Measurement of Allostatic Load in Caregivers of Older Hispanic People With Alzheimer Disease and Related Disorders.

BACKGROUND: Allostatic load (AL) has been studied in the context of biomarkers that may be affected by environmental and contextual stressors, including social determinants of health. The specific stressor studied here is the provision of caregiving to older persons with Alzheimer disease and related disorders. The aims were to examine the factor structure of stress and nonstress biomarkers, different methods for calculating AL, and the relationship of AL with other variables. METHODS: Latent variable models were used to examine biomarkers. Regression analyses were performed with the outcomes: AL calculated as percentile-based and clinically-based for both stress and nonstress components. The sample was 187 Hispanic caregivers to individuals with dementia. RESULTS: The results of the confirmatory factor analyses (CFAs) suggested defining 2 factors: nonstress and stress-related. Performance was better for the CFA results and the associations with covariates when stress and nonstress components were examined separately. Despite some limitations, this is one of the first studies of biomarkers in Hispanic caregivers to patients with dementia. It was possible to explain almost 30% of the variance in the nonstress AL component. CONCLUSION: It may be important to differentiate among biomarkers indicative of cardiovascular, metabolic, and immune response as contrasted with the more stress-related biomarkers.

The lucidity in dementia experience: perspectives from family and professional caregivers.

BACKGROUND: Family and professional caregivers of individuals with dementia often witness care-receiver's lucidity events. OBJECTIVE: A qualitative data analysis was performed of documented family and professional caregivers' experiences and their respective appraisals of lucidity events. RESEARCH DESIGN AND METHODS: Using a reduction method of selection, data from 10 in-home family caregivers and 20 professional caregivers to long-term care residents was content-coded and analysed. Framed by a priori research questions, a summative approach to qualitative content analysis guided the interpretation of findings. RESULTS: Eight of 10 family- and 15 of 20 staff caregivers gave an example of what they believed was a witnessed lucid event; 88% of family- and 40% of staff caregivers' provided examples that appeared to fit the conceptual definition of lucidity. The emotional impact that the events had on both sets of caregivers was reported. Family caregivers' characterization of lucidity events reflected appraisals of a puzzling occurrence while staff caregivers depicted elements associated with dementia, and lucidity descriptors. The enhanced verbal communication followed by the brief, unexpected quality of lucidity, were the main elements highlighted by both sets of caregivers in their description of lucidity to others. The variability and complexity of the lucidity phenomenon and the potential challenges it poses for both sets of caregivers were characterized. Commonalities and divergences across responses were highlighted. DISCUSSION: Findings validated previous studies' results. The notions introduced by both types of caregivers were thought-provoking and borne practical, clinical, ethical, and assessment (measurement) applicability.

Comparison of brief olfactory and cognitive assessments to neuroimaging biomarkers in the prediction of cognitive decline and dementia in the MCSA cohort.

INTRODUCTION: We evaluated impaired odor identification and global cognition as simple, cost-effective alternatives to neuroimaging biomarkers to predict cognitive decline and dementia in the Mayo Clinic Study of Aging. METHODS: Six hundred forty-seven participants (mean 8.1, standard deviation 3.4 years' follow-up) had the following baseline procedures: modified Blessed Information Memory Concentration Test (BIMCT), 12-item Brief Smell Identification Test (BSIT), structural brain magnetic resonance imaging (MRI), and positron emission tomography (PET) imaging with 11C-Pittsburgh compound B (11C-PiB) and fluorodeoxyglucose (FDG; subset). RESULTS: Cognitive decline developed in 102 participants and dementia in 34 participants. In survival analyses, PiB PET showed robust prediction for cognitive decline. Impaired BSIT, impaired BIMCT, MRI, and FDG measures were also significant predictors. The combination of demographics + BSIT + BIMCT showed strong predictive utility (C-index 0.81), similar to demographics + PiB PET (C-index 0.80). Similar but stronger results were obtained for prediction of dementia. DISCUSSION: Impairment in both odor identification test and global cognition was comparable to PiB PET for predicting cognitive decline and dementia. HIGHLIGHTS: In 647 participants in the population-based Mayo Clinic Study of Aging, several clinical markers and biomarkers each predicted cognitive decline or dementia during an average 8 years of follow-up. The combination of the demographic variables of age, sex, and education with a brief odor identification test (BSIT) and a global cognitive test (Blessed Information Memory Concentration Test) showed strong predictive utility (C-index 0.81) for cognitive decline that was similar to the demographic variables combined with Pittsburgh Compound B amyloid imaging (C-index 0.80). Combining a brief odor identification test with a brief cognitive test needs consideration as a simple, cost-effective option in the clinical assessment of individuals at risk of cognitive decline and dementia, as well as a potential tool to identify individuals who may benefit from disease-modifying treatments and to screen participants for prevention trials.

