Genomic Risk Score for Melanoma in a Prospective Study of Older Individuals

BACKGROUND

Recent genome-wide association meta-analysis for melanoma doubled the number of previously identified variants. We assessed the performance of an updated polygenic risk score (PRS) in a population of older individuals, where melanoma incidence and cumulative ultraviolet radiation exposure is greatest.

METHODS

We assessed a PRS for cutaneous melanoma comprising 55 variants in a prospective study of 12 712 individuals in the ASPirin in Reducing Events in the Elderly Trial. We evaluated incident melanomas diagnosed during the trial and prevalent melanomas diagnosed preenrolment (self-reported). Multivariable models examined associations between PRS as a continuous variable (per SD) and categorical (low-risk [0%-20%], medium-risk [21%-80%], high-risk [81%-100%] groups) with incident melanoma. Logistic regression examined the association between PRS and prevalent melanoma.

RESULTS

At baseline, mean participant age was 75 years; 55.0% were female, and 528 (4.2%) had prevalent melanomas. During follow-up (median = 4.7 years), 120 (1.0%) incident cutaneous melanomas occurred, 98 of which were in participants with no history. PRS was associated with incident melanoma (hazard ratio = 1.46 per SD, 95% confidence interval [CI] = 1.20 to 1.77) and prevalent melanoma (odds ratio [OR] = 1.55 per SD, 95% CI = 1.42 to 1.69). Participants in the highest-risk PRS group had increased risk compared with the low-risk group for incident melanoma (OR = 2.51, 95% CI = 1.28 to 4.92) and prevalent melanoma (OR = 3.66, 95% CI = 2.69 to 5.05). When stratifying by sex, only males had an association between the PRS and incident melanoma, whereas both sexes had an association between the PRS and prevalent melanoma.

CONCLUSIONS

A genomic risk score is associated with melanoma risk in older individuals and may contribute to targeted surveillance.

Similar mortality risk in incident cognitive impairment and dementia: Evidence from the ASPirin in Reducing Events in the Elderly (ASPREE) trial

BACKGROUND

This study examined the risk of mortality in older adults with newly detected cognitive impairment or dementia.

METHODS

Data from the Australian cohort of the ASPirin in Reducing Events in the Elderly (ASPREE) trial were examined. The ASPREE clinical trial compared daily low-dose aspirin to a placebo and involved 16,703 individuals aged 70 years and over, who were without major cognitive impairment, physical disability, or cardiovascular disease at recruitment. During the trial, evidence of cognitive impairment, based on cognitive testing and medical record information, triggered dementia adjudication of participants using DSM-IV criteria. Cox proportional hazard models were used to compare mortality rates across the dementia, trigger-only, and no-trigger groups.

RESULTS

Over a median 4.7-year follow-up period, 806 participants triggered dementia adjudication, with 485 (60.2%) judged to have dementia. Following recruitment, mortality risks were 32.9, 33.6, and 10.8 events per 1000 person-years in the dementia, trigger-no-dementia, and no-trigger groups, respectively. In the fully adjusted model, mortality risks remained higher in the dementia and trigger-no-dementia groups, with hazard ratios of 1.7 (95% CI: 1.3-2.1) and 1.9 (95% CI: 1.5-2.6), respectively. There was no discernible difference between the dementia and trigger-no-dementia groups in mortality rates following recruitment, or following a dementia trigger. These two groups were more likely to die from sepsis, respiratory disease, and dementia, but less likely to die from cancer than the no-trigger group, χ²  = 161.5, p < 0.001.

CONCLUSION

ASPREE participants who triggered for a dementia evaluation experienced a substantially higher mortality rate than those who remained cognitively intact. The increase was indistinguishable among persons who met DSM-IV criteria for dementia vs. those who triggered for a dementia evaluation but failed to meet DSM-IV criteria. Future work should investigate whether earlier detection of cognitive decline can be used to identify and prevent early mortality.

The Utility of Assessing Health-Related Quality of Life to Predict Cognitive Decline and Dementia

BACKGROUND

Health-related quality of life (HRQoL) has been shown to predict adverse health outcome in the general population.

OBJECTIVE

We examined the cross-sectional association between HRQoL and cognitive performance at baseline. Next, we explored whether baseline HRQoL predicted 5-year incident cognitive decline and dementia and whether there were gender differences.

METHODS

19,106 community-dwelling participants from the ASPirin in Reducing Events in the Elderly (ASPREE) trial, aged 65-98 years, free of major cognitive impairments, and completed the HRQoL 12-item short-form (SF-12) at baseline (2010-2014), were followed until June 2017. The physical (PCS) and mental component scores (MCS) of SF-12 were calculated. The cognitive tests were assessed at baseline, year 1, 3, 5, and 7 or close-out visit. Cognitive decline was defined as > 1.5 SD drop from baseline on any of the cognitive tests. Dementia was adjudicated according to DSM-IV criteria. Linear and Cox proportional-hazards regressions were used to examine the cross-sectional and longitudinal associations respectively.

RESULTS

At baseline, higher PCS and MCS were associated with better cognition. Over a median 4.7-year follow-up, higher MCS was associated with a reduced risk of cognitive decline and dementia (12% and 15% respectively, per 10-unit increase) and a 10-unit higher PCS was associated with a 6% decreased risk of cognitive decline. PCS did not predict dementia incidence. Findings were not different by gender.

CONCLUSION

Our study found that higher HRQoL, in particular MCS, predicted a reduced risk of cognitive decline and dementia over time in community-dwelling older people.

