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Background Dysregulation of some metabolic factors increases the risk of dementia. It remains unclear if overall metabolic dysregulation, or only certain components, contribute to cognitive aging and if these associations are sex specific. Methods Data from the 2006–2016 waves of the Health and Retirement Study (HRS) was used to analyze 7 103 participants aged 65 and older at baseline (58% women). We created a metabolic-dysregulation risk score (MDRS) composed of blood pressure/hypertension status, glycosylated hemoglobin (HbA1c)/diabetes status, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and waist circumference, and assessed cognitive trajectories from repeated measures of the HRS-Telephone Interview for Cognitive Status (HRS-TICS) over 10 years of follow-up. Linear mixed-effects models estimated associations between MDRS or individual metabolic factors (biomarkers) with mean and change in HRS-TICS scores and assessed sex-modification of these associations. Results Participants with higher MDRSs had lower mean HRS-TICS scores, but there were no statistically significant differences in rate of decline. Sex stratification showed this association was present for women only. MDRS biomarkers revealed heterogeneity in the strength and direction of associations with HRS-TICS. Lower HRS-TICS levels were associated with hypertension, higher HbA1c/diabetes, and lower HDL-C and TC, whereas faster rate of cognitive decline was associated with hypertension, higher HbA1c/diabetes, and higher TC. Participants with higher HbA1c/diabetes presented worse cognitive trajectories. Sex differences indicated that women with higher HbA1c/diabetes to have lower HRS-TICS levels, whereas hypertensive males presented better cognitive trajectory. Conclusions Our results demonstrate that metabolic dysregulation is more strongly associated with cognition in women compared with men, though sex differences vary by individual biomarker.

BACKGROUND: Several studies in the new field of cognitive epidemiology have shown that higher intelligence predicts longer lifespan. This positive correlation might arise from socioeconomic status influencing both intelligence and health; intelligence leading to better health behaviours; and/or some shared genetic factors influencing both intelligence and health. Distinguishing among these hypotheses is crucial for medicine and public health, but can only be accomplished by studying a genetically informative sample.METHODS: We analysed data from three genetically informative samples containing information on intelligence and mortality: Sample 1, 377 pairs of male veterans from the NAS-NRC US World War II Twin Registry; Sample 2, 246 pairs of twins from the Swedish Twin Registry; and Sample 3, 784 pairs of twins from the Danish Twin Registry. The age at which intelligence was measured differed between the samples. We used three methods of genetic analysis to examine the relationship between intelligence and lifespan: we calculated the proportion of the more intelligent twins who outlived their co-twin; we regressed within-twin-pair lifespan differences on within-twin-pair intelligence differences; and we used the resulting regression coefficients to model the additive genetic covariance. We conducted a meta-analysis of the regression coefficients across the three samples.RESULTS: The combined (and all three individual samples) showed a small positive phenotypic correlation between intelligence and lifespan. In the combined sample observed r = .12 (95% confidence interval .06 to .18). The additive genetic covariance model supported a genetic relationship between intelligence and lifespan. In the combined sample the genetic contribution to the covariance was 95%; in the US study, 84%; in the Swedish study, 86%, and in the Danish study, 85%.CONCLUSIONS: The finding of common genetic effects between lifespan and intelligence has important implications for public health, and for those interested in the genetics of intelligence, lifespan or inequalities in health outcomes including lifespan. BACKGROUND: Several studies in the new field of cognitive epidemiology have shown that higher intelligence predicts longer lifespan. This positive correlation might arise from socioeconomic status influencing both intelligence and health; intelligence leading to better health behaviours; and/or some shared genetic factors influencing both intelligence and health. Distinguishing among these hypotheses is crucial for medicine and public health, but can only be accomplished by studying a genetically informative sample.METHODS: We analysed data from three genetically informative samples containing information on intelligence and mortality: Sample 1, 377 pairs of male veterans from the NAS-NRC US World War II Twin Registry; Sample 2, 246 pairs of twins from the Swedish Twin Registry; and Sample 3, 784 pairs of twins from the Danish Twin Registry. The age at which intelligence was measured differed between the samples. We used three methods of genetic analysis to examine the relationship between intelligence and lifespan: we calculated the proportion of the more intelligent twins who outlived their co-twin; we regressed within-twin-pair lifespan differences on within-twin-pair intelligence differences; and we used the resulting regression coefficients to model the additive genetic covariance. We conducted a meta-analysis of the regression coefficients across the three samples.RESULTS: The combined (and all three individual samples) showed a small positive phenotypic correlation between intelligence and lifespan. In the combined sample observed r = .12 (95% confidence interval .06 to .18). The additive genetic covariance model supported a genetic relationship between intelligence and lifespan. In the combined sample the genetic contribution to the covariance was 95%; in the US study, 84%; in the Swedish study, 86%, and in the Danish study, 85%.CONCLUSIONS: The finding of common genetic effects between lifespan and intelligence has important implications for public health, and for those interested in the genetics of intelligence, lifespan or inequalities in health outcomes including lifespan.

