Associations Between Midlife Vascular Risk Factors and 25-Year Incident Dementia in the Atherosclerosis Risk in Communities (ARIC) Cohort

Importance

Vascular risk factors have been associated with cognitive decline. Midlife exposure to these factors may be most important in conferring late-life risk of cognitive impairment.

Objectives

To examine Atherosclerosis Risk in Communities (ARIC) participants in midlife and to explore associations between midlife vascular risk factors and 25-year dementia incidence.

Design, Setting, and Participants

This prospective cohort investigation of the Atherosclerosis Risk in Communities (ARIC) Study was conducted from 1987-1989 through 2011-2013. The dates of this analysis were April 2015 through August 2016. The setting was ARIC field centers (Washington County, Maryland; Forsyth County, North Carolina; Jackson, Mississippi; and Minneapolis suburbs, Minnesota). The study comprised 15 744 participants (of whom 27.1% were black and 72.9% white) who were aged 44 to 66 years at baseline.

Main Outcomes and Measures

Demographic and vascular risk factors were measured at baseline (obesity, smoking, diabetes, prehypertension, hypertension, and hypercholesterolemia) as well as presence of the APOE ε4 genotype. After the baseline visit, participants had 4 additional in-person visits, for a total of 5 in-person visits, hospitalization surveillance, telephone calls, and repeated cognitive evaluations. Most recently, in 2011-2013, through the ARIC Neurocognitive Study (ARIC-NCS), participants underwent a detailed neurocognitive battery, informant interviews, and adjudicated review to define dementia cases. Additional cases were identified through the Telephone Interview for Cognitive Status-Modified or informant interview, for participants not attending the ARIC-NCS visit, or by an International Classification of Diseases, Ninth Revision dementia code during a hospitalization. Fully adjusted Cox proportional hazards regression was used to evaluate associations of baseline vascular and demographic risk factors with dementia.

Results

In total, 1516 cases of dementia (57.0% female and 34.9% black, with a mean [SD] age at visit 1 of 57.4 [5.2] years) were identified among 15 744 participants. Black race (hazard ratio [HR], 1.36; 95% CI, 1.21-1.54), older age (HR, 8.06; 95% CI, 6.69-9.72 for participants aged 60-66 years), lower educational attainment (HR, 1.61; 95% CI, 1.28-2.03 for less than a high school education), and APOE ε4 genotype (HR, 1.98; 95% CI, 1.78-2.21) were associated with increased risk of dementia, as were midlife smoking (HR, 1.41; 95% CI, 1.23-1.61), diabetes (HR, 1.77; 95% CI, 1.53-2.04), prehypertension (HR, 1.31; 95% CI, 1.14-1.51), and hypertension (HR, 1.39; 95% CI, 1.22-1.59). The HR for dementia for diabetes was almost as high as that for APOE ε4 genotype.

Conclusions and Relevance

Midlife vascular risk factors are associated with increased risk of dementia in black and white ARIC Study participants. Further studies are needed to evaluate the mechanism of and opportunities for prevention of the cognitive sequelae of these risk factors in midlife.

Hearing Impairment and Incident Dementia and Cognitive Decline in Older Adults: The Health ABC Study

BACKGROUND

Age-related peripheral hearing impairment (HI) is prevalent, treatable, and may be a risk factor for dementia in older adults. In prospective analysis, we quantified the association of HI with incident dementia and with domain-specific cognitive decline in memory, perceptual speed, and processing speed.

METHODS

Data were from the Health, Aging and Body Composition (Health ABC) study, a biracial cohort of well-functioning adults aged 70-79 years. Dementia was defined using a prespecified algorithm incorporating medication use, hospital records, and neurocognitive test scores. A pure-tone average in decibels hearing level (dBHL) was calculated in the better hearing ear using thresholds from 0.5 to 4kHz, and HI was defined as normal hearing (≤25 dBHL), mild (26-40 dBHL), and moderate/severe (>40 dBHL). Associations between HI and incident dementia and between HI and cognitive change were modeled using Cox proportional hazards models and linear mixed models, respectively.

RESULTS

Three-hundred eighty seven (20%) participants had moderate/severe HI, and 716 (38%) had mild HI. After adjustment for demographic and cardiovascular factors, moderate/severe audiometric HI (vs. normal hearing) was associated with increased risk of incident dementia over 9 years (hazard ratio: 1.55, 95% confidence interval [CI]: 1.10, 2.19). Other than poorer baseline memory performance (difference of -0.24 SDs, 95% CI: -0.44, -0.04), no associations were observed between HI and rates of domain-specific cognitive change during 7 years of follow-up.

CONCLUSIONS

HI is associated with increased risk of developing dementia in older adults. Randomized trials are needed to determine whether treatment of hearing loss could postpone dementia onset in older adults.

Hearing impairment and cognitive decline: a pilot study conducted within the atherosclerosis risk in communities neurocognitive study

Hearing impairment (HI) is prevalent, is modifiable, and has been associated with cognitive decline. We tested the hypothesis that audiometric HI measured in 2013 is associated with poorer cognitive function in 253 men and women from Washington County, Maryland (mean age = 76.9 years) in a pilot study carried out within the Atherosclerosis Risk in Communities Neurocognitive Study. Three cognitive tests were administered in 1990-1992, 1996-1998, and 2013, and a full neuropsychological battery was administered in 2013. Multivariable-adjusted differences in standardized cognitive scores (cross-sectional analysis) and trajectories of 20-year change (longitudinal analysis) were modeled using linear regression and generalized estimating equations, respectively. Hearing thresholds for pure tone frequencies of 0.5-4 kHz were averaged to obtain a pure tone average in the better-hearing ear. Hearing was categorized as follows: ≤25 dB, no HI; 26-40 dB, mild HI; and >40 dB, moderate/severe HI. Comparing participants with moderate/severe HI to participants with no HI, 20-year rates of decline in memory and global function differed by -0.47 standard deviations (P = 0.02) and -0.29 standard deviations (P = 0.02), respectively. Estimated declines were greatest in participants who did not wear a hearing aid. These findings add to the limited literature on cognitive impairments associated with HI, and they support future research on whether HI treatment may reduce risk of cognitive decline.