Validation of a Deficit-Accumulation Frailty Index in the ASPirin in Reducing Events in the Elderly Study and Its Predictive Capacity for Disability-Free Survival

Frailty is a state of heightened vulnerability and susceptibility to physiologic stressors that increases with age. It has shown increasing utility in predicting a range of adverse health outcomes. Here, we characterize a 67-item deficit-accumulation frailty index (FI) in 19 110 community-dwelling individuals in the ASPirin in Reducing Events in the Elderly clinical trial. Participants aged 65-98 years were recruited from the United States and Australia and were without diagnosed dementia and cardiovascular disease, and major physical disability. The median FI score was .10 (interquartile range: .07-.14) at baseline, and the prevalence of frailty (FI > .21) increased from 8.1% to 17.4% after 6 years. FI was positively associated with age, and women had significantly higher scores than men at all ages. The FI was negatively correlated with gait speed (r = -.31) and grip strength (r = -.46), and strongly associated with a modified Fried's frailty phenotype (p < .0001, for all comparisons). Frailty was associated with the primary composite outcome capturing independent life lived free of major disability and dementia, and increased the rate of persistent physical disability (hazard ratio: 21.3, 95% confidence interval: 15.6-28.9). It added significantly to the predictive capacity of these outcomes above age, sex, and ethnicity alone. The FI is thus a useful biomarker of aging even among relatively healthy older individuals and provides important information about an individual's vulnerability to and risk of disease.

Long-Term Blood Pressure Variability and Risk of Cognitive Decline and Dementia Among Older Adults

Background

Blood pressure variability (BPV) in midlife increases risk of late‐life dementia, but the impact of BPV on the cognition of adults who have already reached older ages free of major cognitive deficits is unknown. We examined the risk of incident dementia and cognitive decline associated with long‐term, visit‐to‐visit BPV in a post hoc analysis of the ASPREE (Aspirin in Reducing Events in the Elderly) trial.

Methods and Results

ASPREE participants (N=19 114) were free of dementia and significant cognitive impairment at enrollment. Measurement of BP and administration of a standardized cognitive battery evaluating global cognition, delayed episodic memory, verbal fluency, and processing speed and attention occurred at baseline and follow‐up visits. Time‐to‐event analysis using Cox proportional hazards regression models were used to calculate hazard ratios (HR) and corresponding 95% CI for incident dementia and cognitive decline, according to tertile of SD of systolic BPV. Individuals in the highest BPV tertile compared with the lowest had an increased risk of incident dementia and cognitive decline, independent of average BP and use of antihypertensive drugs. There was evidence that sex modified the association with incident dementia (interaction P=0.02), with increased risk in men (HR, 1.68; 95% CI, 1.19–2.39) but not women (HR, 1.01; 95% CI, 0.72–1.42). For cognitive decline, similar increased risks were observed for men and women (interaction P=0.15; men: HR, 1.36; 95% CI, 1.16–1.59; women: HR, 1.14; 95% CI, 0.98–1.32).

Conclusions

High BPV in older adults without major cognitive impairment, particularly men, is associated with increased risks of dementia and cognitive decline.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01038583; isrctn.com. Identifier: ISRCTN83772183.

Effect of APOE and a polygenic risk score on incident dementia and cognitive decline in a healthy older population

Few studies have measured the effect of genetic factors on dementia and cognitive decline in healthy older individuals followed prospectively. We studied cumulative incidence of dementia and cognitive decline, stratified by APOE genotypes and polygenic risk score (PRS) tertiles, in 12,978 participants of the ASPirin in Reducing Events in the Elderly (ASPREE) trial. At enrolment, participants had no history of diagnosed dementia, cardiovascular disease, physical disability or cognitive impairment. Dementia (adjudicated trial endpoint) and cognitive decline, defined as a >1.5 standard deviation decline in test score for either global cognition, episodic memory, language/executive function or psychomotor speed, versus baseline scores. Cumulative incidence for all‐cause dementia and cognitive decline was calculated with mortality as a competing event, stratified by APOE genotypes and tertiles of a PRS based on 23 common non‐APOE variants. During a median 4.5 years of follow‐up, 324 participants developed dementia, 503 died. Cumulative incidence of dementia to age 85 years was 7.4% in all participants, 12.6% in APOE ε3/ε4 and 26.6% in ε4/ε4. APOE ε4 heterozygosity/homozygosity was associated with a 2.5/6.3‐fold increased dementia risk and 1.4/1.8‐fold cognitive decline risk, versus ε3/ε3 (p < 0.001 for both). High PRS tertile was associated with a 1.4‐fold dementia risk versus low (CI 1.04–1.76, p = 0.02), but was not associated with cognitive decline (CI 0.96–1.22, p = 0.18). Incidence of dementia among healthy older individuals is low across all genotypes; however, APOE ε4 and high PRS increase relative risk. APOE ε4 is associated with cognitive decline, but PRS is not.

Effect of Statin Therapy on Cognitive Decline and Incident Dementia in Older Adults

BACKGROUND

The neurocognitive effect of statins in older adults remain uncertain.

OBJECTIVES

The aim of this study was to investigate the associations of statin use with cognitive decline and incident dementia among older adults.

