PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (1291449)

Clipboard (0)
None

Related Articles

1.  Calorie Restriction Increases Muscle Mitochondrial Biogenesis in Healthy Humans 
PLoS Medicine  2007;4(3):e76.
Background
Caloric restriction without malnutrition extends life span in a range of organisms including insects and mammals and lowers free radical production by the mitochondria. However, the mechanism responsible for this adaptation are poorly understood.
Methods and Findings
The current study was undertaken to examine muscle mitochondrial bioenergetics in response to caloric restriction alone or in combination with exercise in 36 young (36.8 ± 1.0 y), overweight (body mass index, 27.8 ± 0.7 kg/m2) individuals randomized into one of three groups for a 6-mo intervention: Control, 100% of energy requirements; CR, 25% caloric restriction; and CREX, caloric restriction with exercise (CREX), 12.5% CR + 12.5% increased energy expenditure (EE). In the controls, 24-h EE was unchanged, but in CR and CREX it was significantly reduced from baseline even after adjustment for the loss of metabolic mass (CR, −135 ± 42 kcal/d, p = 0.002 and CREX, −117 ± 52 kcal/d, p = 0.008). Participants in the CR and CREX groups had increased expression of genes encoding proteins involved in mitochondrial function such as PPARGC1A, TFAM, eNOS, SIRT1, and PARL (all, p < 0.05). In parallel, mitochondrial DNA content increased by 35% ± 5% in the CR group (p = 0.005) and 21% ± 4% in the CREX group (p < 0.004), with no change in the control group (2% ± 2%). However, the activity of key mitochondrial enzymes of the TCA (tricarboxylic acid) cycle (citrate synthase), beta-oxidation (beta-hydroxyacyl-CoA dehydrogenase), and electron transport chain (cytochrome C oxidase II) was unchanged. DNA damage was reduced from baseline in the CR (−0.56 ± 0.11 arbitrary units, p = 0.003) and CREX (−0.45 ± 0.12 arbitrary units, p = 0.011), but not in the controls. In primary cultures of human myotubes, a nitric oxide donor (mimicking eNOS signaling) induced mitochondrial biogenesis but failed to induce SIRT1 protein expression, suggesting that additional factors may regulate SIRT1 content during CR.
Conclusions
The observed increase in muscle mitochondrial DNA in association with a decrease in whole body oxygen consumption and DNA damage suggests that caloric restriction improves mitochondrial function in young non-obese adults.
Anthony Civitarese and colleagues observed an increase in mitochondrial DNA in muscle and a decrease in whole body oxygen consumption in healthy adults who underwent caloric restriction.
Editors' Summary
Background.
Life expectancy (the average life span) greatly increased during the 20th century in most countries, largely due to improved hygiene, nutrition, and health care. One possible approach to further increase human life span is “caloric restriction.” A calorie-restricted diet provides all the nutrients necessary for a healthy life but minimizes the energy (calories) supplied in the diet. This type of diet increases the life span of mice and delays the onset of age-related chronic diseases such as heart disease and stroke. There are also hints that people who eat a calorie-restricted diet might live longer than those who overeat. People living in Okinawa, Japan, have a lower energy intake than the rest of the Japanese population and an extremely long life span. In addition, calorie-restricted diets beneficially affect several biomarkers of aging, including decreased insulin sensitivity (a precursor to diabetes). But how might caloric restriction slow aging? A major factor in the age-related decline of bodily functions is the accumulation of “oxidative damage” in the body's proteins, fats, and DNA. Oxidants—in particular, chemicals called “free radicals”—are produced when food is converted to energy by cellular structures called mitochondria. One theory for how caloric restriction slows aging is that it lowers free-radical production by inducing the formation of efficient mitochondria.
Why Was This Study Done?
Despite hints that caloric restriction might have similar effects in people as in rodents, there have been few well-controlled studies on the effect of good quality calorie-reduced diets in healthy people. It is also unknown whether an energy deficit produced by increasing physical activity while eating the same amount of food has the same effects as caloric restriction. Finally, it is unclear how caloric restriction alters mitochondrial function. The Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) organization is investigating the effect of caloric restriction interventions on physiology, body composition, and risk factors for age-related diseases. In this study, the researchers have tested the hypothesis that short-term caloric deficit (with or without exercise) increases the efficiency of mitochondria in human muscle.
What Did the Researchers Do and Find?
The researchers enrolled 36 healthy overweight but non-obese young people into their study. One-third of them received 100% of their energy requirements in their diet; the caloric restriction (CR) group had their calorie intake reduced by 25%; and the caloric restriction plus exercise (CREX) group had their calorie intake reduced by 12.5% and their energy expenditure increased by 12.5%. The researchers found that a 25% caloric deficit for six months, achieved by diet alone or by diet plus exercise, decreased 24-hour whole body energy expenditure (i.e., overall calories burned for body function), which suggests improved mitochondrial function. Their analysis of genes involved in mitochondria formation indicated that CR and CREX both increased the number of mitochondria in skeletal muscle. Both interventions also reduced the amount of DNA damage—a marker of oxidative stress—in the participants' muscles.
What Do These Findings Mean?
These results indicate that a short-term caloric deficit, whether achieved by diet or by diet plus exercise, induces the formation of “efficient mitochondria” in people just as in rodents. The induction of these efficient mitochondria in turn reduces oxidative damage in skeletal muscles. Consequently, this adaptive response to caloric restriction might have the potential to slow aging and increase longevity in humans as in other animals. However, this six-month study obviously provides no direct evidence for this, and, by analogy with studies in rodents, an increase in longevity might require lifelong caloric restriction. The results here suggest that even short-term caloric restriction can produce beneficial physiological changes, but more research is necessary before it becomes clear whether caloric restriction should be recommended to healthy individuals.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040076.
The CALERIE (Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy) Web site contains information on the study and how to participate
American Federation for Aging Research includes information on aging with pages on the biology of aging and on caloric restriction
The Okinawa Centenarian Study is a population-based study on long-lived elderly people in Okinawa, Japan
US Government information on nutrition
MedlinePlus encyclopedia pages on diet and calories
The Calorie Restriction Society, a nonprofit organization that provides information on life span and caloric restriction
Wikipedia pages on calorie restriction and on mitochondria (note: Wikipedia is an online encyclopedia that anyone can edit)
doi:10.1371/journal.pmed.0040076
PMCID: PMC1808482  PMID: 17341128
2.  How should COPD patients exercise during respiratory rehabilitation? Comparison of exercise modalities and intensities to treat skeletal muscle dysfunction 
Thorax  2005;60(5):367-375.
Background: Physical exercise is an important component of respiratory rehabilitation because it reverses skeletal muscle dysfunction, a clinically important manifestation of COPD associated with reduced health-related quality of life (HRQL) and survival. However, there is controversy regarding the components of the optimal exercise protocol. A study was undertaken to systematically evaluate and summarise randomised controlled trials (RCTs) comparing different exercise protocols for COPD patients.
Methods: Six electronic databases, congress proceedings and bibliographies of included studies were searched without imposing language restrictions. Two reviewers independently screened all records and extracted data on study samples, interventions and methodological characteristics of included studies.
Results: The methodological quality of the 15 included RCTs was low to moderate. Strength exercise led to larger improvements of HRQL than endurance exercise (weighted mean difference for Chronic Respiratory Questionnaire 0.27, 95% CI 0.02 to 0.52). Interval exercise seems to be of similar effectiveness as continuous exercise, but there are few data on clinically relevant outcomes. One small RCT which included patients with mild COPD compared the effect of high and low intensity exercise (at 80% and 40% of the maximum exercise capacity, respectively) and found larger physiological training effects from high intensity exercise.
Conclusions: Strength exercise should be routinely incorporated in respiratory rehabilitation. There is insufficient evidence to recommend high intensity exercise for COPD patients and investigators should conduct larger high quality trials to evaluate exercise intensities in patients with moderate to severe COPD.
doi:10.1136/thx.2004.033274
PMCID: PMC1758898  PMID: 15860711
3.  Effectiveness and cost-effectiveness of 'BeweegKuur', a combined lifestyle intervention in the Netherlands: Rationale, design and methods of a randomized controlled trial 
BMC Public Health  2011;11:815.
Background
Improving the lifestyle of overweight and obese adults is of increasing interest in view of its role in several chronic diseases. Interventions aiming at overweight or weight-related chronic diseases suffer from high drop-out rates. It has been suggested that Motivational Interviewing and more frequent and more patient-specific coaching could decrease the drop-out rate. 'BeweegKuur' is a multidisciplinary lifestyle intervention which offers three programmes for overweight persons. The effectiveness and the cost-effectiveness of intensively guided programmes, such as the 'supervised exercise programme' of 'BeweegKuur', for patients with high weight-related health risk, remain to be assessed. Our randomized controlled trial compares the expenses and effects of the 'supervised exercise programme' with those of the less intensively supervised 'start-up exercise programme'.
Methods/Design
The one-year intervention period involves coaching by a lifestyle advisor, a physiotherapist and a dietician, coordinated by general practitioners (GPs). The participating GP practices have been allocated to the interventions, which differ only in terms of the amount of coaching offered by the physiotherapist. Whereas the 'start-up exercise programme' includes several consultations with physiotherapists to identify barriers hampering independent exercising, the 'supervised exercise programme' includes more sessions with a physiotherapist, involving exercise under supervision. The main goal is transfer to local exercise facilities. The main outcome of the study will be the participants' physical activity at the end of the one-year intervention period and after one year of follow-up. Secondary outcomes are dietary habits, health risk, physical fitness and functional capacity. The economic evaluation will consist of a cost-effectiveness analysis and a cost-utility analysis. The primary outcome measures for the economic evaluation will be the physical activity and the number of quality-adjusted life years. Costs will be assessed from a societal perspective with a time horizon of two years. Additionally, a process evaluation will be used to evaluate the performance of the intervention and the participants' evaluation of the intervention.