The generation of chromosomal deletions to provide extensive coverage and subdivision of the Drosophila melanogaster genome

Background

Chromosomal deletions are used extensively in Drosophila melanogaster genetics research. Deletion mapping is the primary method used for fine-scale gene localization. Effective and efficient deletion mapping requires both extensive genomic coverage and a high density of molecularly defined breakpoints across the genome.

Results

A large-scale resource development project at the Bloomington Drosophila Stock Center has improved the choice of deletions beyond that provided by previous projects. FLP-mediated recombination between FRT-bearing transposon insertions was used to generate deletions, because it is efficient and provides single-nucleotide resolution in planning deletion screens. The 793 deletions generated pushed coverage of the euchromatic genome to 98.4%. Gaps in coverage contain haplolethal and haplosterile genes, but the sizes of these gaps were minimized by flanking these genes as closely as possible with deletions. In improving coverage, a complete inventory of haplolethal and haplosterile genes was generated and extensive information on other haploinsufficient genes was compiled. To aid mapping experiments, a subset of deletions was organized into a Deficiency Kit to provide maximal coverage efficiently. To improve the resolution of deletion mapping, screens were planned to distribute deletion breakpoints evenly across the genome. The median chromosomal interval between breakpoints now contains only nine genes and 377 intervals contain only single genes.

Conclusions

Drosophila melanogaster now has the most extensive genomic deletion coverage and breakpoint subdivision as well as the most comprehensive inventory of haploinsufficient genes of any multicellular organism. The improved selection of chromosomal deletion strains will be useful to nearly all Drosophila researchers.

Hearing intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA (ACHIEVE): a multicentre, randomised controlled trial

BACKGROUND

Hearing loss is associated with increased cognitive decline and incident dementia in older adults. We aimed to investigate whether a hearing intervention could reduce cognitive decline in cognitively healthy older adults with hearing loss.

METHODS

The ACHIEVE study is a multicentre, parallel-group, unmasked, randomised controlled trial of adults aged 70-84 years with untreated hearing loss and without substantial cognitive impairment that took place at four community study sites across the USA. Participants were recruited from two study populations at each site: (1) older adults participating in a long-standing observational study of cardiovascular health (Atherosclerosis Risk in Communities [ARIC] study), and (2) healthy de novo community volunteers. Participants were randomly assigned (1:1) to a hearing intervention (audiological counselling and provision of hearing aids) or a control intervention of health education (individual sessions with a health educator covering topics on chronic disease prevention) and followed up every 6 months. The primary endpoint was 3-year change in a global cognition standardised factor score from a comprehensive neurocognitive battery. Analysis was by intention to treat. This trial was registered at ClinicalTrials.gov, NCT03243422.

FINDINGS

From Nov 9, 2017, to Oct 25, 2019, we screened 3004 participants for eligibility and randomly assigned 977 (32·5%; 238 [24%] from ARIC and 739 [76%] de novo). We randomly assigned 490 (50%) to the hearing intervention and 487 (50%) to the health education control. The cohort had a mean age of 76·8 years (SD 4·0), 523 (54%) were female, 454 (46%) were male, and most were White (n=858 [88%]). Participants from ARIC were older, had more risk factors for cognitive decline, and had lower baseline cognitive scores than those in the de novo cohort. In the primary analysis combining the ARIC and de novo cohorts, 3-year cognitive change (in SD units) was not significantly different between the hearing intervention and health education control groups (-0·200 [95% CI -0·256 to -0·144] in the hearing intervention group and -0·202 [-0·258 to -0·145] in the control group; difference 0·002 [-0·077 to 0·081]; p=0·96). However, a prespecified sensitivity analysis showed a significant difference in the effect of the hearing intervention on 3-year cognitive change between the ARIC and de novo cohorts (pinteraction=0·010). Other prespecified sensitivity analyses that varied analytical parameters used in the total cohort did not change the observed results. No significant adverse events attributed to the study were reported with either the hearing intervention or health education control.

INTERPRETATION

The hearing intervention did not reduce 3-year cognitive decline in the primary analysis of the total cohort. However, a prespecified sensitivity analysis showed that the effect differed between the two study populations that comprised the cohort. These findings suggest that a hearing intervention might reduce cognitive change over 3 years in populations of older adults at increased risk for cognitive decline but not in populations at decreased risk for cognitive decline.

FUNDING

US National Institutes of Health.

Trends in Health Care Costs and Utilization Associated With Untreated Hearing Loss Over 10 Years

Importance

Nearly 38 million individuals in the United States have untreated hearing loss, which is associated with cognitive and functional decline. National initiatives to address hearing loss are currently under way.

Objective

To determine whether untreated hearing loss is associated with increased health care cost and utilization on the basis of data from a claims database.