METHODS

This analysis included 18,846 participants ≥65 years of age in a randomized trial of aspirin, who had no prior cardiovascular events, major physical disability, or dementia initially and were followed for 4.7 years. Outcome measures included incident dementia and its subclassifications (probable Alzheimer's disease, mixed presentations); mild cognitive impairment (MCI) and its subclassifications (MCI consistent with Alzheimer's disease, other MCI); and changes in domain-specific cognition, including global cognition, memory, language and executive function, psychomotor speed, and the composite of these domains. Associations of baseline statin use versus nonuse with dementia and MCI outcomes were examined using Cox proportional hazards models and with cognitive change using linear mixed-effects models, adjusting for potential confounders. The impact of statin lipophilicity on these associations was further examined, and effect modifiers were identified.

RESULTS

Statin use versus nonuse was not associated with dementia, MCI, or their subclassifications or with changes in cognitive function scores over time (p > 0.05 for all). No differences were found in any outcomes between hydrophilic and lipophilic statin users. Baseline neurocognitive ability was an effect modifier for the associations of statins with dementia (p for interaction < 0.001) and memory change (p for interaction = 0.02).

CONCLUSIONS

In adults ≥65 years of age, statin therapy was not associated with incident dementia, MCI, or declines in individual cognition domains. These findings await confirmation from ongoing randomized trials.

Trajectories of cognitive function in community-dwelling older adults: A longitudinal study of population heterogeneity

INTRODUCTION

This study aimed to investigate cognitive aging trajectories, the associated sociodemographic characteristics, and the association of these trajectories with dementia.

METHODS

Generally healthy older adults (n = 19,114) were followed for up to 7 years, with regular cognitive assessments. Group-based trajectory modeling identified distinct cognitive trajectories.

RESULTS

Four to seven trajectories were identified per cognitive domain. Stable trajectories were observed across domains. Improvement in verbal fluency and minor psychomotor slowing were common. Substantial decline in global cognition and episodic memory were observed in a small proportion of individuals. Older, less educated participants and men were more common in lower-functioning trajectories (p < .001). The highest proportions of dementia cases were in trajectories with major decline in global cognition (56.9%) and memory (33.2%).

DISCUSSION

Inter-individual variability in cognitive trajectories was observed across all domains. Some individuals appear resilient to cognitive decline even with advancing age. Further research into factors promoting cognitive resilience is needed.

Prescription Medication Use in Older Adults Without Major Cardiovascular Disease Enrolled in the Aspirin in Reducing Events in the Elderly (ASPREE) Clinical Trial

BACKGROUND

Efforts to minimize medication risks among older adults include avoidance of potentially inappropriate medications. Contemporary analysis of medication use in community-dwelling older people compared with the general population is lacking.

PARTICIPANTS

A total of 19,114 community-dwelling adults in Australia and the United States aged 70 years or older (65 years or older for U.S. minorities) without histories of major cardiovascular disease, cognitive impairment, or disability participated in a randomized, placebo-controlled trial of aspirin: ASPirin in Reducing Events in the Elderly study. Measurements Prescribed baseline medications obtained by self-report and medical record review were grouped by World Health Organization Anatomic and Therapeutic Chemical category. Potentially inappropriate medications were defined using a modified American Geriatrics Society Beers Criteria. Polypharmacy was defined as 5 or more medications, and hyperpolypharmacy defined as 10 or more medications. Cross-sectional descriptive statistics and adjusted odds ratios were computed.

RESULTS

The median number of prescription medications per participant was three, regardless of age. Women had a higher medication prevalence. Cardiovascular drugs (primarily antihypertensives) were the most commonly reported (64%). Overall, 39% of the cohort reported taking at least one potentially inappropriate medication, with proton-pump inhibitors being the most commonly reported (21.2% of cohort). Of the cohort, 27% had polypharmacy, and 2% hyperpolypharmacy. Age 75 years or older, less than 12 years of education, hypertension, diabetes mellitus, chronic kidney disease, frailty, gastrointestinal complaint, and depressive symptoms were associated with an increased likelihood of potentially inappropriate medications and polypharmacy. For almost all medication classes, prevalence was equivalent or lower than the general older population.

CONCLUSION

Overall medication burden and polypharmacy are low in older adults free of major cardiovascular disease, disability, and cognitive impairment. The prevalence of potentially inappropriate medications is higher than previously reported and similar to more vulnerable populations as a result of the introduction of proton-pump inhibitors to the American Geriatrics Society Beers Criteria. Longitudinal follow-up is required to further understand the balance of benefits and risks for potentially inappropriate medications and polypharmacy in community-dwelling older people.

Baseline characteristics and age-related macular degeneration in participants of the "ASPirin in Reducing Events in the Elderly" (ASPREE)-AMD trial

PURPOSE

To describe the baseline participant characteristics in the ASPREE-AMD study, investigating the effect of aspirin on AMD incidence and progression.

METHODS

Australian participants from the ASPirin in Reducing Events in the Elderly (ASPREE) trial, randomized to 100 mg aspirin daily or placebo, had non-mydriatic, digital color fundus images graded according to the Beckman AMD classification. Associations with AMD were determined for baseline characteristics and genetic risk variants.