This study aims to understand the roles that psychosocial factors play on the longitudinal associations between sensory (including hearing and vision) loss and cognitive decline. Specifically, we hypothesized that (1) loneliness mediates the associations between sensory loss and cognitive decline; and (2) social support moderates the associations between sensory loss and cognitive decline. We used longitudinal parallel process (LPP) modeling with data from the Health and Retirement Study (HRS) and the Aging, Demographics, and Memory study (ADAMS). Age variable centered at its mean age of 82. In the most parsimonious model, loneliness fully mediated the associations between vision loss and the average cognitive status at age 82 (p < .05). Social support moderated the associations between vision loss and the average cognitive status at age 82 (β= .14, p < .05). No moderation or mediation effect was found for the psychosocial factors on the associations between hearing loss and cognition.

Early Alzheimer’s Disease (AD) can be difficult to diagnose with traditional cognitive assessment, but brain imaging studies suggest that people with early AD exhibit an altered metabolic response to certain tasks. This proof-of-concept study was designed to determine whether differences in brain metabolic activity with increasing task demand were related to one’s risk of AD. We recruited 26 individuals (age 59–72) with prior genetic testing who had normal cognitive scores and no cognitive complaints. Because the APOE e4 allele is linked to higher risk and earlier onset of AD, we included 13 APOE e4 carriers (high risk group) and a demographically balanced sample of 13 APOE e4 non-carriers (low risk group). Participants performed executive control tasks while undergoing functional magnetic resonance imaging (fMRI). Participants performed an easier version (neutral condition) followed by a harder version (stress condition) of the task. Groups did not differ in accuracy or response time in the neutral or stress condition. Next, we considered the change in brain activation between neutral and stress conditions. The low risk group exhibited larger increases in activation in right frontoparietal regions, even after adjustment for age. Age was associated with greater neutral-to-stress-condition increase in activation, but the age effect was less pronounced in the high risk group. Our hypothesis is that recruitment of supplemental networks helps support executive control in late life, and early AD may interfere with engagement of these resources. Although less activation was not associated with worse performance here, performance deterioration may occur with more challenging tasks.

Given that African Americans continue to be underrepresented in clinical studies, it is important to develop targeted strategies designed to increase accessibility to participation in clinical research. The Joseph and Kathleen Bryan Alzheimer’s Disease Research Center (Bryan ADRC) through its Alzheimer’s Disease Prevention Registry (ADPR) has established a representative cohort of racially and ethnically diverse “research ready” volunteers willing to participate in a variety of clinical trials. Utilizing a community-engagement approach to accelerate enrollment in clinical trials, the ADPR has demonstrated the successful recruitment and retention of cognitively healthy volunteers, including African Americans. In anticipation of a study involving the disclosure of amyloid PET imaging results to cognitively healthy individuals, we conducted a survey of a subset of ADPR registrants already involved in research to explore differences in reported willingness to participate across diverse racial groups. Participants (N=804; 84.64% White and 15.4% African American) completed neuropsychological testing and a six-item survey assessing willingness to participate in clinical Alzheimer’s disease (AD) biomarker research directed towards evaluating the future risk of AD. Whites and African Americans did not differ in willingness to participate in AD biomarker research. Compared to Whites, African Americans reported fewer concerns about future memory decline and were less likely to participate in studies involving multiple visits over a six-month period. Our study found a link between community partnerships and participation among African Americans. In contrast to previous research, our study found no differences between Whites and African Americans in willingness to participate in AD biomarker research.