Design, Setting, and Participants

Retrospective, propensity-matched cohort study of persons with and without untreated hearing loss based on claims for health services rendered between January 1, 1999, and December 31, 2016, from a large health insurance database. There were 154 414, 44 852, and 4728 participants at the 2-, 5-, and 10-year follow-up periods, respectively. The study was conceptualized and data were analyzed between September 2016 and November 2017.

Exposures

Untreated hearing loss (ie, hearing loss that has not been treated with hearing devices) was identified via claims measures.

Main Outcomes and Measures

Medical costs, inpatient hospitalizations, total days hospitalized, 30-day hospital readmission, emergency department visits, and days with at least 1 outpatient visit.

Results

Among 4728 matched adults (mean age at baseline, 61 years; 2280 women and 2448 men), untreated hearing loss was associated with $22 434 (95% CI, $18 219-$26 648) or 46% higher total health care costs over a 10-year period compared with costs for those without hearing loss. Persons with untreated hearing loss experienced more inpatient stays (incidence rate ratio, 1.47; 95% CI, 1.29-1.68) and were at greater risk for 30-day hospital readmission (relative risk, 1.44; 95% CI, 1.14-1.81) at 10 years postindex. Similar trends were observed at 2- and 5-year time points across measures.

Conclusions and Relevance

Older adults with untreated hearing loss experience higher health care costs and utilization patterns compared with adults without hearing loss. To further define this association, additional research on mediators, such as treatment adherence, and mitigation strategies is needed.

Association of Hearing Impairment With Incident Frailty and Falls in Older Adults

OBJECTIVE

We aimed to determine whether hearing impairment (HI) in older adults is associated with the development of frailty and falls.

METHOD

Longitudinal analysis of observational data from the Health, Aging and Body Composition study of 2,000 participants aged 70 to 79 was conducted. Hearing was defined by the pure-tone-average of hearing thresholds at 0.5, 1, 2, and 4 kHz in the better hearing ear. Frailty was defined as a gait speed of <0.60 m/s and/or inability to rise from a chair without using arms. Falls were assessed annually by self-report.

RESULTS

Older adults with moderate-or-greater HI had a 63% increased risk of developing frailty (adjusted hazard ratio [HR] = 1.63, 95% confidence interval [CI] = [1.26, 2.12]) compared with normal-hearing individuals. Moderate-or-greater HI was significantly associated with a greater annual percent increase in odds of falling over time (9.7%, 95% CI = [7.0, 12.4] compared with normal hearing, 4.4%, 95% CI = [2.6, 6.2]).

DISCUSSION

HI is independently associated with the risk of frailty in older adults and with greater odds of falling over time.

HIV Infection Is Associated With Progression of Subclinical Carotid Atherosclerosis

BACKGROUND

Individuals infected with human immunodeficiency virus (HIV) live longer as a result of effective treatment, but long-term consequences of infection, treatment, and immunological dysfunction are poorly understood.

METHODS

We prospectively examined 1011 women (74% HIV-infected) in the Women's Interagency HIV Study and 811 men (65% HIV-infected) in the Multicenter AIDS Cohort Study who underwent repeated B-mode carotid artery ultrasound imaging in 2004-2013. Outcomes included changes in right common carotid artery intima-media thickness (CCA-IMT) and new focal carotid artery plaque formation (IMT >1.5 mm) over median 7 years. We assessed the association between HIV serostatus and progression of subclinical atherosclerosis, adjusting for demographic, behavioral, and cardiometabolic risk factors.

RESULTS

Unadjusted mean CCA-IMT increased (725 to 752 µm in women, 757 to 790 µm in men), but CCA-IMT progression did not differ by HIV serostatus, either in combined or sex-specific analyses. Focal plaque prevalence increased from 8% to 15% in women and 25% to 34% in men over 7 years. HIV-infected individuals had 1.6-fold greater risk of new plaque formation compared with HIV-uninfected individuals (relative risk [RR] 1.61, 95% CI, 1.12-2.32), adjusting for cardiometabolic factors; the association was similar by sex. Increased plaque occurred even among persistently virologically suppressed HIV-infected individuals compared with uninfected individuals (RR 1.56, 95% CI, 1.07-2.27). HIV-infected individuals with baseline CD4+ ≥ 500 cells/µL had plaque risk not statistically different from uninfected individuals.

CONCLUSIONS

HIV infection is associated with greater increases in focal plaque among women and men, potentially mediated by factors associated with immunodeficiency or HIV replication at levels below current limits of detection.

The Health of America's Aging Prison Population

Older incarcerated individuals comprise the fastest growing demographic in the US prison system. Unhealthy lifestyles among incarcerated individuals and inadequate health care lead to earlier onset and more rapid progression of many chronic conditions that are prevalent among community-living older adults. There are limited peer-reviewed epidemiologic data in this area; however, there is growing interest in identifying strategies for housing aging incarcerated individuals, delivering appropriate health care in prisons, and coordinating after-release health care. In this systematic review, we summarize the epidemiologic evidence of the health challenges facing the aging US prison population. Our comprehensive literature search focused on health outcomes, including diseases, comorbid conditions, mental health, cognition, and mobility. From 12,486 articles identified from the literature search, we reviewed 21 studies published between 2007 and 2017. All the studies were observational and cross-sectional, and most (n = 17) were based on regional samples. Sample sizes varied widely, ranging from 25 to 14,499 incarcerated people (median, 258). In general, compared with their younger counterparts, older incarcerated individuals reported high rates of diabetes mellitus, cardiovascular conditions, and liver disease. Mental health problems were common, especially anxiety, fear of desire for death or suicide, and depression. Activities of daily living were challenging for up to one-fifth of the population. We found no empirical data on cognition among older incarcerated individuals. The findings of this review reveal few empirical data in this area and highlight the need for new data to drive policy and practice patterns that address critical health issues related to the aging prison population.

