bims-empneu 2021-06-20 papers

Issue of 2021–06–20
three papers selected by
Navabeh Zare-Kookandeh, Victoria University

Trials. 2021 Jun 14. 22(1): 394

The Brain in Motion II Study: study protocol for a randomized controlled trial of an aerobic exercise intervention for older adults at increased risk of dementia.

Renata L Krüger, Cameron M Clark, Adrienna M Dyck, Todd J Anderson, Fiona Clement, Patrick J Hanly, Heather M Hanson, Michael D Hill, David B Hogan, Jayna Holroyd-Leduc, R Stewart Longman, Meghan McDonough, G Bruce Pike, Jean M Rawling, Tolulope Sajobi, Marc J Poulin.

BACKGROUND: There remains no effective intervention capable of reversing most cases of dementia. Current research is focused on prevention by addressing risk factors that are shared between cardiovascular disease and dementia (e.g., hypertension) before the cognitive, functional, and behavioural symptoms of dementia manifest. A promising preventive treatment is exercise. This study describes the methods of a randomized controlled trial (RCT) that assesses the effects of aerobic exercise and behavioural support interventions in older adults at increased risk of dementia due to genetic and/or cardiovascular risk factors. The specific aims are to determine the effect of aerobic exercise on cognitive performance, explore the biological mechanisms that influence cognitive performance after exercise training, and determine if changes in cerebrovascular physiology and function persist 1 year after a 6-month aerobic exercise intervention followed by a 1-year behavioural support programme (at 18 months).
METHODS: We will recruit 264 participants (aged 50-80 years) at elevated risk of dementia. Participants will be randomly allocated into one of four treatment arms: (1) aerobic exercise and health behaviour support, (2) aerobic exercise and no health behaviour support, (3) stretching-toning and health behaviour support, and (4) stretching-toning and no health behaviour support. The aerobic exercise intervention will consist of three supervised walking/jogging sessions per week for 6 months, whereas the stretching-toning control intervention will consist of three supervised stretching-toning sessions per week also for 6 months. Following the exercise interventions, participants will receive either 1 year of ongoing telephone behavioural support or no telephone support. The primary aim is to determine the independent effect of aerobic exercise on a cognitive composite score in participants allocated to this intervention compared to participants allocated to the stretching-toning group. The secondary aims are to examine the effects of aerobic exercise on a number of secondary outcomes and determine whether aerobic exercise-related changes persist after a 1-year behavioural support programme (at 18 months).
DISCUSSION: This study will address knowledge gaps regarding the underlying mechanisms of the pro-cognitive effects of exercise by examining the potential mediating factors, including cerebrovascular/physiological, neuroimaging, sleep, and genetic factors that will provide novel biologic evidence on how aerobic exercise can prevent declines in cognition with ageing.
TRIAL REGISTRATION: ClinicalTrials.gov NCT03035851 . Registered on 30 January 2017.

Keywords: Alzheimer’s disease; Behavioural support; Brain health; Cognitive function; Dementia; Physical activity; Sleep quality

DOI: https://doi.org/10.1186/s13063-021-05336-z

Sci Rep. 2021 Jun 17. 11(1): 12776

A methodology for an acute exercise clinical trial called dementia risk and dynamic response to exercise.

Dreu White, Casey S John, Ashley Kucera, Bryce Truver, Rebecca J Lepping, Paul J Kueck, Phil Lee, Laura Martin, Sandra A Billinger, Jeffrey M Burns, Jill K Morris, Eric D Vidoni.

Exercise likely has numerous benefits for brain and cognition. However, those benefits and their causes remain imprecisely defined. If the brain does benefit from exercise it does so primarily through cumulative brief, "acute" exposures over a lifetime. The Dementia Risk and Dynamic Response to Exercise (DYNAMIC) clinical trial seeks to characterize the acute exercise response in cerebral perfusion, and circulating neurotrophic factors in older adults with and without the apolipoprotein e4 genotype (APOE4), the strongest genetic predictor of sporadic, late onset Alzheimer's disease. DYNAMIC will enroll 60 older adults into a single moderate intensity bout of exercise intervention, measuring pre- and post-exercise cerebral blood flow (CBF) using arterial spin labeling, and neurotrophic factors. We expect that APOE4 carriers will have poor CBF regulation, i.e. slower return to baseline perfusion after exercise, and will demonstrate blunted neurotrophic response to exercise, with concentrations of neurotrophic factors positively correlating with CBF regulation. Preliminary findings on 7 older adults and 9 younger adults demonstrate that the experimental method can capture CBF and neurotrophic response over a time course. This methodology will provide important insight into acute exercise response and potential directions for clinical trial outcomes.ClinicalTrials.gov NCT04009629, Registered 05/07/2019.

DOI: https://doi.org/10.1038/s41598-021-92177-0

Psychiatry Res. 2021 Jun 11. pii: S0165-1781(21)00343-7. [Epub ahead of print]302 114046

The anxiolytic effects of exercise for people with anxiety and related disorders: An update of the available meta-analytic evidence.

Carlos Pelayo Ramos-Sanchez, Felipe Barreto Schuch, Soraya Seedat, Quinette Abegail Louw, Brendon Stubbs, Simon Rosenbaum, Joseph Firth, Ruud van Winkel, Davy Vancampfort.

Exercise as a treatment option for people with mental disorders is a field of growing interest. The increased number of published randomized controlled trials (RCTs) evaluating the effects of exercise in the treatment of anxiety and related disorders in recent years calls for an update of the available meta-analytic evidence. Electronic databases (PubMed, CINAHL, PSYCArticles, and Embase) were searched up to 17.2.2021, for RCTs evaluating the effects of exercise on anxiety and stress symptoms in adults with anxiety and related disorders. A random effects meta-analysis was conducted. A total of 13 RCTs comprising 731 adult participants (exercise n=376; control n=355) were included. Exercise had a small, bordering medium, but statistically significant effect on decreasing anxiety symptoms compared to control condition (standardized mean difference=-0.425, 95%CI -0.67 to -0.17; I2 = 47.9%) in people with anxiety and related disorders. Our meta-analysis updates the existing evidence supporting exercise as an efficacious intervention for anxiety and related disorders. Although the updated meta-analytic evidence is less heterogenous than previously reported, future research is still needed to explore the factors moderating the effects of exercise on outcome such as frequency, intensity, duration of the sessions, and type of exercise and qualification of the provider in more detail.

Keywords: Anxiety; Exercise; OCD; PTSD; Physical activity; Stress

DOI: https://doi.org/10.1016/j.psychres.2021.114046