Dual sensory impairment in older adults and risk of dementia from the GEM Study

mHealth Apps for Dementia, Alzheimer Disease, and Other Neurocognitive Disorders: Systematic Search and Environmental Scan

BACKGROUND

Lifestyle behaviors including exercise, sleep, diet, stress, mental stimulation, and social interaction significantly impact the likelihood of developing dementia. Mobile health (mHealth) apps have been valuable tools in addressing these lifestyle behaviors for general health and well-being, and there is growing recognition of their potential use for brain health and dementia prevention. Effective apps must be evidence-based and safeguard user data, addressing gaps in the current state of dementia-related mHealth apps.

OBJECTIVE

This study aims to describe the scope of available apps for dementia prevention and risk factors, highlighting gaps and suggesting a path forward for future development.

METHODS

A systematic search of mobile app stores, peer-reviewed literature, dementia and Alzheimer association websites, and browser searches was conducted from October 19, 2022, to November 2, 2022. A total of 1044 mHealth apps were retrieved. After screening, 152 apps met the inclusion criteria and were coded by paired, independent reviewers using an extraction framework. The framework was adapted from the Silberg scale, other scoping reviews of mHealth apps for similar populations, and background research on modifiable dementia risk factors. Coded elements included evidence-based and expert credibility, app features, lifestyle elements of focus, and privacy and security.

RESULTS

Of the 152 apps that met the final selection criteria, 88 (57.9%) addressed modifiable lifestyle behaviors associated with reducing dementia risk. However, many of these apps (59/152, 38.8%) only addressed one lifestyle behavior, with mental stimulation being the most frequently addressed. More than half (84/152, 55.2%) scored 2 points out of 9 on the Silberg scale, with a mean score of 2.4 (SD 1.0) points. Most of the 152 apps did not disclose essential information: 120 (78.9%) did not disclose expert consultation, 125 (82.2%) did not disclose evidence-based information, 146 (96.1%) did not disclose author credentials, and 134 (88.2%) did not disclose their information sources. In addition, 105 (69.2%) apps did not disclose adherence to data privacy and security practices.

CONCLUSIONS

There is an opportunity for mHealth apps to support individuals in engaging in behaviors linked to reducing dementia risk. While there is a market for these products, there is a lack of dementia-related apps focused on multiple lifestyle behaviors. Gaps in the rigor of app development regarding evidence base, credibility, and adherence to data privacy and security standards must be addressed. Following established and validated guidelines will be necessary for dementia-related apps to be effective and advance successfully.

Interventions to improve social network in older people with sensory impairment: a systematic review

BACKGROUND

Sensory impairment significantly reduces speech discrimination and perception ability, presenting a challenge to effective communication. It can lead to social withdrawal and a reduced social network which can lead to cognitive impairment, seriously affecting the quality of life of older people. However, it is unclear which intervention components are effective to improving social network in older people with sensory impairment.

OBJECTIVE

The aim of this systematic review was to summarize interventions designed to improve social network in older people with sensory impairment.

METHODS

We searched seven databases from inception to December 1, 2023. Eligible studies included randomized clinical trials (RCT) and quasi-experimental studies of interventions for older people with sensory impairment aimed at improving social networks. Two reviewers searched databases, extracted data, and assessed the quality of the included studies independently.

RESULTS

Nine studies including five RCTs and four quasi-experimental studies were selected, enrolling 721 older people with sensory impairment. Methodological quality of the studies was modest. Eight studies demonstrated a positive impact of the interventions used in older people with sensory impairment. The detailed effective intervention components may include communication strategies, resources for older people and their significant others, exercise or tech-back of communication, sensory device fitting, and use and maintenance of sensory devices.

CONCLUSION

There are few interventions available for improving social network in older people with sensory impairment. Most interventions mainly focus on communication education and care, and sensory device fitting and education. To improve the social network in older people with sensory impairment, it is necessary to develop more effective, multidisciplinary collaborative effective interventions and conduct more high-quality original studies.

Sensory impairment and beta-amyloid deposition in the Baltimore longitudinal study of aging

Introduction

Beta-amyloid (Aβ) plaque deposition is a biomarker of preclinical Alzheimer's disease (AD). Impairments in sensory function are associated with cognitive decline. We sought to investigate the relationship between PET-indicated Aβ deposition and sensory impairment.

Methods

Using data from 174 participants ≥55 years in the Baltimore Longitudinal Study of Aging, we analyzed associations between sensory impairments and Aβ deposition measured by PET and Pittsburgh Compound B (PiB) mean cortical distribution volume ratio (cDVR).

