Lifestyle factors and Alzheimer-type dementia: the link between exercise and cognitive change

Alzheimer’s disease (AD) is a neurodegenerative disorder that results in cognitive and functional impairment. Current pharmacological treatments have limited effect on correcting cognitive deficits. However, there is a growing amount of literature to suggest that lifestyle factors, such as physical activity, may have a positive effect on cognitive function for people with AD. Through a series of four articles I have addressed methodological short-comings in the existing literature, and determined, through collection and analysis of data in a longitudinal cohort study, the impact of lifestyle factors on cognitive performance in AD. Article I systematically reviews previous physical activity intervention trials and their effects on cognition in an AD population. Physical activity interventions were found to have a moderately positive effect on global cognition. However, the review highlights the apparent heterogeneity between intervention trials as well as the lack of domain specific cognitive outcome measures. Article II focuses on the importance of sensitive measures of cognition in an AD population. Comparing people with AD and age-matched control volunteers, measures of prospective memory were shown to decline with age in the AD volunteers. Significantly, the cost of carrying a PM intention, a measure of working memory, did not exhibit an age related decline and did not differ compared to cognitively healthy controls. Article III explores whether habitual physical activity, is significantly associated with cognitive outcome on a composite measures of executive function. Habitual physical activity significantly accounted for variance (8%) on executive function even after controlling for covariates. Article IV investigates the contribution of habitual physical activity to executive function change in AD over a year. Habitual physical activity was found to be associated with executive function change. These articles contribute in the understanding of the association between habitual physical activity and cognitive function in an AD population

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, 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 (QUEST). Participants were generally satisfied with most aspects of the devices, though were significantly more satisfied with the Misfit Shine. Participants were critical about their ability to adjust 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 monitor is best suited for older adults

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<0.001). 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

Use of physical activity questionnaires in people with dementia: a scoping review

Physical activity questionnaires are an important means to assess habitual physical activity. It remains unclear what questionnaires are used and whether they are appropriate for people with dementia who have impaired information recall but are also often largely sedentary. This scoping review aimed to identify and quantify the use of physical activity questionnaires within a dementia population. Eighteen studies met the inclusion criteria for this review. The majority of studies used questionnaires that were validated for use within an older adult population (e.g., Modified Baecke Questionnaire for the Elderly), though none had specifically been validated for use in people with dementia. Interestingly, just over half of studies (N= 10, 55.6%) adapted the questionnaires from the original validated version by allowing a proxy to provide input into the responses. Future research needs to robustly validate the use of proxy-report measures of physical activity in people with dementia

Dementia awareness, beliefs and barriers among family caregivers in Pakistan

OBJECTIVES: Dementia research and services in Pakistan are limited. The following was explored in experiences of family caregivers of people with dementia in Pakistan: a) to determine whether culture and religion play a role in caregiving; b) to draw insights on how family caregivers cope, what barriers they face, and what help they would be willing to accept; and c) to determine how these findings could be used to raise awareness and influence public policies in improving the lives of families living with dementia. METHODS: The experiences of family caregivers of people with dementia in Pakistan were explored via semi-structured interviews (10 in Lahore; 10 in Karachi). This was part of a larger qualitative study conducted about dementia in Pakistan. Caregivers interviewed were aged 35-80 (14 female). Most caregivers in the study were educated and affluent. Interviews were conducted in Urdu, translated into English and thematically analysed. RESULTS: Five themes emerged: Knowledge & Awareness; Stigma; Importance of Religion and Duty to Care; Use of Day Care Centres and Home-help; and Barriers. A lack of dementia awareness exists in Pakistan. The religious duty to care for family influenced caregiving decisions. Day care centres and home-help were accessed and viewed positively. The caregivers also wanted extracurricular activities for people with dementia, support groups for caregivers, and better training for healthcare staff. Novel findings included that caregivers felt that dementia should not be stigmatized, and awareness should be raised in Pakistan via TV, radio and social media, but not inside mosques. DISCUSSION: Additional research is necessary to determine if positive views of day care centres and home-help exist more widely. Attitudes and experiences regarding stigma may be different for caregivers of people with more advanced dementia. We recommend raising dementia awareness, allocating more funds to dementia services, and an emphasis on home-based care

