Longitudinal Changes in Hearing and Visual Impairments and Risk of Dementia in Older Adults in the United States

Association of cumulative average sensory impairments with cognitive function and depressive symptoms: Two prospective cohort studies

BACKGROUND

Globally, over 2.2 billion people have a vision impairment and over 1.5 billion live with hearing impairment, which are significant public health concerns given the meaningful impacts on individual and society. We aimed to investigate whether long-term average visual, hearing, and dual sensory impairment was independently associated with cognitive impairment, incident dementia, and incident depressive symptoms.

METHODS

We used data from the Health and Retirement Study (HRS) and the China Health and Retirement Longitudinal Study (CHARLS), two nationally representative and prospective cohorts of community middle aged and older adults. Average sensory impairment was calculated using the area under the curve divided by follow-up time from wave 3 (1996) to wave 15 (2020) in HRS and wave 1 (2011) to wave 4 (2018) in CHARLS. Cox regression models adjusted for multiple covariates were used to estimate adjusted hazard ratios (HRs) and 95 % confidence intervals (95 % CIs).

RESULTS

For each one standard deviation (SD) increment in average visual impairment, the risk of developing cognitive impairment, incident dementia, and incident depressive symptoms increased by 12 %, 34 %, and 39 % in CHARLS and 11 %, 14 % and 10 % in HRS. Similar results were found for each SD increment in average hearing impairment and dual sensory impairment. Nonlinear dose-response relationships were identified between visual impairment and dementia, as well as dual sensory impairment and dementia in both cohorts.

LIMITATIONS

The diagnosis of cognitive impairment, dementia, and depression were based on subjective assessment.

CONCLUSION

Multi-level approaches aimed at improving access to sensory care are needed to improve middle-aged and older adults' visual and auditory functions.

Vision Impairment and the Population Attributable Fraction of Dementia in Older Adults

Importance

Vision impairment is a potentially modifiable risk factor for dementia. Although few prior studies have estimated the contribution of vision impairments to dementia, none have reported on multiple objectively measured vision impairments (eg, distance and near visual acuity and contrast sensitivity) in a nationally representative sample of older adults.

Objective

To quantify population attributable fractions of dementia from objective vision impairments in older adults, stratified by age, self-reported sex, self-reported race and ethnicity, and educational attainment.

Design, Setting, and Participants

This was a population-based cross-sectional analysis in the National Health and Aging Trends Study, which gathers nationally representative information on Medicare beneficiaries aged 65 years and older in the US. A total of 2767 community-dwelling adults eligible for vision and cognitive testing in 2021 were included. Data were analyzed from April to August 2023.

Exposures

Near and distance visual acuity impairments were each defined as >0.30 logMAR. Contrast sensitivity impairment was defined as <1.55 logCS. At least 1 vision impairment was defined as impairment to either near acuity, distance acuity, or contrast sensitivity.

Main Outcomes and Measures

Adjusted population attributable fractions of prevalent dementia, defined using a standardized algorithmic diagnosis (≥1.5 SDs below mean on 1 or more cognitive domains, self- or proxy-reported dementia diagnosis, or the Ascertain Dementia-8 Dementia Screening Interview Score of probable dementia).

Results

The survey-weighted prevalence of vision impairment among participants aged 71 and older (1575 [54.7%] female and 1192 [45.3%] male; 570 [8.0%] non-Hispanic Black, 132 [81.7%] Hispanic, 2004 [81.7%] non-Hispanic White, and 61 [3.3%] non-Hispanic other) was 32.2% (95% CI, 29.7-34.6). The population attributable fraction of prevalent dementia from at least 1 vision impairment was 19.0% (95% CI, 8.2-29.7). Contrast sensitivity impairment yielded the strongest attributable fraction among all impairments (15.0%; 95% CI, 6.6-23.6), followed by near acuity (9.7%; 95% CI, 2.6-17.0) and distance acuity (4.9%; 95% CI, 0.1-9.9). Population attributable fractions from at least 1 impairment were highest among participants aged 71 to 79 years (24.3%; 95% CI, 6.6-41.8), female (26.8%; 95% CI, 12.2-39.9), and non-Hispanic White (22.3%; 95% CI, 9.6-34.5) subpopulations, with estimates consistent across educational strata.

