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Aerobic exercise and vascular cognitive impairment - 74 Year Olds with Vascular Cognitive Impairment
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Download the PDF here
Download the PDF here
Abstract
Objective: To assess the efficacy of a progressive aerobic exercise training program on cognitive and everyday function among adults with mild subcortical ischemic vascular cognitive impairment (SIVCI).
Methods: This was a proof-of-concept single-blind randomized controlled trial comparing a 6-month, thrice-weekly, progressive aerobic exercise training program (AT) with usual care plus education on cognitive and everyday function with a follow-up assessment 6 months after the formal cessation of aerobic exercise training. Primary outcomes assessed were general cognitive function (Alzheimer's Disease Assessment Scale-Cognitive subscale [ADAS-Cog]), executive functions (Executive Interview [EXIT-25]), and activities of daily living (Alzheimer's Disease Cooperative Study-Activities of Daily Living [ADCS-ADL]).
Results: Seventy adults randomized to aerobic exercise training or usual care were included in intention-to-treat analyses (mean age 74 years, 51% female, n = 35 per group). At the end of the intervention, the aerobic exercise training group had significantly improved ADAS-Cog performance compared with the usual care plus education group (-1.71 point difference, 95% confidence interval [CI] -3.15 to -0.26, p = 0.02); however, this difference was not significant at the 6-month follow-up (-0.63 point difference, 95% CI -2.34 to 1.07, p = 0.46). There were no significant between-group differences at intervention completion and at the 6-month follow-up in EXIT-25 or ADCS-ADL performance. Examination of secondary measures showed between-group differences at intervention completion favoring the AT group in 6-minute walk distance (30.35 meter difference, 95% CI 5.82 to 54.86, p = 0.02) and in diastolic blood pressure (-6.89 mm Hg difference, 95% CI -12.52 to -1.26, p = 0.02).
Conclusions: This study provides preliminary evidence for the efficacy of 6 months of thrice-weekly progressive aerobic training in community-dwelling adults with mild SIVCI, relative to usual care plus education.
Participants. The sample consisted of adults with a clinical diagnosis of mild SIVCI. We recruited from the University of British Columbia Hospital Clinic for Alzheimer's Disease and Related Disorders, the Vancouver General Hospital Stroke Prevention Clinic, and specialized geriatric clinics in metro Vancouver, Canada. Clinical diagnosis of VCI was made based on the presence of both small vessel ischemic disease and cognitive syndrome.10 Small vessel ischemic disease was defined as evidence of relevant cerebrovascular disease by brain CT or MRI defined as the presence of both (1) periventricular and deep WMLs and (2) absence of cortical and or cortico-subcortical nonlacunar territorial infarcts and watershed infarcts, hemorrhages indicating large vessel disease, signs of normal-pressure hydrocephalus, or other specific causes of WMLs (i.e., multiple sclerosis, leukodystrophies, sarcoidosis, brain irradiation). In addition to the neuroimaging evidence, the presence or a history of neurologic signs such as Babinski sign, sensory deficit, gait disorder, or extrapyramidal signs consistent with subcortical brain lesions was required and confirmed by study physicians
(G.-Y.R.H. and P.E.L.). Cognitive syndrome was defined as a baseline Montreal Cognitive Assessment (MoCA)11 score <26/30 and a Mini-Mental State Examination (MMSE)12 score of >20 at screening. Progressive cognitive decline was confirmed through medical records or caregiver/family member interviews. For additional details on inclusion and exclusion criteria, see the e-Methods at Neurology.org.
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Aerobic Exercise Found to Improve Cognition in Mild Vascular Cognitive Impairment
Neurology Today: Nov 3 2016
http://journals.lww.com/neurotodayonline/Fulltext/2016/11030/Aerobic_Exercise_Found_to_Improve_Cognition_in.3.aspx
ARTICLE IN BRIEF
Investigators reported that, in a randomized controlled trial, patients with vascular cognitive impairment showed improvement on cognitive tests after participating in a six-month exercise program. Independent experts said the findings were promising, but preliminary.
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Editorial
Pdfs attached
Study
Aerobic exercise and vascular cognitive impairment
Abstract
Objective: To assess the efficacy of a progressive aerobic exercise training program on cognitive and everyday function among adults with mild subcortical ischemic vascular cognitive impairment (SIVCI).
