Modifiable Risk Factors For Dementia Research Articles

Cross-sectional associations between neighborhood characteristics, cognition and dementia risk factor burden in middle-aged and older Australians

Dementia disproportionately affects individuals from disadvantaged backgrounds, including those living in areas of lower neighborhood-level socioeconomic status. It is important to understand whether there are specific neighborhood characteristics associated with dementia risk factors and cognition which may inform dementia risk reduction interventions. We sought to examine whether greenspace, walkability, and crime associated with the cumulative burden of modifiable dementia risk factors and cognition. This was a cross-sectional analysis of 2016–2020 data from the Healthy Brain Project, a population-based cohort of community-dwelling individuals across Australia. Participants were aged 40–70 and free of dementia. Measures included greenspace (greenspace % in the local area, and distance to greenspace, n = 2,181); and intersection density (n = 1,159), and crime (rate of recorded offences; n = 1,159). Outcomes included a modified Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) dementia risk score to index the burden of modifiable vascular dementia risk factors; and composite scores of both memory and attention, derived from the Cogstate Brief Battery. Linear regressions adjusted for age, sex, education, and personal socio-economic status, demonstrated distance to greenspace (b ± SE per 2-fold increase = 0.09 ± 0.03, p =.005) and crime rate (b ± SE per 2-fold increase = 0.07 ± 0.03, p =.018) were associated with higher modified CAIDE. Higher crime was associated with lower memory performance (b ± SE = -0.03 ± 0.01, p =.018). The association between distance to greenspace and modified CAIDE was only present in low-moderate socioeconomic status neighborhoods (p interaction = 0.004). Dementia prevention programs that address modifiable risk factors in midlife should consider the possible role of neighborhood characteristics.

Potentially modifiable risk factors for dementia in six low-income and middle-income countries: A multinational, population-based survey

ObjectivesWe aimed to determine the proportion of dementia cases potentially preventable in six low-income and middle-income countries. Study designWe analyzed data from 19,278 adults aged 50 years or more from China, South Africa, Ghana, India, Russia, and Mexico included in the WHO's Study on global AGEing and adult health. Main outcome measuresWe calculated the population attributable fraction for ten potentially modifiable risk factors: less education, hearing loss, hypertension, diabetes, depression, heavy drinking, obesity, smoking, physical inactivity, and social isolation. Weighted attributable fraction was calculated considering communality among risk factors. ResultsWe estimated that 37.6 % of the burden of dementia might be attributable to these risk factors. The highest and lowest overall weighted attributable fractions were 38.3 % and 22.9 % in China and Ghana, respectively. Less education (8.3 %), smoking (6.3 %), and physical inactivity (5.7 %) showed the highest attributable fraction for dementia. The overall attributable fraction was higher in the poorest (38.1 %) than in the richest (30.9 %) income quintile. The burden of obesity, diabetes, and hypertension was 61 % higher in the wealthiest than in the poorest population. A total of 7.2 million cases of dementia in these six low- and middle-income countries are potentially caused by these ten potentially modifiable risk factors. ConclusionsOverall, 38 % of cases of dementia in China, South Africa, Ghana, India, Russia, and Mexico can be attributable to ten potentially modifiable risk factors. Cardiometabolic risk factors account for a more significant burden of dementia in the wealthiest population. Less education had the highest population attributable fraction independent of living area and income.

Rural-urban disparities in the diagnosis and treatment of hypertension and diabetes among aging Indians.

Hypertension and diabetes are modifiable risk factors for dementia. We aimed to assess rural-urban disparities in the diagnosis and treatment of these conditions among aging Indians. Participants (n=6316) were from two parallel, prospective aging cohorts in rural and urban India. Using self-report and clinical/biochemical assessments, we subdivided participants with diabetes and hypertension into undiagnosed and untreated groups. Logistic regression and Fairlie decomposition analysis were the statistical methods utilized. There was a significant rural-urban disparity in undiagnosed hypertension (25.14%), untreated hypertension (11.75%), undiagnosed diabetes (16.94%), and untreated diabetes (11.62%). Further, sociodemographic and lifestyle factors, such as age and tobacco use were the common contributors to the disparities in both undiagnosed hypertension and undiagnosed diabetes, whereas education and body mass index (BMI) were significant contributors to the disparity in untreated hypertension. Rural Indians face significant healthcare disadvantages as compared to their urban counterparts, which prompts the urgent need for strategies for equitable healthcare.

