Factor structure of the ARIC-NCS Neuropsychological Battery: An evaluation of invariance across vascular factors and demographic characteristics

A comparison of PM2.5 exposure estimates from different estimation methods and their associations with cognitive testing and brain MRI outcomes

BACKGROUND

Reported associations between particulate matter with aerodynamic diameter ≤2.5 μm (PM2.5) and cognitive outcomes remain mixed. Differences in exposure estimation method may contribute to this heterogeneity.

OBJECTIVES

To assess agreement between PM2.5 exposure concentrations across 11 exposure estimation methods and to compare resulting associations between PM2.5 and cognitive or MRI outcomes.

METHODS

We used Visit 5 (2011-2013) cognitive testing and brain MRI data from the Atherosclerosis Risk in Communities (ARIC) Study. We derived address-linked average 2000-2007 PM2.5 exposure concentrations in areas immediately surrounding the four ARIC recruitment sites (Forsyth County, NC; Jackson, MS; suburbs of Minneapolis, MN; Washington County, MD) using 11 estimation methods. We assessed agreement between method-specific PM2.5 concentrations using descriptive statistics and plots, overall and by site. We used adjusted linear regression to estimate associations of method-specific PM2.5 exposure estimates with cognitive scores (n = 4678) and MRI outcomes (n = 1518) stratified by study site and combined site-specific estimates using meta-analyses to derive overall estimates. We explored the potential impact of unmeasured confounding by spatially patterned factors.

RESULTS

Exposure estimates from most methods had high agreement across sites, but low agreement within sites. Within-site exposure variation was limited for some methods. Consistently null findings for the PM2.5-cognitive outcome associations regardless of method precluded empirical conclusions about the potential impact of method on study findings in contexts where positive associations are observed. Not accounting for study site led to consistent, adverse associations, regardless of exposure estimation method, suggesting the potential for substantial bias due to residual confounding by spatially patterned factors.

DISCUSSION

PM2.5 estimation methods agreed across sites but not within sites. Choice of estimation method may impact findings when participants are concentrated in small geographic areas. Understanding unmeasured confounding by factors that are spatially patterned may be particularly important in studies of air pollution and cognitive or brain health.

Patterns of cognitive domain abnormalities enhance discrimination of dementia risk prediction: The ARIC study

INTRODUCTION

The contribution of neuropsychological assessments to risk assessment for incident dementia is underappreciated.

METHODS

We analyzed neuropsychological testing results in dementia-free participants in the Atherosclerosis Risk in Communities (ARIC) study. We examined associations of index domain-specific neuropsychological test performance with incident dementia using cumulative incidence curves and Cox proportional hazards models.

RESULTS

Among 5296 initially dementia-free participants (mean [standard deviation] age of 75.8 [5.1] years; 60.1% women, 22.2% Black) over a median follow-up of 7.9 years, the covariate-adjusted hazard ratio varied substantially depending on the pattern of domain-specific performance and age, in an orderly manner from single domain language abnormalities (lowest risk) to single domain executive or memory abnormalities, to multidomain abnormalities including memory (highest risk).

DISCUSSION

By identifying normatively defined cognitive abnormalities by domains based on neuropsychological test performance, there is a conceptually orderly and age-sensitive spectrum of risk for incident dementia that provides valuable information about the likelihood of progression.

HIGHLIGHTS

Domain-specific cognitive profiles carry enhanced prognostic value compared to mild cognitive impairment. Single-domain non-amnestic cognitive abnormalities have the most favorable prognosis. Multidomain amnestic abnormalities have the greatest risk for incident dementia. Patterns of domain-specific risks are similar by sex and race.

