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.

Physical activity initiated from midlife on risk of dementia and cognitive impairment: The Health and Retirement Study.

BACKGROUND: Physical activity is associated with lower risk of dementia and cognitive impairment, but existing randomized controlled trials have shown conflicting results. As cognitive decline occurs decades before the onset of dementia, physical activity interventions initiated in late life may have missed the potential window for prevention. An ideal trial of physical activity initiated from midlife and lasts till incident dementia and cognitive impairment in late life is not feasible. We aimed to estimate the effectiveness of a hypothetical physical activity intervention initiated from midlife on reducing dementia and cognitive impairment by emulating target trials using observational data. METHODS: The Health and Retirement Study was used to emulate target trials among noninstitutionalized participants aged 45 to 65 years with normal cognition who were physically inactive in the previous 2 years. Cognitive status was determined based on Langa-Weir classification of cognitive function (including immediate and delayed word recall tests, serial sevens subtraction, counting backward). Individuals were categorized as initiating physical activity or not, based on the self-reported physical activity. Intention-to-treat and per-protocol analysis were conducted with pooled logistic regression models with inverse-probability of treatment and censoring weights to estimate risk ratios (RRs), and 95% confidence intervals (95% CIs) were calculated with 200 sets of bootstrapping. RESULTS: Among 1505 participants (average age 57.6 ± 4.8 years, 67% women, 76.5% White), 72 cases of dementia and 409 cases of cognitive impairment occurred. After 12 years of follow-up, physical activity reduced dementia (RR = 0.70, 95% CI: 0.43, 0.99) for intention-to-treat analysis, and reduced dementia (RR = 0.51, 95% CI: 0.19, 0.99) and cognitive impairment (RR = 0.77, 95% CI: 0.61, 0.92) for per-protocol analysis. No significant reduction was found among older adults. CONCLUSIONS: Physical activity initiated during midlife may reduce dementia and cognitive impairment in late life, which highlights the importance of preventing cognitive outcomes at an earlier stage of life.

Supplemental Nutrition Assistance Program and depressive symptoms among adults with low family income in the U.S.: The National Health and Nutrition Examination Survey 2011-2018.

BACKGROUND: The Supplemental Nutrition Assistance Program (SNAP) has been established to reduce food insecurity. Limited evidence is available on SNAP participation status over time and depressive symptoms. We aimed to examine the associations of SNAP status over time among low-income individuals, with depressive symptoms in the U.S. METHODS: NHANES participants aged ≥20 years of low family income from 2011 to 2018 with information available on depressive symptoms and SNAP use were included in analysis. Depressive symptoms were assessed using 9-item Patient Health Questionnaire (PHQ-9), and PHQ-9 score ≥ 10 is indicative of significant depressive symptoms. Multivariable linear and logistic regressions models were conducted to examine the associations of SNAP participation status over time (never receiving SNAP, receiving SNAP prior to >12 months ago, current receiving SNAP, receiving SNAP in the last 12 months but not currently) with depressive symptoms and significant depressive symptoms. RESULTS: Currently receiving SNAP (beta (ß) = 0.17, 95 % CI: 0.10, 0.25; odds ratio (OR) = 1.52, 95 % confidence interval (CI): 1.16, 2.00) and receiving SNAP in the last 12 months but not currently (ß = 0.24, 95 % CI: 0.04, 0.43; OR = 1.83, 95 % CI: 1.16, 2.89) were associated with higher depressive symptoms and higher prevalence of significant depressive symptoms. LIMITATIONS: The cross-sectional design precludes causal interpretation, and key variables were measured with self-report. CONCLUSION: Receiving SNAP in the last 12 months was associated with higher levels of depressive symptoms among individuals with low family income. Improvement on diet quality may be important for reducing depressive symptoms among SNAP users.

Modifiable and Non-Modifiable Risk Factors for Dementia Among Non-Hispanic White and Black Populations Aged 50-64 in the United States, 2006-2016.