Associations between multidomain modifiable dementia risk factors with AD biomarkers and cognition in middle-aged and older adults

This study aimed to determine associations between modifiable dementia risk factors (MDRF), across domains mood symptomatology, lifestyle behaviors, cardiovascular conditions, cognitive/social engagement, sleep disorders/symptomatology, with cognition, beta-amyloid (Aβ) and tau, and brain volume. Middle-aged/older adults (n=82) enrolled in a sub-study of the Healthy Brain Project completed self-report questionnaires and a neuropsychological battery. Cerebrospinal fluid levels of Aβ 1–42, total tau (t-tau), and phosphorylated tau (p-tau181) (Roche Elecsys), and MRI markers of hippocampal volume and total brain volume were obtained. Participants were classified as no/single domain risk (≤1 domains) or multidomain risk (≥2 domains). Compared to the no/single domain risk group, the multidomain risk group performed worse on the Preclinical Alzheimer’s Cognitive Composite (d=0.63, p=.005), and Executive Function (d=0.50, p=.016), and had increased p-tau181 (d=0.47, p=.042) and t-tau (d=0.54, p=.021). In middle-aged/older adults, multidomain MDRFs were related to increases in tau and worse cognition, but not Aβ or brain volume. Findings suggest that increases in AD biomarkers are apparent in midlife, particularly for individuals with greater burden, or variety of MDRFs.

Epilepsy and epileptiform activity in late-onset Alzheimer disease: clinical and pathophysiological advances, gaps and conundrums.

A growing body of evidence has demonstrated a link between Alzheimer disease (AD) and epilepsy. Late-onset epilepsy and epileptiform activity can precede cognitive deterioration in AD by years, and its presence has been shown to predict a faster disease course. In animal models of AD, amyloid and tau pathology are linked to cortical network hyperexcitability that precedes the first signs of memory decline. Thus, detection of epileptiform activity in AD has substantial clinical importance as a potential novel modifiable risk factor for dementia. In this Review, we summarize the epidemiological evidence for the complex bidirectional relationship between AD and epilepsy, examine the effect of epileptiform activity and seizures on cognition in people with AD, and discuss the precision medicine treatment strategies based on the latest research in human and animal models. Finally, we outline some of the unresolved questions of the field that should be addressed by rigorous research, including whether particular clinicopathological subtypes of AD have a stronger association with epilepsy, and the sequence of events between epileptiform activity and amyloid and tau pathology.

Modifiable dementia risk factors and AT(N) biomarkers: findings from the EPAD cohort.

Modifiable risk factors account for a substantial proportion of Alzheimer's disease (AD) cases and we currently have a discrete AT(N) biomarker profile for AD biomarkers: amyloid (A), p-tau (T), and neurodegeneration (N). Here, we investigated how modifiable risk factors relate to the three hallmark AT(N) biomarkers of AD. Participants from the European Prevention of Alzheimer's Dementia (EPAD) study underwent clinical assessments, brain magnetic resonance imaging, and cerebrospinal fluid collection and analysis. Generalized additive models (GAMs) with penalized regression splines were modeled in the AD Workbench on the NTKApp. A total of 1,434 participants were included (56% women, 39% APOE ε4+) with an average age of 65.5 (± 7.2) years. We found that modifiable risk factors of less education (t = 3.9, p < 0.001), less exercise (t = 2.1, p = 0.034), traumatic brain injury (t = -2.1, p = 0.036), and higher body mass index (t = -4.5, p < 0.001) were all significantly associated with higher AD biomarker burden. This cross-sectional study provides further support for modifiable risk factors displaying neuroprotective associations with the characteristic AT(N) biomarkers of AD.

ENHANCE: a comparative prospective longitudinal study of cognitive outcomes after 3 years of hearing aid use in older adults.