Parity and Risk of Dementia in Women: The Atherosclerosis Risk in Communities Study

Objective: Reproductive factors, including parity, may contribute to dementia risk, due to hormonal, physiological, social, and demographic factors. We hypothesized that higher parity would be associated with increased dementia risk. Materials and Methods: We utilized data from the Atherosclerosis Risk in Communities (ARIC) community-based cohort study. Participants were recruited in 1987-1989 and followed through 2017. Participants, all born between 1921 and 1945, were from four U.S. communities in Forsyth County, NC; Jackson, MS; Minneapolis, MN; and Washington County, MD. We included all female participants seen at ARIC visit three or five for whom parity and dementia outcomes were available (N = 7,921). The primary exposure was self-reported number of live births. Our primary outcome was dementia, diagnosed via neurocognitive assessments, informant interviews, and expert adjudication. We created Cox proportional hazards models to evaluate the association between parity and incident dementia, adjusting for demographic factors, education level, apolipoprotein E allele status, and vascular risk factors. We tested for interactions by race and birth cohort. Results: The adjusted hazard ratio was 0.82 (95% confidence intervals [CI] 0.69-0.99) for dementia in women with 0-1 births and 0.85 (95% CI 0.72-0.99) for women with 5+ births, compared to women with 2 births (reference group). This association was present in women born from 1924 to 1934, but not in women born in 1935 or later (p-interaction <0.001). Conclusion: We found an inverted U-shaped association of parity with dementia risk. This effect was modified by birth cohort, suggesting that the association may depend on demographic and sociocultural factors.

Cognitive phenotypes in late-onset epilepsy: results from the atherosclerosis risk in communities study

Introduction

Cognitive phenotyping is a widely used approach to characterize the heterogeneity of deficits in patients with a range of neurological disorders but has only recently been applied to patients with epilepsy. In this study, we identify cognitive phenotypes in older adults with late-onset epilepsy (LOE) and examine their demographic, clinical, and vascular profiles. Further, we examine whether specific phenotypes pose an increased risk for progressive cognitive decline.

Methods

Participants were part of the Atherosclerosis Risk in Communities Study (ARIC), a prospective longitudinal community-based cohort study of 15,792 individuals initially enrolled in 1987-1989. LOE was identified from linked Centers for Medicare and Medicaid Services claims data. Ninety-one participants with LOE completed comprehensive testing either prior to or after seizure onset as part of a larger cohort in the ARIC Neurocognitive Study in either 2011-2013 or 2016-2017 (follow-up mean = 4.9 years). Cognitive phenotypes in individuals with LOE were derived by calculating test-level impairments for each participant (i.e., ≤1 SD below cognitively normal participants on measures of language, memory, and executive function/processing speed); and then assigning participants to phenotypes if they were impaired on at least two tests within a domain. The total number of impaired domains was used to determine the cognitive phenotypes (i.e., Minimal/No Impairment, Single Domain, or Multidomain).

Results

At our baseline (Visit 5), 36.3% met criteria for Minimal/No Impairment, 35% for Single Domain Impairment (with executive functioning/ processing speed impaired in 53.6%), and 28.7% for Multidomain Impairment. The Minimal/No Impairment group had higher education and occupational complexity. There were no differences in clinical or vascular risk factors across phenotypes. Of those participants with longitudinal data (Visit 6; n = 24), 62.5% declined (i.e., progressed to a more impaired phenotype) and 37.5% remained stable. Those who remained stable were more highly educated compared to those that declined.

Discussion

Our results demonstrate the presence of identifiable cognitive phenotypes in older adults with LOE. These results also highlight the high prevalence of cognitive impairments across domains, with deficits in executive function/processing speed the most common isolated impairment. We also demonstrate that higher education was associated with a Minimal/No Impairment phenotype and lower risk for cognitive decline over time.

Methodological considerations when establishing reliable and valid normative data: Canadian Longitudinal Study on Aging (CLSA) neuropsychological battery

Objective: Creation of normative data with regression corrections for demographic covariates reduces risk of small cell sizes compared with traditional normative approaches. We explored whether methods of correcting for demographic covariates (e.g., full regression models versus hybrid models with stratification and regression) and choice of covariates (i.e., correcting for age with or without sex and/or education correction) impacted reliability and validity of normative data. Method: Measurement invariance for sex and education was explored in a brief telephone-administered cognitive battery from the Canadian Longitudinal Study on Aging (CLSA; after excluding persons with neurological conditions N = 12,350 responded in English and N = 1,760 in French). Results: Measurement invariance was supported in hybrid normative models where different age-based regression models were created for groups based on sex and education level. Measurement invariance was not supported in full regression models where age, sex, and education were simultaneous predictors. Evidence for reliability was demonstrated by precision defined as the 95% inter-percentile range of the 5^th percentile. Precision was higher for full regression models than for hybrid models but with negligible differences in precision for the larger English sample. Conclusions: We present normative data for a remotely administered brief neuropsychological battery that best mitigates measurement bias and are precise. In the smaller French speaking sample, only one model reduced measurement bias, but its estimates were less precise, underscoring the need for large sample sizes when creating normative data. The resulting normative data are appended in a syntax file.

