The association between dual sensory impairment and dementia: a meta-analysis and systematic review of the literature

We aimed to determine whether self-assessed single (hearing or visual) and dual sensory (hearing and visual) impairments are associated with cognitive decline and incident possible cognitive impairment, no dementia (CIND) and probable dementia. Data were drawn from the 1996-2014 surveys of the Health and Retirement Study (HRS), involving 19,618 respondents who had no probable dementia and who were aged 50 years or older at the baseline. We used linear mixed models to test the association between self-assessed sensory impairment and cognitive decline followed by a Cox proportional hazard model to estimate the relative risk of incident possible CIND and probable dementia associated with the presence of sensory impairment. Respondents with self-assessed single and dual sensory impairment performed worse in cognitive tests than those without sensory impairment. The fully adjusted incidence of developing possible CIND was 17% higher for respondents with hearing impairment than those without hearing impairment. Respondents with visual impairment had 35% and 25% higher risk for developing possible CIND and probable dementia, respectively, than those without visual impairment. Respondents with dual sensory impairment at baseline were 38% and 26% more likely to develop possible CIND and probable dementia, respectively, than those with no sensory impairment. Self-assessed sensory impairment is independently associated with cognitive decline and incident possible CIND and probable dementia. Further studies are needed to identify the mechanism underlying this association and to determine whether treatment of sensory impairment could ameliorate cognitive decline and delay the onset of dementia among older adults.

Dual Sensory Impairment in an Aging Population

Objective Previous studies have shown the influence of visual and auditory sensory impairment on dementia incidence. In this study, we tested the hypothesis that the incidence of dementia will increase with visual and auditory impairments than with visual or auditory impairment.Methods Data from the Korea National Health Insurance Service database were used, including disease and medication codes from 2009 to 2018, and the 2011 national health check-up results. Participants were grouped based on their sensory abilities: normal, visual impairment, auditory impairment, and both visual and auditory impairments (dual sensory impairment). To compare the incidence of dementia, hazard ratios were calculated for each group, with reference to the normal sensory (NS) group. Sensitivity analyses were performed comparing dementia incidence from 2014 to 2018, excluding the onset of the disease in 2012 and 2013.Results We identified 8,289 cases of dementia during the seven-year follow-up. In the multiple Cox regression analysis, adjusted for sex, social economic status, age, comorbidities, smoking, alcohol consumption, and activity level, the auditory impairment (hazard ratio= 1.1908) and visual impairment (hazard ratio=1.3553) groups showed a significantly higher dementia incidence than the NS group. Dual sensory impairment (hazard ratio=1.5267) showed the highest incidence. The sensitivity analysis yielded similar results.Conclusion Visual and auditory impairments are associated with an increased risk of dementia, particularly in individuals with dual sensory impairment. Hence, visual and auditory impairments might have increased the risk of dementia through independent pathological processes. Therefore, preventing and correcting sensory impairment is necessary to reduce the risk of dementia.

Vision and hearing impairments often co-exist with dementia, and all are independently associated with limitations in daily activities. Our aim was to examine the association of dual sensory impairment with functional limitations, and further examine the combined estimated association of sensory impairment and dementia with these functional limitations. Cross-sectional analysis of the National Health and Aging Trends Study (NHATS), a population-based cohort of Medicare beneficiaries, was performed. Participants were selected from the 2015 round. Survey weighted Poisson regression models adjusted for dementia, demographics, and health status variables examined the association of self-reported dual sensory impairment (no sensory impairment, single sensory impairment, dual sensory impairment) with scores of limitations in mobility, self-care, and household activities. Models were repeated to take into account the combined effects of dual sensory impairment and dementia. Overall, 7124 participants representative of Medicare beneficiaries 65 years or older were included. Of them, 43.9% were 75 years or older and 55.3% were female. Older adults with dual sensory impairment had greater limitations with mobility (prevalence rate ratio [PRR]=1.45, 95% CI=1.28-1.63), self-care (PRR=1.41, 95% CI=1.25-1.59), and household activities (PRR=1.54, 95% CI=1.37-1.72) compared with those without sensory impairment. They also had greater limitations than those with a single sensory impairment across the different activity categories. In models taking into account the combined estimated effect of both sensory impairment and dementia, those with dual sensory impairment and dementia had greater limitations than those without sensory impairment or dementia in each category (mobility: PRR=1.85, 95% CI=1.59-2.14, self-care: PRR=1.86, 95% CI=1.59-2.18, household: PRR=2.41, 95% CI=2.09-2.77). Older adults with dual sensory impairment had greater functional limitations compared with those without sensory impairment and those with a single sensory impairment. Strategies to improve visual and/or hearing function (e.g., sensory aids, rehabilitation) could potentially help prevent or minimize disability, even among those with dementia.