With an aging population, the prevalence of hearing loss and dementia are increasing rapidly. Hearing loss is currently considered the largest potentially modifiable risk factor for dementia. The effect of hearing interventions on cognitive function should therefore be investigated, as if effective, these may be successfully implemented to modify cognitive outcomes for older adults with hearing loss. This prospective longitudinal observational cohort study compared outcomes of a convenience sample of prospectively recruited first-time hearing aid users without dementia from an audiology center with those of community-living older adults participating in a large prospective longitudinal cohort study with/without hearing loss and/or hearing aids. All participants were assessed at baseline, 18 months, and 36 months using the same measures. Participants were 160 audiology clinic patients (48.8% female patient; mean age 73.5 years) with mild-severe hearing loss, fitted with hearing aids at baseline, and 102 participants of the Australian Imaging, Biomarkers and Lifestyle Flagship Study of Aging (AIBL) (55.9% female patient; mean age 74.5 years). 18- and 36-month outcomes of subsets of the first participants to reach these points and complete the cognition assessment to date are compared. Primary comparative analysis showed cognitive stability for the hearing aid group while the AIBL group declined on working memory, visual attention, and psychomotor function. There was a non-significant trend for decline in visual learning for the AIBL group versus no decline for the hearing aid group. The hearing aid group showed significant decline on only 1 subtest and at a significantly slower rate than for the AIBL participants (p < 0.05). When education effects on cognitive trajectory were controlled, the HA group still performed significantly better on visual attention and psychomotor function (lower educated participants only) compared to the AIBL group but not on working memory or visual learning. Physical activity had no effect on cognitive performance trajectory. Hearing aid users demonstrated significantly better cognitive performance to 3 years post-fitting, suggesting that hearing intervention may delay cognitive decline/dementia onset in older adults. Further studies using appropriate measures of cognition, hearing, and device use, with longer follow-up, are required.

1955 Multimodal critical discourse analysis of current representations of hearing loss in the UK news media

Abstract Introduction Hearing loss (HL) affects 12 million UK adults, including 70% of those aged over 70 years. It is associated with social isolation, anxiety, and depression. Furthermore, HL in midlife is the largest modifiable risk factor for dementia. However, many individuals delay or avoid treatment. This may be due to limited understanding of HL amongst the public, and the considerable stigma surrounding HL and hearing aids. The media play a crucial role in shaping public perceptions of age-related conditions. Therefore, this study investigated representations of HL in UK newspapers, especially representations of the relationship between HL and mental health. Method Using Nexis (a news database), 7173 newspaper articles featuring HL between May 2022-May 2023 were retrieved. Following screening, 20 articles were analysed using multimodal critical discourse analysis. This qualitative approach regards communicative choices (here, images and text) as able to both reflect and shape society, including propagating or challenging stigma. A Patient and Public Involvement (PPI) panel contributed to study design and data interpretation. Results Most articles featured young adults with HL, particularly celebrities. Whilst this could challenge the stereotype that HL only affects older adults, it could also increase the invisibility of older adults in the media. Many articles contained inspirational stories, which may help reduce the stigma of HL. However, some people with HL do not want to be portrayed differently to other people. Some articles discussed HL and mental health, especially its association with dementia, loneliness, and depression. PPI contributors indicated that newspapers should provide diverse HL representations and should help improve public awareness of this condition, especially its impact on mental health. Discussion This research has important implications for clinicians, researchers, charities, the media, and all those who communicate with the public about HL. Future research should investigate HL representations in other media, particularly social media.

Impact of airborne particulate matter exposure on hospital admission for Alzheimer's disease and the attributable economic burden: evidence from a time-series study in Sichuan, China

BackgroundAlzheimer's disease (AD) and other forms of dementia are the seventh leading cause of death. Studies discern the inclusion of air pollution among modifiable risk factors for dementia, while limited studies are for China. This study aims to examine the short-term association between airborne particulate matter (PM) and the hospitalizations of AD, including the economic costs in China.MethodsA total of 4975 cases of AD patients hospitalized from 2017 to 2019, were collected from nine city and 411 medical institutions in Sichuan Province, China. Data on air pollutants such as PM2.5, PM10, and NO2 were obtained from 183 air quality monitoring stations in Sichuan Province. A time series-generalized additive model was used to estimate the association between short-term exposure to PM (lag1–lag7 and moving average lag01–lag07) and AD hospital admissions (HAs), stratified by gender, age, and season.ResultsPositive short-term exposure to airborne PM was found for the HAs of AD. The greatest effect on the number of AD inpatients was on single-day lag1 (PM2.5:1.034 (95% confidence interval (CI) 1.011, 1.058)). The association was also significant in the two-pollutant model. In the study period, 16.48% of AD HAs were attributed to the effect of PM. The total economic costs of AD attributable to PM exposure were US$ 2.56 million, including US$ 2.25 million of direct medical costs and US$ 0.31 million of indirect economic costs.ConclusionsThis study suggests that short-term exposure to airborne PM may increase the risk of AD HAs in Sichuan Province and result in associated economic costs.