Associations of vascular risk and amyloid burden with subsequent dementia

OBJECTIVE

Midlife vascular risk factors (MVRF) are associated with incident dementia, as are amyloid β(Aβ) deposition and neurodegeneration. Whether vascular and Alzheimer Disease (AD)-associated factors contribute to dementia independently or interact synergistically to reduce cognition is poorly understood.

METHODS

Participants in the Atherosclerosis Risk in Communities (ARIC)-PET study were followed from 1987-89(45-64 yo) through 2016-17(74-94 yo), with repeat cognitive assessment and dementia adjudication. In 2011-13, dementia-free participants underwent brain MRI (with white matter hyperintensity (WMH) and brain volume measurement) and florbetapir (Aβ) PET. The relative contributions of vascular risk and injury (MVRF, WMH volume), elevated Aβ standardized uptake value ratio (SUVR), and neurodegeneration (smaller temporo-parietal brain regions) to incident dementia were evaluated with adjusted Cox models.

RESULTS

In 298 individuals, 36 developed dementia (median follow-up 4.9 years). Midlife hypertension and Aβ each independently predicted dementia risk (hypertension:HR 2.57 (95% CI 1.16-5.67); Aβ SUVR(per SD):HR 2.57 (1.72-3.84)), but didn't interact significantly, whereas late-life diabetes (HR 2.50 (1.18 to 5.28)) and Aβ independently predicted dementia risk. WMH(per SD):HR 1.51 (1.03-2.20) and Aβ SUVR (HR 2.52 (1.83-3.47)) independently contributed to incident dementia but WMH lost significance when MVRF were included. Smaller temporo-parietal brain regions were associated with incident dementia, independent of Aβ and MVRF (HR 2.18 (1.18-4.01)).

INTERPRETATION

Midlife hypertension and late-life Aβ are independently associated with dementia risk, without evidence for synergy on a multiplicative scale. Given the independent contributions of vascular and amyloid mechanisms, multiple pathways should be considered when evaluating interventions to reduce the burden of dementia. This article is protected by copyright. All rights reserved.

Endurance and gait speed relationships with mild cognitive impairment and dementia

INTRODUCTION

Slower mobility is associated with mild cognitive impairment (MCI) and dementia. We examined the interaction of endurance with gait speed on prevalent MCI and dementia.

METHODS

Cross-sectional multinomial regression in the ARIC cohort (n = 2844 participants; 71 to 94 years; 44% men; 18% Black persons) with cognitive status (normal/MCI/dementia), 4 m gait speed, and endurance (2 minute walk [2MW]).

RESULTS

Faster gait speed (up to but not above 1 m/s) and better 2MW were separately associated with lower dementia risk. Good performance in both (2MW = 200 m, gait speed = 1.2 m/s) was associated with 99% lower dementia (Relative Prevalence Ratio [RPR] = 0.01 [95% CI: 0.0 to 0.06]) and 73% lower MCI, RPR = 0.27 (0.15 to 0.48) compared to poor performance in both (2MW = 100 m, gait speed = 0.8 m/s). Models incorporating a gait speed-by-2MW interaction term outperformed gait speed-only models (P < .001).

DISCUSSION

Gait speed relationships with dementia diminish at faster gait speeds. Combining endurance with gait speed may yield more sensitive markers of MCI and dementia than gait speed alone.

Factors Associated With Cognitive Impairment in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Cognitive impairment is prevalent in heart failure and is associated with higher mortality rates. The mechanism behind cognitive impairment in heart failure with preserved ejection fraction (HFpEF) has not been established.

OBJECTIVE

The aim of this study was to evaluate associations between abnormal cardiac hemodynamics and cognitive impairment in individuals with HFpEF.