Association of fractal dimension and other retinal vascular network parameters with cognitive performance and neuroimaging biomarkers: The Multi-Ethnic Study of Atherosclerosis (MESA).

INTRODUCTION: Retinal vascular network changes may reflect the integrity of the cerebral microcirculation, and may be associated with cognitive impairment. METHODS: Associations of retinal vascular measures with cognitive function and MRI biomarkers were examined amongst Multi-Ethnic Study of Atherosclerosis (MESA) participants in North Carolina who had gradable retinal photographs at Exams 2 (2002 to 2004, n = 313) and 5 (2010 to 2012, n = 306), and detailed cognitive testing and MRI at Exam 6 (2016 to 2018). RESULTS: After adjustment for covariates and multiple comparisons, greater arteriolar fractal dimension (FD) at Exam 2 was associated with less isotropic free water of gray matter regions (ß = -0.0005, SE = 0.0024, p = 0.01) at Exam 6, while greater arteriolar FD at Exam 5 was associated with greater gray matter cortical volume (in mm3 , ß = 5458, SE = 20.17, p = 0.04) at Exam 6. CONCLUSION: Greater arteriolar FD, reflecting greater complexity of the branching pattern of the retinal arteries, is associated with MRI biomarkers indicative of less neuroinflammation and neurodegeneration.

ATP-binding cassette protein ABCA7 deficiency impairs sphingomyelin synthesis, cognitive discrimination, and synaptic plasticity in the entorhinal cortex.

Sphingomyelin (SM) is an abundant plasma membrane and plasma lipoprotein sphingolipid. We previously reported that ATP-binding cassette family A protein 1 (ABCA1) deficiency in humans and mice decreases plasma SM levels. However, overexpression, induction, downregulation, inhibition, and knockdown of ABCA1 in human hepatoma Huh7 cells did not decrease SM efflux. Using unbiased siRNA screening, here, we identified that ABCA7 plays a role in the biosynthesis and efflux of SM without affecting cellular uptake and metabolism. Since loss of function mutations in the ABCA7 gene exhibit strong associations with late-onset Alzheimer's disease across racial groups, we also studied the effects of ABCA7 deficiency in the mouse brain. Brains of ABCA7-deficient (KO) mice, compared with WT, had significantly lower levels of several SM species with long chain fatty acids. In addition, we observed that older KO mice exhibited behavioral deficits in cognitive discrimination in the active place avoidance task. Next, we performed synaptic transmission studies in brain slices obtained from older mice. We found anomalies in synaptic plasticity at the intracortical synapse in layer II/III of the lateral entorhinal cortex but not in the hippocampal CA3-CA1 synapses in KO mice. These synaptic abnormalities in KO brain slices were rescued with extracellular SM supplementation but not by supplementation with phosphatidylcholine. Taken together, these studies identify a role of ABCA7 in brain SM metabolism and the importance of SM in synaptic plasticity and cognition, as well as provide a possible explanation for the association between ABCA7 and late-onset Alzheimer's disease.

Unexpected lucidity in dementia: application of qualitative methods to develop an informant-reported lucidity measure.