Disparate Dementia Risk Factors Are Associated with Cognitive Impairment and Rates of Decline in African Americans.

This study was undertaken to evaluate the frequency of modifiable dementia risk factors and their association with cognitive impairment and rate of decline in diverse participants engaged in studies of memory and aging. Modifiable dementia risk factors and their associations with cognitive impairment and cognitive decline were determined in community-dwelling African American (AA; n = 261) and non-Hispanic White (nHW; n = 193) participants who completed ≥2 visits at the Mayo Clinic Alzheimer Disease Research Center in Jacksonville, Florida. Risk factors and their associations with cognitive impairment (global Clinical Dementia Rating [CDR] ≥ 0.5) and rates of decline (CDR Sum of Boxes) in impaired participants were compared in AA and nHW participants, controlling for demographics, APOE ɛ4 status, and Area Deprivation Index. Hypertension, hypercholesterolemia, obesity, and diabetes were overrepresented in AA participants, but were not associated with cognitive impairment. Depression was associated with increased odds of cognitive impairment in AA (odds ratio [OR] = 4.30, 95% confidence interval [CI] = 2.13-8.67) and nHW participants (OR = 2.79, 95% CI = 1.21-6.44) but uniquely associated with faster decline in AA participants (β = 1.71, 95% CI = 0.69-2.73, p = 0.001). Fewer AA participants reported antidepressant use (9/49, 18%) than nHW counterparts (57/78, 73%, p < 0.001). Vitamin B12 deficiency was also associated with an increased rate of cognitive decline in AA participants (β = 2.65, 95% CI = 0.38-4.91, p = 0.023). Modifiable dementia risk factors are common in AA and nHW participants, representing important risk mitigation targets. Depression was associated with dementia in AA and nHW participants, and with accelerated declines in cognitive function in AA participants. Optimizing depression screening and treatment may improve cognitive trajectories and outcomes in AA participants. ANN NEUROL 2024;95:518-529.

ASSOCIATIONS OF VISUAL IMPAIRMENTS AND OCULAR DISEASE WITH BRAIN VOLUMES AND DEMENTIA IN UK BIOBANK

Abstract Visual impairments and ocular diseases are emerging potentially modifiable risk factors for dementia, however, causal relationships are poorly understood and vision impairment may also impact dementia evaluations. Few studies have examined associations of multiple measures of visual impairments with markers of neurodegeneration. We investigated associations of visual acuity and history of ocular diseases with dementia and brain MRI outcomes. UK Biobank participants aged 40-70 without dementia at assessment (n=496,938) self-reported history of cataract, glaucoma, age-related macular degeneration Subsets had visual acuity exams and refractive error measured by autorefractor (n=117,163) and brain MRIs (n=33,923). In cox proportional-hazard models adjusted for demographics and other health conditions, history of cataracts was associated with higher risk of all-cause dementia (HR:1.19: 95%CI: 1.09-1.31) but other eye conditions were not associated. History of cataract was associated with significantly smaller total gray matter volume (β=-2483 mm3, 95% CI: -4225 to -741) but not an AD brain signature based on cortical thickness. Worse than 20/40 visual acuity was associated with dementia (HR = 1.40, 95% CI: 1.11-1.77) but myopia defined based on refractive error was not, and neither were associated with total or regional volumes on brain MRI. History of cataract and binary 20/40 vision are associated with dementia risk. Our results suggest that cataract, but not myopia, may increase risk of neurodegeneration independent of typical AD, but more investigation is needed.