Results

The combinations of hearing and proprioceptive impairment and hearing, vision, and proprioceptive impairment, were positively correlated with cDVR (β = 0.087 and p = 0.036, β = 0.110 and p = 0.018, respectively). In stratified analyses of PiB+ participants, combinations of two, three, and four sensory impairments (all involving proprioception) were associated with higher cDVR.

Discussion

Our findings suggest a relationship between multi-sensory impairment (notably proprioceptive impairment) and Aβ deposition, which could reflect sensory impairment as an indicator or potentially a risk factor for Aβ deposition.

Sensory impairment and algorithmic classification of early cognitive impairment

INTRODUCTION

Sensory impairment (SI) is linked to cognitive decline, but its association with early cognitive impairment (ECI) is unclear.

METHODS

Sensory functions (vision, hearing, vestibular function, proprioception, and olfaction) were measured between 2012 and 2018 in 414 Baltimore Longitudinal Study of Aging (BLSA) participants (age 74 ± 9 years; 55% women). ECI was defined as 1 standard deviation below age-, sex-, race-, and education-specific mean performance in Card Rotations or California Verbal Learning Test immediate recall. Log binomial models (cross-sectional analysis) and Cox regression models (time-to-event analysis) were used to examine the association between SI and ECI.

RESULTS

Cross-sectionally, participants with ≥3 SI had twice the prevalence of ECI (prevalence ratio = 2.10, p = 0.02). Longitudinally, there was no significant association between SI and incident ECI over up to 6 years of follow-up.

DISCUSSION

SI is associated with higher prevalence, but not incident ECI. Future studies with large sample sizes need to further elucidate the relationship between SI and ECI.

Highlights

Sensory impairment is associated with high prevalence of early cognitive impairmentMultisensory impairment may pose a strong risk of early changes in cognitive functionIdentifying multisensory impairment may help early detection of dementia.

Associations between physical activity and cognitive dysfunction in older companion dogs: results from the Dog Aging Project

Canine cognitive dysfunction (CCD) is a form of dementia that shares many similarities with Alzheimer's disease. Given that physical activity is believed to reduce risk of Alzheimer's disease in humans, we explored the association between physical activity and cognitive health in a cohort of companion dogs, aged 6-18 years. We hypothesized that higher levels of physical activity would be associated with lower (i.e., better) scores on a cognitive dysfunction rating instrument and lower prevalence of dementia, and that this association would be robust when controlling for age, comorbidities, and other potential confounders. Our sample included 11,574 companion dogs enrolled through the Dog Aging Project, of whom 287 had scores over the clinical threshold for CCD. In this observational, cross-sectional study, we used owner-reported questionnaire data to quantify dog cognitive health (via a validated scale), physical activity levels, health conditions, training history, and dietary supplements. We fit regression models with measures of cognitive health as the outcome, and physical activity-with several important covariates-as predictors. We found a significant negative relationship between physical activity and current severity of cognitive dysfunction symptoms (estimate =  - 0.10, 95% CI: - 0.11 to - 0.08, p < 0.001), extent of symptom worsening over a 6-month interval (estimate =  - 0.07, 95% CI: - 0.09 to - 0.05, p < 0.001), and whether a dog reached a clinical level of CCD (odds ratio = 0.53, 95% CI: 0.45 to 0.63, p < 0.001). Physical activity was robustly associated with better cognitive outcomes in dogs. Our findings illustrate the value of companion dogs as a model for investigating relationships between physical activity and cognitive aging, including aspects of dementia that may have translational potential for Alzheimer's disease. While the current study represents an important first step in identifying a relationship between physical activity and cognitive function, it cannot determine causality. Future studies are needed to rule out reverse causation by following the same dogs prospectively over time, and to evaluate causality by administering physical activity interventions.

Evaluation of cognitive function in the Dog Aging Project: associations with baseline canine characteristics

Canine cognitive dysfunction (CCD) is a neurodegenerative disease in aging dogs. It has been described previously in relatively small cohorts of dogs using multiple different rating scales. This study aimed to use a minimally modified CCD rating scale developed by previous researchers to describe the prevalence of CCD more thoroughly in a large, nationwide cohort of companion dogs participating in the Dog Aging Project (DAP) (n = 15,019). Associations between various canine characteristics, predicted lifespan quartiles, and CCD were examined using univariable and multivariable logistic regression models and receiver operating curve (ROC) analysis. When controlling for all other characteristics, the odds of CCD increased 52% with each additional year of age. Among dogs of the same age, health status, breed type, and sterilization status, odds of CCD were 6.47 times higher in dogs who were not active compared to those who were very active. When controlling for age, breed type, activity level, and other comorbidities, dogs with a history of neurological, eye, or ear disorders had higher odds of CCD. Lifespan quartile analysis showed excellent discriminating ability between CCD positive and negative dogs. Weight-based lifespan quartile estimation could therefore serve as a tool to inform CCD screening by veterinarians.