Methods: This was a proof-of-concept single-blind randomized controlled trial comparing a 6-month, thrice-weekly, progressive aerobic exercise training program (AT) with usual care plus education on cognitive and everyday function with a follow-up assessment 6 months after the formal cessation of aerobic exercise training. Primary outcomes assessed were general cognitive function (Alzheimer's Disease Assessment Scale-Cognitive subscale [ADAS-Cog]), executive functions (Executive Interview [EXIT-25]), and activities of daily living (Alzheimer's Disease Cooperative Study-Activities of Daily Living [ADCS-ADL]).
Results: Seventy adults randomized to aerobic exercise training or usual care were included in intention-to-treat analyses (mean age 74 years, 51% female, n = 35 per group). At the end of the intervention, the aerobic exercise training group had significantly improved ADAS-Cog performance compared with the usual care plus education group (-1.71 point difference, 95% confidence interval [CI] -3.15 to -0.26, p = 0.02); however, this difference was not significant at the 6-month follow-up (-0.63 point difference, 95% CI -2.34 to 1.07, p = 0.46). There were no significant between-group differences at intervention completion and at the 6-month follow-up in EXIT-25 or ADCS-ADL performance. Examination of secondary measures showed between-group differences at intervention completion favoring the AT group in 6-minute walk distance (30.35 meter difference, 95% CI 5.82 to 54.86, p = 0.02) and in diastolic blood pressure (-6.89 mm Hg difference, 95% CI -12.52 to -1.26, p = 0.02).
Conclusions: This study provides preliminary evidence for the efficacy of 6 months of thrice-weekly progressive aerobic training in community-dwelling adults with mild SIVCI, relative to usual care plus education.
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Progressive aerobic-exercise training for six months appeared to improve cognition in adults with mild subcortical ischemic vascular cognitive impairment, defined by the presence of white matter lesions and lacunar infarcts, according to a Canadian study reported in the October 19 online edition of Neurology.
Despite its small sample size, this proof-of-concept study - one of the only randomized controlled trials to investigate the association - provides class 2 evidence of exercise's positive impact on cognition, the study authors said.
Previous research had been based mainly on observational studies evaluating aerobic exercise as a means to boost cognitive function in individuals with mild subcortical ischemic vascular cognitive impairment, the most common form of vascular cognitive impairment.
STUDY METHODS
The new study followed 70 community-dwelling adults with subcortical ischemic vascular cognitive impairment, confirmed with neuroimaging, who were randomized to aerobic training or usual care plus education during a six-month intervention phase and a subsequent six-month follow-up phase. Participants were recruited from the University of British Columbia Hospital Clinic for Alzheimer's Disease and Related Disorders, the Vancouver General Hospital Stroke Prevention Clinic, and specialized geriatric clinics in Metro Vancouver, British Columbia.
By altering cardiovascular and metabolic risk factors, researchers said they observed a delay in the progression of mild vascular cognitive impairment. "This is significant [because] it potentially provides a fairly straightforward or simple approach in the treatment of individuals with mild vascular cognitive impairment," Teresa Liu-Ambrose, PhD, PT, the study's lead author and an associate professor and Canada research chair in the physical therapy department of the Djavad Mowafaghian Centre for Brain Health/Centre for Hip Health and Mobility, told Neurology Today.
The improvement was no longer apparent six months after the intervention ended, however, suggesting that continuing the exercise would be necessary to reap any benefits, the study authors said.
STUDY METHODOLOGY
The study participants - averaging 74 years of age - consented to measurements at baseline, the end of the intervention period, and a six-month follow-up assessment after the formal cessation of training. Investigators evaluated three primary outcomes: general cognitive function based on scores on the Alzheimer's Disease Assessment Scale Cognitive Subscale (ADAS-Cog); executive function (EXIT-25), and activities of daily living (Alzheimer's Disease Co-operative Study-Activities of Daily Living (ADCS-ADL).
Instructors certified to teach seniors led the experimental group in aerobic training. They recorded class attendance for each participant during the six-month intervention, which included a 60-minute class, a 10-minute warm-up, a 40-minute outdoor walk, and a 10-minute cool down.
The control group received usual care as well as monthly educational materials about vascular cognitive impairment and a healthy diet. Specific information about physical activity was not offered. The research staff phoned the control group's participants on a monthly basis to stay in contact and to collect data.