IntroductionStrong evidence supports the importance of potentially modifiable risk factors for dementia, with sensory loss, particularly visual and hearing impairment, being prominent among them. While single sensory impairment has been...

To address an existing gap in knowledge due to limited and inconclusive evidence, we aimed to investigate the association between sensory impairments and cognitive decline among older Chinese individuals. We retrieved data on 6862 adults aged ≥65 years that were collected through the Chinese Longitudinal Healthy Longevity Study (CLHLS), a nationwide, prospective, community-based elderly cohort study. Visual or hearing impairment in the CLHLS were identified through self-reported questionnaire. Sensory impairments were categorised as no sensory impairment, hearing impairment only, visual impairment only, and dual sensory impairment according to hearing and vision function. Cognitive impairment was defined as having a score <18 on the Chinese version of the Mini Mental State Examination. We used a Cox proportional hazard model to evaluate the relationship between sensory and cognitive impairments. Among 6862 participants, 5.7% had dual sensory impairment, 7.4% had hearing impairment only, and had 17.2% visual impairment only. Compared with participants with no sensory impairment, those with hearing impairment only (adjusted hazard ratio (aHR) = 1.65; 95% confidence interval (CI) = 1.41, 1.92), visual impairment only (aHR = 1.25; 95% CI = 1.11, 1.41), and dual sensory impairment (aHR = 1.47; 95% CI = 1.25, 1.74) were significantly associated with higher risk of cognitive impairment in the fully adjusted model. Our results show that having hearing impairment only, visual impairment only, and dual sensory impairment was significantly associated with a higher risk of cognitive impairment among Chinese older adults aged ≥65 years. This suggest a need for the timely identification and management of sensory impairments for the elderly to reduce dementia risk.

BackgroundAlthough visual and hearing impairment have been identified as established risk factors for dementia, evidence was limited on the association of the coexistence of these two sensory impairments with incident dementia, especially in the U.S. The study aimed to examine the associations between sensory impairment and 10‐year risk of dementia or Alzheimer’s disease.MethodA prospective cohort study was designed based on the Health and Retirement Study from 2010 to 2020. Individuals aged 50 years and older without self‐reported dementia and Alzheimer’s disease were included in the analysis. Information of self‐reported visual and hearing impairment was obtained at Wave 10 in 2010, and participants were categorized as normal, with visual impairment only, hearing impairment only, and dual sensory impairment. Main failure events included self‐reported incident dementia and Alzheimer’s disease over a 10‐year follow‐up period. Fine‐Gray competing risk regression models were applied for the associations of sensory impairment with incident dementia and Alzheimer’s disease, adjusted for demographic characteristics, health behaviors, and health conditions at baseline.ResultOf 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 adjustment for all covariates, dual sensory impairment was associated with higher risk of dementia (hazards ratio (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 associated with incident dementia (HR = 1.98, 95% CI: 1.38‐2.83) and Alzheimer’s disease (HR = 2.99, 95% CI: 1.60‐5.62) among individuals &lt;65 years. No association was observed between hearing impairment only and incident dementia or Alzheimer’s disease.ConclusionOlder adults in the U.S. with visual and hearing impairments simultaneously had a particularly greater risk of dementia and Alzheimer’s disease, and having visual impairment alone was associated with an elevated risk of dementia; the associations were stronger among people &lt;65 years.

IntroductionThe 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.MethodsThe 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.ResultsAmong 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.ConclusionsVisual, 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.

Studies have examined the association between dual sensory impairment and late-life cognitive outcomes in the U.S with inconsistent findings. To examine the associations between sensory impairment and 10-year risk of dementia or Alzheimer's disease among U.S. adults aged ≥ 50. 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. 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. 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.

