, although they were attenuated after adjustment for diabetes. Associations between PA and other neuroimaging markers were not significant.Being exercise active predicts greater memory-related microstructural integrity in older adults. Future studies in older adults with diabetes are warranted to examine the neuroprotective effect of PA in these networks.