Association of Visual, Hearing, and Dual Sensory Impairment With Incident Dementia

Introduction

The relationship between sensory impairments and the risk of dementia is inconclusive. We aim to investigate the association of visual impairment (VI), hearing impairment (HI), and dual sensory impairment (DSI) with incident dementia.

Methods

The UK Biobank study recruited more than 500,000 participants aged 40-69 years across the United Kingdom. Participants with available visual acuity (VA) measurements and speech-reception-threshold (SRT) information and free of dementia at the baseline assessment were included in the analysis. VI was defined as VA worse than 0.3 LogMAR units and HI were defined as an SRT of -5.5 dB or over. DSI was defined as the presence of both VI and HI. Incident dementia was identified through linked data to primary care or hospital admission records and death registries. Multivariable Cox proportional hazard regression models were used to examine the association of VI, HI, and DSI with incident dementia.

Results

Among 113,511 participants (mean age: 56.8 ± 8.09 years, female: 54.4%), a total number of 1,135 (1.00%) cases of incident dementia were identified during a median follow up period of 11.1 years [interquartile range (IQR): 10.9-11.4 years]. The incidence of dementia showed significant differences among the non-sensory impairment (NSI) group, VI-only group, HI-only group, and DSI group (p < 0.001). After adjusting for demographic, lifestyle, health, and genetic factors, isolated VI (HR = 1.50, 95% CI: 1.06-2.12, p = 0.023), isolated HI (HR = 1.42, 95% CI:1.20-1.69, p < 0.001), and DSI (HR = 1.82, 95% CI: 1.10-3.00, p = 0.020) were independently associated with higher risks of incident dementia.

Conclusions

Visual, hearing, and dual sensory impairments were associated with an increased risk of developing dementia, suggesting that visual and hearing impairments are modifiable risk factors that can be targeted to prevent dementia.

Current Alzheimer disease research highlights: evidence for novel risk factors

Alzheimer disease (AD) is the most common type of dementia characterized by the progressive cognitive and social decline. Clinical drug targets have heavily focused on the amyloid hypothesis, with amyloid beta (Aβ), and tau proteins as key pathophysiologic markers of AD. However, no effective treatment has been developed so far, which prompts researchers to focus on other aspects of AD beyond Aβ, and tau proteins. Additionally, there is a mounting epidemiologic evidence that various environmental factors influence the development of dementia and that dementia etiology is likely heterogenous. In the past decades, new risk factors or potential etiologies have been widely studied. Here, we review several novel epidemiologic and clinical research developments that focus on sleep, hypoxia, diet, gut microbiota, and hearing impairment and their links to AD published in recent years. At the frontiers of AD research, these findings and updates could be worthy of further attention.

Prevalence, Associated Factors and Health-related Quality of Life of Dual Sensory Impairment in Residential Care Facilities in Singapore

Purpose: To investigate the prevalence of dual sensory impairment (DSI), its associated factors and relationship with health-related quality of life (HR-QoL) in residential care facilities (RCF) in Singapore.Methods: This was a cross-sectional study of 123 residents aged ≥40 years from six RCFs, conducted between 2016 and 2018. DSI was defined as concomitant presenting visual acuity (better-eye) >0.3 logarithm of the minimum angle of resolution and a pure-tone air conduction threshold (better-ear) >40 dB HL in any of the four tested frequencies (500, 1000, 2000 and 4000 Hz). HR-QoL was quantified using the EuroQol five-dimension questionnaire. Multivariable Poisson regression was used to determine the associated factors of DSI. Multivariable linear regression was used to determine the association between DSI and HR-QoL adjusted for traditional confounders.Results: Of the 123 residents (age [mean±standard deviation] 75.3 ± 10.8 years; 56.9% male), 97 (78.9%[95% confidence interval(CI):71.6%, 86.1%]) had DSI, with 110 (98.2%) not on follow-up care for their sensory disabilities. In multivariable models, male gender (prevalence ratio(PR) [95%CI] = 1.3[1.1, 1.6]), older age (per 10-year increase (1.2[1.1, 1.3])), education ≤6 years (1.3[1.1, 1.7]) and the presence of cataract (1.3[1.0, 1.7]) were independently associated with DSI. DSI was independently associated with a substantial worsening in HR-QoL (β = -0.61; 95%CI: -0.76, -0.45; p < .001).Conclusions: DSI affects four in five residential care residents and is substantially associated with reductions in HR-QoL in these residents. Our finding highlights an urgent need for the implementation of routine vision and hearing screening and follow-up care for residents living in these facilities.