Incident Hearing Loss and Comorbidity: A Longitudinal Administrative Claims Study

Importance

Because hearing loss is highly prevalent and treatable, determining its association with morbidity has major public health implications for disease prevention and the maintenance of health in adults with hearing loss.

Objective

To investigate the association between the diagnosis of incident hearing loss and medical comorbidities in adults 50 years or older.

Design, Setting, and Participants

Retrospective, propensity-matched cohort study using administrative claims data from commercially insured and Medicare Advantage members in a geographically diverse US health plan. Adults 50 years or older with claims for services rendered from January 1, 2000, to December 31, 2016, were observed for 2 (n = 154 414), 5 (n = 44 852), and 10 (n = 4728) years. This research was conceptualized and data were analyzed between September 2016 and November 2017.

Exposures

A claim for incident hearing loss is defined as 2 claims for hearing loss within 2 consecutive years without evidence of hearing device use, excluding claims for sudden hearing loss or hearing loss secondary to medical conditions.

Main Outcomes and Measures

Incident claims for dementia, depression, accidental falls, nonvertebral fractures, acute myocardial infarction, and stroke.

Results

After cohort matching, 48% of participants were women (n = 74 464), 61% were white (n = 93 442), and 31% (n = 48 056) were Medicare Advantage insured, with a mean (SD) age of 64 (10) years. In a multivariate-adjusted modified Poisson regression with robust standard errors, relative associations were strongest for dementia (relative risk at 5 years, 1.50; 95% CI, 1.38-1.64) and depression (relative risk at 5 years, 1.41; 95% CI, 1.26-1.58). The absolute risk of all outcomes was greater in persons with hearing loss than in those without hearing loss at all times, with the greatest risk difference observed at 10 years for all outcomes. The 10-year risk attributable to hearing loss was 3.20 per 100 persons (95% CI, 1.76-4.63) for dementia, 3.57 per 100 persons (95% CI, 1.67-5.47) for falls, and 6.88 per 100 persons (95% CI, 4.62-9.14) for depression.

Conclusions and Relevance

In this large observational study using administrative claims data, incident untreated hearing loss was associated with greater incident morbidity than no hearing loss across a range of health conditions. Future studies are needed to elucidate the mechanisms underlying these associations and to determine if treatment for hearing loss could reduce the risk of comorbidity.

Smoking and white matter hyperintensity progression: the ARIC-MRI Study

OBJECTIVE

Our objective was to examine the link between smoking and smoking history, including smoking intensity and cessation, overall and by race, in a biracial prospective cohort study.

METHODS

A subset of Atherosclerosis Risk in Communities Study participants (n = 972, 49% black) completed brain MRI scans twice (1993-1995 and 2004-2006). We defined white matter hyperintensity (WMH) progression as an increase of ≥2 points on the 9-point Cardiovascular Health Study scale across scans. Participants reported information on smoking behavior at the baseline MRI and at 2 prior study visits, approximately 3 and 6 years before baseline. We used adjusted logistic regression to evaluate the association between smoking variables and WMH progression in the total sample and separately by race (black and white).

RESULTS

We found WMH progression in 23% of participants (30% of black participants, 17% of white participants). Overall, being a current smoker 6 years before baseline was associated with WMH progression. In race-stratified analyses, we found adverse associations with smoking status at multiple time points and persistent smoking in white but not in black participants. However, we found no statistical support for effect modification by race for most of these analyses. Increasing pack-years of smoking was associated with greater risk of WMH progression, while time since quitting and age at smoking initiation were not associated with WMH progression, with little indication of differences in these associations by race.

CONCLUSIONS

Our findings concur with previous studies suggesting a relationship between smoking and WMH progression, and further demonstrate a dose-dependent association.

Diabetes mellitus and the incidence of hearing loss: a cohort study

Background

To evaluate the association between diabetes mellitus (DM) and the development of incident hearing loss.

Methods

Prospective cohort study was performed in 253 301 adults with normal hearing tests who participated in a regular health-screening exam between 2002 and 2014. The main exposure was the presence of DM at baseline, defined as a fasting serum glucose ≥ 126 mg/dL, a self-reported history of DM or current use of anti-diabetic medications. Pre-diabetes was defined as a fasting glucose 100-125 mg/dL and no history of DM or anti-diabetic medication use. Incident hearing loss was defined as a pure-tone average of thresholds at 0.5, 1.0 and 2.0 kHz > 25 dB in both right and left ears.

Results

During 1 285 704 person-years of follow-up (median follow-up of four years), 2817 participants developed incident hearing loss. The rate of hearing loss in participants with normal glucose levels, pre-diabetes and DM were 1.8, 3.1 and 9.2 per 1000 person-years, respectively ( P < 0.001). The multivariable-adjusted hazard ratios for incident hearing loss for participants with pre-diabetes and DM compared with those with normal glucose levels were 1.04 (95% confidence interval 0.95-1.14) and 1.36 (1.19-1.56), respectively. In spline regression analyses, the risk of incident hearing loss increased progressively with HbA1c levels above 5%.

Conclusions

In this large cohort study of young and middle-aged men and women, DM was associated with the development of bilateral hearing loss. DM patients have a moderately increased risk of future hearing loss.