Homocysteine concentrations in the cognitive progression of Alzheimer’s disease

Objectives: Hyperhomocysteinemia in Alzheimer’s 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. Spearman’s 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

Adaptive Basis Scan by Wavelet Prediction for Single-Pixel Imaging

International audienceSingle pixel camera imaging is an emerging paradigm that allows high-quality images to be provided by a device only equipped with a single point detector. A single pixel camera is an experimental setup able to measure the inner product of the scene under view –the image– with any user-defined pattern. Post-processing a sequence of point measurements obtained with different patterns permits to recover spatial information, as it has been demonstrated by state-of-the art approaches belonging to the compressed sensing framework. In this paper, a new framework for the choice of the patterns is proposed together with a simple and efficient image recovery scheme. Our goal is to overcome the computationally demanding 1-minimization of compressed sensing. We propose to choose patterns among a wavelet basis in an adaptive fashion, which essentially relies onto the prediction of the significant wavelet coefficients' location. More precisely, we adopt a multiresolution strategy that exploits the set of measurements acquired at coarse scales to predict the set of measurements to be performed at a finer scale. Prediction is based on a fast cubic interpolation in the image domain. A general formalism is given so that any kind of wavelets can be used, which enables one to adjust the wavelet to the type of images related to the desired application. Both simulated and experimental results demonstrate the ability of our technique to reconstruct biomedical images with improved quality compared to CS-based recovery. Application to real-time fluorescence imaging of biological tissues could benefit from the proposed method

Adaptation of the DEMQOL-Proxy for routine use in care homes: a cross sectional study of the reliability and validity of DEMQOL-CH

Objective: To investigate the routine use of a measure of quality of life (QoL) in care homes and assess its psychometric properties when used by care staff Design: A cross-sectional two-phase study. Setting and participants: Data were collected from care staff in seven care homes in East Sussex, England. Method: Phase 1: The ability of care staff from two care homes to use the DEMQOL-Proxy without interviewer-administration was assessed using agreement analysis between a selfand interviewer-administered version of the instrument. Based on these findings, DEMQOLProxy was adapted into a new version, DEMQOL-CH, for use as a self-administered instrument in care homes. We assessed agreement between the new DEMQOL-CH and DEMQOL-Proxy to ensure DEMQOL-CH was used correctly. Phase 2: A preliminary assessment of the psychometric properties of DEMQOL-CH when used routinely was completed in a further five care homes. Results: Phase 1: Nineteen care staff from two care homes completed QoL measurements for residents. Systematic error was identified when staff self-completed the DEMQOL-Proxy without an interviewer. We modified the DEMQOL-Proxy to create DEMQOL-CH; this reduced the error, producing a version that could be used more accurately by care staff. Phase 2: Eleven care staff from five care homes rated resident QoL routinely. DEMQOL-CH showed acceptable psychometric properties with satisfactory reliability and validity and a clear factor structure. Conclusions: The research presents positive preliminary data on the acceptability, feasibility and performance of routine QoL measurement in care homes using an adapted version of DEMQOL-Proxy, the DEMQOL-CH. Results provide evidence to support the concept that routine measurement of QoL may be possible in care homes. Research is needed to refine and test the methodology and instrument further, and to explore the potential for benefits to residents, staff, and care homes in larger and more representative populations

Psychometric properties and feasibility of use of dementia specific quality of life instruments for use in care settings: a systematic review

Background: Over 400,000 people live in care home settings in the UK. One way of understanding and improving the quality of care provided is by measuring and understanding the quality of life (QoL) of those living in care homes. This review aimed to identify and examine the psychometric properties including feasibility of use of dementia-specific QoL measures developed or validated for use in care settings. Design: Systematic review. Methods: Instruments were identified using four electronic databases (PubMed, PsycINFO, Web of Science, and CINAHL) and lateral search techniques. Searches were conducted in January 2017. Studies which reported on the development and/or validation of dementia specific QoL instruments for use in care settings written in English were eligible for inclusion. The methodological quality of the studies was assessed using the COSMIN checklist. Feasibility was assessed using a checklist developed specifically for the review. Results: Six hundred and sixteen articles were identified in the initial search. After de-duplication, screening and further lateral searches were performed, 25 studies reporting on 9 dementia-specific QoL instruments for use in care home settings were included in the review. Limited evidence was available on the psychometric properties of many instruments identified. Higher-quality instruments were not easily accessible or had low feasibility of use. Conclusions: Few high-quality instruments of QoL validated for use in care home settings are readily or freely available. This review highlights the need to develop a well-validated measure of QoL for use within care homes that is also feasible and accessible

