Nicolas Farina

The effect of exercise interventions on cognitive outcome in Alzheimer's disease: a systematic review

BACKGROUND Non-pharmacological interventions may have a role in both the prevention and slowing down of disease progression in Alzheimers disease (AD). The role of exercise in disease prevention, for example, has been extensively evaluated in large epidemiological studies. Much less is known about the potential benefit of exercise in patients already diagnosed with AD. It was therefore the aim of this systematic review to assess the effectiveness of exercise in attenuating cognitive decline within AD. METHOD A systematic review was conducted statistically accompanied by a meta-analysis. Publications between January 1991 and October 2012 were identified by searching the electronic databases PubMed, Science Direct, Web of Knowledge, and PsychINFO. Selected studies required AD patients to take part in an exercise-based randomized controlled trial (RCT) and have a cognitive outcome measure. RESULTS Six RCTs were identified that exclusively considered the effect of exercise in AD patients. Exercise generally had a positive effect on rate of cognitive decline in AD. A meta-analysis found that exercise interventions have a positive effect on global cognitive function, 0.75 (95% CI = 0.32-1.17). CONCLUSIONS From the six studies reviewed, the evidence suggests that exercise can have a positive effect on rate of cognitive decline in AD. However, the variation between study designs makes conclusions regarding the optimum intervention on cognitive outcome in AD difficult. Well-designed and powered RCTs are still needed to ascertain the efficacy of exercise in slowing down cognitive impairment in AD patients. However, a positive initial indication for exercise efficacy justifies such efforts.

Factors associated with the quality of life of family carers of people with dementia: A systematic review

Family carers of people with dementia are their most important support in practical, personal, and economic terms. Carers are vital to maintaining the quality of life (QOL) of people with dementia. This review aims to identify factors related to the QOL of family carers of people with dementia.

Prospective memory in Alzheimer-type dementia: exploring prospective memory performance in an age-stratified sample.

Prospective memory (PM), the memory for future intentions, is an essential component of many day-to-day activities. PM accuracy has consistently been found to decline as a function of age and is further impaired in Alzheimer’s disease (AD). In the present study, subjective PM failures, PM accuracy, and cost of carrying a PM were recorded in 42 healthy elderly, 34 younger old, and 45 older old AD participants. It was found that PM deficits across the AD cohort did not change as a function of age. In addition, while PM accuracy was impaired compared to age-matched controls, cost of carrying a PM intention did not differ across the three groups. Evidence that AD participants show a reaction time (RT) cost of PM intention alongside an impaired PM accuracy indicates that the PM intention is held, but is not implemented effectively. The fact that the cost is independent of age and dementia suggests that it may not index working memory (WM) resource. At a practical level, the study suggests that for a comprehensive evaluation of PM competence cost of carrying a PM intention should be measured alongside PM accuracy.

The Validity of Consumer-Level Activity Monitors in Healthy Older Adults in Free-Living Conditions

Consumer-level activity monitors, such as Fitbit and Misfit devices, are a popular and low-cost means of measuring physical activity. This study aims to compare the accuracy of step counts from two consumer-level activity monitors against two reference devices in healthy, community-dwelling older adults in free-living conditions. Twenty-five older adults (aged 65-84) simultaneously wore 5 devices (e.g., Misfit Shine and Fitbit Charge HR) over 7 consecutive days. All consumer-level activity monitors positively correlated with reference devices (p < .001). There was also substantial to near perfect agreement between all consumer-level activity monitors and reference devices. Compared to the ActiGraph GT3X+, the waist-worn Misfit Shine displayed the highest agreement amongst the devices worn (ICC = 0.96, 95% 0.91 to 0.99). The wrist-worn devices showed poorer agreement to reference devices. Future research needs to consider that not all consumer-level activity monitors are equal in terms of accuracy, design, and function.

What is the therapeutic value of antidepressants in dementia? A narrative review

Antidepressants are commonly used in dementia. Depression is a frequent and important co‐morbidity in dementia, and antidepressants are often used to treat depression and more widely. However, there are questions about their utility in depression in dementia and other behavioural and psychological symptoms of dementia. The aim of this narrative review is to summarize the evidence on whether there is therapeutic value in prescribing antidepressants to people with dementia.

The relationship between habitual physical activity status and executive function in individuals with Alzheimer’s disease: a longitudinal, cross-lagged panel analysis

Abstract To determine whether habitual physical activity status specifically influences executive function change in Alzheimer’s disease (AD) over 1 year. In this longitudinal cohort study, 45 participants with AD were recruited and provided follow-up data approximately 1 year later. Executive function measures (map search task, digit symbol substitution task, controlled oral word association task, verbal fluency task) and habitual physical activity measures (Physical Activity Scale for the Elderly (PASE) and handgrip strength) were taken at baseline and follow-up. Individual composites were subsequently created. Additional demographic, lifestyle, and neuropsychiatric measures were also taken. In a structural equation model (χ2(26) = 9.84, p = .998, comparative fit index = 1.00, root mean square error of approximation = .00), a significant association was found between habitual physical activity and executive function change (β = .27, p = .04). In a cross-lagged panel analysis, a significant path was found between the PASE score and executive change (β = .22, p = .01). As higher habitual physical activity levels were associated with reduced executive function change, the promotion of low-intensity habitual physical activities in individuals with a diagnosis of AD may be warranted. Further research is needed, however, to explore the impact of habitual physical activity on the trajectory of change across cognitive domains, and how this relates to the progression of the underlying pathology associated with this disease.