Conclusions and Relevance

The population attributable fraction of dementia from vision impairments ranged from 4.9%-19.0%. While not proving a cause-and-effect relationship, these findings support inclusion of multiple objective measures of vision impairments, including contrast sensitivity and visual acuity, to capture the total potential impact of addressing vision impairment on dementia.

The Associations of Sensory Impairment With 10-Year Risk of Dementia and Alzheimer's Disease: The Health and Retirement Study, 2010-2020

BACKGROUND

Studies have examined the association between dual sensory impairment and late-life cognitive outcomes in the U.S with inconsistent findings.

OBJECTIVE

To examine the associations between sensory impairment and 10-year risk of dementia or Alzheimer's disease among U.S. adults aged ≥ 50.

METHODS

A prospective cohort study based on the Health and Retirement Study from 2010 to 2020. Individuals aged ≥ 50 years without self-reported dementia and Alzheimer's disease in 2010 were included in the analysis. Self-reported visual and hearing impairments were measures in 2010. Main failure events included self-reported incident dementia and Alzheimer's disease over a 10-year follow-up period. Participants were categorized as having no visual or hearing impairment, visual impairment only, hearing impairment only, and dual sensory impairment. Fine-Gray competing risk regression model was applied to estimate the associations of sensory impairment with incident dementia and Alzheimer's disease, adjusted for demographic characteristics, health behaviors, and health conditions at baseline.

RESULTS

Of 20,248 identified individuals, 14.6% had visual impairment only, 11.2% had hearing impairment only, and 9.1% had dual impairment at baseline. After adjusting for all covariates, dual sensory impairment was associated with higher risk of dementia (HR = 1.46, 95% CI: 1.23-1.73) and Alzheimer's disease (HR = 1.35, 95% CI: 1.03-1.76). Visual impairment only was also associated with incident dementia and Alzheimer's disease among individuals <65 years.

CONCLUSION

Older adults in the U.S. with visual and hearing impairments simultaneously had a particularly greater risk of dementia and Alzheimer's disease, indicating the needs of targeted screening for timely treatment and further prevention of dementia and Alzheimer's disease.

Adult-onset hearing loss and incident cognitive impairment and dementia - A systematic review and meta-analysis of cohort studies

BACKGROUND

We comprehensively summarized the cohort evidence to date on adult-onset hearing loss as risk factor for incident cognitive impairment and dementia, and examined the evidence for dose-response, risk for various dementia subtypes, and other moderators. Previous meta-analyses were less comprehensive.

METHODS

We included cohort studies with participants without dementia and with hearing assessments at baseline, minimum 2 years follow-up and incident cognitive outcomes. We used random-effect models and subgroup and meta-regression on moderator analyses.

RESULTS

We identified fifty studies (N=1,548,754). Hearing loss (yes/no) was associated with incident dementia risk (HR=1.35 [95% CI = 1.26 - 1.45), mild cognitive impairment (MCI HR=1.29 [95% CI = 1.11 - 1.50]), cognitive decline not specified as MCI or dementia (HR=1.29 [95% CI = 1.17 - 1.42]), and Alzheimer's disease dementia (ADD, HR=1.56 [95% CI = 1.30 - 1.87]), but not with vascular dementia (HR, 1.30 [95% CI = 0.83 - 2.05]). Each 10-decibel worsening of hearing was associated with a 16% increase in dementia risk (95% CI = 1.07 - 1.27). The effect of hearing loss did not vary across potential moderators.

CONCLUSIONS

Cohort studies consistently support that adult-onset hearing loss increases the risk of incident cognitive decline, dementia, MCI, and ADD.

Visual Impairment, Eye Conditions, and Diagnoses of Neurodegeneration and Dementia

Importance

Vision and eye conditions are associated with increased risk for Alzheimer disease and related dementias (ADRDs), but the nature of the association and the underlying biological pathways remain unclear. If causal, vision would be an important modifiable risk factor with viable population-level interventions.

Objective

To evaluate potentially causal associations between visual acuity, eye conditions (specifically cataracts and myopia), neuroimaging outcomes, and ADRDs.