OBJECTIVES: Unexpected lucidity is a phenomenon of scientific, clinical, and psychological relevance to health professionals, to those who experience it, and their relatives. This paper describes qualitative methods used to develop an informant-based measure of lucidity episodes. METHODS: The approach was refinement of the operationalization of the construct; review of seminal items, modification, and purification; and confirmation of the feasibility of reporting methodology. Modified focus groups were conducted with 20 staff and 10 family members using a web-based survey. Themes included reaction when hearing the term; words that come to mind; description of and first reaction to referenced or observed 'lucidity' events. Semi-structured cognitive interviews were conducted with 10 health professionals working with older adults with cognitive impairment. Data were extracted from Qualtrics or Microsoft 365 Word® for analysis using NVivo. RESULTS: Conceptual issues, as well as issues regarding comprehension, interpretation, clarity, semantics, and standardization of definitions derived from an external advisory board, focus groups and cognitive interviews informed items' modification, and resulted in the final lucidity measure. CONCLUSIONS: An obstacle to understanding the mechanisms and estimating the prevalence of lucid events among individuals with dementia and other neurological conditions is the scarcity of reliable and valid measures. The substantive and varied data gathered from multiple methods including the collaborative work of an External Advisory Board, modified focus groups with staff and family caregivers, and structured cognitive interviews with health professionals were central in creating the revised version of the lucidity measure.

Reports About Paradoxical Lucidity from Health Care Professionals: A Pilot Study.

Although clinicians caring for persons at the end of life recognize the phenomenon of paradoxical/terminal lucidity, systematic evidence is scant. The current pilot study aimed to develop a structured interview instrument for health care professionals to report lucidity. A questionnaire measuring lucidity length, degree, content, coinciding circumstances, and time from episode to death was expanded to include time of day, expressive and receptive communication, and speech during the month prior to and during the event. Thirty-three interviews were conducted; 73% of participants reported ever witnessing paradoxical lucidity. Among 29 events reported, 31% lasted several days, 20.7% lasted 1 day, and 24.1% lasted <1 day. In 78.6% of events, the person engaged in unexpected activity; 22.2% died within 3 days, and 14.8% died within 3 months of the event. The phenomenological complexity of lucidity presents challenges to eliciting reports in a systematic fashion; however, staff respondents were able to report lucidity events and detailed descriptions of person-specific characteristics. [Journal of Gerontological Nursing, 49(1), 18-26.].

Effect of renin-angiotensin system antihypertensive medication use on cognitive function in diabetes mellitus with obesity or overweight: An ancillary study to the Action for Health in Diabetes (Look AHEAD) trial.

AIM: To determine whether antihypertensive medication (AHM) acting through the renin angiotensin system (RAS-AHM), compared with other AHM, can mitigate effects on cognitive function and risk for impairment in a population with type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: This secondary analysis of the randomized controlled Action for Health in Diabetes (Look AHEAD) study included 712 community-dwelling participants who were followed over 15 years. Logistic regression was used to relate RAS-AHM use to cognitive impairment, and linear regression was used to relate RAS-AHM use to domain-specific cognitive function after adjusting for potential confounders. RESULTS: A total of 563 individuals reported RAS-AHM use and 149 reported other-AHM use during the study. RAS-AHM users have college or higher education (53%), had higher baseline glycated haemoglobin (57 mmol/mol), and reported higher diabetes medication use (86%), while other-AHM users were more likely to be White (72%), obese (25%) and to have cardiovascular history (19%). RAS-AHM use was not associated with a reduced risk of dementia compared with other-AHM use. We did observe better executive function (Trail Making Test, part B, P < 0.04), processing speed (Digit Symbol Substitution Test, P < 0.004), verbal memory (Rey Auditory Verbal Learning Test-delayed recall, P < 0.005), and composite score (P < 0.008) among RAS-AHM users compared with other-AHM users. CONCLUSION: In this sample of adults with T2DM, free of dementia at baseline, we observed a slower decline in processing speed, executive function, verbal memory, and composite score among RAS-AHM users.

Patterns of tau pathology identified with 18 F-MK-6240 PET imaging.