RESULTS

ASPREE-AMD sub-study enrolled 4993 participants with gradable macular images. Median age was 73.4 years (IQR, 71.5, 76.6), 52% were female, 10% had diabetes mellitus, 73% had hypertension, and 44% were former/current smokers. Early, intermediate and late AMD (detected in 20.6%, 16.1%, 1.1%, respectively), significantly associated with age, were also associated with increasing HDL levels: OR = 1.52 (95%CI, 1.26, 1.84), OR = 1.43 (1.17, 1.77) and OR = 1.96 (1.02, 3.76), respectively. Female sex was associated with early [OR = 1.37 (1.16, 1.62)], and intermediate [OR = 1.35 (1.12, 1.63)] AMD, as was previous regular use of aspirin, with OR = 1.46 (1.11, 1.92) and OR = 1.37 (1.01, 1.85), respectively. Current smoking had increased odds for late AMD, OR = 4.02 (1.42, 11.36). Genetic risk variant rs3750846 (ARMS2/HTRA1) was associated with each AMD stage (p < 0.001), risk variants rs570618 and rs10922109 (CFH) with intermediate and late AMD (p < 0.001), and rare variant rs147859257 (C3) with late AMD (p < 0.001). The randomized groups were well balanced for all analyzed AMD risk factors.

CONCLUSIONS

Observed associations are typical of AMD. The ASPREE-AMD clinical trial provides a unique opportunity to determine the risks and benefits of low-dose aspirin for AMD incidence and progression in elderly population.

TRIAL REGISTRATION

Australian New Zealand Clinical Trial Registry: ACTRN 12613000755730.

Abstract P160: Long-term Blood Pressure Variability And Cognitive Decline And Dementia Among Community-dwelling Elderly

Greater blood pressure variability (BPV) in midlife increases the risk of dementia, but the impact of BPV in cognitively intact older adults is unknown. We examined the risk of incident dementia and cognitive decline associated with long-term, visit-to-visit BPV in participants of the ASPirin in Reducing Events in the Elderly (ASPREE) study, a randomized primary prevention trial of daily low-dose aspirin in community-dwelling adults in Australia and the US aged 70 and older (65 if US minority), who were free of dementia or evidence of cognitive impairment at enrollment. The mean of three BPs using an automated cuff was recorded at baseline and annually; participants also underwent baseline and biennial standardized assessments of global cognition, delayed episodic memory, verbal fluency, processing speed and attention. Cognitive decline was pre-specified as a >1.5 standard deviation (SD) decline in score from baseline on any of the cognitive tests, while incident dementia was a pre-specified secondary endpoint of ASPREE which was adjudicated using DSM-IV criteria. BPV was estimated using within-individual SD of mean systolic BP across baseline and the first two annual visits, and participants with cognitive decline or incident dementia during this period were excluded from the analysis to avoid immortal time bias. After adjustment for key covariates, Cox proportional hazards regression revealed increased risks for dementia and cognitive decline during follow-up for individuals in the highest SD tertile of BPV (Table). Our findings suggest that high BPV in older ages should be considered a potential therapeutic target to preserve cognitive function.

Effect of Aspirin on Cancer Incidence and Mortality in Older Adults

Background

ASPirin in Reducing Events in the Elderly, a randomized, double-blind, placebo-controlled trial of daily low-dose aspirin (100 mg) in older adults, showed an increase in all-cause mortality, primarily due to cancer. In contrast, prior randomized controlled trials, mainly involving younger individuals, demonstrated a delayed cancer benefit with aspirin. We now report a detailed analysis of cancer incidence and mortality.

Methods

19 114 Australian and US community-dwelling participants aged 70 years and older (US minorities 65 years and older) without cardiovascular disease, dementia, or physical disability were randomly assigned and followed for a median of 4.7 years. Fatal and nonfatal cancer events, a prespecified secondary endpoint, were adjudicated based on clinical records.

Results

981 cancer events occurred in the aspirin and 952 in the placebo groups. There was no statistically significant difference between groups for all incident cancers (hazard ratio [HR] = 1.04, 95% confidence interval [CI] = 0.95 to 1.14), hematological cancer (HR = 0.98, 95% CI = 0.73 to 1.30), or all solid cancers (HR = 1.05, 95% CI = 0.95 to 1.15), including by specific tumor type. However, aspirin was associated with an increased risk of incident cancer that had metastasized (HR = 1.19, 95% CI = 1.00 to 1.43) or was stage 4 at diagnosis (HR = 1.22, 95% CI = 1.02 to 1.45), and with higher risk of death for cancers that presented at stages 3 (HR = 2.11, 95% CI = 1.03 to 4.33) or 4 (HR = 1.31, 95% CI = 1.04 to 1.64).

Conclusions

In older adults, aspirin treatment had an adverse effect on later stages of cancer evolution. These findings suggest that in older persons, aspirin may accelerate the progression of cancer and, thus, suggest caution with its use in this age group.

Normative Data for the Symbol Digit Modalities Test in Older White Australians and Americans, African-Americans, and Hispanic/Latinos

Background

Processing speed, which can be assessed using the Symbol Digit Modalities Test (SDMT), is central to many brain functions. Processing speed declines with advanced age but substantial impairments are indicative of brain injury or disease.

Objective

The purpose of this study was to provide SDMT normative data for older community-dwelling individuals in the U.S. and Australia.

Methods

The ASPREE trial recruited 19,114 relatively healthy older men and women in Australia and the U.S. from the general community. All participants were without a diagnosis of dementia and with a Modified Mini-Mental State examination score of 78 or more at enrolment. The SDMT was administered at baseline as part of a neuropsychological test battery.

Results

The median age of participants was 74 years (range 65-99), and 56% were women. The median years of education was 12. Ethno-racial differences in SDMT performance were observed and normative data were thus presented separately for 16,289 white Australians, 1,082 white Americans, 891 African-Americans, and 316 Hispanic/Latinos. There were consistent positive associations found between SDMT and education level, and negative associations between SDMT and age. Mean scores for women were consistently higher than men with the exception of Hispanic/Latinos aged ≥70 years.