DEMENTIA is characterized by significant declines in cognitive and physical functioning and is a leading cause of disability in later life. Despite the importance of functional status to the diagnosis of dementia, there is currently limited information on differences in functional limitations across subgroups of patients that differ in their dementia etiology. An improved understanding of functional profiles for older adults with dementia could play a role in the effective design of community-based programs that address the growing epidemic of this disease. High-quality, community-based, and institutional services are increasingly needed for patients with dementia to lessen its impact on individuals, families, and the health care system. More specific information on the likely functional needs of dementia patients could also be helpful to clinicians, in particular primary care physicians, in accurately predicting which patients will be able to live independently and safely. There are some clinical features that distinguish Alzheimer’s disease from vascular dementia (VaD), and these differences may translate into differences in function. However, current evidence is mixed regarding how different dementia diagnoses affect activities of daily living (ADLs) and instrumental activities of daily living (IADLs). In one study, hospital utilization was higher for those with VaD compared with those with Alzheimer’s dementia (AD) (1). Another study found no differences using the Disability Assessment for Dementia when comparing individuals with VaD and AD (2). A third study documented a higher prevalence of autonomic instability in patients with VaD comparable to Parkinson’s and Lewy body dementia, suggesting that individuals with VaD may be at greater risk for falls as well as gait abnormalities relative to those with AD (3). Difficulties performing ADLs and IADLs among patients with VaD are often due to the neurological sequelae of a stroke. Depending on the location of the infarct/hemorrhage, a patient may have motor, language, visual, and/or postural functions affected. The risk of cognitive impairment after stroke increases with increasing age, stroke severity, and stroke recurrences among other risk factors (4). Furthermore, VaD patients likely have greater functional impairment due to the added impact of comorbid illnesses, such as heart failure, peripheral vascular disease, and complications of type 2 diabetes (2). In addition, executive function deficits are predictive of functional decline in patients with VaD (5–7). Although cognitive changes are dependent on the location of the ischemic event, deficits in executive function are common in patients with vascular cognitive impairment (8,9). In contrast, AD patients experience a progressive decline in their ability to independently perform ADL and IADLs as cognition deteriorates. IADLs are typically affected at earlier stages with worsening of memory and the development of behavioral disturbances, followed by a progressive decline in ADLs as executive function becomes more affected at later stages of the dementia (10–12). Thus, the psychometric differences that exist between VaD and AD patients may also explain differences in functional limitations. We hypothesized that a unique functional profile exists for individuals with VaD compared with those with AD. To test this hypothesis, we examined data from a nationally representative cohort of participants in the Aging, Demographics, and Memory Study (ADAMS) to determine the nature and severity of functional impairment among older adults with dementia due to different etiologies.

Background. Both oral health problems and cognitive impairment are relatively common among older adults. Poorer oral health appears to contribute to a decline in quality of life and to be related to various medical conditions. Little is known about the relationship of cognitive function to oral health among community-dwelling older adults. Methods. The sample included 1984 dentate community-dwelling older adults 60 years old or older from the National Health and Nutrition Examination Survey (NHANES, 1999-2002) who completed both the study cognitive measure and dental examination. Weighted descriptive and multivariate regression analyses were performed. Results. Multivariate analyses showed that cognitive function was associated with oral health. Individuals with lower cognitive scores had a higher number of decayed and missing teeth and a higher proportion of periodontitis sites. The predicted number of decayed teeth increased by 0.01 with each 1-point decrease in the Digit Symbol Substitution Test score; the number of missing teeth increased by 0.02; and the percentage of sites with periodontal disease increased by 0.02. In addition, individuals' sociodemographic characteristics, health behavior, and regular dental checkups were significantly associated with oral health. Conclusions. This study suggests that community-dwelling elders with lower cognitive function scores have greater deterioration of oral health. This study provides a preliminary knowledge base for the development of early intervention strategies to address oral health problems among older adults.

Background. A key element in the quality of later life is the prevalence of age-related functional impairments. The objective of this study was to quantify the genetic and environmental influences on age-related functional impairment in a population of white male twin elders who were fit in young adulthood when entering military service. The extent of genetic influence on functioning in later life affects the role of public health, personal initiative, and service interventions. Methods. Indicators of functional impairment were determined by telephone survey and by twin pair responses to 10 indicators of basic, instrumental, and social activities, and mobility. Responses were analyzed using structural equation modeling. Prevalence and concordances were determined by zygosity status. Covariance was partitioned between twins in a pair into components attributable to additive genetics, common environment, and unique environment. Results. Data from 2721 twin pairs (1384 monozygotic and 1337 dizygotic) were analyzed for the 10 dichotomous indicators of functional impairment and for a subscale of 8 of these indicators. For the subscale, additive genes accounted for approximately 21% of covariance in liability for a higher score, whereas unique environment accounted for approximately 78% of variance, with age accounting for a very small proportion. In two indicators there were nontrivial effects of common environment. Conclusions. Within the expressed limits on generalization, the study findings suggest a major potential role for interventions aimed at a person’s unique environment to maintain good functioning in aging and to lengthen the period of active life. Genetic effects play a modest but also important role in age-related functional impairment.

This research depicted distinct courses of periodontal disease among older Americans and ascertained how these trajectories were associated with chronic diseases (i.e., hypertension, heart disease, stroke, diabetes, and cancer). Data came from the Piedmont Dental Study, which involved repeated observations of 810 dentate individuals aged 65 and over in North Carolina from 1988 to 1994. Attachment loss (AL) and pocket depth (PD) were clinically assessed. While group-based, semi-parametric mixture models (Proc Traj) were used for data analysis. Our data showed four distinct courses of change in periodontal disease over a five-year period. Whereas prior research has shown that oral health predicts heart disease and diabetes in old age, our findings suggest that these diseases may increase the risk for poor oral health as well.