Discussion
This study is expected to provide information regarding the additional costs and effects of the 'supervised exercise programme' in adults with very high weight-related health risk.
Trial registration number
ISRCTN: ISRCTN46574304
doi:10.1186/1471-2458-11-815
PMCID: PMC3213225  PMID: 22011308
4.  Physical exercise and cognitive performance in the elderly: current perspectives 
In an aging population with increasing incidence of dementia and cognitive impairment, strategies are needed to slow age-related decline and reduce disease-related cognitive impairment in older adults. Physical exercise that targets modifiable risk factors and neuroprotective mechanisms may reduce declines in cognitive performance attributed to the normal aging process and protect against changes related to neurodegenerative diseases such as Alzheimer’s disease and other types of dementia. In this review we summarize the role of exercise in neuroprotection and cognitive performance, and provide information related to implementation of physical exercise programs for older adults. Evidence from both animal and human studies supports the role of physical exercise in modifying metabolic, structural, and functional dimensions of the brain and preserving cognitive performance in older adults. The results of observational studies support a dose-dependent neuroprotective relationship between physical exercise and cognitive performance in older adults. Although some clinical trials of exercise interventions demonstrate positive effects of exercise on cognitive performance, other trials show minimal to no effect. Although further research is needed, physical exercise interventions aimed at improving brain health through neuroprotective mechanisms show promise for preserving cognitive performance. Exercise programs that are structured, individualized, higher intensity, longer duration, and multicomponent show promise for preserving cognitive performance in older adults.
doi:10.2147/CIA.S39506
PMCID: PMC3872007  PMID: 24379659
aging; neurodegeneration; dementia; brain; physical activity
5.  Exercise based rehabilitation for heart failure 
Background
The prevalence of chronic heart failure is increasing, and increases with increasing age. Major symptoms include breathlessness and restricted activities of daily living due to reduced functional capacity, which in turn affects quality of life. Exercise training has been shown to be effective in patients with coronary heart disease and has been proposed as an intervention to improve exercise tolerance in patients with heart failure.
Objectives
To determine the effectiveness of exercise based interventions compared with usual medical care on the mortality, morbidity, exercise capacity and health related quality of life, of patients with heart failure.
Search strategy
We searched the Cochrane Controlled Trials Register (The Cochrane Library Issue 2, 2001), MEDLINE (2000 to March 2001), EMBASE (1998 to March 2001), CINAHL (1984 to March 2001) and reference lists of articles. We also sought advice from experts.
Selection criteria
RCTs of exercise based interventions. The comparison group was usual medical care as defined by the study, or placebo. Adults of all ages with chronic heart failure. Only those studies with criteria for diagnosis of heart failure (based on clinical findings or objective indices) have been included.
Data collection and analysis
Studies were selected, and data were abstracted, independently by two reviewers. Authors were contacted where possible to obtain missing information.
Main results
Twenty-nine studies met the inclusion criteria, with 1126 patients randomised. The majority of studies included both patients with primary and secondary heart failure, NYHA class II or III. Only one study specifically examined the effect of exercise training on mortality and morbidity. Exercise training significantly increased VO2 max by (WMD random effects model) 2.16 ml/kg/min (95% CI 2.82 to 1.49), exercise duration increased by 2.38 minutes (95% CI 2.85 to 1.9), work capacity by 15.1 Watts (95% CI 17.7 to 12.6) and distance on the six minute walk by 40.9 metres (95% CI 64.7 to 17.1). Improvements in VO2 max were greater for training programmes of greater intensity and duration. HRQoL improved in the seven of nine trials that measured this outcome.
Authors’ conclusions
Exercise training improves exercise capacity and quality of life in patients mild to moderate heart failure in the short term. One study found beneficial effects of exercise on cardiac mortality and hospital readmissions over 3 years of follow-up, the remaining included studies did not aim to measure clinical outcomes and were of short duration. The findings of the review are based on small-scale trials in patients who are unrepresentative of the total population of patients with heart failure. Other groups (more severe patients, the elderly, women) may also benefit. Large-scale pragmatic trials of exercise training of longer duration, recruiting a wider spectrum of patients are needed to address these issues.
doi:10.1002/14651858.CD003331.pub2
PMCID: PMC4164468  PMID: 15266480
*Exercise Therapy; Cardiac Output, Low [*rehabilitation; therapy]; Chronic Disease; Heart Failure [*rehabilitation; therapy]; Quality of Life; Randomized Controlled Trials as Topic; Humans
6.  Interval exercise versus continuous exercise in patients with moderate to severe chronic obstructive pulmonary disease – study protocol for a randomised controlled trial [ISRCTN11611768] 
Background
Physical exercise has become a cornerstone of management of chronic obstructive pulmonary disease (COPD) because it leads to clinically relevant improvements of exercise capacity and health-related quality of life (HRQL). Despite the scarcity of randomised trials directly comparing exercise protocols, current guidelines recommend high intensity continuous exercise for lower extremities as the probably most effective exercise modality. However, for patients admitted to inpatient respiratory rehabilitation programmes, it is often difficult to initiate such an exercise programme because they are severely limited by dyspnoea and leg fatigue and therefore unable to perform continuous exercise at higher intensities and for periods longer than 30 minutes. Interval exercise may be an attractive alternative for these COPD patients because it allows high intensity exercise with recovery periods. The aim of this study is to assess if interval exercise compared to high intensity continuous exercise is not of inferior effectiveness in terms of HRQL and exercise capacity improvements but associated with better exercise tolerance in patients with moderate to severe COPD at the beginning of a respiratory rehabilitation.
Methods/Design
We will assign patients with moderately severe to severe COPD to either continuous exercise or interval exercise using a stratified randomisation. Patients will follow 12–15 exercise sessions during a comprehensive inpatient respiratory rehabilitation. Primary end point for effectiveness is HRQL as measured by the Chronic Respiratory Questionnaire (CRQ) two weeks after the end of rehabilitation and secondary endpoints include additional clinical outcomes such as functional exercise capacity, other HRQL measures, patients' experience of physical exercise as well as physiological measures of the effects of physical exercise such as cardiopulmonary exercise testing. Including expected drop-outs, we will need 52 patients per group to show differences corresponding to the minimal clinically important difference of the CRQ. Outcome assessors and investigators involved in data analysis will be blinded to group assignment until analyses have been carried out.
Discussion
Clinicians and the scientific community need evidence on the benefits and tolerance of exercise protocols available in clinical practice. The proposed trial will provide important and needed data on interval and continuous exercise for decision making in clinical practice.
doi:10.1186/1471-2466-4-5
PMCID: PMC514611  PMID: 15310394
7.  Caregiver- and Patient-Directed Interventions for Dementia 
Executive Summary
In early August 2007, the Medical Advisory Secretariat began work on the Aging in the Community project, an evidence-based review of the literature surrounding healthy aging in the community. The Health System Strategy Division at the Ministry of Health and Long-Term Care subsequently asked the secretariat to provide an evidentiary platform for the ministry’s newly released Aging at Home Strategy.
After a broad literature review and consultation with experts, the secretariat identified 4 key areas that strongly predict an elderly person’s transition from independent community living to a long-term care home. Evidence-based analyses have been prepared for each of these 4 areas: falls and fall-related injuries, urinary incontinence, dementia, and social isolation. For the first area, falls and fall-related injuries, an economic model is described in a separate report.
Please visit the Medical Advisory Secretariat Web site, http://www.health.gov.on.ca/english/providers/program/mas/mas_about.html, to review these titles within the Aging in the Community series.
Aging in the Community: Summary of Evidence-Based Analyses
Prevention of Falls and Fall-Related Injuries in Community-Dwelling Seniors: An Evidence-Based Analysis
Behavioural Interventions for Urinary Incontinence in Community-Dwelling Seniors: An Evidence-Based Analysis
Caregiver- and Patient-Directed Interventions for Dementia: An Evidence-Based Analysis
Social Isolation in Community-Dwelling Seniors: An Evidence-Based Analysis
The Falls/Fractures Economic Model in Ontario Residents Aged 65 Years and Over (FEMOR)
This report features the evidence-based analysis on caregiver- and patient-directed interventions for dementia and is broken down into 4 sections:
Introduction
Caregiver-Directed Interventions for Dementia
Patient-Directed Interventions for Dementia
Economic Analysis of Caregiver- and Patient-Directed Interventions for Dementia
Caregiver-Directed Interventions for Dementia
Objective
To identify interventions that may be effective in supporting the well-being of unpaid caregivers of seniors with dementia living in the community.
Clinical Need: Target Population and Condition
Dementia is a progressive and largely irreversible syndrome that is characterized by a loss of cognitive function severe enough to impact social or occupational functioning. The components of cognitive function affected include memory and learning, attention, concentration and orientation, problem-solving, calculation, language, and geographic orientation. Dementia was identified as one of the key predictors in a senior’s transition from independent community living to admission to a long-term care (LTC) home, in that approximately 90% of individuals diagnosed with dementia will be institutionalized before death. In addition, cognitive decline linked to dementia is one of the most commonly cited reasons for institutionalization.