Hearing and vision problems are individually associated with increased dementia risk, but the impact of having concurrent hearing and vision deficits, ie, dual sensory impairment (DSI), on risk of dementia, including its major subtypes Alzheimer disease (AD) and vascular dementia (VaD), is not well known. To evaluate whether DSI is associated with incident dementia in older adults. This prospective cohort study from the Cardiovascular Health Study (CHS) was conducted between 1992 and 1999, with as many as 8 years of follow-up. The multicenter, population-based sample was recruited from Medicare eligibility files in 4 US communities with academic medical centers. Of 5888 participants aged 65 years and older in CHS, 3602 underwent cranial magnetic resonance imaging and completed the modified Mini-Mental State Examination in 1992 to 1994 as part of the CHS Cognition Study. A total of 227 participants were excluded due to prevalent dementia, leaving a total of 3375 participants without dementia at study baseline. The study hypothesis was that DSI would be associated with increased risk of dementia compared with no sensory impairment. The association between the duration of DSI with risk of dementia was also evaluated. Data analysis was conducted from November 2019 to February 2020. Hearing and vision impairments were collected via self-report at baseline and as many as 5 follow-up visits. All-cause dementia, AD, and VaD, classified by a multidisciplinary committee using standardized criteria. A total of 2927 participants with information on hearing and vision at all available study visits were included in the analysis (mean [SD] age, 74.6 [4.8] years; 1704 [58.2%] women; 455 [15.5%] African American or Black; 2472 [85.5%] White). Compared with no sensory impairment, DSI was associated with increased risk of all-cause dementia (hazard ratio [HR], 2.60; 95% CI, 1.66-2.06; P < .001), AD (HR, 3.67; 95% CI, 2.04-6.60; P < .001) but not VaD (HR, 2.03; 95% CI, 1.00-4.09; P = .05). In this cohort study, DSI was associated with increased risk of dementia, particularly AD. Evaluation of hearing and vision in older adults may help to identify those at high risk of developing dementia.

highly prevalagent hearing and vision sensory impairments among older people may contribute to the risk of cognitive decline and pathological impairments including dementia.This study aims to determine whether single and dual sensory impairment (hearing and/or vision) are independently associated with cognitive decline among older adults and to describe cognitive trajectories according to their impairment pattern. we used data from totals of 13,123, 11,417 and 21,265 respondents aged 50+ at baseline from the Health and Retirement Study (HRS), the English Longitudinal Study of Ageing (ELSA) and the Survey of Health, Ageing and Retirement in Europe (SHARE), respectively. We performed growth curve analysis to identify cognitive trajectories, and a joint model was used to deal with attrition problems in longitudinal ageing surveys. respondents with a single sensory impairment had lower episodic memory score than those without sensory impairment in HRS (β = -0.15, P < 0.001), ELSA (β = -0.14, P < 0.001) and SHARE (β = -0.26, P < 0.001). The analysis further shows that older adults with dual sensory impairment in HRS (β = -0.25, P < 0.001), ELSA (β = -0.35, P < 0.001) and SHARE (β = -0.68, P < 0.001) remembered fewer words compared with those with no sensory impairment. The stronger associations between sensory impairment and lower episodic memory levels were found in the joint model which accounted for attrition. hearing and/or vision impairments are a marker for the risk of cognitive decline that could inform preventative interventions to maximise cognitive health and longevity. Further studies are needed to investigate how sensory markers could inform strategies to improve cognitive ageing.

The association between adverse childhood experiences and sensory impairment in middle-aged and older adults: Evidence from a nationwide cohort study in China

Dementia and behavioural and psychological symptoms of dementia affect older adults' care-need levels. With aging comes an increase in the incidence of sensory impairments, which promotes the development of dementia. We investigated the association between sensory impairments - visual impairment (VI), hearing impairment (HI), and dual sensory impairment (DSI), the behavioural and psychological symptoms of dementia, and dementia incidence. This was a retrospective study that used Japanese long-term care insurance certification data from 2010 to 2017 of City A. The 2190 older adults who did not have dementia in 2010 were classified into four impairment categories: VI, HI, DSI, and no sensory impairment. The incidence of dementia was examined using Kaplan-Meier survival analysis and log-rank testing. Cox proportional hazards analysis was used to investigate the risk of developing dementia associated with sensory impairments, compared to the risk for no sensory impairment. Pearson's χ2 tests were used to compare the prevalence of behavioural and psychological symptoms of dementia among the four groups. HI and DSI were associated with a higher cumulative dementia incidence compared to no sensory impairment (log-rank χ2 = 10.42; P < 0.001, and log-rank χ2 = 39.92; P < 0.001, respectively), and DSI showed higher cumulative dementia incidence than HI (log-rank χ2 = 11.37; P = 0.001). Cox proportional hazards analysis showed that DSI is the greatest risk factor for developing dementia among sensory impairments (hazard ratio, 1.45; 95% CI, 1.22-1.71; P < 0.001). Older adults with VI had a significantly higher prevalence of day-night reversal than the other groups. Our results indicate that older adults with sensory impairments have a high incidence of dementia, with DSI presenting the greatest risk. Older adults with VI were found to be more likely to have day-night reversal symptoms when dementia occurs.