BACKGROUND AND OBJECTIVES: Non-Hispanic Black populations (NHB) have a significantly higher prevalence of dementia than non-Hispanic Whites in the U.S., and the underlying risk factors may play a role in this racial disparity. We aimed to calculate risk scores for dementia among non-Hispanic White (NHW) and non-Hispanic Black populations aged 50-64 years over a period of 10 years, and to estimate potential differences of scores between NHW and NHB. RESEARCH DESIGN AND METHODS: The Health and Retirement Study from 2006 to 2016 was used to calculate the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) risk score, a validated score for predicting dementia risk. Weighted average CAIDE score, as well as CAIDE score for modifiable factors hypertension, obese, hypercholesterolemia, physical inactivity), and non-modifiable factors (age, sex, education) were calculated for adults aged 50-64 years with normal cognition for 2006-2008, 2010-2012, 2014-2016. The associations of race with CAIDE score and elevated CAIDE score were examined. RESULTS: A total of 10,871 participants were included in the analysis. The CAIDE score showed declining trends for NHB from 2006 to 2016, while NHB consistently had a higher total CAIDE score and CAIDE score for modifiable factors from 2006 to 2016, but not for non-modifiable factors. DISCUSSION AND IMPLICATIONS: NHB had a higher level of dementia risk factors than NHW among adults aged 50-64 years in the U.S. from 2006 to 2016, and the difference is attributable to modifiable risk factors, which holds promise for risk reduction of dementia.

Trends in cause-specific mortality among persons with Alzheimer's disease in South Carolina: 2014 to 2019.

Introduction: Inconsistencies of reports contributes to the underreporting of Alzheimer's disease (AD) on death certificates. Whether underreporting exists within South Carolina has not been studied. Methods: We conducted a prospective, population-based study on a cohort of persons (N = 78,534) previously diagnosed with AD and died between 2014-2019. We linked vital records with the South Carolina Alzheimer's Disease and Related Dementias Registry to investigate their cause of death and survival rates. Descriptive analyses calculated frequencies of demographic and health-related characteristics. Turnbull's method estimated the survival probabilities for different subgroups of patients. Hazard ratios were computed from the Cox proportional hazards model, adjusting for the following confounding variables of age at diagnosis, education level, gender, and race. Results: The top immediate cause of death was Alzheimer's disease among all racial groups, except for Native American/American Indian. More females (60.3%) were affected by AD compared to males (39.7%). There is a 25% probability of survival, beyond 5 years, after AD diagnosis. Black/African American AD patients have the smallest risk of all-cause mortality across all racial/ethnic groups (HR 0.87; 95% CI, 0.85-0.89). Individuals with lower education had a lower likelihood of mortality. Conclusion: Although AD was not underreported in the state of South Carolina further research is needed to develop protocols around classification of deaths among those diagnosed with dementia and comorbidities, including cardiovascular disease, to ensure dementia is properly reported as we move to prevent and treat Alzheimer's disease by 2025 and beyond.

Features of the Physical and Social Neighborhood Environment and Neighborhood-Level Alzheimer's Disease and Related Dementia in South Carolina.