Prevalence estimates of dementia in the Ontario population have largely been extrapolated from the Canadian Study of Health and Aging conducted in 1991. Based on these estimates, it is projected that there will be approximately 165,000 dementia cases in Ontario in the year 2008, and by 2010 the number of cases will increase by nearly 17% over 2005 levels. By 2020 the number of cases is expected to increase by nearly 55%, due to a rise in the number of people in the age categories with the highest prevalence (85+). With the increase in the aging population, dementia will continue to have a significant economic impact on the Canadian health care system. In 1991, the total costs associated with dementia in Canada were $3.9 billion (Cdn) with $2.18 billion coming from LTC.
Caregivers play a crucial role in the management of individuals with dementia because of the high level of dependency and morbidity associated with the condition. It has been documented that a greater demand is faced by dementia caregivers compared with caregivers of persons with other chronic diseases. The increased burden of caregiving contributes to a host of chronic health problems seen among many informal caregivers of persons with dementia. Much of this burden results from managing the behavioural and psychological symptoms of dementia (BPSD), which have been established as a predictor of institutionalization for elderly patients with dementia.
It is recognized that for some patients with dementia, an LTC facility can provide the most appropriate care; however, many patients move into LTC unnecessarily. For individuals with dementia to remain in the community longer, caregivers require many types of formal and informal support services to alleviate the stress of caregiving. These include both respite care and psychosocial interventions. Psychosocial interventions encompass a broad range of interventions such as psychoeducational interventions, counseling, supportive therapy, and behavioural interventions.
Assuming that 50% of persons with dementia live in the community, a conservative estimate of the number of informal caregivers in Ontario is 82,500. Accounting for the fact that 29% of people with dementia live alone, this leaves a remaining estimate of 58,575 Ontarians providing care for a person with dementia with whom they reside.
Description of Interventions
The 2 main categories of caregiver-directed interventions examined in this review are respite care and psychosocial interventions. Respite care is defined as a break or relief for the caregiver. In most cases, respite is provided in the home, through day programs, or at institutions (usually 30 days or less). Depending on a caregiver’s needs, respite services will vary in delivery and duration. Respite care is carried out by a variety of individuals, including paid staff, volunteers, family, or friends.
Psychosocial interventions encompass a broad range of interventions and have been classified in various ways in the literature. This review will examine educational, behavioural, dementia-specific, supportive, and coping interventions. The analysis focuses on behavioural interventions, that is, those designed to help the caregiver manage BPSD. As described earlier, BPSD are one of the most challenging aspects of caring for a senior with dementia, causing an increase in caregiver burden. The analysis also examines multicomponent interventions, which include at least 2 of the above-mentioned interventions.
Methods of Evidence-Based Analysis
A comprehensive search strategy was used to identify systematic reviews and randomized controlled trials (RCTs) that examined the effectiveness of interventions for caregivers of dementia patients.
Questions
Section 2.1
Are respite care services effective in supporting the well-being of unpaid caregivers of seniors with dementia in the community?
Do respite care services impact on rates of institutionalization of these seniors?
Section 2.2
Which psychosocial interventions are effective in supporting the well-being of unpaid caregivers of seniors with dementia in the community?
Which interventions reduce the risk for institutionalization of seniors with dementia?
Outcomes of Interest
any quantitative measure of caregiver psychological health, including caregiver burden, depression, quality of life, well-being, strain, mastery (taking control of one’s situation), reactivity to behaviour problems, etc.;
rate of institutionalization; and
cost-effectiveness.
Assessment of Quality of Evidence
The quality of the evidence was assessed as High, Moderate, Low, or Very low according to the GRADE methodology and GRADE Working Group. As per GRADE the following definitions apply:
Summary of Findings
Conclusions in Table 1 are drawn from Sections 2.1 and 2.2 of the report.
Summary of Conclusions on Caregiver-Directed Interventions
There is limited evidence from RCTs that respite care is effective in improving outcomes for those caring for seniors with dementia.
There is considerable qualitative evidence of the perceived benefits of respite care.
Respite care is known as one of the key formal support services for alleviating caregiver burden in those caring for dementia patients.
Respite care services need to be tailored to individual caregiver needs as there are vast differences among caregivers and patients with dementia (severity, type of dementia, amount of informal/formal support available, housing situation, etc.)
There is moderate- to high-quality evidence that individual behavioural interventions (≥ 6 sessions), directed towards the caregiver (or combined with the patient) are effective in improving psychological health in dementia caregivers.
There is moderate- to high-quality evidence that multicomponent interventions improve caregiver psychosocial health and may affect rates of institutionalization of dementia patients.
RCT indicates randomized controlled trial.
Patient-Directed Interventions for Dementia
Objective
The section on patient-directed interventions for dementia is broken down into 4 subsections with the following questions:
3.1 Physical Exercise for Seniors with Dementia – Secondary Prevention
What is the effectiveness of physical exercise for the improvement or maintenance of basic activities of daily living (ADLs), such as eating, bathing, toileting, and functional ability, in seniors with mild to moderate dementia?
3.2 Nonpharmacologic and Nonexercise Interventions to Improve Cognitive Functioning in Seniors With Dementia – Secondary Prevention
What is the effectiveness of nonpharmacologic interventions to improve cognitive functioning in seniors with mild to moderate dementia?
3.3 Physical Exercise for Delaying the Onset of Dementia – Primary Prevention
Can exercise decrease the risk of subsequent cognitive decline/dementia?
3.4 Cognitive Interventions for Delaying the Onset of Dementia – Primary Prevention
Does cognitive training decrease the risk of cognitive impairment, deterioration in the performance of basic ADLs or instrumental activities of daily living (IADLs),1 or incidence of dementia in seniors with good cognitive and physical functioning?
Clinical Need: Target Population and Condition
Secondary Prevention2
Exercise
Physical deterioration is linked to dementia. This is thought to be due to reduced muscle mass leading to decreased activity levels and muscle atrophy, increasing the potential for unsafe mobility while performing basic ADLs such as eating, bathing, toileting, and functional ability.
Improved physical conditioning for seniors with dementia may extend their independent mobility and maintain performance of ADL.
Nonpharmacologic and Nonexercise Interventions
Cognitive impairments, including memory problems, are a defining feature of dementia. These impairments can lead to anxiety, depression, and withdrawal from activities. The impact of these cognitive problems on daily activities increases pressure on caregivers.
Cognitive interventions aim to improve these impairments in people with mild to moderate dementia.
Primary Prevention3
Exercise
Various vascular risk factors have been found to contribute to the development of dementia (e.g., hypertension, hypercholesterolemia, diabetes, overweight).
Physical exercise is important in promoting overall and vascular health. However, it is unclear whether physical exercise can decrease the risk of cognitive decline/dementia.
Nonpharmacologic and Nonexercise Interventions
Having more years of education (i.e., a higher cognitive reserve) is associated with a lower prevalence of dementia in crossectional population-based studies and a lower incidence of dementia in cohorts followed longitudinally. However, it is unclear whether cognitive training can increase cognitive reserve or decrease the risk of cognitive impairment, prevent or delay deterioration in the performance of ADLs or IADLs or reduce the incidence of dementia.
Description of Interventions
Physical exercise and nonpharmacologic/nonexercise interventions (e.g., cognitive training) for the primary and secondary prevention of dementia are assessed in this review.
Evidence-Based Analysis Methods
A comprehensive search strategy was used to identify systematic reviews and RCTs that examined the effectiveness, safety and cost effectiveness of exercise and cognitive interventions for the primary and secondary prevention of dementia.
Questions
Section 3.1: What is the effectiveness of physical exercise for the improvement or maintenance of ADLs in seniors with mild to moderate dementia?
Section 3.2: What is the effectiveness of nonpharmacologic/nonexercise interventions to improve cognitive functioning in seniors with mild to moderate dementia?
Section 3.3: Can exercise decrease the risk of subsequent cognitive decline/dementia?
Section 3.4: Does cognitive training decrease the risk of cognitive impairment, prevent or delay deterioration in the performance of ADLs or IADLs, or reduce the incidence of dementia in seniors with good cognitive and physical functioning?
Assessment of Quality of Evidence
The quality of the evidence was assessed as High, Moderate, Low, or Very low according to the GRADE methodology. As per GRADE the following definitions apply:
Summary of Findings
Table 2 summarizes the conclusions from Sections 3.1 through 3.4.
Summary of Conclusions on Patient-Directed Interventions*
Previous systematic review indicated that “cognitive training” is not effective in patients with dementia.
A recent RCT suggests that CST (up to 7 weeks) is effective for improving cognitive function and quality of life in patients with dementia.
Regular leisure time physical activity in midlife is associated with a reduced risk of dementia in later life (mean follow-up 21 years).
Regular physical activity in seniors is associated with a reduced risk of cognitive decline (mean follow-up 2 years).
Regular physical activity in seniors is associated with a reduced risk of dementia (mean follow-up 6–7 years).
Evidence that cognitive training for specific functions (memory, reasoning, and speed of processing) produces improvements in these specific domains.
Limited inconclusive evidence that cognitive training can offset deterioration in the performance of self-reported IADL scores and performance assessments.
1° indicates primary; 2°, secondary; CST, cognitive stimulation therapy; IADL, instrumental activities of daily living; RCT, randomized controlled trial.
Benefit/Risk Analysis
As per the GRADE Working Group, the overall recommendations consider 4 main factors:
the trade-offs, taking into account the estimated size of the effect for the main outcome, the confidence limits around those estimates, and the relative value placed on the outcome;
the quality of the evidence;
translation of the evidence into practice in a specific setting, taking into consideration important factors that could be expected to modify the size of the expected effects such as proximity to a hospital or availability of necessary expertise; and
uncertainty about the baseline risk for the population of interest.