INTRODUCTION: Positron emission tomography (PET) imaging for neurofibrillary tau allows investigation of the in vivo spatiotemporal progression of Alzheimer's disease (AD) pathology. We evaluated the suitability of 18 F-MK-6240 in a clinical sample and determined the relationships among 18 F-MK-6240 binding, age, cognition, and cerebrospinal fluid (CSF)-based AD biomarkers. METHODS: Participants (n = 101, 72 ± 9 years, 52% women) underwent amyloid PET, tau PET, structural T1-weighted magnetic resonance imaging, and neuropsychological evaluation. Twenty-one participants had lumbar puncture for CSF measurement of amyloid beta (Aß)42 , tau, and phosphorylated tau (p-tau). RESULTS: 18 F-MK-6240 recapitulated Braak staging and correlated with CSF tau and p-tau, normalized to Aß42 . 18 F-MK-6240 negatively correlated with age across Braak regions in amyloid-positive participants, consistent with greater tau pathology in earlier onset AD. Domain-specific, regional patterns of 18 F-MK-6240 binding were associated with reduced memory, executive, and language performance, but only in amyloid-positive participants. DISCUSSION: 18 F-MK-6240 can approximate Braak staging across the AD continuum and provide region-dependent insights into biomarker-based AD models.

Nutritional metabolism and cerebral bioenergetics in Alzheimer's disease and related dementias.

Disturbances in the brain's capacity to meet its energy demand increase the risk of synaptic loss, neurodegeneration, and cognitive decline. Nutritional and metabolic interventions that target metabolic pathways combined with diagnostics to identify deficits in cerebral bioenergetics may therefore offer novel therapeutic potential for Alzheimer's disease (AD) prevention and management. Many diet-derived natural bioactive components can govern cellular energy metabolism but their effects on brain aging are not clear. This review examines how nutritional metabolism can regulate brain bioenergetics and mitigate AD risk. We focus on leading mechanisms of cerebral bioenergetic breakdown in the aging brain at the cellular level, as well as the putative causes and consequences of disturbed bioenergetics, particularly at the blood-brain barrier with implications for nutrient brain delivery and nutritional interventions. Novel therapeutic nutrition approaches including diet patterns are provided, integrating studies of the gut microbiome, neuroimaging, and other biomarkers to guide future personalized nutritional interventions.

Legacy of a 10-Year Multidomain Lifestyle Intervention on the Cognitive Trajectories of Individuals with Overweight/Obesity and Type 2 Diabetes Mellitus.

INTRODUCTION: Weight loss and increased physical activity interventions are commonly recommended for individuals with type 2 diabetes (T2D) and overweight or obesity. We examined the impact of randomization to an intensive lifestyle intervention (ILI) on trajectories of cognitive function over 10 years in a cohort of participants in a randomized clinical trial who had T2D and overweight/obesity at baseline. METHODS: Participants aged 45-76 years were enrolled in 2001-2004 and were randomized to the ILI or a diabetes support and education (DSE) condition. Cognitive function was assessed in 3,938 participants at up to 4 time points 8-18 years after randomization. General linear mixed effects models examined cognitive trajectories over time. Subgroup analyses focused on sex, individuals with baseline body mass index >30, those carrying the APOE ε4 allele, and those with a baseline history of cardiovascular disease (CVD). RESULTS: Overall, there were no differences in the rate of cognitive decline by intervention arm. Subgroup analyses showed that participants who had a baseline history of CVD and were randomized to the ILI arm of the study performed significantly worse on the Stroop Color Word Test than those in the DSE arm. DISCUSSION/CONCLUSIONS: The ILI did not result in preserved cognitive function or slower rates of cognitive decline in this cohort of individuals who had T2D and were overweight or obese at baseline.

Metabolic Syndrome and Cognitive Function.

PURPOSE OF REVIEW: Metabolic syndrome (MetS) is a cluster of cardiovascular disease risk factors that are related to several adverse health outcomes, including poor cognitive function. This review seeks to summarize and critically review select recent findings on the association between MetS and cognition. RECENT FINDINGS: MetS was associated with lower domain-specific and global cognitive function in most cross-sectional studies, but findings from longitudinal studies are not consistent. The associations varied depending on age, sex, cognitive test, genetic susceptibility, and the duration of follow-up in prospective studies. MetS was associated with a higher risk of mild cognitive impairment (MCI) and progression from MCI to dementia, particularly vascular dementia. Among MetS components, high blood pressure, high waist circumference, and hyperglycemia were the strongest predictors of cognitive function. MetS is associated with higher risk of cognitive impairment. Research is needed on how preventing or treating MetS affects cognition.