Conclusion

This study provides comprehensive SDMT normative data for whites (Australian and U.S.), Hispanic/Latinos, and African-Americans, according to gender, age, and education level. These norms can be used clinically as reference standards to screen for cognitive impairments in older individuals.

Cancer history and risk factors in healthy older people enrolling in the ASPREE clinical trial

BACKGROUND

Cancer is a leading cause of death globally. Given the elevated risk of cancer with age and an ageing population, it is important to understand the changing burden of cancer in older populations. The ASPirin in Reducing Events in the Elderly (ASPREE) study randomised healthy older individuals to 100 mg aspirin or placebo, with clinical outcomes and disability-free survival endpoints. Detailed baseline data provides a rare opportunity to explore cancer burden in a uniquely healthy older population.

METHODS

At study enrolment (2010-2014), self-reported personal cancer history, cancer type and cancer risk factor data were sought from 19,114 participants (Australia, n = 16,703; U.S., n = 2411). Eligible participants were healthy, free of major diseases and expected to survive 5 years.

RESULTS

Nearly 20% of enrolling ASPREE participants reported a prior cancer diagnosis; 18% of women and 22% of men, with women diagnosed younger (16% vs 6% of diagnoses <50 years). Cancer prevalence increased with age. Prevalence of prostate and breast cancer history were higher in U.S. participants; melanoma and colorectal cancer were higher in Australian participants. Cancer history prevalence was not associated with contemporary common risk factors nor previous aspirin use, but was associated with poor health ratings in men. Blood and breast cancer history were more common with past aspirin use.

CONCLUSIONS

Personal cancer history in healthy older ASPREE participants was as expected for the most common cancer types in the respective populations, but was not necessarily aligned with known risk factors. We attribute this to survivor bias, likely driven by entry criteria.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Register (ISRCTN83772183) and clinicaltrials.gov (NCT01038583).

Randomized placebo-controlled trial of the effects of aspirin on dementia and cognitive decline

OBJECTIVE

To determine the effect of low-dose aspirin vs placebo on incident all-cause dementia, incident Alzheimer disease (AD), mild cognitive impairment (MCI), and cognitive decline in older individuals.

METHODS

Aspirin in Reducing Events in the Elderly (ASPREE) was a double-blind, placebo-controlled trial of low-dose aspirin. In the United States and Australia, community-dwelling individuals aged ≥70 years (US minorities ≥65 years) and free of cardiovascular disease, physical disability, and diagnosed dementia were enrolled. Participants were randomized 1:1-100 mg daily aspirin or placebo. The Modified Mini-Mental State Examination, Hopkins Verbal Learning Test-Revised, Symbol Digit Modalities Test, and Controlled Oral Word Association Test assessed cognition at baseline and over follow-up. Additional cognitive testing was performed in participants with suspected dementia ("trigger") based on within-study assessments or clinical history. Dementia was adjudicated according to DSM-IV criteria. National Institute on Aging-Alzheimer's Association criteria were used for AD and MCI subclassification.

RESULTS

A total of 19,114 participants were followed over a median 4.7 years and 964 triggered further dementia assessments. There were 575 adjudicated dementia cases, and 41% were classified as clinically probable AD. There was no substantial difference in the risk of all dementia triggers (hazard ratio [HR], 1.03; 95% confidence interval [CI], 0.91-1.17), probable AD (HR, 0.96; 95% CI, 0.74-1.24), or MCI (HR, 1.12; 95% CI, 0.92-1.37) between aspirin and placebo. Cognitive change over time was similar in the aspirin and placebo groups.

CONCLUSIONS

There was no evidence that aspirin was effective in reducing risk of dementia, MCI, or cognitive decline. Follow-up of these outcomes after initial exposure is ongoing.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for healthy older individuals, low-dose aspirin does not significantly reduce the incidence of dementia, probable AD, MCI, or cognitive decline.

CLINICALTRIALSGOV IDENTIFIER

NCT01038583.

Antihypertensive medication use and blood pressure control among treated older adults

The association of different antihypertensive regimens with blood pressure (BP) control is not well-described among community-dwelling older adults with low comorbidity. We examined antihypertensive use and BP control in 10 062 treated hypertensives from Australia and the United States (US) using baseline data from the ASPirin in Reducing Events in the Elderly (ASPREE) trial. Renin-angiotensin system (RAS) drugs were the most prevalently used antihypertensive in both countries (Australia: 81.7% of all regimens; US: 62.9% of all regimens; P < .001). Diuretics were the next most commonly used antihypertensive in both countries, but were more often included in regimens of US participants (48.9%, vs 33.3% of regimens in Australia; P < .001). Among all antihypertensive classes and possible combinations, monotherapy with a RAS drug was the most common regimen in both countries, but with higher prevalence in Australian than US participants (35.9% vs 20.9%; P < .001). For both monotherapy and combination users, BP control rates across age, ethnicity, and sex were consistently lower in Australian than US participants. After adjustment for age, sex, ethnicity, and BMI, significantly lower BP control rates remained in Australian compared to US participants for the most commonly used classes and regimens (RAS blocker monotherapy: BP control = 45.5% vs 54.2%; P = .002; diuretic monotherapy: BP control = 45.2% vs 64.5%; P = .001; and RAS blocker/diuretic combo: BP control = 50.2% vs 65.6%; P = .001). Our findings highlight variation in antihypertensive use in older adults treated for hypertension, with implications for BP control. Differences in BP control that were observed may be influenced, in part, by reasons other than choice of specific regimens.