The GRADE Working Group also recommends that incremental costs of health care alternatives should be considered explicitly alongside the expected health benefits and harms. Recommendations rely on judgments about the value of the incremental health benefits in relation to the incremental costs. The last column in Table 3 reflects the overall trade-off between benefits and harms (adverse events) and incorporates any risk/uncertainty (cost-effectiveness).
Overall Summary Statement of the Benefit and Risk for Patient-Directed Interventions*
Economic Analysis
Budget Impact Analysis of Effective Interventions for Dementia
Caregiver-directed behavioural techniques and patient-directed exercise programs were found to be effective when assessing mild to moderate dementia outcomes in seniors living in the community. Therefore, an annual budget impact was calculated based on eligible seniors in the community with mild and moderate dementia and their respective caregivers who were willing to participate in interventional home sessions. Table 4 describes the annual budget impact for these interventions.
Annual Budget Impact (2008 Canadian Dollars)
Assumed 7% prevalence of dementia aged 65+ in Ontario.
Assumed 8 weekly sessions plus 4 monthly phone calls.
Assumed 12 weekly sessions plus biweekly sessions thereafter (total of 20).
Assumed 2 sessions per week for first 5 weeks. Assumed 90% of seniors in the community with dementia have mild to moderate disease. Assumed 4.5% of seniors 65+ are in long-term care, and the remainder are in the community. Assumed a rate of participation of 60% for both patients and caregivers and of 41% for patient-directed exercise. Assumed 100% compliance since intervention administered at the home. Cost for trained staff from Ministry of Health and Long-Term Care data source. Assumed cost of personal support worker to be equivalent to in-home support. Cost for recreation therapist from Alberta government Website.
Note: This budget impact analysis was calculated for the first year after introducing the interventions from the Ministry of Health and Long-Term Care perspective using prevalence data only. Prevalence estimates are for seniors in the community with mild to moderate dementia and their respective caregivers who are willing to participate in an interventional session administered at the home setting. Incidence and mortality rates were not factored in. Current expenditures in the province are unknown and therefore were not included in the analysis. Numbers may change based on population trends, rate of intervention uptake, trends in current programs in place in the province, and assumptions on costs. The number of patients was based on patients likely to access these interventions in Ontario based on assumptions stated below from the literature. An expert panel confirmed resource consumption.
PMCID: PMC3377513  PMID: 23074509
8.  Dietary weight loss and exercise interventions effects on quality of life in overweight/obese postmenopausal women: a randomized controlled trial 
Background
Although lifestyle interventions targeting multiple lifestyle behaviors are more effective in preventing unhealthy weight gain and chronic diseases than intervening on a single behavior, few studies have compared individual and combined effects of diet and/or exercise interventions on health-related quality of life (HRQOL). In addition, the mechanisms of how these lifestyle interventions affect HRQOL are unknown. The primary aim of this study was to examine the individual and combined effects of dietary weight loss and/or exercise interventions on HRQOL and psychosocial factors (depression, anxiety, stress, social support). The secondary aim was to investigate predictors of changes in HRQOL.
Methods
This study was a randomized controlled trial. Overweight/obese postmenopausal women were randomly assigned to 12 months of dietary weight loss (n = 118), moderate-to-vigorous aerobic exercise (225 minutes/week, n = 117), combined diet and exercise (n = 117), or control (n = 87). Demographic, health and anthropometric information, aerobic fitness, HRQOL (SF-36), stress (Perceived Stress Scale), depression [Brief Symptom Inventory (BSI)-18], anxiety (BSI-18) and social support (Medical Outcome Study Social Support Survey) were assessed at baseline and 12 months. The 12-month changes in HRQOL and psychosocial factors were compared using analysis of covariance, adjusting for baseline scores. Multiple regression was used to assess predictors of changes in HRQOL.
Results
Twelve-month changes in HRQOL and psychosocial factors differed by intervention group. The combined diet + exercise group improved 4 aspects of HRQOL (physical functioning, role-physical, vitality, and mental health), and stress (p ≤ 0.01 vs. controls). The diet group increased vitality score (p < 0.01 vs. control), while HRQOL did not change differently in the exercise group compared with controls. However, regardless of intervention group, weight loss predicted increased physical functioning, role-physical, vitality, and mental health, while increased aerobic fitness predicted improved physical functioning. Positive changes in depression, stress, and social support were independently associated with increased HRQOL, after adjusting for changes in weight and aerobic fitness.
Conclusions
A combined diet and exercise intervention has positive effects on HRQOL and psychological health, which may be greater than that from exercise or diet alone. Improvements in weight, aerobic fitness and psychosocial factors may mediate intervention effects on HRQOL.
doi:10.1186/1479-5868-8-118
PMCID: PMC3215656  PMID: 22026966
health-related quality of life; exercise; dietary weight loss; postmenopausal women
9.  Physical Exercise and Quality of Life in Breast Cancer Survivors 
An important goal for cancer patients is to improve the quality of life (QOL) by maximising functions affected by the disease and its therapy. Preliminary research suggests that exercise may be an effective intervention for enhancing QOL in cancer survivors. Research has provided preliminary evidence for the safety, feasibility, and efficacy of exercise training in breast cancer survivors. The aim of this study was to assess the association between physical exercise and quality of life in a population of female breast cancer survivors, followed up from diagnosis to the off-treatment time period, and investigated about their exercise habits in pre-diagnosis.
A total of 212 female breast cancer survivors consecutively registered from January 2002 to December 2006 at a Supportive Care Unit in an Italian Oncology Department were enrolled. Exercise behaviour was assessed by the Leisure Score Index (LSI) of the Godin Leisure-Time Exercise Questionnaire. Patients were asked to report their average weekly exercise for three cancer-related time periods, i.e. pre-diagnosis, during active treatment and off-treatment. Quality of life was assessed by the Italian version of the WHOQOL-BREF standardised instrument.
Statistical analysis indicated significant differences across the cancer-relevant time-periods for all exercise behaviour outcomes: the exercise behaviour was significantly lower during both on- and off- treatment than during prediagnosis; exercise during active treatment was significantly lower than during off-treatment. QOL strongly decreases during active treatment. Significant correlations were found between total exercise on- and off-treatment and all QOL indicators. Strenuous exercise is strongly correlated with QOL. Absent/mild exercise seems to be inversely correlated with a positive perception of disease severity and with quality of life on all axes.
Need clearly results for inclusion of physical activity programs in comprehensive, complementary treatment regimes for breast cancer patients in Italian oncology departments.
PMCID: PMC2204041  PMID: 18219372
Physical exercise; quality of life; breast cancer survivors; Italian Oncology
10.  Patient Activation through Counseling and Exercise – Acute Leukemia (PACE-AL) – a randomized controlled trial 
BMC Cancer  2013;13:446.
Background
Patients with acute leukemia experience a substantial symptom burden and are at risk of developing infections throughout the course of repeated cycles of intensive chemotherapy. Physical activity in recent years has been a strategy for rehabilitation in cancer patients to remedy disease and treatment related symptoms and side effects. To date, there are no clinical practice exercise guidelines for patients with acute leukemia undergoing induction and consolidation chemotherapy. A randomized controlled trial is needed to determine if patients with acute leukemia can benefit by a structured and supervised counseling and exercise program.
Methods/design
This paper presents the study protocol: Patient Activation through Counseling and Exercise – Acute Leukemia (PACE-AL) trial, a two center, randomized controlled trial of 70 patients with acute leukemia (35 patients/study arm) following induction chemotherapy in the outpatient setting. Eligible patients will be randomized to usual care or to the 12 week exercise and counseling program. The intervention includes 3 hours + 30 minutes per week of supervised and structured aerobic training (moderate to high intensity 70 - 80%) on an ergometer cycle, strength exercises using hand weights and relaxation exercise. Individual health counseling sessions include a self directed home walk program with a step counter. The primary endpoint is functional performance/exercise capacity (6 minute walk distance). The secondary endpoints are submaximal VO2 max test, sit to stand and bicep curl test, physical activity levels, patient reported outcomes (quality of life, anxiety and depression, symptom prevalence, intensity and interference). Evaluation of clinical outcomes will be explored including incidence of infection, hospitalization days, body mass index, time to recurrence and survival. Qualitative exploration of patients’ health behavior and experiences.
Discussion
PACE-AL will provide evidence of the effect of exercise and health promotion counseling on functional and physical capacity, the symptom burden and quality of life in patients with acute leukemia during out patient management. The results will inform clinical practice exercise guidelines and rehabilitation programs for patients undergoing treatment for acute leukemia. Optimizing the treatment and care pathway may ease the transition for patients from illness to the resumption of everyday activities.
Trial registration
ClinicalTrials.gov Identifier: NCT01404520.
doi:10.1186/1471-2407-13-446
PMCID: PMC3850718  PMID: 24083543
Acute leukemia; Cancer; Chemotherapy; Exercise; Health counseling; Physical and functional capacity; Quality of life; Symptoms; Outpatient management; Randomised controlled trial; Qualitative evaluation
11.  Efficacy and safety of a modular multi-modal exercise program in prostate cancer patients with bone metastases: a randomized controlled trial 
BMC Cancer  2011;11:517.
Background
The presence of bone metastases has excluded participation of prostate cancer patients in exercise intervention studies to date and is also a relative contraindication to supervised exercise in the community setting because of concerns of fragility fracture. However, this group of patients often have developed significant muscle atrophy and functional impairments from prior and continuing androgen deprivation that is exacerbated by subsequent and more intensive interventions such as chemotherapy. The aim of this study is to determine the efficacy and safety of a modular multi-modal exercise program in prostate cancer patients with bone metastases.