Subclinical Hearing Loss is Associated With Depressive Symptoms.

OBJECTIVE: To assess whether the relationship between hearing and depressive symptoms is present among older adults classified as normal hearing (≤25 dB). DESIGN: Cross-sectional epidemiologic study (Hispanic Community Health Study). SETTING: US multicentered. PARTICIPANTS: Adults ≥50 years old (n = 5,499) with normal hearing or hearing loss (HL). MEASUREMENTS: The primary exposure was hearing, defined continuously by the 4-frequency pure-tone average threshold (dB) on audiometry. Hearing was additionally categorized into normal hearing (≤25 dB) and HL (>25 dB). The main outcome was depressive symptoms, measured with the Center for Epidemiologic Studies Depression Scale-10 (CESD-10). Depressive symptoms were defined both continuously and binarily (where CESD-10 ≥10 was categorized as clinically significant depressive symptoms). Multivariable linear, logistic, and generalized additive modeling (GAM) regressions were performed. RESULTS: Among those with normal hearing, the CESD-10 score increased by 1.04 points (95% confidence interval [CI]: 0.70, 1.37) for every 10 dB decrease in hearing, adjusting for age, gender, education, cardiovascular disease, and hearing aid use. Among those with HL, the CESD-10 score increased by 0.62 points (95% CI: 0.23, 1.01) for every 10 dB decrease in hearing, adjusting for the same confounders. Similar findings were noted when the outcome was clinically significant depressive symptoms (adjusted odds ratio: 1.28 [1.14, 1.44] in normal hearing versus 1.26 [1.11, 1.44] in HL). In certain sensitivity analyses, the relationship between hearing and depressive symptoms was significantly stronger among those with normal hearing than in those with HL. CONCLUSION: The relationship between hearing and clinically significant depressive symptoms is present among older adults with normal hearing (<25 dB). We introduce the term subclinical HL as imperfect hearing that is classically defined as normal (1-25 dB). The relationship between hearing and late life depressive symptoms may be more sensitive than previously recognized.

Intact global cognitive and olfactory ability predicts lack of transition to dementia.

INTRODUCTION: Odor identification deficits characterize Alzheimer's disease and other dementias. We examined if intact performance on brief cognitive and odor identification tests predicts lack of transition to dementia. METHODS: In an urban community, 1037 older adults without dementia completed the 40-item University of Pennsylvania Smell Identification Test, which includes the 12-item Brief Smell Identification Test (B-SIT). Data from 749 participants followed up for 4 years were analyzed. RESULTS: In covariate-adjusted survival analyses, impairment on the Blessed Orientation Memory Concentration Test and B-SIT each predicted dementia (n = 109), primarily Alzheimer's disease (n = 101). Among participants with intact olfactory (B-SIT ≥ 11/12 correct) and cognitive (Blessed Orientation Memory Concentration Test ≤ 5/28 incorrect) ability, 3.4% (4/117) transitioned to dementia during follow-up with no transitions in the 70-75 and 81-83 years age group quartiles. DISCUSSION: Odor identification testing adds value to global cognitive testing, and together can identify individuals who rarely transition to dementia, thereby avoiding unnecessary diagnostic investigation.

Psychometric Properties of a Spanish-Language Version of a Short-Form FAMCARE: Applications to Caregivers of Patients With Alzheimer's Disease and Related Dementias.

Although family satisfaction is recognized as a critical indicator of quality care for persons with serious illness, Spanish-language measures are limited. The study aims were to develop a Spanish translation of the short-form Family Satisfaction With End-of-Life Care (FAMCARE), investigate its psychometric properties in Hispanic caregivers to patients with Alzheimer's disease and related dementias (ADRD; N = 317; 209 interviewed in Spanish), and add parameters to an existing item bank. Based on factor analyses, the measure was found to be essentially unidimensional. Reliabilities from a graded item response theory model were high; the average estimate was 0.93 for the total and Spanish-language subsample. Discrimination parameters were high, and the model fit adequate. This is the first study to examine the performance of the short-form FAMCARE measure among Hispanics and caregivers to patients with ADRD. The short-form measure can be recommended for Hispanics and caregivers to patients with ADRD.