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.

Hearing treatment for reducing cognitive decline: Design and methods of the Aging and Cognitive Health Evaluation in Elders randomized controlled trial

INTRODUCTION

Hearing impairment is highly prevalent and independently associated with cognitive decline. The Aging and Cognitive Health Evaluation in Elders study is a multicenter randomized controlled trial to determine efficacy of hearing treatment in reducing cognitive decline in older adults. Clinicaltrials.gov Identifier: NCT03243422.

METHODS

Eight hundred fifty participants without dementia aged 70 to 84 years with mild-to-moderate hearing impairment recruited from four United States field sites and randomized 1:1 to a best-practices hearing intervention or health education control. Primary study outcome is 3-year change in global cognitive function. Secondary outcomes include domain-specific cognitive decline, incident dementia, brain structural changes on magnetic resonance imaging, health-related quality of life, physical and social function, and physical activity.

RESULTS

Trial enrollment began January 4, 2018 and is ongoing.

DISCUSSION

When completed in 2022, Aging and Cognitive Health Evaluation in Elders study should provide definitive evidence of the effect of hearing treatment versus education control on cognitive decline in community-dwelling older adults with mild-to-moderate hearing impairment.

Association of Midlife Hearing Impairment With Late-Life Temporal Lobe Volume Loss

IMPORTANCE

Hearing impairment (HI) in midlife (45-65 years of age) may be associated with longitudinal neurodegeneration of temporal lobe structures, a biomarker of early Alzheimer disease.

OBJECTIVE

To evaluate the association of midlife HI with brain volume trajectories in later life (≥65 years of age).

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study used data from the Baltimore Longitudinal Study of Aging to evaluate hearing from November 5, 1990, to October 3, 1994, and late-life volume change from July 10, 2008, to January 29, 2015, using magnetic resonance imaging (MRI) (mean follow-up time, 19.3 years). Data analysis was performed from September 22, 2017, to August 27, 2018. A total of 194 community-dwelling older adults who had midlife measures of peripheral hearing at a mean age of 54.5 years and late-life volume change of up to 6 years between the first and most recent MRI assessment were studied. Excluded were those with baseline cognitive impairment, stroke, head injuries, Parkinson disease, and bipolar disorder.

EXPOSURES

Hearing as measured with pure tone audiometry in each ear from November 5, 1990, to October 3, 1994, and late-life temporal lobe volume change measured by MRI.

MAIN OUTCOMES AND MEASURES

Linear mixed-effects models with random intercepts were used to examine the association of midlife hearing (pure tone average of 0.5-4 kHz tones in the better ear and each ear separately) with longitudinal late-life MRI-based measures of temporal lobe structures (hippocampus, entorhinal cortex, parahippocampal gyrus, and superior, middle, and inferior temporal gyri) in the left and right hemispheres, in addition to global and lobar regions, adjusting for baseline demographic characteristics (age, sex, subsequent cognitive impairment status, and educational level) and intracranial volume.

RESULTS

A total of 194 patients (mean [SD] age at hearing assessment, 54.5 [10.0] years; 106 [54.6%] female; 169 [87.1%] white) participated in the study. After Bonferroni correction, poorer midlife hearing in the better ear was associated with steeper late-life volumetric declines in the right temporal gray matter (β = -0.113; 95% CI, -0.182 to -0.044), right hippocampus (β = -0.008; 95% CI, -0.012 to -0.004), and left entorhinal cortex (β = -0.009; 95% CI, -0.015 to -0.003). Poorer midlife hearing in the right ear was associated with steeper late-life volumetric declines in the right temporal gray matter (β = -0.136; 95% CI, -0.197 to -0.075), right hippocampus (β = -0.008; 95% CI, -0.012 to -0.004), and left entorhinal cortex (β = -0.009; 95% CI, -0.015 to -0.003), whereas there were no associations between poorer midlife hearing in the left ear with late-life volume loss.

CONCLUSIONS AND RELEVANCE

The findings suggest that midlife HI is a risk factor for temporal lobe volume loss. Poorer midlife hearing, particularly in the right ear, was associated with declines in hippocampus and entorhinal cortex.

Glucose Peaks and the Risk of Dementia and 20-Year Cognitive Decline

OBJECTIVE

Hemoglobin A_1c (HbA_1c), a measure of average blood glucose level, is associated with the risk of dementia and cognitive impairment. However, the role of glycemic variability or glucose excursions in this association is unclear. We examined the association of glucose peaks in midlife, as determined by the measurement of 1,5-anhydroglucitol (1,5-AG) level, with the risk of dementia and 20-year cognitive decline.

RESEARCH DESIGN AND METHODS

Nearly 13,000 participants from the Atherosclerosis Risk in Communities (ARIC) study were examined. Dementia was ascertained from surveillance, neuropsychological testing, telephone calls with participants or their proxies, or death certificate dementia codes. Cognitive function was assessed using three neuropsychological tests at three visits over 20 years and was summarized as z scores. We used Cox and linear mixed-effects models. 1,5-AG level was dichotomized at 10 μg/mL and examined within clinical categories of HbA_1c.

RESULTS

Over a median time of 21 years, dementia developed in 1,105 participants. Among persons with diabetes, each 5 μg/mL decrease in 1,5-AG increased the estimated risk of dementia by 16% (hazard ratio 1.16, P = 0.032). For cognitive decline among participants with diabetes and HbA_1c <7% (53 mmol/mol), those with glucose peaks had a 0.19 greater z score decline over 20 years (P = 0.162) compared with those without peaks. Among participants with diabetes and HbA_1c ≥7% (53 mmol/mol), those with glucose peaks had a 0.38 greater z score decline compared with persons without glucose peaks (P < 0.001). We found no significant associations in persons without diabetes.