Factors Associated With Treatment and Control of Hypertension in a Healthy Elderly Population Free of Cardiovascular Disease: A Cross-sectional Study

BACKGROUND

Despite readily available treatments, control of blood pressure (BP) with population aging remains suboptimal. Further, there are gaps in the understanding of the management of high BP in the aged. We explored antihypertensive treatment and control among elderly hypertensive participants free from overt cardiovascular disease (CVD), and identified factors related to both "untreated" and "treated but uncontrolled" high BP.

METHODS

We analyzed baseline data from 19,114 individuals aged ≥65 years enrolled from Australia and United States (US) in the ASPirin in Reducing Events in the Elderly study. Hypertension was defined as an average systolic/diastolic BP ≥140/90 mm Hg and/or the use of any BP lowering medication. "Controlled hypertension" was defined if participants were receiving antihypertensive medication and BP <140 and 90 mm Hg. Descriptive analyses were used to summarize hypertension control rates; logistic regression was used to investigate relationships with treatment and BP control.

RESULTS

Overall, 74% (14,213/19,114) of participants were hypertensive; and of these 29% (4,151/14,213) were untreated. Among those treated participants, 53% (5,330/10,062) had BP ≥140/90 mm Hg. Participants who were untreated were more likely to be men, have higher educational status, and be in good physical health, and less likely to have significant comorbidities. The factors related to "treated but uncontrolled" BP included older age, male, Black race (vs. White), using antihypertensive monotherapy (vs. multiple) and residing in Australia (vs. US).

CONCLUSIONS

High levels of "untreated" and "treated but uncontrolled" BP occur in healthy elderly people without CVD, suggesting there are opportunities for better BP control in the primary prevention of CVD in this population.

CLINICAL TRIALS REGISTRATION

NCT01038583.

Normative performance of older individuals on the Hopkins Verbal Learning Test-Revised (HVLT-R) according to ethno-racial group, gender, age and education level

OBJECTIVE

The Hopkins Verbal Learning Test-Revised (HVLT-R) provides a measure of verbal learning and memory. The aim of this study was to provide normative performance data on the HVLT-R for community-dwelling older individuals according to ethno-racial group, age, gender, and years of completed education, in Australia and the U.S.

METHOD

The ASPirin in Reducing Events in the Elderly (ASPREE) study recruited 19,114 generally healthy community dwelling individuals aged 70 years and over (65 years and over for U.S minorities), who were without a diagnosis of dementia and scored above 77 on the modified Mini-Mental State (3MS) examination. Included in the analysis presented here were 16,251 white Australians, and in the U.S. 1,082 white, 894 African American and 314 Hispanic/Latino individuals at baseline.

RESULTS

Performance on each of the components of the HVLT-R (trials 1-3, total, learning, delayed recall, delayed recognition, percentage retention and recognition discrimination index [RDI]) differed by demographic variables. In country and ethno-racial stratified analyses, female gender, younger age and higher education were significantly associated with better total recall, delayed recall and RDI. Among white Australians these characteristics were also associated with better retention. Age, education and gender-specific reference values across ethno-racial categories were determined.

CONCLUSIONS

Ethno-racial, age, gender and education-stratified normative data from this large cohort of community-dwelling older individuals will serve as important reference standards in Australia and the U.S. to assess cognition in older individuals.

Overcoming challenges to data quality in the ASPREE clinical trial

Background

Large-scale studies risk generating inaccurate and missing data due to the complexity of data collection. Technology has the potential to improve data quality by providing operational support to data collectors. However, this potential is under-explored in community-based trials. The Aspirin in reducing events in the elderly (ASPREE) trial developed a data suite that was specifically designed to support data collectors: the ASPREE Web Accessible Relational Database (AWARD). This paper describes AWARD and the impact of system design on data quality.

Methods

AWARD’s operational requirements, conceptual design, key challenges and design solutions for data quality are presented. Impact of design features is assessed through comparison of baseline data collected prior to implementation of key functionality (n = 1000) with data collected post implementation (n = 18,114). Overall data quality is assessed according to data category.

Results

At baseline, implementation of user-driven functionality reduced staff error (from 0.3% to 0.01%), out-of-range data entry (from 0.14% to 0.04%) and protocol deviations (from 0.4% to 0.08%). In the longitudinal data set, which contained more than 39 million data values collected within AWARD, 96.6% of data values were entered within specified query range or found to be accurate upon querying. The remaining data were missing (3.4%). Participant non-attendance at scheduled study activity was the most common cause of missing data. Costs associated with cleaning data in ASPREE were lower than expected compared with reports from other trials.

Conclusions

Clinical trials undertake complex operational activity in order to collect data, but technology rarely provides sufficient support. We find the AWARD suite provides proof of principle that designing technology to support data collectors can mitigate known causes of poor data quality and produce higher-quality data. Health information technology (IT) products that support the conduct of scheduled activity in addition to traditional data entry will enhance community-based clinical trials. A standardised framework for reporting data quality would aid comparisons across clinical trials.

Trial registration

International Standard Randomized Controlled Trial Number Register, ISRCTN83772183. Registered on 3 March 2005.