At the end of the intervention, the aerobic-training group showed a significant boost in ADAS-Cog performance compared with the control group (-1.71 point difference, 95% CI: -3.15,-0.26, p=.02), the authors noted.
But the difference in ADAS-Cog performance was not significant at the six-month follow-up, and there were no major differences between the two groups at completion of the intervention and at the six-month follow-up in measures for executive function and activities of daily living.
An examination of secondary measures demonstrated variations between the groups at completion of the intervention, favoring the aerobic-training group in six-minute walk distance (30.35 meter difference, 95% CI: 5.82,54.86, p=.02) and in diastolic blood pressure (-6.89 mmHg difference, 95% CI: -12.52,-1.26, p=.02).
EXPERTS COMMENT
The benefits of physical activity may include a decreased risk of cardiovascular disease as well as other more complex mechanisms, such as a surge in brain neurotrophins or an effect on neurogenesis, the authors of an editorial accompanying the study wrote.
But the editorial cast the positive effects in a much more modest light, and questioned whether the findings should be consider class 2 evidence. "The clinical meaningfulness of this study is relatively small," Alexandra Foubert-Samier, MD, PhD, the editorial's co-author and a researcher at Bordeaux University Hospital's Institut des Maladies Neurodegeneratives-Clinique in Bordeaux, France, told Neurology Today. "To have an impact on cognition, the difference would need to be at least four points."
A positive result on only one of three outcome measures does not offer adequate justification for this study to be considered as class 2 evidence, she and her colleagues wrote in the editorial. They also found it surprising that the aerobic exercise program did not improve executive functions, which would have been expected following several observational studies.
"However, physical activity may require a longer period to improve executive function, as it may exert its effect by lowering the diastolic blood pressure, as demonstrated in this study," they wrote.
A higher withdrawal rate in the control group than in the intervention group could have affected the results, said Jeffrey Burns, MD, MS, the Edward H. Hashinger professor of neurology and co-director of the Alzheimer's Disease Center at the University of Kansas Medical Center in Kansas City, KS, who was not involved with the study.
"This is more evidence that what's good for the heart is good for the brain," said "We as neurologists should be finding ways not just to encourage people to exercise, but we need proven ways and tools to get people to exercise - to initiate and sustain exercise over time. Overall, this is an encouraging preliminary study looking at a patient population's the use of exercise in a specific patient population to reduce vascular risk."
As the accompanying editorial highlighted, the study is unique in its enrollment of participants specifically with vascular cognitive impairment, added Kristine Yaffe, MD, FAAN, professor of psychiatry, neurology and epidemiology and the Roy and Marie Scola endowed chair and vice chair of research in psychiatry at the University of California, San Francisco.
Exercise may indeed play a role in vascular etiology, she said. "It's another piece of the puzzle adding to evidence that physical activity is beneficial for brain health," she said, adding: "The small sample size may have hindered greater detection of an effect."
Other diagnostic criteria, such as the vascular cognitive scale, may have been more helpful in evaluating participants' response to exercise, said Majaz Moonis, MD, MRCP, DM, FAAN, FAHA, a professor of neurology and medical director of the stroke center at UMass Memorial Medical Center and the Day Kimball Hospital Sleep Disorder Center affiliated with UMass Memorial Health Care in Worcester, MA.
Adjusting for comorbid depression also could have elicited more information, considering that patients tend to be less depressed when they exercise, and a reduction in depression is associated with better attention span and hence memory, Dr. Moonis said. He suspected that more vigorous exercise would have led to a more pronounced difference between the two groups.
Arthur F. Kramer, PhD, a neuroscientist and senior vice provost of research and graduate education at Northeastern University in Boston, concurred that "a longer intervention might have worked better" also in preventing the improvement from dissipating six months after the intervention's endpoint. He also questioned whether a placebo effect could have influenced the positive results on one of the three outcome measures, factoring in that the experimental group interacted more with researchers in person than the control group.
⋅. Liu-Ambrose T, Best JR, Davis JC, et al. Aerobic exercise and vascular cognitive impairment: A randomized controlled trial http://neurology.org/lookup/doi/10.1212/WNL.0000000000003332. Neurology 2016; Epub 2016 Oct 19.
⋅. Foubert-Samier A, Flicker L. Editorial: Aerobic exercise - A possible therapy for vascular cognitive impairment http://neurology.org/lookup/doi/10.1212/WNL.0000000000003343. Neurology 2016; Epub 2016 Oct 19.
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