CONCLUSIONS

Among participants with diabetes, glucose peaks are a risk factor for cognitive decline and dementia. Targeting glucose peaks, in addition to average glycemia, may be an important avenue for prevention.

Hearing Loss and Cognition: What We Know and Where We Need to Go

Although a causal association remains to be determined, epidemiologic evidence suggests an association between hearing loss and increased risk of dementia. If we determine the association is causal, opportunity for targeted intervention for hearing loss may play a fundamental role in dementia prevention. In this discussion, we summarize current research on the association between hearing loss and dementia and review potential casual mechanisms behind the association (e.g., sensory-deprivation hypothesis, information-degradation hypothesis, common cause). We emphasize key areas of research which might best inform our investigation of this potential casual association. These selected research priorities include examination of the causal mechanism, measurement of co-existing hearing loss and cognitive impairment and determination of any bias in testing, potential for managing hearing loss for prevention of dementia and cognitive decline, or the potential to reduce dementia-related symptoms through the management of hearing loss. Addressing these research gaps and how results are then translated for clinical use may prove paramount for dementia prevention, management, and overall health of older adults.

Central Arterial Stiffness Is Associated With Structural Brain Damage and Poorer Cognitive Performance: The ARIC Study

Background Central arterial stiffening and increased pulsatility, with consequent cerebral hypoperfusion, may result in structural brain damage and cognitive impairment. Methods and Results We analyzed a cross-sectional sample of ARIC - NCS (Atherosclerosis Risk in Communities-Neurocognitive Study) participants (aged 67-90 years, 60% women) with measures of cognition (n=3703) and brain magnetic resonance imaging (n=1255). Central arterial hemodynamics were assessed as carotid-femoral pulse wave velocity and pressure pulsatility (central pulse pressure). We derived factor scores for cognitive domains. Brain magnetic resonance imaging using 3-Tesla scanners quantified lacunar infarcts; cerebral microbleeds; and volumes of white matter hyperintensities, total brain, and the Alzheimer disease signature region. We used logistic regression, adjusted for demographics, apolipoprotein E ɛ4, heart rate, mean arterial pressure, and select cardiovascular risk factors, to estimate the odds of lacunar infarcts or cerebral microbleeds. Linear regression, additionally adjusted for intracranial volume, estimated the difference in log-transformed volumes of white matter hyperintensities , total brain, and the Alzheimer disease signature region. We estimated the mean difference in cognitive factor scores across quartiles of carotid-femoral pulse wave velocity or central pulse pressure using linear regression. Compared with participants in the lowest carotid-femoral pulse wave velocity quartile, participants in the highest quartile of carotid-femoral pulse wave velocity had a greater burden of white matter hyperintensities ( P=0.007 for trend), smaller total brain volumes (-18.30 cm3; 95% CI , -27.54 to -9.07 cm3), and smaller Alzheimer disease signature region volumes (-1.48 cm3; 95% CI , -2.27 to -0.68 cm3). These participants also had lower scores in executive function/processing speed (β=-0.04 z score; 95% CI , -0.07 to -0.01 z score) and general cognition (β=-0.09 z score; 95% CI , -0.15 to -0.03 z score). Similar results were observed for central pulse pressure . Conclusions Central arterial hemodynamics were associated with structural brain damage and poorer cognitive performance among older adults.

National Prevalence of Disability and Disability Types Among Adults in the US, 2019

This cross-sectional study uses data from the 2019 Behavioral Risk Factor Surveillance System to examine the most recent estimates of disability prevalence among adults in the US.

Prevalence of Concurrent Functional Vision and Hearing Impairment and Association With Dementia in Community-Dwelling Medicare Beneficiaries

IMPORTANCE

Impairments in vision or hearing are common and have been independently linked to higher risk of dementia in older adults. There is a limited understanding of the prevalence of concurrent functional vision and hearing impairment (dual sensory impairment) and its contribution to dementia risk.

OBJECTIVE

To examine the age-specific prevalence of functional dual sensory impairment among older adults, and to investigate the cross-sectional and 7-year longitudinal associations between functional dual sensory impairment and dementia.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study of 7562 older adults used data from the US National Health and Aging Trends Study (NHATS), a nationally representative cohort study of community-dwelling, Medicare beneficiaries aged 65 years and older in the US. Participants in the study with complete data on hearing, vision, and dementia were included in analysis. Data were collected between 2011 and 2018, and between March 2018 and May 2020.

EXPOSURES

Self-reported functional sensory impairments (ie, no sensory impairment, functional vision impairment only, functional hearing impairment only, and functional dual sensory impairment).

MAIN OUTCOMES AND MEASURES

Age-specific prevalence of functional sensory impairments was calculated. Generalized linear regression with a complementary log-log link and a discrete time proportional hazards model with a complementary log-log link were used to assess the cross-sectional and 7-year longitudinal hazard of dementia.