Design, Setting, and Participants

A cohort and 2-sample bidirectional mendelian randomization (MR) study was conducted using UK Biobank participants and summary statistics from previously published genome-wide association studies on cataract, myopia, and AD. The participants included in the analysis were aged 55 to 70 years without dementia at baseline (calendar years 2006 to 2010), underwent genotyping, and reported on eye conditions; a subset completed visual acuity examinations (n = 69 852-71 429) or brain imaging (n = 36 591-36 855). Data were analyzed from August 15, 2022, through November 28, 2023.

Exposure

Self-reported cataracts, visual acuity, and myopia measured by refraction error.

Main Outcomes and Measures

ADRD, AD, and vascular dementia were identified from electronic medical records. Total and regional brain volumes were determined using magnetic resonance imaging.

Results

The sample included 304 953 participants (mean [SD] age, 62.1 (4.1) years; 163 825 women [53.72%]); 14 295 (4.69%) had cataracts and 2754 (3.86%) had worse than 20/40 vision. Cataracts (hazard ratio [HR], 1.18; 95% CI, 1.07-1.29) and myopia (HR, 1.35; 95% CI, 1.06-1.70) were associated with a higher hazard of ADRD. In MR analyses to estimate potential causal effects, cataracts were associated with increased risk of vascular dementia (inverse variance-weighted odds ratio [OR], 1.92; 95% CI, 1.26-2.92) but were not associated with increased dementia (OR, 1.21; 95% CI, 0.98-1.50). There were no associations between myopia and dementia. In MR for potential reverse causality, AD was not associated with cataracts (inverse variance-weighted OR, 0.99; 95% CI, 0.96-1.01). Genetic risk for cataracts was associated with smaller total brain (β = -597.43 mm3; 95% CI, -1077.87 to -117.00 mm3) and gray matter (β = -375.17 mm3; 95% CI, -680.10 to -70.24 mm3) volumes, but not other brain regions.

Conclusions and Relevance

In this cohort and MR study of UK Biobank participants, cataracts were associated with increased risk of dementia, especially vascular dementia, and reduced total brain volumes. These findings lend further support to the hypothesis that cataract extraction may reduce the risk for dementia.

Progress on early diagnosing Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects both cognition and non-cognition functions. The disease follows a continuum, starting with preclinical stages, progressing to mild cognitive and behavioral impairment, ultimately leading to dementia. Early detection of AD is crucial for better diagnosis and more effective treatment. However, the current AD diagnostic tests of biomarkers using cerebrospinal fluid and/or brain imaging are invasive or expensive, and mostly are still not able to detect early disease state. Consequently, there is an urgent need to develop new diagnostic techniques with higher sensitivity and specificity during the preclinical stages of AD. Various non-cognitive manifestations, including behavioral abnormalities, sleep disturbances, sensory dysfunctions, and physical changes, have been observed in the preclinical AD stage before occurrence of notable cognitive decline. Recent research advances have identified several biofluid biomarkers as early indicators of AD. This review focuses on these non-cognitive changes and newly discovered biomarkers in AD, specifically addressing the preclinical stages of the disease. Furthermore, it is of importance to explore the potential for developing a predictive system or network to forecast disease onset and progression at the early stage of AD.

A Prospective Association Between Sensory Impairment and Cognitive Performance Among Older Community-Dwelling Adults: The Role of Depressive Symptoms

We examined whether vision impairment (VI) and hearing impairment (HI) and dual sensory impairment (DSI) affect cognitive performance and whether depression mediates that effect. We examined 55,340 participants from the Survey of Health, Aging and Retirement in Europe, which assessed 32,325 participants in 2011 (baseline, Time 1), 2015 (follow-up, Time 2), sociodemographic data and health factors, self-reported VI, HI, and DSI at baseline, depression, and cognitive performance after four years. A multiple mediator model was tested using bootstrapping and resampling. At baseline, 22.9% had VI, 10.2% HI, and 10.4% had DSI. We found a significant negative association between VI (b = -0.023, p = .001) and DSI (b = -0.083, p = .001) and cognitive performance; both were also associated with depression, which was linked with poor cognition. VI or DSI among older adults are associated with poor cognitive function directly and indirectly by increasing depression symptoms.

Update on modifiable risk factors for Alzheimer's disease and related dementias

PURPOSE OF REVIEW

All human beings undergo a lifelong cumulative exposure to potentially preventable adverse factors such as toxins, infections, traumatisms, and cardiovascular risk factors, collectively termed exposome. The interplay between the individual's genetics and exposome is thought to have a large impact in health outcomes such as cancer and cardiovascular disease. Likewise, a growing body of evidence is supporting the idea that preventable factors explain a sizable proportion of Alzheimer's disease and related dementia (ADRD) cases.