EFFECT OF INITIATING ASPIRIN ON CANCER EVENTS IN THE HEALTHY ELDERLY

In ASPREE, we previously reported a surprising increase in cancer-related deaths associated with initiating aspirin. We now report primary incident cancer events. Aspirin was not associated with risk of incident cancer (HR=1.04, 95% CI 0.95-1.14), including non-metastatic cancer (HR=0.99, 95% CI, 0.89-1.11) and colorectal cancer (HR=1.02; 95% CI, 0.81-1.30). However, risk of incident metastatic cancer was elevated with aspirin (HR=1.18; 95% CI,0.96-1.46), although this could be attributable to chance. In ASPREE, the increase in cancer deaths associated with initiation of aspirin was not accompanied by a significant increase in overall incident cancer after 4.7 years. However, there did appear to be an increase in the incidence of advanced cancer in the aspirin arm. These data support the possibility that aspirin may adversely affect short-term outcomes among elderly participants with undiagnosed cancers (e.g. prevalent tumors at enrollment or early incident tumors) and/or may have differential effects according to age.

Recruiting general practice patients for large clinical trials: lessons from the Aspirin in Reducing Events in the Elderly (ASPREE) study

OBJECTIVE

To assess the factors that contributed to the successful completion of recruitment for the largest clinical trial ever conducted in Australia, the Aspirin in Reducing Events in the Elderly (ASPREE) study.

DESIGN

Enrolment of GPs; identification of potential participants in general practice databases; screening of participants.

SETTING, PARTICIPANTS

Selected general practices across southeast Australia (Tasmania, Victoria, Australian Capital Territory, New South Wales, South Australia).

MAJOR OUTCOMES

Numbers of patients per GP screened and randomised to participation; geographic and demographic factors that influenced screening and randomising of patients.

RESULTS

2717 of 5833 GPs approached (47%) enrolled to recruit patients for the study; 2053 (76%) recruited at least one randomised participant. The highest randomised participant rate per GP was for Tasmania (median, 5; IQR, 1-11), driven by the high rate of participant inclusion at phone screening. GPs in inner regional (adjusted odds ratio [aOR], 1.45; 95% CI, 1.14-1.84) and outer regional areas (aOR, 1.86; 95% CI, 1.19-2.88) were more likely than GPs in major cities to recruit at least one randomised participant. GPs in areas with a high proportion of people aged 70 years or more were more likely to randomise at least one participant (per percentage point increase: aOR, 1.10; 95% CI, 1.05-1.15). The number of randomised patients declined with time from GP enrolment to first randomisation.

CONCLUSION

General practice can be a rich environment for research when barriers to recruitment are overcome. Including regional GPs and focusing efforts in areas with the highest proportions of potentially eligible participants improves recruitment. The success of ASPREE attests to the clinical importance of its research question for Australian GPs.

Effect of Aspirin on All-Cause Mortality in the Healthy Elderly

BACKGROUND

In the primary analysis of the Aspirin in Reducing Events in the Elderly (ASPREE) trial, now published in the Journal, we report that the daily use of aspirin did not provide a benefit with regard to the primary end point of disability-free survival among older adults. A numerically higher rate of the secondary end point of death from any cause was observed with aspirin than with placebo.

METHODS

From 2010 through 2014, we enrolled community-dwelling persons in Australia and the United States who were 70 years of age or older (or ≥65 years of age among blacks and Hispanics in the United States) and did not have cardiovascular disease, dementia, or disability. Participants were randomly assigned to receive 100 mg of enteric-coated aspirin or placebo. Deaths were classified according to the underlying cause by adjudicators who were unaware of trial-group assignments. Hazard ratios were calculated to compare mortality between the aspirin group and the placebo group, and post hoc exploratory analyses of specific causes of death were performed.

RESULTS

Of the 19,114 persons who were enrolled, 9525 were assigned to receive aspirin and 9589 to receive placebo. A total of 1052 deaths occurred during a median of 4.7 years of follow-up. The risk of death from any cause was 12.7 events per 1000 person-years in the aspirin group and 11.1 events per 1000 person-years in the placebo group (hazard ratio, 1.14; 95% confidence interval [CI], 1.01 to 1.29). Cancer was the major contributor to the higher mortality in the aspirin group, accounting for 1.6 excess deaths per 1000 person-years. Cancer-related death occurred in 3.1% of the participants in the aspirin group and in 2.3% of those in the placebo group (hazard ratio, 1.31; 95% CI, 1.10 to 1.56).

CONCLUSIONS

Higher all-cause mortality was observed among apparently healthy older adults who received daily aspirin than among those who received placebo and was attributed primarily to cancer-related death. In the context of previous studies, this result was unexpected and should be interpreted with caution. (Funded by the National Institute on Aging and others; ASPREE ClinicalTrials.gov number, NCT01038583 .).

Effect of Aspirin on Cardiovascular Events and Bleeding in the Healthy Elderly

BACKGROUND

Aspirin is a well-established therapy for the secondary prevention of cardiovascular events. However, its role in the primary prevention of cardiovascular disease is unclear, especially in older persons, who have an increased risk.

METHODS

From 2010 through 2014, we enrolled community-dwelling men and women in Australia and the United States who were 70 years of age or older (or ≥65 years of age among blacks and Hispanics in the United States) and did not have cardiovascular disease, dementia, or disability. Participants were randomly assigned to receive 100 mg of enteric-coated aspirin or placebo. The primary end point was a composite of death, dementia, or persistent physical disability; results for this end point are reported in another article in the Journal. Secondary end points included major hemorrhage and cardiovascular disease (defined as fatal coronary heart disease, nonfatal myocardial infarction, fatal or nonfatal stroke, or hospitalization for heart failure).