Relationship of Lipids and Lipid-Lowering Medications With Cognitive Function: The Multi-Ethnic Study of Atherosclerosis.

Studies on the relationship of cholesterol concentrations and lipid-lowering medications with dementia risk have yielded inconsistent findings. Therefore, we investigated the association of lipid concentrations and lipid-lowering medications with cognitive function in the Multi-Ethnic Study of Atherosclerosis across 3 different cognitive domains assessed by means of the Cognitive Abilities Screening Instrument (CASI; version 2), the Digit Symbol Coding (DSC) Test, and the Digit Span (DS) Test in 2010-2012. After adjustment for sociodemographic and confounding factors, including concentrations of other lipids and use of lipid-lowering medication, higher total cholesterol, low-density lipoprotein cholesterol, and non-high-density-lipoprotein cholesterol concentrations were modestly associated with higher DS Test scores. None of the lipid parameters were associated with CASI or DSC Test scores. Similarly, changes in lipid concentrations were not associated with any cognitive function test score. Using treatment effects model analysis and after adjusting for confounding factors, including lipid concentrations, the use of any lipid-lowering medication, especially statins, was associated with higher scores on the CASI and backward DS tests but not on the DSC and forward DS tests. Our study does not support a robust association between lipid concentrations and cognitive function or between the use of lipid-lowering medication, especially statins, and worse cognitive function.

White matter integrity as a mediator in the relationship between dietary nutrients and cognition in the elderly.

OBJECTIVE: We examined the association of nutrient intake with microstructural white matter integrity, and the role of white matter integrity in the association between nutrient consumption and cognition. METHODS: This cross-sectional analysis included 239 elderly (age ≥ 65 years) participants of a multiethnic cohort. White matter integrity was measured with fractional anisotropy (FA) from diffusion tensor magnetic resonance imaging. Nutrient patterns were derived from principal component analysis based on energy-adjusted intake of 24 selected nutrients. Generalized linear models were used to assess the association between nutrient patterns and mean FA of 26 white matter tracts. Mediation analysis was used to determine whether FA mediates the nutrient-cognition relationship. All models were adjusted for age at time of scan, gender, ethnicity, education, caloric intake, and apolipoprotein genotype. RESULTS: Among the identified 6 nutrient patterns, 1 (nutrient pattern 6, characterized by high intakes of Ω-3 and Ω-6 polyunsaturated fatty acids and vitamin E) was positively associated with FA. Those with the highest tertile of nutrient pattern 6 score had a mean of 0.01 (p = 0.01) higher FA value than those with the lowest tertile, similar to the effect of a 10-year decrease in age (b for age = -0.001, p = 0.01). FA mediated the relationship between nutrient pattern 6 and memory, language, visuospatial and speed/executive function, and mean cognitive scores. INTERPRETATION: Our study suggests that older adults consuming more polyunsaturated fatty acids and vitamin E rich foods had better white matter integrity, and that maintaining white matter microstructural integrity might be a mechanism for the beneficial role of diet on cognition. Ann Neurol 2016;79:1014-1025.

Circulating inflammatory biomarkers in relation to brain structural measurements in a non-demented elderly population.