RECENT FINDINGS

Here, we will review the most recent epidemiological, experimental preclinical, and interventional clinical studies examining some of these potentially modifiable risk factors for ADRD. We will focus on new evidence regarding cardiovascular risk factors, air pollution, viral and other infectious agents, traumatic brain injury, and hearing loss.

SUMMARY

While greater and higher quality epidemiological and experimental evidence is needed to unequivocally confirm their causal link with ADRD and/or unravel the underlying mechanisms, these modifiable risk factors may represent a window of opportunity to reduce ADRD incidence and prevalence at the population level via health screenings, and education and health policies.

Strategies used during the cognitive evaluation of older adults with dual sensory impairment: a scoping review

BACKGROUND

Dual sensory impairment (DSI), the combination of visual and hearing impairments, is associated with increased risk for age-related cognitive decline and dementia. Administering cognitive tests to individuals with sensory impairment is challenging because most cognitive measures require sufficient hearing and vision. Considering sensory limitations during cognitive test administration is necessary so that the effects of sensory and cognitive abilities on test performance can be differentiated and the validity of test results optimized.

OBJECTIVE

To review empirical strategies that researchers have employed to accommodate DSI during cognitive testing of older adults.

METHODS

Seven databases (MEDLINE, Embase, Web of Science, CINAHL, PsycINFO, Global Health and the Evidence-Based Medicine Reviews databases) were searched for relevant articles integrating the three concepts of cognitive evaluation, aging, and DSI. Given the inclusion criteria, this scoping review included a total of 67 papers.

RESULTS

Twenty-eight studies reported five categories of strategies for cognitive testing of older adult participants with DSI: the assistance of experts, the modification of standardized test scoring procedures, the use of communication strategies, environmental modifications, and the use of cognitive tests without visual and/or auditory items.

CONCLUSIONS

The most used strategy reported in the included studies was drawing on the assistance of team members from related fields during the administration and interpretation of cognitive screening measures. Alternative strategies were rarely employed. Future research is needed to explore the knowledge-to-practice gap between research and current clinical practice, and to develop standardized testing strategies.

Prodromes in demyelinating disorders, amyotrophic lateral sclerosis, Parkinson disease, and Alzheimer's dementia

A prodrome is an early set of symptoms, which indicates the onset of a disease; these symptoms are often non-specific. Prodromal phases are now recognized in multiple central nervous system diseases. The depth of understanding of the prodromal phase varies across diseases, being more nascent for multiple sclerosis for example, than for Parkinson disease or Alzheimer's disease. Key challenges when identifying the prodromal phase of a disease include the lack of specificity of prodromal symptoms, and consequent need for accessible and informative biomarkers. Further, heterogeneity of the prodromal phase may be influenced by age, sex, genetics and other poorly understood factors. Nonetheless, recognition that an individual is in the prodromal phase of disease offers the opportunity for earlier diagnosis and with it the opportunity for earlier intervention.

[Prevention of dementia]

With increasing life expectancy, the prevalence of dementia is increasing worldwide. Dementia is among the greatest challenges for healthcare and social systems of the future. Approximately 40% of newly diagnosed cases of dementia are associated with risk factors that can potentially be influenced by preventive measures. Based on the evidence from longitudinal studies, systematic reviews and meta-analyses, the Lancet commission on dementia prevention, intervention and care has defined 12 risk factors that are associated with an increased risk for dementia: low level of education, hearing impairment, traumatic brain injury, arterial hypertension, diabetes mellitus, smoking, excessive alcohol consumption, depression, obesity, social isolation, and air pollution.