METHODS

A secondary analysis of Atherosclerosis Risk in Communities (Atherosclerosis Risk in Communities) study data was performed. Participants free of stroke or dementia who completed in-person assessments at visit 5 were included. Neurocognitive test scores among participants with HFpEF, heart failure with reduced ejection fraction (HFrEF), and no heart failure were compared. Sociodemographics, comorbid illnesses, medications, and echocardiographic measures of cardiac function that demonstrated significant (P < .10) bivariate associations with neurocognitive test scores were included in multivariate models to identify predictors of neurocognitive test scores among those with HFpEF. Multiple imputation by chained equations was used to account for missing values.

RESULTS

Scores on tests of attention, language, executive function, and global cognitive function were worse among individuals with HFpEF than those with no heart failure. Neurocognitive test scores were not significantly different among participants with HFpEF and HFrEF. Worse diastolic function was weakly associated with worse performance in memory, attention, and language. Higher cardiac index was associated with worse performance on 1 test of attention.

CONCLUSIONS

Cognitive impairment is prevalent in HFpEF and affects several cognitive domains. The current study supports the importance of cognitive screening in patients with heart failure. An association between abnormal cardiac hemodynamics and cognitive impairment was observed, but other factors are likely involved.

Associations of Visual Function With Cognitive Performance in Community-Based Older Adults: The Eye Determinants of Cognition Study

BACKGROUND

Given the detrimental impacts of visual and cognitive impairment separately, in older adults, understanding their coexistence could inform strategies against age-related cognitive changes.

METHODS

Participants from Washington County (White) and Jackson (Black) sites of the Atherosclerosis Risk in Communities Study were recruited who differed on racial, regional, urbanicity, and community-based factors. Presenting distance visual acuity (DVA; representing vision loss due to disease or lack of eye-care), corrected DVA (representing optimal correction for refractive loss of vision), and contrast sensitivity were measured. Factor scores for global cognition, memory, executive function, and language domains were calculated for 3 visits. We quantified the associations of vision measures with change in cognitive scores, stratified by community/race, using generalized estimating equations.

RESULTS

In 982 participants, mean (standard deviation [SD]) baseline age was 74 (4) years, with 37% males and 45% Jackson/Black participants. As hypothesized, after accounting for potential confounders, in the better-eye, worse presenting DVA was associated with greater 10-year decline rate in global cognition, memory, and executive function in Washington County/White participants (eg, global cognition: -0.08 SD [95% confidence interval: -0.12, -0.04]). Worse corrected DVA was associated with greater 10-year decline rate in executive function in Washington County/White participants (-0.10 SD [-0.15, -0.04]). Better contrast sensitivity was associated with lower 10-year decline rate in global cognition and executive function in Washington County/White participants (eg, global cognition: 0.10 SD [0.06,0.14]). None of these associations were confirmed in Jackson/Black participants.

CONCLUSIONS

Our study supports a functional link between some vision measures and cognition in older adults, but in only 1 of the 2 communities studied.

Cognitive decline in older adults: What can we learn from optical coherence tomography (OCT)-based retinal vascular imaging?

INTRODUCTION

Accumulated vascular damage contributes to the onset and progression of vascular dementia and possibly to Alzheimer's disease. Here we evaluate the feasibility and utility of using retinal imaging of microvascular markers to identify older adults at risk of cognitive disease.

METHODS

The "Eye Determinants of Cognition" (EyeDOC) study recruited a biracial, population-based sample of participants from two sites: Jackson, MS, and Washington Co, MD. Optical coherence tomographic angiography (OCTA) was used to capture vessel density (VD) from a 6 × 6 mm scan of the macula in several vascular layers from 2017 to 2019. The foveal avascular zone (FAZ) area was also estimated. Image quality was assessed by trained graders at a reading center. A neurocognitive battery of 10 tests was administered at three time points from 2011 to 2019 and incident mild cognitive impairement (MCI)/dementia cases were ascertained. Linear mixed-effects models were used to evaluate associations of retinal vascular markers with cognitive factor score change over time.

RESULTS

Nine-hundred and seventy-six older adults (mean age of 78.7 (± 4.4) years, 44% black) were imaged. Gradable images were obtained in 55% (535/976), with low signal strength (66%) and motion artifact (22%) being the largest contributors to poor quality. Among the 297 participants with both high-quality images and no clinically significant retinal pathology, the average decline in global cognitive function factor score was -0.03 standard deviations per year. In adjusted analyses, no associations of VD or FAZ with longitudinal changes in either global cognitive function or with incident MCI/dementia were found.