MODEM: A comprehensive approach to modelling outcome and costs impacts of interventions for dementia. Protocol paper

BackgroundThe MODEM project (A comprehensive approach to MODelling outcome and costs impacts of interventions for DEMentia) explores how changes in arrangements for the future treatment and care of people living with dementia, and support for family and other unpaid carers, could result in better outcomes and more efficient use of resources.MethodsMODEM starts with a systematic mapping of the literature on effective and (potentially) cost-effective interventions in dementia care. Those findings, as well as data from a cohort, will then be used to model the quality of life and cost impacts of making these evidence-based interventions more widely available in England over the period from now to 2040. Modelling will use a suite of models, combining microsimulation and macrosimulation methods, modelling the costs and outcomes of care, both for an individual over the life-course from the point of dementia diagnosis, and for individuals and England as a whole in a particular year.Project outputs will include an online Dementia Evidence Toolkit, making evidence summaries and a literature database available free to anyone, papers in academic journals and other written outputs, and a MODEM Legacy Model, which will enable local commissioners of services to apply the model to their own populations.DiscussionModelling the effects of evidence-based cost-effective interventions and making this information widely available has the potential to improve the health and quality of life both of people with dementia and their carers, while ensuring that resources are used efficiently.

Older adults’ satisfaction of wearing consumer-level activity monitors

There is a growing body of evidence to suggest that consumer-level activity monitors are a valid means of measuring physical activity in older adults. Understanding whether older adults are satisfied with wearing these activity monitors is an important step to ensuring that devices can be successfully implemented in clinical and research settings. Twenty-five older adults (mean age = 72.5 years, standard deviation = 4.9) wore two consumer-level activity monitors (Misfit Shine and Fitbit Charge HR) for seven consecutive days. After the week, participants were asked for their views and satisfaction of wearing each device, measured in part by the Quebec User Evaluation of Satisfaction with assistive Technology. Participants were generally satisfied with most aspects of the devices, though they were significantly more satisfied with the Misfit Shine. Participants were critical about their ability to adjust the fit of both the Misfit Shine and Fitbit Charge HR. Interestingly, the perceived satisfaction with the device was not associated with participants’ consideration of wearing the device again. Future research needs to consider whether the design of consumer-level activity monitors are best suited for older adults.

Knowledge and attitudes towards dementia in adolescent students

Abstract Background: Improving people’s knowledge, perceptions and attitudes of dementia is important in the formation of dementia-friendly communities. However, at present, there is very little evidence from adolescents, who are already the junior members of such communities and will be carers in their own rights in the future. Our aim was to evaluate adolescents’ knowledge and attitudes of dementia. Methods: Four-hundred and fifty adolescents, aged 15–18 years, from schools in Sussex (UK) were invited to complete a series of questions that assessed their dementia knowledge and attitudes. Results: A total of 359 adolescent students completed the questionnaire. Out of 15 questions on dementia knowledge, participants were on average able to answer less than half correctly (M = 6.65, standard deviation = 2.34). Responses to the attitudes questionnaire showed that adolescent students had both positive and negative attitudes toward dementia. Discussion: There is scope for adolescents attending school to improve their dementia knowledge and attitudes. More effort is needed to embed initial dementia understanding in the school curriculum which will improve awareness about dementia at an earlier age and will enhance dementia-friendly communities.

Homocysteine concentrations in the cognitive progression of Alzheimer’s disease

Objectives: Hyperhomocysteinemia in Alzheimers disease (AD) is widely reported and appears to worsen as the disease progresses. While active dietary intervention with vitamins B12 and folate decreases homocysteine blood levels, with promising clinical outcomes in Mild Cognitive Impairment (MCI), this so far has not been replicated in established AD populations. The aim of the study is to explore the relationship between hyperhomocystenemia and relevant vitamins as the disease progresses. Methods: In this longitudinal cohort study, 38 participants with mild to moderate AD were followed for an average period of 13 months. Plasma folate, vitamin B12 and homocysteine concentrations were measured at baseline and at follow‐up. Dietary intake of B vitamins was also measured. Spearmans correlations were conducted by homocysteine and B vitamin status. Results: As expected, cognitive status significantly declined over the follow‐up period and this was paralleled by a significant increase in homocysteine concentrations (p = 0.006). However, during this follow‐up period there was no significant decline in neither dietary intake, nor the corresponding blood concentrations of vitamin B12/folate, with both remaining within normal values. Changes in blood concentrations of B vitamins were not associated with changes in homocysteine levels (p > 0.05). Conclusion: In this study, the increase in homocysteine observed in AD patients as the disease progresses cannot be solely explained by dietary and blood levels of folate and vitamin B12. Other dietary and non‐dietary factors may contribute to hyperhomocysteinemia and its toxic effect in AD, which needs to be explored to optimise timely intervention strategies.