The aim of this investigation was to determine whether circulating inflammatory biomarkers c-reactive protein (CRP), interleukin-6 (IL6), and alpha 1-antichymotrypsin (ACT) were related to structural brain measures assessed by magnetic resonance imaging (MRI). High-resolution structural MRI was collected on 680 non-demented elderly (mean age 80.1years) participants of a community-based, multiethnic cohort. Approximately three quarters of these participants also had peripheral inflammatory biomarkers (CRP, IL6, and ACT) measured using ELISA. Structural measures including brain volumes and cortical thickness (with both global and regional measures) were derived from MRI scans, and repeated MRI measures were obtained after 4.5years. Mean fractional anisotropy was used as the indicator of white matter integrity assessed with diffusion tensor imaging. We examined the association of inflammatory biomarkers with brain volume, cortical thickness, and white matter integrity using regression models adjusted for age, gender, ethnicity, education, APOE genotype, and intracranial volume. A doubling in CRP (b=-2.48, p=0.002) was associated with a smaller total gray matter volume, equivalent to approximately 1.5years of aging. A doubling in IL6 was associated with smaller total brain volume (b=-14.96, p<0.0001), equivalent to approximately 9years of aging. Higher IL6 was also associated with smaller gray matter (b=-6.52, p=0.002) and white matter volumes (b=-7.47, p=0.004). The volumes of most cortical regions including frontal, occipital, parietal, temporal, as well as subcortical regions including pallidum and thalamus were associated with IL6. In a model additionally adjusted for depression, vascular factors, BMI, and smoking status, the association between IL6 and brain volumes remained, and a doubling in ACT was marginally associated with 0.054 (p=0.001) millimeter thinner mean cortical thickness, equivalent to that of approximately 2.7years of aging. None of the biomarkers was associated with mean fractional anisotropy or longitudinal change of brain volumes and thickness. Among older adults, increased circulating inflammatory biomarkers were associated with smaller brain volume and cortical thickness but not the white matter tract integrity. Our preliminary findings suggest that peripheral inflammatory processes may be involved in the brain atrophy in the elderly.

Diabetes, glycaemia, and cognition-a secondary analysis of the Finnish Diabetes Prevention Study.

BACKGROUND: Type 2 diabetes is linked with cognitive dysfunction and dementia in epidemiological studies, but these observations are limited by lack of data on the exact timing of diabetes onset. We investigated diabetes, dysglycaemia, and cognition in the Finnish Diabetes Prevention Study, in which the timing and duration of diabetes are well documented. METHODS: The Finnish Diabetes Prevention Study comprised middle-aged, overweight participants with impaired glucose tolerance but no diabetes at baseline (n = 522), randomized to lifestyle intervention or a control group. After an intervention period (mean duration 4 years) and follow-up (additional 9 years), cognitive assessment with the CERAD test battery and Trail Making Test A (TMT) was executed twice within a 2-year interval. Of the 364 (70%) participants with cognitive assessments, 171 (47%) had developed diabetes. RESULTS: Cognitive function did not differ between those who developed diabetes and those who did not. Lower mean 2-h glucose at an oral glucose tolerance test (OGTT) and HbA1C during the intervention period predicted better performance in the TMT (p = 0.012 and 0.024, respectively). Those without diabetes or with short duration of diabetes improved in CERAD total score between the two assessments (p = 0.001) whereas those with long duration of diabetes did not (p = 0.844). CONCLUSIONS: Better glycemic control among persons with baseline impaired glucose tolerance predicted better cognitive performance 9 years later in this secondary analysis of the Finnish Diabetes Prevention Study population. In addition, learning effects in cognitive testing were not evident in people with long diabetes duration. Copyright © 2015 John Wiley & Sons, Ltd.

Glycemia, Diabetes Status, and Cognition in Hispanic Adults Aged 55-64 Years.

OBJECTIVES: To examine the association of glycemia and diabetes status with cognition among 600 Hispanics aged 55 to 64 years from Northern Manhattan. METHODS: Diabetes was ascertained by history or hemoglobin A1c. Normal glucose tolerance and prediabetes were ascertained with hemoglobin A1c. Memory was assessed with the Selective Reminding Test. Executive abilities were assessed using the Color Trails 1 and 2 and verbal fluency test. The cross-sectional association of glycemia and diabetes status with cognitive performance was examined using linear regression. RESULTS: Participants had a mean age of 59.2 (2.9) years, 76.7% were women, and more than 65% had prediabetes or diabetes. HbA1C (ß = -0.97, p < .001) and diabetes (ß = -2.06, p = .001) were related with lower Selective Reminding Test total recall after adjustment for demographics, education, and vascular risk factors. Prediabetes was associated with worse performance in Color Trail 2 (ß = -6.45 p = .022) after full adjustment. CONCLUSIONS: Higher glycemia and diabetes are related to worse memory and executive abilities in late middle age, whereas prediabetes is related only to worse executive abilities. Longitudinal follow-up is needed to understand the order and progression of these deficits.