TOXIC CHEMICAL EMISSIONS AND DEMENTIA RISK: RESULTS FROM THE CARDIOVASCULAR HEALTH COGNITION STUDY

Abstract Air pollution is a modifiable risk factor for dementia. Yet, studies on specific forms of air pollution (e.g., toxic chemical emissions from industrial facilities) and dementia risk are underexplored. We examined associations between toxicity-weighted concentrations of industrial pollution and dementia outcomes among a large, multi-site cohort of older adults. Participants (n=2,770) were ≥ 65 years old (M=75.3, SD=5.1 years) from the Cardiovascular Health Cognition Study. Toxicity-weighted concentrations were estimated using the Risk Screening Environmental Indicator (RSEI) model which incorporates total reported chemical emissions with toxicity, fate, and transport models. Estimates were aggregated to participants’ baseline census tract, averaged across 1988-1992, and log10-transformed. Dementia status was clinically adjudicated in 1998-1999 (M=5.2 person-periods) by subtype (all-cause, Alzheimer’s, vascular, mixed). We assessed whether RSEI-estimated toxicity-weighted concentrations were associated with: 1) odds of prevalent dementia and 2) incident dementia risk by subtype. After adjusting for individual and neighborhood-level covariates, a 1-unit increase in log10-toxicity was associated with a 34% increase in the odds of prevalent dementia (OR=1.34, 95% CI: 1.01, 1.78). In discrete-time survival models, each 1-unit increase in log10-toxicity was associated with a 65% increased hazard of vascular dementia (HR=1.65, 95% CI: 1.04, 2.61) but was not significantly associated with all-cause, Alzheimer’s disease, or mixed dementia. Living in regions with higher toxic air emissions was associated with greater odds of prevalent dementia and a heightened risk of incident vascular dementia. Results suggest that the RSEI model may be a novel screening tool for examining associations between toxic chemical releases and dementia risk.

Sarcopenia and diabetes-induced dementia risk.

This study aimed to investigate whether sarcopenia independently increases the risk of diabetes-induced dementia in elderly individuals diagnosed with type 2 diabetes mellitus. The study cohort consisted of a large sample of elderly individuals aged 60 years and above, who were diagnosed with type 2 diabetes mellitus between 2008 and 2018. To minimize potential bias and achieve covariate balance between the sarcopenia and non-sarcopenia groups, we employed propensity score matching. Various statistical analyses, including Cox regression models to assess dementia risk and associations, competing risk analysis to account for mortality and Poisson regression analysis for incidence rates, were used. Before propensity score matching, the study included 406 573 elderly type 2 diabetes mellitus patients, with 20 674 in the sarcopenia group. Following propensity score matching, the analysis included a total of 41 294 individuals, with 20 647 in the sarcopenia group and 20 647 in the non-sarcopenia group. Prior to propensity score matching, elderly type 2 diabetes mellitus patients with sarcopenia exhibited a significantly higher risk of dementia (adjusted hazard ratio: 1.12, 95% confidence interval: 1.07-1.17). After propensity score matching, the risk remained significant (adjusted hazard ratio: 1.14, 95% confidence interval: 1.07-1.21). Incidence rates of dementia were notably higher in the sarcopenia group both before and after propensity score matching, underscoring the importance of sarcopenia as an independent risk factor. Our study highlights sarcopenia as an independent risk factor for diabetes-induced dementia in elderly type 2 diabetes mellitus patients. Advanced age, female gender, lower income levels, rural residency, higher adapted diabetes complication severity index and Charlson Comorbidity Index scores and various comorbidities were associated with increased dementia risk. Notably, the use of statins was linked to a reduced risk of dementia. This research underscores the need to identify and address modifiable risk factors for dementia in elderly type 2 diabetes mellitus patients, offering valuable insights for targeted interventions and healthcare policies.

Unsupervised detection of dementia based on longitudinal data from the Survey of Health, Ageing and Retirement in Europe

AbstractBackgroundIn the Survey of Health, Ageing and Retirement in Europe (SHARE), a population‐based survey of aging in multiple countries, dementia status is self‐reported. However, more than half of dementia cases remain underdiagnosed, which may hinder the use of SHARE data to study dementia determinants and outcomes. We use unsupervised machine learning and longitudinal data from SHARE to discover clusters of patients with probable dementia.MethodsWe selected participants aged 50 or more with consecutive follow‐ups across all SHARE prospective waves. We chose variables informative of participants’ daily function and cognitive performance. We applied a Multiple Factor Analysis followed by a Hierarchical Clustering to the whole longitudinal data set. To evaluate our algorithm, we looked at its discrimination power by comparing it to the self‐reported dementia. We also checked if increased risk of transition to probable dementia was associated with non‐modifiable (age, sex) and modifiable (education, hypertension, obesity, hearing loss, diabetes, physical inactivity, smoking, drinking alcohol, social isolation, depression, air pollution) dementia risk factors. Finally, we replicated this study in the English Longitudinal Survey of Aging (ELSA).ResultsThe baseline sample consisted of 15,278 initial participants across 12 countries. The algorithm identified a higher number of probable dementia cases compared with self‐reported cases. Its discriminative power was good discriminative power across all waves (Area Under the Curve &gt; 0.75). Sensitivity attained its highest value at wave 4 reaching 0.71 [0.66–0.77]. Specificity remained high (&gt; 0.9) in all waves. Both non‐modifiable and modifiable dementia risk factors were associated with increased risk of transition to probable dementia. These results were replicated in ELSA.ConclusionDetection of probable dementia with longitudinal data and unsupervised clustering could be used to study dementia in SHARE and ELSA cohorts. Further validation of this method is needed to apply it in other surveys of aging.