Methods/Design
Multi-site randomized controlled trial in Western Australia and New South Wales to examine the efficacy and safety of a modular multi-modal physical exercise program in 90 prostate cancer survivors with bone metastases. Participants will be randomized to (1) modular multi-modal exercise intervention group or (2) usual medical care group. The modular multi-modal exercise group will receive a 3-month supervised exercise program based on bone lesion location/extent. Measurements for primary and secondary endpoints will take place at baseline, 3 months (end of the intervention) and 6 months follow-up.
Discussion
Delaying or preventing skeletal complication and improving physical function for men with bone metastases would provide clinically meaningful benefits to patients. However, exercise programs must be designed and executed with careful consideration of the skeletal complications associated with bone metastatic disease and cumulative toxicities from androgen deprivation such as osteoporosis and increased risk of fractures. The results from this study will form the basis for the development of a specific exercise prescription in this patient group in order to alleviate disease burden, counteract the adverse treatment related side-effects and enhance quality of life.
Trial Registration
ACTRN: ACTRN12611001158954
doi:10.1186/1471-2407-11-517
PMCID: PMC3267706  PMID: 22166044
12.  Influence of a six month endurance exercise program on the immune function of prostate cancer patients undergoing Antiandrogen- or Chemotherapy: design and rationale of the ProImmun study 
BMC Cancer  2013;13:272.
Background
Exercise seems to minimize prostate cancer specific mortality risk and treatment related side effects like fatigue and incontinence. However the influence of physical activity on the immunological level remains uncertain. Even prostate cancer patients undergoing palliative treatment often have a relatively long life span compared to other cancer entities. To optimize exercise programs and their outcomes it is essential to investigate the underlying mechanisms. Further, it is important to discriminate between different exercise protocols and therapy regimes.
Methods/Design
The ProImmun study is a prospective multicenter patient preference randomized controlled trial investigating the influence of a 24 week endurance exercise program in 80–100 prostate cancer patients by comparing patients undergoing Antiandrogen therapy combined with exercise (AE), Antiandrogen therapy without exercise (A), Chemotherapy with exercise(CE) or Chemotherapy without exercise (C). The primary outcome of the study is a change in prostate cancer relevant cytokines and hormones (IL-6, MIF, IGF-1, Testosterone). Secondary endpoints are immune cell ratios, oxidative stress and antioxidative capacity levels, VO2 peak, fatigue and quality of life. Patients of the intervention group exercise five times per week, while two sessions are supervised. During the supervised sessions patients (AE and CE) exercise for 33 minutes on a bicycle ergometer at 70-75% of their VO2 peak. To assess long term effects and sustainability of the intervention two follow-up assessments are arranged 12 and 18 month after the intervention.
Discussion
The ProImmun study is the first trial which primarily investigates immunological effects of a six month endurance exercise program in prostate cancer patients during palliative care. Separating patients treated with Antiandrogen therapy from those who are additionally treated with Chemotherapy might allow a more specific view on the influence of endurance training interventions and the impact of different therapy protocols on the immune function.
Trial registration
German Clinical Trials Register: DRKS00004739
doi:10.1186/1471-2407-13-272
PMCID: PMC3681550  PMID: 23731674
Exercise; Prostate cancer; Immune function
13.  Feasibility of a Caregiver Assisted Exercise Program for Preterm Infants 
Purpose
Mounting evidence shows that low birth weight and prematurity are related to serious health problems in adulthood, including increased body fat, decreased fitness, poor bone mineralization, pulmonary problems, and cardiovascular disease. There is data to suggest that increasing physical activity in preterm infants will have effects on short term muscle mass and fat mass, but we also hypothesized that increasing physical activity early in life can lead to improved health outcomes in adulthood. Because few studies have addressed the augmentation of physical activity in premature babies, the objective of this study was to evaluate the feasibility of whether caregivers (mostly mothers) can learn from nurses and other health care providers to implement a program of assisted infant exercise following discharge.
Study Design and Methods
Ten caregivers of preterm infants were taught by nurses, along with occupational therapists and other health care providers, to perform assisted infant exercise and instructed to conduct the exercises daily for approximately three weeks. The researchers made home visits and conducted qualitative interviews to understand the caregivers’ (mostly mothers’) experiences with this exercise protocol. Quantitative data included a caregiver’s daily log of the exercises completed to measure adherence as well as videotaped caregiver sessions, which were used to record errors as a measure of proficiency in the exercise technique.
Results
On average, the caregivers completed a daily log on 92% of the days enrolled in the study and reported performing the exercises on 93% of the days recorded. Caregivers made an average of 1.8 errors on two tests (with a maximum of 23 or 35 items on each, respectively) when demonstrating proficiency in the exercise technique. All caregivers described the exercises as beneficial for their infants, and many reported that these interventions fostered increased bonding with their babies. Nearly all reported feeling “scared” of hurting their babies during the first few days of home exercise, but stated that fears were alleviated by practice in the home and further teaching and learning.
Clinical Implications
Caregivers were willing and able to do the exercises correctly, and they expressed a belief that the intervention had positive effects on their babies and on caregiver-infant interactions. These findings have important implications for nursing practice because nurses are in key positions to teach and encourage caregivers to practice these exercises with their newborn babies.
doi:10.1097/JPN.0b013e31828b244a
PMCID: PMC3651855  PMID: 23618941
14.  Left Ventricle Fibrosis Associated With Nonsustained Ventricular Tachycardia in an Elite Athlete: Is Exercise Responsible? A Case Report 
Journal of Athletic Training  2012;47(2):224-227.
Objective:
To emphasize the potentially harmful effects of high-intensity exercise on cardiac health and the fine line between physiologic and pathologic adaptation to chronic exercise in the elite athlete. This case also highlights the crucial need for regular evaluation of symptoms that suggest cardiac abnormality in athletes.
Background:
Sudden cardiac death (SCD) of young athletes is always a tragedy because they epitomize health. However, chronic, high-intensity exercise sometimes has harmful effects on cardiac health, and pathologic changes, such as myocardial fibrosis, have been observed in endurance athletes. In this case, a highly trained 30-year-old cyclist reported brief palpitations followed by presyncope feeling while exercising. Immediate investigations revealed nonsustained ventricular tachycardia originating from the left ventricle on a stress test associated with myocardial fibrosis of the left ventricle as shown with magnetic resonance imaging. Despite complete cessation of exercise, life-threatening arrhythmia and fibrosis persisted, leading to complete restriction from competition.
Differential Diagnosis:
Hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, myocarditis, postmyocarditis, use of drugs and toxic agents, doping, and systemic disease.
Treatment:
The arrhythmia could not be treated with catheter ablation procedure or drug suppression. Therefore, the athlete was instructed to withdraw completely from sport participation and to have a medical follow-up twice each year.
Uniqueness:
To our knowledge, no other report of left ventricle exercise-induced fibrosis associated with life-threatening arrhythmia in a living young elite athlete exists. Only postmortem evidence supports such myocardial pathologic adaptation to exercise.
Conclusions:
To prevent SCD in young athletes, careful attention must be paid to exercise-related symptoms that suggest a cardiac abnormality because they more often are linked to life-threatening cardiovascular disease.
PMCID: PMC3418136  PMID: 22488290
myocardial fibrosis; high-intensity exercise; sudden death
15.  The Effect of Omega-3 Fatty Acid Supplementation on the Inflammatory Response to eccentric strength exercise 
Omega-3 fatty acids (omega-3) have anti-inflammatory properties. However, it is not known if omega-3 supplementation attenuates exercise-induced inflammation. We tested the hypothesis that omega-3 supplementation reduces inflammation that is induced by eccentric arm curl exercise. Healthy adult men and women (n=11; 35 ± 10 y) performed eccentric biceps curls on two occasions, once after 14d of dietary omega-3 restriction (control trial) and again after 7d of 3,000 mg/d omega-3 supplementation (omega-3 trial). Before and 48 h after eccentric exercise, signs of inflammation was assessed by measuring soreness ratings, swelling (arm circumference and arm volume), and temperature (infrared skin sensor). Arm soreness increased (p < 0.0001) in response to eccentric exercise; the magnitude of increase in soreness was 15% less in the omega-3 trial (p = 0.004). Arm circumference increased after eccentric exercise in the control trial (p = 0.01) but not in the omega-3 trial (p = 0.15). However, there was no difference between trials (p = 0.45). Arm volume and skin temperature did not change in response to eccentric exercise in either trial. These findings suggest that omega-3 supplementation decreases soreness, as a marker of inflammation, after eccentric exercise. Based on these findings, omega-3 supplementation could provide benefits by minimizing post-exercise soreness and thereby facilitate exercise training in individuals ranging from athletes undergoing heavy conditioning to sedentary subjects or patients who are starting exercise programs or medical treatments such as physical therapy or cardiac rehabilitation.
Key pointsDietary supplementation with omega-3 fatty acids has been shown to reduce inflammation in numerous inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease, and Chrohn’s disease.Although strenuous exercise is known to cause acute increases in inflammation, it is not clear if omega-3 fatty acid supplementation attenuates this adverse response to exercise.Our research demonstrates that 3000 mg·d-1 omega-3 fatty acid supplementation minimizes the severe, delayed-onset muscle soreness that results from strenuous eccentric strength exercise.This information, along with a plethora of information showing that omega-3 fatty acid supplementation has other health benefits, demonstrates that a readily available over the counter nutritional supplement (i.e. omega-3 fatty acids) reduces delayed-onset soreness caused by strenuous strength exercise.This information has obvious relevance to athletic populations but also to other groups such as physical therapy patients and newly admitted cardiac rehabilitation patients, as muscle soreness, if left unchecked, can slow the progress in adapting to a new exercise program.Furthermore, as inflammation is known to be involved in the pathogenesis if numerous diseases, including heart disease, cancer, and diabetes, it is likely prudent for individuals to use inflammation-attenuating interventions, such as omega-3 supplementation, to keep inflammatory responses to physical activity at a minimum.