BACKGROUND: Studies are increasingly examining the relationship between the neighborhood environment and cognitive decline; yet, few have investigated associations between multiple neighborhood features and Alzheimer's disease and related dementias (ADRD). OBJECTIVE: We investigated the relationship between neighborhood features and ADRD cumulative incidence from 2010 to 2014 in the South Carolina Alzheimer's Disease Registry (SCADR). METHODS: Diagnosed ADRD cases ≥50 years of age were ascertained from the SCADR by ZIP code and census tract. Neighborhood features from multiple secondary sources included poverty, air pollution [particulate matter with a diameter of 2.5 micrometers or less (PM2.5)], and rurality at the census-tract level and access to healthy food, recreation facilities, and diabetes screening at the county level. In addition to using Poisson generalized linear regression to estimate ADRD incident rate ratios (IRR) with 95% confidence intervals (CIs), we applied integrated nested Laplace approximations and stochastic partial differential equations (INLA-SPDE) to address disparate spatial scales. We estimated associations between neighborhood features and ADRD cumulative incidence. RESULTS: The average annual ADRD cumulative incidence was 690 per 100,000 people per census tract (95% CI: 660, 710). The analysis was limited to 98% of census tracts with a population ≥50 years old (i.e., 1,081 of 1,103). The average percent of families living below the federal poverty line per census tract was 18.8%, and ∼20% of census tracts were considered rural. The average percent of households with limited access to healthy food was 6.4%. In adjusted models, every 5µg/m3) increase of PM2.5 was associated with 65% higher ADRD cumulative incidence (IRR=1.65; 95% CI: 1.30, 2.09), where PM2.5 at or below 12 µg/m3 is considered healthy. Compared to large urban census tracts, rural and small urban tracts had 10% (IRR=1.10; 95% CI: 1.00, 1.23) and 5% (IRR=1.05; 95% CI: 0.96, 1.16) higher ADRD, respectively. For every percent increase of the county population with limited access to healthy food, ADRD was 2% higher (IRR=1.02; 95% CI: 1.01, 1.04). CONCLUSIONS: Neighborhood environment features, such as higher air pollution levels, were associated with higher neighborhood ADRD incidence. The INLA-SPDE method could have broad applicability to data collected across disparate spatial scales. https://doi.org/10.1289/EHP13183.

Association between clusters of antibodies against periodontal microorganisms and Alzheimer disease mortality: Evidence from a nationally representative survey in the USA.

BACKGROUND: Alzheimer disease (AD) has been linked with periodontal microorganisms such as Porphyromonas gingivalis in observational and mechanistic studies. IgG antibodies against periodontal microorganisms which are markers of past and current periodontal infection have been correlated with cognitive impairment. We examined associations between empirically derived groups of 19 IgG antibodies against periodontal microorganisms and AD mortality. METHODS: Individuals participating in the Third National Health and Nutrition Examination Survey (NHANES III) with complete data on IgG titers were followed up between 1988 and December 31, 2019. The outcome was AD mortality, and the main exposures were IgG antibodies against periodontal microorganisms classified into four mutually exclusive groups using cluster analysis. Survey-weighted Cox proportional hazard models were used to evaluate adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for the relationship between clusters and AD mortality. RESULTS: With up to 21 years of follow-up, 160 AD-related deaths were documented. In the multivariable-adjusted model, AD mortality overall was not associated with the Red-Green (aHR 1.18; 95% CI, 0.46-3.07), Yellow-Orange (aHR 1.36; 95% CI, 0.58-3.19), Orange-Blue (aHR 0.63; 95%, CI, 0.33-1.21), and the Orange-Red (aHR 0.79; 95% CI, 0.37-1.70) when the upper tertiles were compared to the bottom tertiles. However, the subgroup of middle-aged individuals in the highest tertile of the Red-Green cluster, but not older individuals, had a 13% higher risk of AD mortality (aHR 1.13; 95% CI, 1.02-1.26) compared with those in the bottom tertile. CONCLUSION: Clusters of IgG antibodies against periodontal microorganisms did not predict AD mortality in this study.

Longitudinal Associations of Diet, Food Insecurity, and Supplemental Nutrition Assistance Program Use with Global Cognitive Performance in Middle-Aged and Older Adults.