RESULTS

Of 7562 participants, 3073 (40.7%) were ages 80 years or older and 4411 (58.3%) were women. Overall, 5.4% (95% CI, 4.7%-6.1%) of participants reported functional vision impairment only, 18.9% (95% CI, 18.9%-17.8%) reported functional hearing impairment only, and 3.1% (95% CI, 2.7%-3.5%) reported functional dual sensory impairment (prevalence estimates are weighted). Participants reporting sensory impairments were older (no impairment: age ≥90 years, 2.12% [95% CI, 1.79%-2.46%] vs functional dual sensory impairment: age ≥90 years, 20.06% [95% CI, 16.02%-24.10%]), had lower education (no impairment: <high school, 19.05% [95% CI, 17.27%-20.83%] vs functional dual sensory impairment: <high school, 46.15% [95% CI, 38.38%-53.92%]), and greater disease burden (eg, heart disease: no impairment, 15.30% [95% CI, 14.04%-16.55%] vs functional dual sensory impairment, 25.49% [95% CI, 19.96%-31.02%]). Compared with no impairment, functional vision impairment (adjusted hazard ratio [aHR], 1.89; 95% CI, 1.57-2.28), functional hearing impairment (aHR, 1.14; 95% CI, 1.00-1.31), and functional dual sensory impairment (aHR, 2.00; 95% CI, 1.57-2.53) were associated with a higher cross-sectional hazard of dementia. Over 7 years, functional vision impairment (aHR, 1.40; 95% CI, 1.12-1.74), functional hearing impairment (aHR, 1.09; 95% CI, 0.95-1.24), and functional dual sensory impairment (aHR, 1.50; 95% CI, 1.12-2.02) were associated with a higher hazard of incident dementia compared with no impairment.

CONCLUSIONS AND RELEVANCE

In this cohort study of US Medicare beneficiaries, dual sensory impairment was prevalent in older adults and associated with increased risk of dementia. These findings suggest that sensory rehabilitative interventions for multiple impairments may be an additional resource in efforts to reduce dementia risk.

Association of Age-Related Hearing Impairment With Physical Functioning Among Community-Dwelling Older Adults in the US

IMPORTANCE

Hearing impairment, a common treatable condition, may contribute to poorer physical function with aging.

OBJECTIVE

To assess whether hearing impairment is associated with poorer physical function, reduced walking endurance, and faster decline in physical function.

DESIGN, SETTING, AND PARTICIPANTS

In this cohort study, cross-sectional and longitudinal analyses were performed using data from the 2011 to 2019 period of the Atherosclerosis Risk in Communities study, a population-based study of community-dwelling adults at 4 sites in the US.

EXPOSURES

Hearing thresholds (per 10 dB) assessed with pure tone audiometry and categorized as normal hearing or mild, moderate, or severe hearing impairment.

MAIN OUTCOMES AND MEASURES

Physical function was assessed using the short physical performance battery (SPPB), with composite scores ranging from 0 to 12. A composite score of 6 or less and a score for each component (balance, gait speed, and chair stands) of 2 or less indicated poor performance. Walking endurance was assessed using a 2-minute fast-paced walk test. Tobit regression models adjusted for sociodemographic factors and medical history were used to calculate the mean differences in SPPB composite scores; logistic regression models, to estimate the odds ratios (ORs) of low SPPB composite and component scores; and linear mixed-effects models, to estimate the mean rate of change in SPPB composite scores over time.

RESULTS

Of the 2956 participants (mean [SD] age, 79 [4.6] years) who attended study visit 6 between 2016 and 2017, 1722 (58.3%) were women, and 2356 (79.7%) were White. As determined by pure tone audiometry, 973 (33%) participants had normal hearing, 1170 (40%) had mild hearing impairment, 692 (23%) had moderate hearing impairment, and 121 (4%) had severe hearing impairment. In the Tobit regression model, severe hearing impairment was associated with a lower mean SPPB score (β, -0.82; 95% CI, -0.34 to -1.30) compared with normal hearing. In fully adjusted logistic regression models, hearing impairment was associated with higher odds of low physical performance scores (severe impairment vs normal hearing: OR for composite physical performance, 2.51 [95% CI, 1.47-4.27]; OR for balance, 2.58 [95% CI, 1.62-4.12]; OR for gait speed, 2.11 [95% CI, 1.03-4.33]). Over time (2 to 3 visits; maximum, 8.9 years), participants with hearing impairment had faster declines in SPPB compared with those with normal hearing (moderate hearing impairment × time interaction, -0.34 [-0.52 to -0.16]). In adjusted models for walking endurance, participants with moderate or severe hearing impairment walked a mean distance of -2.81 m (95% CI, -5.45 to -0.17 m) and -5.31 m (95% CI, -10.20 to -0.36 m) than those with normal hearing, respectively, during the 2-minute walk test.

CONCLUSIONS AND RELEVANCE

In this cohort study, hearing impairment was associated with poorer performance, faster decline in physical function, and reduced walking endurance. The results of the longitudinal analysis suggest that hearing impairment may be associated with poorer physical function with aging. Whether management of hearing impairment could delay decline in physical function requires further investigation.

Anemia and 9-year domain-specific cognitive decline in community-dwelling older women: The Women's Health and Aging Study II

OBJECTIVES

To test the hypothesis that anemia (hemoglobin <12 g/dL) is associated with a faster rate of cognitive decline over 9 years in a community-dwelling sample of women aged 70 to 80 at baseline.

DESIGN

A population-based, prospective cohort study.

SETTING

East Baltimore, Maryland.

PARTICIPANTS

Four hundred thirty-six women sampled to be representative of the two-thirds least-disabled women aged 70 to 80 at baseline (1994-1996).

MEASUREMENTS

Nine-year trajectories of cognitive decline, analyzed using linear random effects models, in the domains of immediate verbal recall, delayed verbal recall, psychomotor speed, and executive function.