CONCLUSIONS

In this large biracial community sample of older adults representative of the target population for retinal screening of cognitive risk, we found that obtaining high-quality OCTA scans was infeasible in a nearly half of older adults. Among the select sample of healthier older adults with scans, OCTA markers were not predictive of cognitive impairment.

Association of Midlife Plasma Amyloid-β Levels With Cognitive Impairment in Late Life: The ARIC Neurocognitive Study

OBJECTIVE

To evaluate the association between midlife plasma amyloid-beta (Aβ_1-42, Aβ_1-40, Aβ₄₂:Aβ₄₀) and risk of MCI and dementia.

METHODS

Plasma Aβ₄₂ and Aβ₄₀ were retrospectively measured using a fluorimetric bead-based immunoassay in a subsample of the Atherosclerosis Risk in Communities cohort study. We investigated the relationship of plasma Aβ₄₂, Aβ₄₀, and Aβ₄₂:Aβ₄₀ ratio measured in midlife, late-life, and the change from midlife to late-life, to risk of MCI, dementia, and combined MCI/dementia outcomes in late-life (from 2011-19). We used multinomial logistic regressions estimating relative risk ratios (RRR) of these cognitive outcomes vs cognitively normal adjusted for age, sex, education, site-race, APOE, hypertension, diabetes, and body mass index.

RESULTS

A total of 2284 participants were included (midlife mean age=59.2±5.2, 57% female, 22% Black). Each doubling of midlife Aβ₄₂:Aβ₄₀ was associated with 37% lower risk of MCI/dementia (RRR=0.63, 95% CI: 0.46, 0.87), but only up to approximately the median (spline model threshold 0.20). Every standard deviation increase in plasma Aβ₄₂ (10 pg/mL) was associated with 13% lower risk of MCI/dementia (RRR=0.87, 95% CI: 0.77, 0.98), whereas every standard deviation increase in plasma Aβ₄₀ (67 pg/mL) was associated with 15% higher risk of MCI/dementia (RRR=1.15, 95% CI: 1.01, 1.29). Associations were comparable, but slightly weaker statistically, when repeating models using late-life plasma Aβ predictors. Aβ₄₂ and Aβ₄₀ increased from midlife to late-life, but changes were not associated with cognitive outcomes.

CONCLUSION

Midlife measurement of plasma Aβ may have utility as a blood-based biomarker indicative of risk for future cognitive impairment.

The Uniform Dataset 3.0 Neuropsychological Battery: Factor Structure, Invariance Testing, and Demographically Adjusted Factor Score Calculation

OBJECTIVE

The goals of this study were to (1) specify the factor structure of the Uniform Dataset 3.0 neuropsychological battery (UDS3NB) in cognitively unimpaired older adults, (2) establish measurement invariance for this model, and (3) create a normative calculator for factor scores.

METHODS

Data from 2520 cognitively intact older adults were submitted to confirmatory factor analyses and invariance testing across sex, age, and education. Additionally, a subsample of this dataset was used to examine invariance over time using 1-year follow-up data (n = 1061). With the establishment of metric invariance of the UDS3NB measures, factor scores could be extracted uniformly for the entire normative sample. Finally, a calculator was created for deriving demographically adjusted factor scores.

RESULTS

A higher order model of cognition yielded the best fit to the data χ2(47) = 385.18, p < .001, comparative fit index = .962, Tucker-Lewis Index = .947, root mean square error of approximation = .054, and standardized root mean residual = .036. This model included a higher order general cognitive abilities factor, as well as lower order processing speed/executive, visual, attention, language, and memory factors. Age, sex, and education were significantly associated with factor score performance, evidencing a need for demographic correction when interpreting factor scores. A user-friendly Excel calculator was created to accomplish this goal and is available in the online supplementary materials.

CONCLUSIONS

The UDS3NB is best characterized by a higher order factor structure. Factor scores demonstrate at least metric invariance across time and demographic groups. Methods for calculating these factors scores are provided.