A Multivariate Genome‐Wide Association Study of the Shared Genetic Architecture Among Modifiable Risk Factors for Dementia: 590 Loci Associated with Brain Health

AbstractBackgroundTargeting modifiable risk factors may prevent or delay dementia. The mechanisms by which some risk factors influence dementia remain unclear and commonality between risk factors is often overlooked. We aimed to characterize the shared genetic architecture of modifiable risk factors for dementia, and use this to explore whether shared pathways influence dementia pathogenesis and brain health.MethodWe performed two multivariate genome‐wide association studies (GWAS) to characterize the shared genetic architecture of 12 modifiable risk factors for dementia using genomic structural equation modeling (GSEM). One GWAS measured genetic associations with 3 latent subgroups of closely correlated risk factors, whereas our second GWAS measured genetic associations shared across all 12 risk factors (Figure 1). We tested whether the associated variants were enriched in neuronal/glial subtypes and epigenetic marks found in different brain regions using stratified‐GSEM and identified potentially causal genes for each of the latent factors using gene mapping techniques and summary‐data‐based Mendelian randomization. Pathway analysis was conducted to examine whether the prioritized genes were implicated in dementia‐related biological pathways.ResultWe identified 305 genome‐wide significant loci for the 3‐factor model of modifiable dementia risk and 285 genome‐wide significant loci for the Common Factor. Thirty‐four of these loci were novel (not previously associated with any phenotype by GWAS). Post‐GWAS analyses uncovered multiple links between the shared risk factor loci and dementia pathogenesis. Stratified‐GSEM showed that shared risk factor variants are significantly enriched in regions of the brain that degenerate in dementia, including the hippocampus and prefrontal cortex. Gene mapping identified potentially shared causal genes between risk factor loci and Alzheimer’s disease (AD) loci. Pathway analysis indicated that our prioritized genes were enriched in AD pathways, protein aggregation and neuronal cell signaling. Mendelian randomization provided evidence for a causal role of the shared risk factor variants in AD pathogenesis.ConclusionWe highlight multiple genomic regions where genetic overlap between modifiable risk factors seems to directly influence dementia‐related pathways in regions of the brain that are known to degenerate in dementia. Our findings provide novel insights into the potential biological mechanisms by which modifiable risk factors may increase risk for dementia.

Cataract, cataract surgery, and risk of incident dementia: a prospective cohort study of 300,823 participants

AbstractBackgroundConsidering the increasing rate of cataract surgery and postoperative efficacy, the cataract may be one of the most modifiable risk factors for dementia if surgery reverses the increased risk of dementia caused by cataract.MethodWe used multivariate Cox proportional hazard regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations, with healthy controls as a reference. The same method was used to explore the effects of surgery on the dementia outcomes of cataract patients.ResultMultivariable Cox proportional hazard models showed that the non‐surgical cataract group had a 21.4% increased risk of ACD (HR: 1.214, 95% CI = 1.012‐1.456, P = 0.037) and a 47.9% increased risk of AD (HR: 1.479, 95% CI = 1.105‐1.981, P = 0.009) in the fully adjusted model. However, there was no difference in dementia risk between the cataract surgery group and the healthy control. Cataract surgery was associated with decreased risk of ACD (HR: 0.632, 95% CI = 0.421‐0.947, P = 0.026) and AD (HR: 0.399, 95% CI = 0.196‐0.812, P = 0.011) compared with non‐surgical group.ConclusionOur study supports the hypothesis that cataract surgery reverses the risk of dementia, providing new insights into the prevention and treatment of dementia. Cataract should be considered a significant modifiable risk factor for dementia in dementia prevention strategies.