Hearing and vision impairment have been independently linked to accelerated cognitive decline in older adults, however there is limited evidence on the effect of dual sensory impairment (DSI) (both hearing and vision impairment) on cognition. Additionally, the impact of social isolation and loneliness, both correlates of DSI and independent risk factors for cognitive decline, on the DSI-cognition relationship has yet to be studied. Using data from the National Social Life, Health, and Aging Project (N=3,091), multivariable linear regression models were used to describe the cross-sectional relationship between self-reported functional sensory impairment (none, hearing only, vision only, DSI) and cognitive function, measured by the survey adapted Montreal Cognitive Assessment. We also included an interaction term in the model to investigate whether cognition is worse among older adults with sensory impairment who also are socially isolated or lonely. Participants in this sample are between 62-91 years with 15% reporting hearing impairment, 11% reporting vision impairment, and 7% reporting DSI. DSI was associated with significantly lower global cognitive function compared to no sensory impairment (-0.31 standard deviations (SD), 95% CI:-0.44 to-0.18), hearing impairment alone (-0.29 SD, 95% CI: -0.44 to -0.15), and vision impairment alone (-0.22 SD, 95% CI: -0.39 to -0.06). Furthermore, cognitive function was significantly worse among older adults with both DSI and smaller social networks (p-interaction <0.05). No differences in the DSI-cognition relationship were observed by level of loneliness. These findings add to the limited research on the relationship between DSI, social isolation and loneliness, and cognition.

Loneliness and social isolation are global public health challenges. Sensory impairments (SIs) are highly prevalent among older adults but are often ignored as a part of normal aging. Identifying the role of SIs in loneliness and social isolation could provide insight into strategies for improving public health among older adults. This study aims to analyze the effects of SIs on loneliness and social isolation among older adults in rural and urban China. This cohort study of 3069 older adults (aged 60+) used data from 4 waves (2011, 2013, 2015, and 2018) of the China Health and Retirement Longitudinal Study (CHARLS), a nationally representative survey of adults aged 45 years or older. SIs include hearing impairment (HI), vision impairment (VI), and dual sensory impairment (DSI). DSI is defined as the co-occurrence of VI and HI. Participants with complete data on hearing, vision, social isolation, and loneliness were included in the analysis. Generalized estimating equation models adjusted for covariates were used to examine the relationships of DSI with loneliness and social isolation among older adults. Older adults in rural areas have higher prevalence of DSI, loneliness, and social isolation than their urban counterparts. In rural areas, participants with VI only (odds ratio [OR] 1.34, 95% CI 1.12-1.62; P=.002), HI only (OR 1.32, 95% CI 1.02-1.71; P=.03), and DSI (OR 1.84, 95% CI 1.56-2.18; P<.001) were more likely to experience loneliness compared with participants without SIs. DSI showed a statistically significant association with loneliness compared with VI only (OR 1.37, 95% CI 1.22-1.54; P<.001) and HI only (OR 1.39, 95% CI 1.13-1.72; P=.002). In urban areas, participants with VI only (OR 2.44, 95% CI 1.57-3.80; P<.001), HI only (OR 2.47, 95% CI 1.41-4.32; P=.002), and DSI (OR 1.88, 95% CI 1.24-2.85; P=.003) were more likely to experience loneliness compared with participants without SIs. DSI was not associated with the increased likelihood of loneliness compared with HI only or VI only. SIs were not associated with social isolation among older adults in urban and rural areas. Until 2018, 86.97% (2669/3069) reported VI, but only 27.11% (832/3069) and 9.45% (290/3069) were treated with glasses and cataract surgery, respectively; besides, 75 individuals received both glasses and cataract surgery treatment. The prevalence of HI was 74.39% (2283/3069) in 2018, but only 0.72% (22/3069) were treated with a hearing aid. SIs are associated with an increased risk of loneliness rather than social isolation. A compounded risk of DSI on loneliness exists in rural areas rather than in urban areas. These findings expand our knowledge about the effects of SIs on loneliness and social isolation in non-Western populations. Interventions targeting HI only and DSI might be particularly effective for mitigating loneliness of older adults in urban and rural areas, respectively. Considering the high prevalence and low treatment rate of SIs, measures should be taken to make treatment more accessible.