Association of Left Atrial Enlargement and Atrial Fibrillation With Cognitive Function and Decline: The ARIC-NCS

Background Atrial fibrillation (AF) is associated with cognitive decline. Whether left atrial enlargement (LAE), a critical substrate for AF, is also associated is less well established. Therefore, we assessed the association of LAE and AF with cognitive decline in the ARIC-NCS (Atherosclerosis Risk in Communities Neurocognitive Study). Methods and Results Participants (n=3391; mean age, 75±5 years; 59% women) underwent cognitive tests and 2-dimensional echocardiograms at visit 5 (2011-2013) and follow-up cognitive tests at visit 6 (2016-2017). LAE was defined as left atrium volume index ≥34 mL/m2. AF was ascertained using study ECGs and hospitalization discharge codes. We assessed the association of AF and LAE with (a) cognitive domain scores at visit 5 and (b) cognitive domain score changes between visit 5 and visit 6. At visit 5, compared with the reference group (without AF, normal left atrium), participants with LAE and AF had significantly lower global cognition (Z score, -0.24; 95% CI, -0.38 to -0.10), whereas participants with AF and without LAE and participants with LAE and without AF did not have lower global cognition. In longitudinal analysis, compared with the reference group, participants with AF but without LAE had significantly greater decline in global cognition (Z score, -0.13; 95% CI, -0.21 to -0.06). However, LAE, with or without AF, was not associated with greater cognitive decline. Conclusion Although LAE with AF was significantly associated with lower cognitive function in cross-sectional analysis, LAE, with or without AF, was not associated with greater cognitive decline over 5 years, highlighting the importance of evaluating longitudinal cognitive function. Future studies should have longer follow-up and evaluate left atrium function.

Association of white matter microstructural integrity with cognition and dementia

Late-life measures of white matter (WM) microstructural integrity may predict cognitive status, cognitive decline, and incident mild cognitive impairment (MCI) or dementia. We considered participants of the Atherosclerosis Risk in Communities study who underwent cognitive assessment and neuroimaging in 2011-2013 and were followed through 2016-2017 (n = 1775 for analyses of prevalent MCI and dementia, baseline cognitive performance, and longitudinal cognitive change and n = 889 for analyses of incident MCI, dementia, or death). Cross-sectionally, both overall WM fractional anisotropy and overall WM mean diffusivity were strongly associated with baseline cognitive performance and risk of prevalent MCI or dementia. Longitudinally, greater overall WM mean diffusivity was associated with accelerated cognitive decline, as well as incident MCI, incident dementia, and mortality, but WM fractional anisotropy was not robustly associated with cognitive change or incident cognitive impairment. Both cross-sectional and longitudinal associations were attenuated after additionally adjusting for likely downstream pathologic changes. Increased WM mean diffusivity may provide an early indication of dementia pathogenesis.

Mid-life serum Vitamin D concentrations were associated with incident dementia but not late-life neuropsychological performance in the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Activated Vitamin D has anti-inflammatory properties and adequate 25-hydroxyvitamin D [25(OH)D] concentrations may be important for neurocognitive function and protection against neurologic injury. We examined whether mid-life 25(OH) D concentrations were associated with later-life performance on neuropsychological testing, functional ability, depressive symptoms, and incident dementia.

METHODS

We studied 13,039 white and black ARIC participants who had serum 25(OH) D measured mid-life at visit 2 (1990-1992). Over the next ~ 20 years through visit 5 (2011-2013), participants underwent 3 additional in-person visits, annual telephone calls, and hospitalization surveillance. An extensive battery of neuropsychological outcomes were assessed at visit 5 using standardized protocols. Incident dementia was ascertained through a formal algorithm that included data from in-person cognitive testing, telephone interviews, hospital discharge codes, and death certificate codes. Diagnoses of dementia were adjudicated by expert clinician committee. For the primary cognitive analyses, we imputed for missing covariates and outcomes and used linear regression to evaluate non-concurrent cross-sectional associations of mid-life 25(OH) D (visit 2) with late-life neuropsychological outcomes (visit 5). We also used Cox regression models to examine associations of mid-life 25(OH) D and incident dementia.