Cognitive Impairment in Heart Failure: A Heart Failure Society of America Scientific Statement

Cognitive impairment is common among adults with heart failure (HF), as both diseases are strongly related to advancing age and multimorbidity (including both cardiovascular and noncardiovascular conditions). Moreover, HF itself can contribute to alterations in the brain. Cognition is critical for a myriad of self-care activities that are necessary to manage HF, and it also has a major impact on prognosis; consequently, cognitive impairment has important implications for self-care, medication management, function and independence, and life expectancy. Attuned clinicians caring for patients with HF can identify clinical clues present at medical encounters that suggest cognitive impairment. When present, screening tests such as the Mini-Cog, and consideration of referral for comprehensive neurocognitive testing may be indicated. Management of cognitive impairment should focus on treatment of underlying causes of and contributors to cognitive impairment, medication management/optimization, and accommodation of deficiencies in self-care. Given its implications on care, it is important to integrate cognitive impairment into clinical decision making. Although gaps in knowledge and challenges to implementation exist, this scientific statement is intended to guide clinicians in caring for and meeting the needs of an increasingly complex and growing subpopulation of patients with HF.

Persistently short or long sleep duration increases the risk of sensory impairment in Chinese older adults

Background

Cross-sectional evidence suggests that persistently short or long sleep duration is associated with sensory impairment. Thus, this study was conducted to investigate the associations between sleep duration and altered sleep duration with sensory impairment in Chinese older adults.

Methods

Longitudinal data (2008-2014) obtained through the Chinese Longitudinal Healthy Longevity Survey (CLHLS) were analyzed. Sleep duration was classified as normal (7-8 h), short (<7 h), or long (≥9 h). Sensory impairment was assessed using individuals' self-reported data on visual and hearing functions. Cox regression was performed to evaluate the effects of sleep duration and altered sleep duration on sensory impairment, including visual impairment (VI) and hearing impairment (HI).

Results

This study included 3,578 older adults (mean age: 78.12 ± 9.59 years). Among them, 2,690 (75.2%) were aged 65-84 years and 1798 (50.3%) were women. The risks of VI (hazard ratio [HR]: 1.14; 95% confidence interval [CI]: 1.02-1.29), HI (HR: 1.14; 95% CI: 1.00-1.30), and dual sensory impairment (both VI and HI; HR: 1.26; 95% CI: 1.03-1.55) were high in older adults with long sleep duration. In addition, the risks of VI, HI, and dual sensory impairment were high in individuals whose sleep duration changed from normal to short or long (HR: 1.20 [95% CI: 1.02-1.42], 1.26 [95% CI: 1.03-1.53], and 1.54 [95% CI: 1.11-2.12], respectively) and those with persistently short or long sleep duration (HR: 1.25 [95% CI: 1.07-1.46], 1.34 [95% CI: 1.11-1.61], and 1.67 [95% CI: 1.22-2.27], respectively).

Conclusion

A prospective association was identified between altered sleep duration and sensory impairment in Chinese older adults. Our findings highlight the importance of optimal sleep duration and healthy sleep habits in preventing sensory impairment in older adults.

Hearing Loss, Hearing Aid Use, and Risk of Dementia in Older Adults

Importance

Hearing loss has been suggested as a risk factor for dementia, but there is still a need for high-quality research to better understand the association between these 2 conditions and the underlying causal mechanisms and treatment benefits using larger cohorts and detailed data.

Objective

To investigate the association between hearing loss and incident dementia, as well as how hearing aid use contributes to this association.

Design, Setting, and Participants

This population-based cohort study was conducted in Southern Denmark between January 2003 and December 2017 and included all residents 50 years and older. We excluded all persons with dementia before baseline as well as those who did not live in the region 5 years before baseline, with incomplete address history, or who had missing covariate information.

Exposures

Individual hearing status based on the Hearing Examinations in Southern Denmark database, which contains data on all pure-tone audiometry examinations performed at public hearing rehabilitation clinics in Southern Denmark.

Main Outcomes and Measures

Incident cases of dementia and Alzheimer disease as identified from national registries.

Results

The study population comprised 573 088 persons (298 006 women [52%]; mean [SD] age, 60.8 [11.3] years) with 23 023 cases of dementia and mean (SD) follow-up of 8.6 (4.3) years. Having a hearing loss was associated with an increased risk of dementia, with an adjusted hazard ratio (HR) of 1.07 (95% CI, 1.04-1.11) compared with having no hearing loss. Severe hearing loss in the better and worse ear was associated with a higher dementia risk, with an HR of 1.20 (95% CI, 1.09-1.32) and 1.13 (95% CI, 1.06-1.20), respectively, compared with having no hearing loss in the corresponding ear. Compared with people without hearing loss, the risk of dementia was higher among people with hearing loss who were not using hearing aids than those who had hearing loss and were using hearing aids, with HRs of 1.20 (95% CI, 1.13-1.27) and 1.06 (95% CI, 1.01-1.10), respectively.