Kidney function and risk of incident dementia in 202,702 UK Biobank participants

AbstractBackgroundPoorer kidney function could represent a novel modifiable risk factor for dementia, however previous findings are inconclusive. In the current study, we utilized a large population‐based cohort with long follow‐up to investigate whether glomerular filtration rate (GFR), an indicator of kidney function, and albuminuria, an indicator of kidney damage, were associated with an increased risk of all‐cause dementia.MethodThe sample consisted of 202,702 UK Biobank participants aged ≥60 years and free from dementia and end‐stage kidney disease at baseline between 2006‐2010. Estimated GFR was derived from serum creatinine and cystatin C (eGFRcr‐cys) and categorized as ≥90 (normal/high function), 60‐89 (mildly decreased function) and &lt;60 ml/min/1.73m2 (moderately/severely decreased function). Albuminuria was defined using the urinary albumin to creatinine ratio (ACR). ACR was categorized into &lt;3 (normal/mildly increased), 3‐30 (moderately increased), and &gt;300 (severely increased) mg/mmol. Incident dementia was determined through cohort‐wide linkage to hospital and death records. The associations were assessed using Cox proportional‐hazard models adjusted for age, sex, ethnicity, socioeconomic status, education, household income, country, smoking status, alcohol intake, body mass index, hypertension, diabetes, and APOE‐ε4 allele status.ResultOver 15 years of follow‐up, 6,042 participants developed incident dementia. The fully‐adjusted Hazard Ratios (HR) were 1.00 (95% Confidence Interval [CI] 0.94‐1.06) and 1.42 (95% CI 1.28‐1.58) for eGFRcr‐cys 60‐89 and &lt;60 respectively, compared to ≥90 ml/min/1.73m2. Moderately/severely decreased eGFRcr‐cys remained associated with incident dementia after restricting to participants with more than 10 years of follow‐up (HR = 1.33, 95% CI 1.13‐1.56). The HRs for moderate and severely increased ACR were 1.16 (95% CI 1.07‐1.26) and 2.24 (95% CI 1.79‐2.80), respectively, compared to normal/mildly increased ACR (&lt;3mg/mmol). Dose‐response associations were observed when combining eGFRcr‐cys and ACR, with those in the severest eGFRcr‐cys and ACR group having the greatest risk of dementia (HR = 4.70, 95% CI 2.34‐9.43).ConclusionKidney dysfunction and albuminuria were associated with a higher risk of incident all‐cause dementia. These findings provide additional evidence that kidney dysfunction could be a potential modifiable risk factor for dementia or target for identifying those at high risk of the condition.

Indigenous individuals present distinct modifiable risk factors of dementia than white individuals: an ELSI‐Brazil study

AbstractBackgroundRisk factors for dementia have distinct frequency and impact according to racial origins. Our aim was to identify differences of modifiable risk factors of dementia related to Indigenous and White individuals, estimate their Population Attributable Fraction (PAF) and highlight the differences between races.MethodsAn epidemiological cohort named ELSI‐Brazil was used to estimate the prevalence of 10 modifiable risk factors for dementia among 2 races ‐ White and Indigenous. he ELSI‐Brazil cohort consists of 9412 individuals (63.55+‐10.14 years of age). This cohort comprises individuals at/ or above 50 years of age from across the country. Complex sampling warrants nationwide representativity for diseases with low prevalence. Races were self‐reported according to the Brazilian Census. Sample weighting was used to estimate the prevalence and PAF of each risk factor in each race.ResultsAmong 3810 individuals included, 220 were Indigenous individuals. The Indigenous were younger (mean age 62.6 [±9.6] years) and less educated (mean 4.3 [±4.0] years) than the White (mean age 64 years [±10.2], mean education years 6.2 [±4.4]). Both were composed by most females. The most important weighted PAF were hearing loss for both races (Indigenous 16.7%; White 15.2%). The most prevalent risk factor for both were less education, which were higher in Indigenous individuals (69.5%) than in White individuals (55.1%). By contrast, social isolation was less prevalent in Indigenous (1.5%) than White (5.1%). Overall adjusted PAF was lower in Indigneous (38.9%), compared to White (49,2%).ConclusionWhite and Indigenous presented different prevalence of risk factors, though they had hearing loss as the most impacting risk factor for dementia. However, it seemed that Ocidental risk factors didn’t produce the same effect in indigenous individuals as in white individuals. Thus, indigenous individuals presented a distinct profile of risk factors of dementia than individuals from other self‐reported races.