RESULTS

In mid-life, the mean (SD) age of participants was 57 (6) years, 57% were women, and 24% black. Mean (SD) 25(OH) D was 24.3 (8.6) ng/mL; 33% had deficient (< 20 ng/mL), 44% intermediate (20- < 30 ng/mL), and 23% sufficient (≥30 ng/mL) 25(OH) D concentrations. Association between mid-life 25(OH) D and late-life performance on neuropsychological testing were mostly null. There was no significant association with functional ability or depressive symptoms. Results were similar in a sensitivity analysis using complete-case data (no imputation). However, after a median follow-up of 20 years, low 25(OH) D concentrations were associated with increased risk for incident dementia (p = 0.01 for trend across categories), with HR of 1.26 (95% CI 1.06, 1.49) for participants with deficient 25(OH) D, compared to sufficient concentrations.

CONCLUSION

In this community cohort, mid-life serum 25(OH) D concentrations were associated with incident dementia but not with performance on neuropsychological testing, functional ability, or depressive symptoms, 20 years later. Whether serum 25(OH) D concentrations are causally related to dementia or confounded by poorer health status remains uncertain.

TRIAL REGISTRATION

Registered on clinicaltrials.gov NCT00005131 .

Self-reported cognitive scales in a US National Survey: reliability, validity, and preliminary evidence for associations with alcohol and drug use

AIMS

To evaluate relationships between measures of cognitive functioning and alcohol or drug use among adults (≥ 18 years) in the US general population.

DESIGN

Two cognitive scales were created based on dimensionality and reliability of self-reported Executive Function Index items. Relationships between the two scales and validators were evaluated. Associations between the cognitive scales and past-year frequency of alcohol or drug use were estimated with adjusted odds ratios (aOR).

SETTING

United States, using the 2012-13 National Epidemiologic Survey on Alcohol and Related Conditions-III, a nationally representative adult sample selected by multi-stage probability sampling.

PARTICIPANTS

36 085 respondents.

MEASUREMENTS

Past-year substance use outcome variables categorized binge drinking, marijuana, cocaine, opioid, sedative/tranquilizer and stimulant use as frequent (at least weekly to daily), infrequent (any to two to three times/month) or no use, assessed by the Alcohol Use Disorder and Associated Disabilities Interview Schedule-5. Key predictors were the two cognitive scales. Construct validators included education and functional impairment. Covariates included age, gender, income and race/ethnicity.

FINDINGS

Nine cognitive items fitted a two-factor model (comparative fit index = 0.973): attention (five items) and executive functioning (four items). Both scales were associated positively with higher education (Ps < 0.001) and negatively with functional impairment (Ps < 0.001), demonstrating construct validity. Poorer attention was associated with frequent and infrequent binge drinking and use of drugs [aOR range = 1.07 (binge drinking) to 1.72 (stimulants), Ps ≤ 0.01]. Poorer executive functioning was associated with frequent binge drinking and use of drugs [aOR range = 1.22 (binge drinking) to 2.03 (cocaine), Ps < 0.001] and infrequent use of all drugs [aOR range = 1.19 (marijuana) to 1.63 (cocaine), Ps < 0.001].

CONCLUSIONS

Impairments in attention and executive functioning are positively associated with substance use in the US general population.

A randomized feasibility pilot trial of hearing treatment for reducing cognitive decline: Results from the Aging and Cognitive Health Evaluation in Elders Pilot Study

Introduction

Hearing loss (HL) is prevalent and independently related to cognitive decline and dementia. There has never been a randomized trial to test if HL treatment could reduce cognitive decline in older adults.

Methods

A 40-person (aged 70–84 years) pilot study in Washington County, MD, was conducted. Participants were randomized 1:1 to a best practices hearing or successful aging intervention and followed for 6 months. clinicaltrials.gov Identifier: NCT02412254.

Results

The Aging and Cognitive Health Evaluation in Elders Pilot (ACHIEVE-P) Study demonstrated feasibility in recruitment, retention, and implementation of interventions with no treatment-related adverse events. A clear efficacy signal of the hearing intervention was observed in perceived hearing handicap (mean of 0.11 to −1.29 standard deviation [SD] units; lower scores better) and memory (mean of −0.10 SD to 0.38 SD).

Discussion

ACHIEVE-P sets the stage for the full-scale ACHIEVE trial (N = 850, recruitment beginning November 2017), the first randomized trial to determine efficacy of a best practices hearing (vs. successful aging) intervention on reducing cognitive decline in older adults with HL.