Vitamin E for Alzheimer's dementia and mild cognitive impairment

Background Vitamin E occurs naturally in the diet. It has several biological activities, including functioning as an antioxidant to scavenge toxic free radicals. Evidence that free radicals may contribute to the pathological processes behind cognitive impairment has led to interest in the use of vitamin E supplements to treat mild cognitive impairment (MCI) and Alzheimer's disease (AD). This is an update of a Cochrane Review first published in 2000, and previously updated in 2006 and 2012. Objectives To assess the efficacy of vitamin E in the treatment of MCI and dementia due to AD. Search methods We searched the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (ALOIS), the Cochrane Library, MEDLINE, Embase, PsycINFO, CINAHL, LILACS as well as many trials databases and grey literature sources on 22 April 2016 using the terms: "Vitamin E", vitamin‐E, alpha‐tocopherol. Selection criteria We included all double‐blind, randomised trials in which treatment with any dose of vitamin E was compared with placebo in people with AD or MCI. Data collection and analysis We used standard methodological procedures according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the quality of the evidence using the GRADE approach. Where appropriate we attempted to contact authors to obtain missing information. Main results Four trials met the inclusion criteria, but we could only extract outcome data in accordance with our protocol from two trials, one in an AD population (n = 304) and one in an MCI population (n = 516). Both trials had an overall low to unclear risk of bias. It was not possible to pool data across studies owing to a lack of comparable outcome measures. In people with AD, we found no evidence of any clinically important effect of vitamin E on cognition, measured with change from baseline in the Alzheimer's Disease Assessment Scale ‐ Cognitive subscale (ADAS‐Cog) over six to 48 months (mean difference (MD) ‐1.81, 95% confidence interval (CI) ‐3.75 to 0.13, P = 0.07, 1 study, n = 272; moderate quality evidence). There was no evidence of a difference between vitamin E and placebo groups in the risk of experiencing at least one serious adverse event over six to 48 months (risk ratio (RR) 0.86, 95% CI 0.71 to 1.05, P = 0.13, 1 study, n = 304; moderate quality evidence), or in the risk of death (RR 0.84, 95% CI 0.52 to 1.34, P = 0.46, 1 study, n = 304; moderate quality evidence). People with AD receiving vitamin E showed less functional decline on the Alzheimer's Disease Cooperative Study/Activities of Daily Living Inventory than people receiving placebo at six to 48 months (mean difference (MD) 3.15, 95% CI 0.07 to 6.23, P = 0.04, 1 study, n = 280; moderate quality evidence). There was no evidence of any clinically important effect on neuropsychiatric symptoms measured with the Neuropsychiatric Inventory (MD ‐1.47, 95% CI ‐4.26 to 1.32, P = 0.30, 1 study, n = 280; moderate quality evidence). We found no evidence that vitamin E affected the probability of progression from MCI to probable dementia due to AD over 36 months (RR 1.03, 95% CI 0.79 to 1.35, P = 0.81, 1 study, n = 516; moderate quality evidence). Five deaths occurred in each of the vitamin E and placebo groups over the 36 months (RR 1.01, 95% CI 0.30 to 3.44, P = 0.99, 1 study, n = 516; moderate quality evidence). We were unable to extract data in accordance with the review protocol for other outcomes. However, the study authors found no evidence that vitamin E differed from placebo in its effect on cognitive function, global severity or activities of daily living . There was also no evidence of a difference between groups in the more commonly reported adverse events. Authors' conclusions We found no evidence that the alpha‐tocopherol form of vitamin E given to people with MCI prevents progression to dementia, or that it improves cognitive function in people with MCI or dementia due to AD. However, there is moderate quality evidence from a single study that it may slow functional decline in AD. Vitamin E was not associated with an increased risk of serious adverse events or mortality in the trials in this review. These conclusions have changed since the previous update, however they are still based on small numbers of trials and participants and further research is quite likely to affect the results