PMCID: PMC3737804  PMID: 24150614
Fish oil; muscle soreness; eicosapentaenoic acid; docosahexaenoic acid
16.  EXERCISE in pediatric autologous stem cell transplant patients: a randomized controlled trial protocol 
BMC Cancer  2012;12:401.
Background
Hematopoietic stem cell transplantation is an intensive therapy used to improve survivorship and cure various oncologic diseases. However, this therapy is associated with high mortality rates and numerous negative side-effects. The recovery of the immune system is a special concern and plays a key role in the success of this treatment. In healthy populations it is known that exercise plays an important role in immune system regulation, but little is known about the role of exercise in the hematological and immunological recovery of children undergoing hematopoietic stem cell transplant. The primary objective of this randomized-controlled trial (RCT) is to study the effect of an exercise program (in- and outpatient) on immune cell recovery in patients undergoing an autologous stem cell transplantation. The secondary objective is to determine if an exercise intervention diminishes the usual deterioration in quality of life, physical fitness, and the acquisition of a sedentary lifestyle.
Methods
This RCT has received approval from The Conjoint Health Research Ethics Board (CHREB) of the University of Calgary (Ethics ID # E-24476). Twenty-four participants treated for a malignancy with autologous stem cell transplant (5 to 18 years) in the Alberta Children’s Hospital will be randomly assigned to an exercise or control group. The exercise group will participate in a two-phase exercise intervention (in- and outpatient) from hospitalization until 10 weeks after discharge. The exercise program includes strength, flexibility and aerobic exercise. During the inpatient phase this program will be performed 5 times/week and will be supervised. The outpatient phase will combine a supervised session with two home-based exercise sessions with the use of the Wii device. The control group will follow the standard protocol without any specific exercise program. A range of outcomes, including quantitative and functional recovery of immune system, cytokine levels in serum, natural killer (NK) cells and their subset recovery and function, and gene expression of activating and inhibitory NK cell receptors, body composition, nutrition, quality of life, fatigue, health-related fitness assessment and physical activity levels will be examined, providing the most comprehensive assessment to date.
Discussion
We expect to find improvements in immunological recovery and quality of life, and decreased acquisition of sedentary behavior and fitness deconditioning. The comprehensive outcomes generated in this RCT will provide preliminary data to conduct a multisite study that will generate stronger outcomes.
Trial registration
Gov identification # NCT01666015
doi:10.1186/1471-2407-12-401
PMCID: PMC3503655  PMID: 22963378
Pediatric; Hematopoietic stem cell transplant; Cancer; Exercise; Quality of life; Immune system; Physical activity levels
17.  Efficacy of a physical exercise training programme COPD in primary care: study protocol of a randomized controlled trial 
BMC Public Health  2014;14(1):788.
Background
Chronic obstructive pulmonary disease (COPD) is recognized as a systemic illness with significant extra-pulmonary features, such as exercise intolerance and muscle weakness. Pulmonary rehabilitation has been shown to be very effective in counteracting these consequences in patients with more advanced COPD. However, limited data is available on the efficacy of a physical exercise training programme in patients with mild to moderate COPD in primary care. Furthermore, it is unknown if improved exercise capacity translates into enhanced daily physical activities. The aim of this paper is to describe the design of a randomized controlled trial to assess the efficacy of a physical exercise training programme in patients with mild to moderate COPD.
Methods/design
In this randomized controlled trial situated in the primary care setting, 102 patients with mild to moderate airflow obstruction (FEV1 ≥ 50% of predicted), dyspnoea and a physically inactive lifestyle will be randomized to an intervention or control group. The intervention group receives a 4-month physical exercise training programme at a local physiotherapy practice, which includes exercise training, resistance training, breathing exercises and advises on how to increase the level of physical activity. The control group receives usual care, i.e. advises on how to increase the level of physical activity and a sham treatment at a local physiotherapy practice of which no physiological training stimulus can be expected. Primary outcome is functional exercise capacity at 4-months measured on the six-minute walk distance. Secondary outcomes include peripheral muscle strength, physical activity in daily life, health related quality of life, Medical Research Council (MRC) dyspnoea score and patients’ perceived effectiveness. Follow-up measurement will take place at 6 months after baseline.
Discussion
This will be one of the first studies to evaluate the efficacy of a physical exercise training programme in patients with mild to moderate COPD completely recruited and assessed in primary care. The results of this trial may give a unique insight into the potential of the implementation of an easy, close-to-home rehabilitation programme.
Trial registration
The Netherlands National Trial Register NTR1471.
doi:10.1186/1471-2458-14-788
PMCID: PMC4246559  PMID: 25086593
Chronic obstructive pulmonary disease; Exercise training; Physical activity; Primary care; Randomized controlled trial
18.  Effect of exercise and calorie restriction on biomarkers of aging in mice 
Unlike, calorie restriction, exercise fails to extend maximum life span, but the mechanisms that explain this disparate effect are unknown. We used a 24-wk protocol of treadmill running, weight matching, and pair feeding to compare the effects of exercise and calorie restriction on biomarkers related to aging. This study consisted of young controls, an ad libitum-fed sedentary group, two groups that were weight matched by exercise or 9% calorie restriction, and two groups that were weight matched by 9% calorie restriction + exercise or 18% calorie restriction. After 24 wk, ad libitum-fed sedentary mice were the heaviest and fattest. When weight-matched groups were compared, mice that exercised were leaner than calorie-restricted mice. Ad libitum-fed exercise mice tended to have lower serum IGF-1 than fully-fed controls, but no difference in fasting insulin. Mice that underwent 9% calorie restriction or 9% calorie restriction + exercise, had lower insulin levels; the lowest concentrations of serum insulin and IGF-1 were observed in 18% calorie-restricted mice. Exercise resulted in elevated levels of tissue heat shock proteins, but did not accelerate the accumulation of oxidative damage. Thus, failure of exercise to slow aging in previous studies is not likely the result of increased accrual of oxidative damage and may instead be due to an inability to fully mimic the hormonal and/or metabolic response to calorie restriction.
doi:10.1152/ajpregu.00890.2007
PMCID: PMC4332519  PMID: 18321952
energetics; obesity; energy balance
19.  Muscle-Strengthening and Conditioning Activities and Risk of Type 2 Diabetes: A Prospective Study in Two Cohorts of US Women 
PLoS Medicine  2014;11(1):e1001587.
Anders Grøntved and colleagues examined whether women who perform muscle-strengthening and conditioning activities have an associated reduced risk of type 2 diabetes mellitus.
Please see later in the article for the Editors' Summary
Background
It is well established that aerobic physical activity can lower the risk of type 2 diabetes (T2D), but whether muscle-strengthening activities are beneficial for the prevention of T2D is unclear. This study examined the association of muscle-strengthening activities with the risk of T2D in women.
Methods and Findings
We prospectively followed up 99,316 middle-aged and older women for 8 years from the Nurses' Health Study ([NHS] aged 53–81 years, 2000–2008) and Nurses' Health Study II ([NHSII] aged 36–55 years, 2001–2009), who were free of diabetes, cancer, and cardiovascular diseases at baseline. Participants reported weekly time spent on resistance exercise, lower intensity muscular conditioning exercises (yoga, stretching, toning), and aerobic moderate and vigorous physical activity (MVPA) at baseline and in 2004/2005. Cox regression with adjustment for major determinants for T2D was carried out to examine the influence of these types of activities on T2D risk. During 705,869 person years of follow-up, 3,491 incident T2D cases were documented. In multivariable adjusted models including aerobic MVPA, the pooled relative risk (RR) for T2D for women performing 1–29, 30–59, 60–150, and >150 min/week of total muscle-strengthening and conditioning activities was 0.83, 0.93, 0.75, and 0.60 compared to women reporting no muscle-strengthening and conditioning activities (p<0.001 for trend). Furthermore, resistance exercise and lower intensity muscular conditioning exercises were each independently associated with lower risk of T2D in pooled analyses. Women who engaged in at least 150 min/week of aerobic MVPA and at least 60 min/week of muscle-strengthening activities had substantial risk reduction compared with inactive women (pooled RR = 0.33 [95% CI 0.29–0.38]). Limitations to the study include that muscle-strengthening and conditioning activity and other types of physical activity were assessed by a self-administered questionnaire and that the study population consisted of registered nurses with mostly European ancestry.
Conclusions
Our study suggests that engagement in muscle-strengthening and conditioning activities (resistance exercise, yoga, stretching, toning) is associated with a lower risk of T2D. Engagement in both aerobic MVPA and muscle-strengthening type activity is associated with a substantial reduction in the risk of T2D in middle-aged and older women.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Worldwide, more than 370 million people have diabetes mellitus, a disorder characterized by poor glycemic control—dangerously high amounts of glucose (sugar) in the blood. Blood sugar levels are normally controlled by insulin, a hormone released by the pancreas. In people with type 2 diabetes (the commonest form of diabetes), blood sugar control fails because the fat and muscle cells that normally respond to insulin by removing excess sugar from the blood become less responsive to insulin. Type 2 diabetes, which was previously known as adult-onset diabetes, can often initially be controlled with diet and exercise, and with antidiabetic drugs such as metformin and sulfonylureas. However, as the disease progresses, the pancreatic beta cells, which make insulin, become impaired and patients may eventually need insulin injections. Long-term complications of diabetes, which include an increased risk of cardiovascular problems such as heart disease and stroke, reduce the life expectancy of people with diabetes by about 10 years compared to people without diabetes.