RESULTS

At baseline and after adjustment for demographic and disease covariates, women with anemia were slower to complete a test of executive function; the difference in baseline function between women with anemia and those without was -0.43 standard deviations (SDs) (95% confidence interval (CI)=-0.74 to -0.13) on the Trail Making Test Part B. During follow-up, anemia was associated with a faster rate of decline in memory. Between baseline and Year 3, the difference in the rates of decline between women with anemia and those without was -0.18 SDs per year (95% CI=-0.29 to -0.06) on the Hopkins Verbal Learning Test (HVLT) and -0.15 SDs per year (95% CI=-0.26 to -0.04) on the HVLT-Delayed.

CONCLUSION

Anemia was associated with poorer baseline performance on a test of executive function and with faster rates of decline on tests of immediate and delayed verbal recall. If this relationship is causal, it is possible that treatment of anemia could prevent or postpone cognitive decline.

Leisure-time physical activity sustained since midlife and preservation of cognitive function: The Atherosclerosis Risk in Communities Study

INTRODUCTION

We tested the hypotheses that higher levels of and persistence of midlife leisure-time physical activity (LTPA) are associated long-term with lower cognitive decline and less incident dementia.

METHODS

A total of 10,705 participants (mean age: 60 years) had LTPA (no, low, middle, or high) measured in 1987-1989 and 1993-1995. LTPA was assessed in relation to incident dementia and 14-year change in general cognitive performance.

RESULTS

Over a median follow-up of 17.4 years, 1063 dementia cases were observed. Compared with no LTPA, high LTPA in midlife was associated with lower incidence of dementia (hazard ratio [95% confidence interval], 0.71 [0.61, 0.86]) and lower declines in general cognitive performance (-0.07 standard deviation difference [-0.12 to -0.04]). These associations were stronger when measured against persistence of midlife LTPA over 6 years.

DISCUSSION

LTPA is a readily modifiable factor associated inversely with long-term dementia incidence and cognitive decline.

Interleukin-6 and C-Reactive Protein Levels and 9-Year Cognitive Decline in Community-Dwelling Older Women: The Women's Health and Aging Study II

BACKGROUND

Elevated inflammation is a proposed mechanism relating chronic diseases to cognitive dysfunction. The objective of this study was to test the hypothesis that greater levels of inflammation, as measured by the proinflammatory cytokine interleukin-6 (IL-6) and C-reactive protein, are associated with faster rates of cognitive decline among cognitively intact community-dwelling older women.

METHODS

We analyzed 336 women from the Women's Health and Aging Study II. Cognitive assessments were performed at baseline and every 18-36 months, and included the following domains: immediate and delayed memory (Hopkins Verbal Learning Test), psychomotor speed (Trail Making Test, Part A), and executive function (Trail Making Test, Part B). Aggregate measures of IL-6 and C-reactive protein, based on the average from visits one and two, were analyzed categorically. Random effects models were employed to test the relationship between tertiles of each inflammatory marker and changes in cognitive domain scores over 9 years.

RESULTS

Moderate and high levels of IL-6 predicted early declines in psychomotor speed by 1.0 connection/min per year. There were no differences in baseline scores or rates of change across tertiles of IL-6 in memory or executive function. No differences were observed across tertiles of C-reactive protein for all cognitive domains.

CONCLUSIONS

Higher levels of serum IL-6 were associated with greater declines in psychomotor speed over 9 years. This finding could suggest that elevated IL-6 may result in microvascular changes that may lead to damage of myelin sheaths that line neuronal axons, leading to decreased neuron propagation and impaired processing speed; however, mechanistic studies are needed to evaluate these hypotheses.

Association of Central Arterial Stiffness and Pressure Pulsatility with Mild Cognitive Impairment and Dementia: The Atherosclerosis Risk in Communities Study-Neurocognitive Study (ARIC-NCS)

BACKGROUND

The association of central arterial stiffness and pressure pulsatility with mild cognitive impairment (MCI) and dementia is not well characterized in the population-based setting.

OBJECTIVE

The aim of this study was to quantify the cross-sectional association of arterial stiffness and pressure pulsatility with MCI and dementia among 4,461 older white and black adults from the population-based Atherosclerosis Risk in Communities Study-Neurocognitive Study.

METHODS

We used race-stratified multinomial logistic regression to evaluate associations of percentile cut points of carotid-femoral pulse wave velocity, central systolic blood pressure, central pulse pressure, and pulse pressure amplification with MCI and dementia versus no cognitive impairment.

RESULTS

Among whites, those with carotid-femoral pulse wave velocity or central systolic blood pressure ≥75th percentile had a higher prevalence of MCI compared to participants <75th percentile (conditional odds ratio (OR); 95% confidence interval (CI): 1.27 (1.02, 1.56) and 1.28 (1.04, 1.57), respectively) and those with central pulse pressure ≥75th percentile had a higher prevalence of MCI (OR 1.27 (95% CI: 1.03, 1.58)) and dementia (OR 1.76 (95% CI: 1.06, 2.92) compared to participants <75th percentile. Also among whites, those with pulse pressure amplification ≤25th percentile had a higher prevalence of dementia compared to participants >25th percentile (OR 1.65; (95% CI: 1.01, 2.70). Weaker associations were seen among black participants.

CONCLUSION

Higher arterial stiffness and pulsatility were associated with MCI and dementia in white participants. Longitudinal characterization of the observed associations is warranted to assess whether arterial stiffness and pressure pulsatility predict MCI and dementia among older adults.