Conclusions and Relevance

The results of this cohort study suggest that hearing loss was associated with increased dementia risk, especially among people not using hearing aids, suggesting that hearing aids might prevent or delay the onset and progression of dementia. The risk estimates were lower than in previous studies, highlighting the need for more high-quality longitudinal studies.

Reduction in Constitutively Activated Auditory Brainstem Microglia in Aging and Alzheimer's Disease

Background

Alzheimer's disease (AD) pathology is considered to begin in the brainstem, and cerebral microglia are known to play a critical role in AD pathogenesis, yet little is known about brainstem microglia in AD. Translocator protein (TSPO) PET, sensitive to activated microglia, shows high signal in dorsal brainstem in humans, but the precise location and clinical correlates of this signal are unknown.

Objective

To define age and AD associations of brainstem TSPO PET signal in humans.

Methods

We applied new probabilistic maps of brainstem nuclei to quantify PET-measured TSPO expression over the whole brain including brainstem in 71 subjects (43 controls scanned using 11C-PK11195; 20 controls and 8 AD subjects scanned using 11C-PBR28). We focused on inferior colliculi (IC) because of visually-obvious high signal in this region, and potential relevance to auditory dysfunction in AD. We also assessed bilateral cortex.

Results

TSPO expression was normally high in IC and other brainstem regions. IC TSPO was decreased with aging (p = 0.001) and in AD subjects versus controls (p = 0.004). In cortex, TSPO expression was increased with aging (p = 0.030) and AD (p = 0.033).

Conclusions

Decreased IC TSPO expression with aging and AD-an opposite pattern than in cortex-highlights underappreciated regional heterogeneity in microglia phenotype, and implicates IC in a biological explanation for strong links between hearing loss and AD. Unlike in cerebrum, where TSPO expression is considered pathological, activated microglia in IC and other brainstem nuclei may play a beneficial, homeostatic role. Additional study of brainstem microglia in aging and AD is needed.

Association between changes in sensory impairment and functional disability in older adults: A longitudinal study

BACKGROUND

Given the rapidly aging population, the relationship between sensory impairment and functional disability in older adults is gaining attention. Dual sensory impairment is a known risk factor for every competency. Therefore, this study aimed to investigate the impact of changes in sensory impairments on functional disabilities.

METHODS

The study targeted 5,852 participants from the Korean Longitudinal Study of Aging (2006-2020). Functional disability was measured using the Korean version of the activities of daily Life and the instrumental activities of daily life scales. Sensory impairment was assessed using self-reported questionnaires. A generalized estimation equation model was used to evaluate the effect of sensory impairment on functional disability over time.

RESULTS

After adjusting for covariates, we observed an association between changes in sensory impairment and functional disability measured by activities of daily life and instrumental activities of daily life. Groups with worsened sensory impairment had a high risk of every competence (activities of daily life: odds ratio [OR] 1.23; 95% confidence interval [CI], 1.08-1.40; instrumental activities of daily life: OR, 1.29; 95% CI, 1.19-1.39). In addition, strong associations have also been shown in dual sensory impairment (activities of daily life: OR, 2.04; 95% CI, 1.57-2.65; instrumental activities of daily life: OR, 2.34; 95% CI, 1.95-2.80).

CONCLUSION

By addressing sensory impairment early, healthcare providers in Korea can prevent functional disabilities and improve the overall well-being of middle-aged and older adults. Managing the decline in their senses can be beneficial in enhancing their quality of life.

Altered auditory processes pattern predicts cognitive decline in older adults: different modalities with aging

Background

Cohort studies have shown that older adults with hearing impairment as assessed by self-report or behavioral measures are at higher risk of developing dementia many years later. A fine-grained examination of auditory processing holds promise for more effective screening of older adults at risk of cognitive decline. The auditory mismatch negativity (MMN) measure enables one to gain insights into the neurobiological substrate of central auditory processing. We hypothesized that older adults showing compromised indexes of MMN at baseline would exhibit cognitive decline at the one-year follow-up.

Methods

We performed cognitive evaluations with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS; Form A and Form B) in 108 community-dwelling older adults and acquired EEG via the classic passive auditory oddball paradigm at baseline and 12-month follow-up.