Why Was This Study Done?
Type 2 diabetes is becoming increasingly common worldwide so better preventative strategies are essential. It is well-established that regular aerobic exercise—physical activity in which the breathing and heart rate increase noticeably such as jogging, brisk walking, and swimming—lowers the risk of type 2 diabetes. The World Health Organization currently recommends that adults should do at least 150 min/week of moderate-to-vigorous aerobic physical activity to reduce the risk of diabetes and other non-communicable diseases. It also recommends that adults should undertake muscle-strengthening and conditioning activities such as weight training and yoga on two or more days a week. However, although studies have shown that muscle-strengthening activity improves glycemic control in people who already have diabetes, it is unclear whether this form of exercise prevents diabetes. In this prospective cohort study (a study in which disease development is followed up over time in a group of people whose characteristics are recorded at baseline), the researchers investigated the association of muscle-strengthening activities with the risk of type 2 diabetes in women.
What Did the Researchers Do and Find?
The researchers followed up nearly 100,000 women enrolled in the Nurses' Health Study (NHS) and the Nurses' Health Study II (NHSII), two prospective US investigations into risk factors for chronic diseases in women, for 8 years. The women provided information on weekly participation in muscle-strengthening exercise (for example, weight training), lower intensity muscle-conditioning exercises (for example, yoga and toning), and aerobic moderate and vigorous physical activity (aerobic MVPA) at baseline and 4 years later. During the study 3,491 women developed diabetes. After allowing for major risk factors for type 2 diabetes (for example, diet and a family history of diabetes) and for aerobic MVPA, compared to women who did no muscle-strengthening or conditioning exercise, the risk of developing type 2 diabetes among women declined with increasing participation in muscle-strengthening and conditioning activity. Notably, women who did more than 150 min/week of these types of exercise had 40% lower risk of developing diabetes as women who did not exercise in this way at all. Muscle-strengthening and muscle-conditioning exercise were both independently associated with reduced diabetes risk, and women who engaged in at least 150 min/week of aerobic MVPA and at least 60 min/week of muscle-strengthening exercise were a third as likely to develop diabetes as inactive women.
What Do These Findings Mean?
These findings show that, among the women enrolled in NHS and NHSII, engagement in muscle-strengthening and conditioning activities lowered the risk of type 2 diabetes independent of aerobic MVPA. That is, non-aerobic exercise provided protection against diabetes in women who did no aerobic exercise. Importantly, they also show that doing both aerobic exercise and muscle-strengthening exercise substantially reduced the risk of type 2 diabetes. Because nearly all the participants in NHS and NHSII were of European ancestry, these results may not be generalizable to women of other ethnic backgrounds. Moreover, the accuracy of these findings may be limited by the use of self-administered questionnaires to determine how much exercise the women undertook. Nevertheless, these findings support the inclusion of muscle-strengthening and conditioning exercises in strategies designed to prevent type 2 diabetes in women, a conclusion that is consistent with current guidelines for physical activity among adults.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001587.
The US National Diabetes Information Clearinghouse provides information about diabetes for patients, health-care professionals and the general public, including information on diabetes prevention (in English and Spanish)
The UK National Health Service Choices website provides information for patients and carers about type 2 diabetes and explains the benefits of regular physical activity
The World Health Organization provides information about diabetes and about physical activity and health (in several languages); its 2010 Global Recommendations on Physical Activity for Health are available in several languages
The US Centers for Disease Control and Prevention provides information on physical activity for different age groups; its Physical Activity for Everyone web pages include guidelines, instructional videos and personal success stories
More information about the Nurses Health Study and the Nurses Health Study II is available
The UK charity Healthtalkonline has interviews with people about their experiences of diabetes
MedlinePlus provides links to further resources and advice about diabetes and about physical exercise and fitness (in English and Spanish)
doi:10.1371/journal.pmed.1001587
PMCID: PMC3891575  PMID: 24453948
20.  Effects of Aerobic Exercise on Mild Cognitive Impairment 
Archives of neurology  2010;67(1):71-79.
Objectives
To examine the effects of aerobic exercise on cognition and other biomarkers associated with Alzheimer disease pathology for older adults with mild cognitive impairment, and assess the role of sex as a predictor of response.
Design
Six-month, randomized, controlled, clinical trial.
Setting
Veterans Affairs Puget Sound Health Care System clinical research unit.
Participants
Thirty-three adults (17 women) with amnestic mild cognitive impairment ranging in age from 55 to 85 years (mean age,70 years).
Intervention
Participants were randomized either to a high-intensity aerobic exercise or stretching control group. The aerobic group exercised under the supervision of a fitness trainer at 75% to 85% of heart rate reserve for 45 to 60 min/d, 4 d/wk for 6 months. The control group carried out supervised stretching activities according to the same schedule but maintained their heart rate at or below 50% of their heart rate reserve. Before and after the study, glucometabolic and treadmill tests were performed and fat distribution was assessed using dual-energy x-ray absorptiometry. At baseline, month 3, and month 6, blood was collected for assay and cognitive tests were administered.
Main Outcome Measures
Performance measures on Symbol-Digit Modalities, Verbal Fluency, Stroop, Trails B, Task Switching, Story Recall, and List Learning. Fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulinlike growth factor-I, and β-amyloids 40 and 42.
Results
Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men, aerobic exercise increased plasma levels of insulinlike growth factor I and had a favorable effect only on Trails B performance.
Conclusions
This study provides support, using rigorous controlled methodology, for a potent nonpharma-cologic intervention that improves executive control processes for older women at high risk of cognitive decline. Moreover, our results suggest that a sex bias in cognitive response may relate to sex-based differences in glucometabolic and hypothalamic-pituitary-adrenal axis responses to aerobic exercise.
doi:10.1001/archneurol.2009.307
PMCID: PMC3056436  PMID: 20065132
21.  Study protocol to investigate the effects of testosterone therapy as an adjunct to exercise rehabilitation in hypogonadal males with chronic heart failure 
Background
Testosterone deficiency is a common occurrence in men with chronic heart failure (CHF) and may underpin features of advanced disease, including reduced skeletal muscle mass and fatigue. It is positively correlated with cardiac output and exercise capacity in patients with CHF, whereas a significant improvement in both these parameters has been observed following testosterone replacement therapy. Testosterone therapy has also been shown to reduce circulating levels of inflammatory markers, (TNF-α, sICAM-1 and sVCAM-1) in patients with established coronary artery disease and testosterone deficiency. This pilot study will assess the feasibility of a combined exercise rehabilitation and adjunctive testosterone therapy intervention for evoking improvements in exercise capacity, circulating inflammatory markers, cardiac and skeletal muscle function, indices of psychological health status and quality of life in hypogonadal males with chronic heart failure.
Methods/design
Following ethical approval, 36 patients will be randomly allocated to one of two groups: testosterone or placebo therapy during exercise rehabilitation. A combined programme of moderate intensity aerobic exercise and resistance (strength) training will be used. The primary outcome measure is exercise capacity, assessed using an incremental shuttle walk test. Secondary outcome measures include measures of peak oxygen uptake, cardiac function, lower-limb skeletal muscle contractile function and oxygenation during exercise, circulating inflammatory markers, psychological health status and quality of life.
Discussion
Exercise rehabilitation can safely increase exercise capacity in stable CHF patients but there is a need for studies which are aimed at evaluating the long-term effects of physical training on functional status, morbidity and mortality. This pilot study will provide valuable preliminary data on the efficacy of testosterone therapy as an adjunct to exercise rehabilitation on a range of functional, physiological and health-related outcomes in this patient population. Preliminary data will be used in the design of a large-scale randomised controlled trial, aimed at informing clinical practice with respect to optimisation of exercise rehabilitation in this patient group.
doi:10.1186/1471-2261-6-46
PMCID: PMC1693568  PMID: 17137495
22.  Prevention of relapsing backache 
Background
The condition of non-specific back pain is characterized by high prevalence, non satisfactory therapeutic options and severe socioeconomic consequences. Therefore prevention seems an attractive option to downsize the problem. However, the construction of effective preventive measures is complicated by the obscure aetiology of the condition, the multidimensionality of risk and prognostic factors (bio psychosocial model!) and the variability of its natural as well as clinical course. This led to the development of a wide variety of preventive measures: e. g. exercise programs, educational measures (including back school), ergonomic modification of the work environment, mechanical supports (e. g. back belts) as well as multidisciplinary interventions. For two reasons the workplace seems to be a suitable setting for prevention. First, because a number of strong risk factors are associated with working conditions and second, because it allows addressing a large proportion of the adult population. Against this background the assessment at hand sets out to answer the following questions:
What is the amount and methodological quality of the available scientific literature on the effectiveness of back pain prevention in the workplace environment? What are effective measures for the prevention of back pain and its consequences in the workplace environment and how effective are they? Is back pain prevention in the workplace environment cost-effective? Is there a need for more research? As primary outcomes for effectiveness the assessment will focus on time lost from work and the frequency and duration of episodes with back pain. The preventive measures assessed belong to the following categories: exercise programs, educational and information measures, multidimensional interventions, back belts, lifting teams and ergonomic interventions.