Socioeconomic variation in modifiable risk factors for dementia

AbstractBackgroundMost studies on modifiable risk factors for dementia are in relatively affluent populations, but dementia risk is higher among those who are more materially deprived. We aimed to consider whether this is accounted for by potentially modifiable risk factors, and compare the overall population attributable fraction (PAF) in the least and most socioeconomically deprived participants within the UK Biobank (UKB).MethodThe UKB is a cohort study with 502,656 volunteer participants registered between 2006‐2010, aged 40‐60 years at baseline, and followed for up to 16.8 years. Material deprivation was quantified using the Townsend Deprivation Index grouped into quintiles, with higher scores meaning higher deprivation. We assessed interactions between Townsend quintiles (using least deprived as reference), and each modifiable risk factor. To estimate the PAFs of 12 modifiable risk factors (diabetes, hypertension, depression, hearing loss, obesity, traumatic brain injury, less education, social isolation, physical inactivity, air pollution, and smoking), we first estimated hazard ratios (HRs) (adjusted for age, gender, and ethnicity) stratified by Townsend. HRs were then converted to relative risk for PAF calculation.Results6,624 incident cases of dementia developed in 1.6%(95%CI = 1.5‐1.7)(n = 11679/10369) of participants in the most deprived group, compared to 1.2%(95%CI = 1.1‐1.3)(n = 1174/98074) in the least deprived group. The mean age at dementia diagnosis were 72.7 years(SD,6.3){in most deprived}, and 73.8 years(SD,5.1){in least deprived}. The combined PAF(95%CI) for dementia was 40.3%(40.0‐40.6){most deprived}, versus 27.2%(27.0‐27.5){least deprived}. The most deprived, compared to the least deprived, had higher PAFs for: (a)Midlife hypertension: 7.7%(7.6‐7.9) vs 4.1%(3.9‐4.2); (b)Less education: 5.8%(5.6‐5.9) vs 3.4%(3.2‐3.6); (c)Diabetes: 4.4%(4.3‐4.6) vs 3.1%(3.0‐3.2); (d)Physical inactivity: 3.5%(3.4‐3.6) vs 0.7%(0.6‐0.7);) (e)Social isolation: 3.4%(3.3‐3.5) vs 1.0%(1.0‐1.1); (f)Midlife obesity: 2.1%(2.0‐2.2) vs 1.2%(1.2‐1.3); and (g)Smoking 1.8%(1.7‐1.9) vs 0.5%(0.5‐0.6). Air pollution had a PAF of 1.8%(1.7‐1.9) in the least deprived, and 0.0% in the most deprived. The remaining risk factor PAFs did not differ between the most and least deprived.ConclusionsIn this volunteer cohort, which is relatively wealthy, a higher proportion of dementia cases were attributable to major modifiable risk factors in more socioeconomically disadvantaged participants. Targeted interventions particularly addressing midlife hypertension, education, physical activity and social isolation might mitigate known inequalities in dementia risk according to socioeconomic status.

Association between Anemia and Dementia in Korea older adults: A national cohort study

AbstractBackgroundAs the global elderly population increases, the prevalence of dementia is also increasing. Korea is one of the rapidly aging countries in the world, and 10.33% of elderly people aged 65 and older are receiving treatment for dementia as reported in 2021. Since disease modifying drugs have not yet been developed for dementia, the importance of modifiable risk factors that can lower the risk of dementia is being emphasized, and one of them is anemia in the elderly. We analyze national cohort data of approximately 20 years to disclose the relationship between anemia and dementia in Korean elderly, and suggest that anemia is a modifiable risk factor for dementia needed active intervention.MethodWe analyzed a large population‐based cohort study of aged ³65 years who participated in the national health screening program including blood tests and cognitive function tests from 2007 to 2008 in Korean National Health Insurance Service database 2006‐2020. The risk of AD according to the presence and severity of anemia was evaluated using a multivariable Cox regression model, after adjustments for sex, BMI, HTN, DM, LDL, TG, SCr, GFR and past medical history (depression, HTN, DM, cardiovascular disease, cerebrovascular disease).ResultAs a result of the analysis, dementia occurred in 27.9% of the total subjects (316,881 persons) during the follow‐up period until 2020. Also, dementia occurred in 27.5% of the normal group, but 30.1% of the anemia group. As a result of survival analysis, even after adjusting for sex, there was a statistically significant difference between the presence of anemia and the prevalence of dementia (HR 1.07, 95% CI 1.05‐1.09). In addition, even after adjusting for sex, BMI, HTN, DM, LDL, SCr, GFR, and past medical history, there was a statistically significant association between anemia and dementia (HR 1.05, 95% CI 1.03‐1.07).ConclusionWe reported that the presence of anemia statue and the severity of anemia in the elderly were related to the occurrence of dementia through a national date of Korea. We suggest that anemia is a modifiable risk factor for dementia and requires intensive intervention in the elderly.