BACKGROUND: Diet quality, food access, and food assistance policies may be key modifiable factors related to cognitive decline. OBJECTIVE: We aimed to evaluate whether diet quality, food insecurity, and Supplemental Nutrition Assistance Program (SNAP) use are associated with longitudinal changes in cognition among older adults in the United States. METHODS: Food intake data from the Health Care and Nutrition Study were linked with longitudinal health information from 5 waves of the Health and Retirement Study (2012-2020). The analytic sample (n = 6968) included community-dwelling United States adults aged ≥51 y without cognitive impairment. Global cognition was measured using a telephone-based cognitive status interview (range: 0-27). Diet quality was measured with the Healthy Eating Index, using participants' average intake of 13 dietary components. Questions regarding food access and affordability were used to determine food insecurity and use of SNAP benefits. Linear mixed-effects regression models were used to estimate longitudinal associations between diet-related factors and cognitive score changes. RESULTS: Poorer diets [ß: -0.24; 95% confidence interval (CI): -0.33, -0.15], food insecurity (ß: -1.08; 95% CI: -1.31, -0.85), and SNAP use (ß: -0.57; 95% CI: -0.82, -0.32) were associated with lower baseline cognitive scores. Poorer diets (ß: -0.17; 95% CI: -0.29, -0.05) and food insecurity (ß: -0.23; 95% CI: -0.47, -0.01) were associated with significantly steeper declines in cognitive scores over time, after 8 and 2 y of follow-up, respectively; however, SNAP use was not significantly associated with the rate of cognitive decline over time. Estimates were qualitatively similar when restricting the sample to participants aged ≥65 y. CONCLUSIONS: Results suggest that food access and adherence to healthy diet recommendations may be important elements to maintain cognitive health in aging. SNAP benefits may be insufficient to prevent negative cognitive effects of poor diet and limited access to nutritious foods.

Highlighting the value of Alzheimer's disease-focused registries: lessons learned from cancer surveillance.

Like cancer, Alzheimer's disease and related dementias (ADRD) comprise a global health burden that can benefit tremendously from the power of disease registry data. With an aging population, the incidence, treatment, and mortality from ADRD is increasing and changing rapidly. In the same way that current cancer registries work toward prevention and control, so do ADRD registries. ADRD registries maintain a comprehensive and accurate registry of ADRD within their state, provide disease prevalence estimates to enable better planning for social and medical services, identify differences in disease prevalence among demographic groups, help those who care for individuals with ADRD, and foster research into risk factors for ADRD. ADRD registries offer a unique opportunity to conduct high-impact, scientifically rigorous research efficiently. As research on and development of ADRD treatments continue to be a priority, such registries can be powerful tools for conducting observational studies of the disease. This perspectives piece examines how established cancer registries can inform ADRD registries' impact on public health surveillance, research, and intervention, and inform and engage policymakers.

Neighborhood Socioeconomic Status, Green Space, and Walkability and Risk for Falls Among Postmenopausal Women: The Women's Health Initiative.

PURPOSE: This study estimated associations between neighborhood socioeconomic status (NSES), walkability, green space, and incident falls among postmenopausal women and evaluated modifiers of these associations, including study arm, race and ethnicity, baseline household income, baseline walking, age at enrollment, baseline low physical functioning, baseline fall history, climate region, and urban-rural residence. METHODS: The Women's Health Initiative recruited a national sample of postmenopausal women (50-79 years) across 40 U.S. clinical centers and conducted yearly assessments from 1993 to 2005 (n = 161,808). Women reporting a history of hip fracture or walking limitations were excluded, yielding a final sample of 157,583 participants. Falling was reported annually. NSES (income/wealth, education, occupation), walkability (population density, diversity of land cover, nearby high-traffic roadways), and green space (exposure to vegetation) were calculated annually and categorized into tertiles (low, intermediate, high). Generalized estimating equations assessed longitudinal relationships. RESULTS: NSES was associated with falling before adjustment (high vs. low, odds ratio, 1.01; 95% confidence interval, 1.00-1.01). Walkability was significantly associated with falls after adjustment (high vs. low, odds ratio, 0.99; 95% confidence interval, 0.98-0.99). Green space was not associated with falling before or after adjustment. Study arm, race and ethnicity, household income, age, low physical functioning, fall history, and climate region modified the relationship between NSES and falling. Race and ethnicity, age, fall history, and climate region modified relationships between walkability and green space and falling. CONCLUSIONS: Our results did not show strong associations of NSES, walkability, or green space with falling. Future research should incorporate granular environmental measures that may directly relate to physical activity and outdoor engagement.