Results

The results showed that young-old adults with future cognitive decline showed a decrease in MMN peak amplitude, accompanied by a forward-shifting latency, whereas in older adults it showed a delay in MMN latency, and unchanged MMN peak amplitude at midline electrodes (Fz, FCz and Cz). Furthermore, the peak amplitude of the MMN decreases with age in older adults aged 70-80 years rather than 60-70 years or > 80 years.

Conclusion

The altered MMN model exists in different aging stages and it's a promising electrophysiological predictor of cognitive decline in older adults. In addition, further research is needed to determine the neural mechanisms and potential implications of the accelerated decline in MMN in older adults.

Association Between Sensory Impairment and Dementia: The Roles of Social Network and Leisure Activity

BACKGROUND

Evidence suggests that sensory impairment is linked to dementia; however, the role of social network and leisure activity in this relationship is unclear.

OBJECTIVE

Examine the association of hearing and visual impairment with dementia, and whether a rich social network and leisure activity moderates this association.

METHODS

Dementia-free older adults from the Swedish National Study on Aging and Care in Kungsholmen (n = 2,579) were followed up for up for a median of 10 years (interquartile range = 6). Visual impairment was assessed with a reading acuity test, and hearing impairment was ascertained via self-report and medical records. Dementia was diagnosed following international criteria. Data on social network and leisure activity was collected via self-report. Hazard ratios (HRs) of dementia risk were derived from Cox regression models.

RESULTS

Dual impairment, but not single impairment in hearing and vision was associated with a higher risk of dementia (HR: 1.62, 95% CI: 1.16 to 2.27). Compared to participants with no sensory impairment and a moderate-to-rich social network, those with dual impairment and low social network or leisure activity had higher dementia risk (HR: 2.08, 95% CI: 1.43 to 3.22; HR: 2.08, 95% CI: 1.43 to 3.22, respectively), whereas participants with dual impairment with a moderate-to-rich social network or leisure activity did not have significantly higher dementia risk (HR; 1.42, 95% CI: 0.87 to 2.33; HR; 1.42, 95% CI: 0.87 to 2.33, respectively).

CONCLUSION

A richer social network and participation in stimulating activities may mitigate the higher dementia risk in older adults with dual impairment in vision and hearing.

[Prevention of dementia]

With increasing life expectancy, the prevalence of dementia is increasing worldwide. Dementia is among the greatest challenges for healthcare and social systems of the future. Approximately 40% of newly diagnosed cases of dementia are associated with risk factors that can potentially be influenced by preventive measures. Based on the evidence from longitudinal studies, systematic reviews and meta-analyses, the Lancet commission on dementia prevention, intervention and care has defined 12 risk factors that are associated with an increased risk for dementia: low level of education, hearing impairment, traumatic brain injury, arterial hypertension, diabetes mellitus, smoking, excessive alcohol consumption, depression, obesity, social isolation, and air pollution.

Do Sensory Impairments Portend Cognitive Decline in Older Chinese Adults? Longitudinal Evidence from a Nationally Representative Survey, 2011-2018

Previous studies on longitudinal sensory-cognition association are limited and have yielded inconsistent conclusions in western and developed countries. The present study obtained data from the China Health and Retirement Longitudinal Survey (CHARLS, 2011−2018) and aimed to investigate the longitudinal effects of sensory impairments including single vision impairment (SVI), single hearing impairment (SHI), and dual sensory impairment (DSI) on cognitive decline in middle-aged and older Chinese population. In total, 11,122 participants accomplished all 4 interviews over 8 years and were included. Cognitive performances were assessed using Mini-Mental Status Examination (MMSE) and self-reported sensory status were accepted as well. Confounding variables included age, sex, educational level, marital status, medical, and lifestyle related information. The impact of sensory impairment on cognitive decline over time was assessed using linear mixed-effects models (LMM). After being adjusted for multiple confounders, SVI/SHI/DSI were all shown to be significantly associated with executive functions, episodic memory impairment, and global cognitive decline over 8 years (all p < 0.05). Such associations become less significant among female and relatively younger populations (45−59 years old). Single vision and hearing impairments, along with dual sensory impairment, are all independently associated with subsequent cognitive decline among middle-aged and older Chinese populations over 8 years of longitudinal observation.