Methods
The assessment is based on a systematic review of the published literature according to the methodological requirements of DAHTA. Proceedings of the electronic literature searches are documented in the appendix. In addition references of review articles were searched. Methodological quality of publications (systematic reviews, HTA reports) was assessed using the checklists developed by the German Scientific Working Group for Technology Assessment in Health Care (GSWGTAHC) or with the Jadad-Score (controlled trials) respectively. Due to the large number of relevant publications the assessment is mainly based on data reported by systematic reviews and supplemented by the results of newer trials. A separate economic assessment was not performed because of the low amount of available data. An assessment of ethical, legal and social impact was omitted due to resource constraints.
Results
For preventive interventions based on exercise programs most of the analysed trials demonstrate some effectiveness. Due to the heterogeneity of the programs it is not possible to conclude whether positive effects are associated with a special type, duration or intensity of exercise. For purely educational measures or information strategies applied in a workplace setting the available trials were not able to demonstrate effectiveness. Back school programs, which in addition to theoretical instructions offer intensive exercising may in the short term, be successful in reducing the incidence of new episodes of back pain. Some trials in high risk groups demonstrate effectiveness of multidimensional interventions on time lost from work. These programs include education and exercise as well as cognitive behavioural interventions to change pain perception. The assessment of the benefits of back belts for the prevention of back pain is based on results of high quality efficacy as well as effectiveness trials. Their results imply for the otherwise healthy working population no protective effect of back belts on time lost from work due to back pain, on the incidence of painful episodes or on days with impairment by back pain. So far there are no data from controlled trials that demonstrate the effectiveness of "lifting teams" in nursing care to prevent back pain or its consequences. However, results from uncontrolled pilot studies indicate a potential for effectiveness. Among "ergonomic interventions" three different approaches have to be distinguished: interventions addressing changes of the workplace setting, interventions addressing the individual's behaviour and combined interventions. Studies evaluating the effectiveness of setting interventions (modification of the physical workplace environment, changes of production processes, organisational changes) yield no dependable results. This conclusion is not based on indifferent trial results but rather on the lack of methodologically sound studies. Results from studies on ergonomic interventions addressing the individual confirm the conclusions drawn for exercise and educational measures. The most marked results are found in trials that examine the effectiveness of combined interventions in high risk groups and contain a strong participatory component. Hardly any of the trials studying the effects of ergonomic interventions satisfied methodological quality criteria that are accepted standard for clinical or public health intervention studies.
There were no data allowing firm conclusions on the cost-effectiveness of interventions from any of the categories.
Discussion
The significance of the results of the assessment at hand is strongly limited by the comprehensiveness of the questions addressed. Reviewing the literature on the basis of (even systematic) review articles impairs the differentiated examination of the role of target groups, program contents, application and duration, effect sizes and context factors. While the methodological quality of the review articles is quite high, the quality of individual trials (even those included in the review papers) is highly variable. While most trials examining preventive interventions addressed at individuals satisfy at least some methodological requirements many studies dealing with setting interventions do not.
Conclusions
In conclusion, sound scientific evidence for the effectiveness and cost-effectiveness of back pain prevention in the workplace environment is still quite scarce. Further research should include:
The development of interventions guided by the bio psychosocial model of back pain aetiology that combines individual prevention as well as measures addressing the workplace environment.The integration of results from basic ergonomic research into prevention concepts and the conduct of trials focussing outcomes with relevance to health.at the workplace setting. The conduct of qualitative studies to identify factors that impair the effectiveness of prevention programs (e. g. motivation, compliance, people skills).The integration of cost-effectiveness evaluations into all interventional studies.
PMCID: PMC3011361  PMID: 21289963
23.  Activity restriction in mild COPD: a challenging clinical problem 
Dyspnea, exercise intolerance, and activity restriction are already apparent in mild chronic obstructive pulmonary disease (COPD). However, patients may not seek medical help until their symptoms become troublesome and persistent and significant respiratory impairment is already present; as a consequence, further sustained physical inactivity may contribute to disease progression. Ventilatory and gas exchange impairment, cardiac dysfunction, and skeletal muscle dysfunction are present to a variable degree in patients with mild COPD, and collectively may contribute to exercise intolerance. As such, there is increasing interest in evaluating exercise tolerance and physical activity in symptomatic patients with COPD who have mild airway obstruction, as defined by spirometry. Simple questionnaires, eg, the modified British Medical Research Council dyspnea scale and the COPD Assessment Test, or exercise tests, eg, the 6-minute or incremental and endurance exercise tests can be used to assess exercise performance and functional status. Pedometers and accelerometers are used to evaluate physical activity, and endurance tests (cycle or treadmill) using constant work rate protocols are used to assess the effects of interventions such as pulmonary rehabilitation. In addition, alternative outcome measurements, such as tests of small airway dysfunction and laboratory-based exercise tests, are used to measure the extent of physiological impairment in individuals with persistent dyspnea. This review describes the mechanisms of exercise limitation in patients with mild COPD and the interventions that can potentially improve exercise tolerance. Also discussed are the benefits of pulmonary rehabilitation and the potential role of pharmacologic treatment in symptomatic patients with mild COPD.
doi:10.2147/COPD.S62766
PMCID: PMC4051517  PMID: 24940054
chronic obstructive pulmonary disease (COPD); small airway dysfunction; dyspnea; physical activity; exercise
24.  Design of the Resistance and Endurance exercise After ChemoTherapy (REACT) study: A randomized controlled trial to evaluate the effectiveness and cost-effectiveness of exercise interventions after chemotherapy on physical fitness and fatigue 
BMC Cancer  2010;10:658.
Background
Preliminary studies suggest that physical exercise interventions can improve physical fitness, fatigue and quality of life in cancer patients after completion of chemotherapy. Additional research is needed to rigorously test the effects of exercise programmes among cancer patients and to determine optimal training intensity accordingly. The present paper presents the design of a randomized controlled trial evaluating the effectiveness and cost-effectiveness of a high intensity exercise programme compared to a low-to-moderate intensity exercise programme and a waiting list control group on physical fitness and fatigue as primary outcomes.
Methods
After baseline measurements, cancer patients who completed chemotherapy are randomly assigned to either a 12-week high intensity exercise programme or a low-to-moderate intensity exercise programme. Next, patients from both groups are randomly assigned to immediate training or a waiting list (i.e. waiting list control group). After 12 weeks, patients of the waiting list control group start with the exercise programme they have been allocated to.
Both interventions consist of equal bouts of resistance and endurance interval exercises with the same frequency and duration, but differ in training intensity. Additionally, patients of both exercise programmes are counselled to improve compliance and achieve and maintain an active lifestyle, tailored to their individual preferences and capabilities.
Measurements will be performed at baseline (t = 0), 12 weeks after randomization (t = 1), and 64 weeks after randomization (t = 2). The primary outcome measures are cardiorespiratory fitness and muscle strength assessed by means of objective performance indicators, and self-reported fatigue. Secondary outcome measures include health-related quality of life, self-reported physical activity, daily functioning, body composition, mood and sleep disturbances, and return to work. In addition, compliance and satisfaction with the interventions will be evaluated. Potential moderation by pre- and post-illness lifestyle, health and exercise-related attitudes, beliefs and motivation will also be assessed. Finally, the cost-effectiveness of both exercise interventions will be evaluated.
Discussion
This randomized controlled trial will be a rigorous test of effects of exercise programmes for cancer patients after chemotherapy, aiming to contribute to evidence-based practice in cancer rehabilitation programmes.
Trial registration
This study is registered at the Netherlands Trial Register (NTR2153)
doi:10.1186/1471-2407-10-658
PMCID: PMC3009679  PMID: 21118564
25.  Physical Exercise as a Preventive or Disease-Modifying Treatment of Dementia and Brain Aging 
Mayo Clinic Proceedings  2011;86(9):876-884.
A rapidly growing literature strongly suggests that exercise, specifically aerobic exercise, may attenuate cognitive impairment and reduce dementia risk. We used PubMed (keywords exercise and cognition) and manuscript bibliographies to examine the published evidence of a cognitive neuroprotective effect of exercise. Meta-analyses of prospective studies documented a significantly reduced risk of dementia associated with midlife exercise; similarly, midlife exercise significantly reduced later risks of mild cognitive impairment in several studies. Among patients with dementia or mild cognitive impairment, randomized controlled trials (RCTs) documented better cognitive scores after 6 to 12 months of exercise compared with sedentary controls. Meta-analyses of RCTs of aerobic exercise in healthy adults were also associated with significantly improved cognitive scores. One year of aerobic exercise in a large RCT of seniors was associated with significantly larger hippocampal volumes and better spatial memory; other RCTs in seniors documented attenuation of age-related gray matter volume loss with aerobic exercise. Cross-sectional studies similarly reported significantly larger hippocampal or gray matter volumes among physically fit seniors compared with unfit seniors. Brain cognitive networks studied with functional magnetic resonance imaging display improved connectivity after 6 to 12 months of exercise. Animal studies indicate that exercise facilitates neuroplasticity via a variety of biomechanisms, with improved learning outcomes. Induction of brain neurotrophic factors by exercise has been confirmed in multiple animal studies, with indirect evidence for this process in humans. Besides a brain neuroprotective effect, physical exercise may also attenuate cognitive decline via mitigation of cerebrovascular risk, including the contribution of small vessel disease to dementia. Exercise should not be overlooked as an important therapeutic strategy.
doi:10.4065/mcp.2011.0252
PMCID: PMC3258000  PMID: 21878600

Results 1-25 (1291449)