RESULTS

Of the 19,114 persons who were enrolled in the trial, 9525 were assigned to receive aspirin and 9589 to receive placebo. After a median of 4.7 years of follow-up, the rate of cardiovascular disease was 10.7 events per 1000 person-years in the aspirin group and 11.3 events per 1000 person-years in the placebo group (hazard ratio, 0.95; 95% confidence interval [CI], 0.83 to 1.08). The rate of major hemorrhage was 8.6 events per 1000 person-years and 6.2 events per 1000 person-years, respectively (hazard ratio, 1.38; 95% CI, 1.18 to 1.62; P<0.001).

CONCLUSIONS

The use of low-dose aspirin as a primary prevention strategy in older adults resulted in a significantly higher risk of major hemorrhage and did not result in a significantly lower risk of cardiovascular disease than placebo. (Funded by the National Institute on Aging and others; ASPREE ClinicalTrials.gov number, NCT01038583 .).

Effect of Aspirin on Disability-free Survival in the Healthy Elderly

BACKGROUND

Information on the use of aspirin to increase healthy independent life span in older persons is limited. Whether 5 years of daily low-dose aspirin therapy would extend disability-free life in healthy seniors is unclear.

METHODS

From 2010 through 2014, we enrolled community-dwelling persons in Australia and the United States who were 70 years of age or older (or ≥65 years of age among blacks and Hispanics in the United States) and did not have cardiovascular disease, dementia, or physical disability. Participants were randomly assigned to receive 100 mg per day of enteric-coated aspirin or placebo orally. The primary end point was a composite of death, dementia, or persistent physical disability. Secondary end points reported in this article included the individual components of the primary end point and major hemorrhage.

RESULTS

A total of 19,114 persons with a median age of 74 years were enrolled, of whom 9525 were randomly assigned to receive aspirin and 9589 to receive placebo. A total of 56.4% of the participants were women, 8.7% were nonwhite, and 11.0% reported previous regular aspirin use. The trial was terminated at a median of 4.7 years of follow-up after a determination was made that there would be no benefit with continued aspirin use with regard to the primary end point. The rate of the composite of death, dementia, or persistent physical disability was 21.5 events per 1000 person-years in the aspirin group and 21.2 per 1000 person-years in the placebo group (hazard ratio, 1.01; 95% confidence interval [CI], 0.92 to 1.11; P=0.79). The rate of adherence to the assigned intervention was 62.1% in the aspirin group and 64.1% in the placebo group in the final year of trial participation. Differences between the aspirin group and the placebo group were not substantial with regard to the secondary individual end points of death from any cause (12.7 events per 1000 person-years in the aspirin group and 11.1 events per 1000 person-years in the placebo group), dementia, or persistent physical disability. The rate of major hemorrhage was higher in the aspirin group than in the placebo group (3.8% vs. 2.8%; hazard ratio, 1.38; 95% CI, 1.18 to 1.62; P<0.001).

CONCLUSIONS

Aspirin use in healthy elderly persons did not prolong disability-free survival over a period of 5 years but led to a higher rate of major hemorrhage than placebo. (Funded by the National Institute on Aging and others; ASPREE ClinicalTrials.gov number, NCT01038583 .).

Normative performance of healthy older individuals on the Modified Mini-Mental State (3MS) examination according to ethno-racial group, gender, age, and education level

OBJECTIVE

To present normative performance data on the Modified Mini-Mental State (3MS) examination for healthy community-dwelling older individuals according to gender, age, education level, and ethno-racial group.

METHOD

More than 19,000 generally healthy older men and women without a diagnosis of dementia were recruited from the general population in Australia and the U.S. for the ASPirin in Reducing Events in the Elderly (ASPREE) study. The 3MS exam was administered as part of the baseline screening and individuals scoring above 77 were eligible to participate.

RESULTS

The sample comprised 16,360 Australian whites, 1080 U.S. whites, 895 African-Americans and 316 Hispanic/Latinos. The median age of participants was 74 years (range 65-98), with an average of 12 years of education and 56% were female. Increasing age and fewer years of completed education were associated with lower scores on the 3MS. Women scored higher than men in most age and education categories. Differences across ethno-racial groups were found. With factor analysis, four factors were identified which accounted for 35% of the between-person variance in 3MS scores for white Australians.

CONCLUSIONS

This large cohort of older individuals provides some of the most comprehensive 3MS normative data to be generated for whites (Australian and U.S.), Hispanic/Latinos and African-Americans, by age, gender, and educational attainment. These findings will serve as important reference standards for monitoring cognitive function in generally healthy older individuals, becoming increasingly important as this fraction of the population increases.

Baseline Characteristics of Participants in the ASPREE (ASPirin in Reducing Events in the Elderly) Study

BACKGROUND

There are no primary prevention trials of aspirin with relevant geriatric outcomes in elderly people. ASPirin in Reducing Events in the Elderly (ASPREE) is a placebo-controlled trial of low-dose aspirin that will determine whether 5 years of daily 100-mg enteric-coated aspirin extends disability-free and dementia-free life in a healthy elderly population and whether these benefits outweigh the risks.

METHODS

Set in primary care, this randomized double-blind placebo-controlled trial has a composite primary endpoint of death, incident dementia or persistent physical disability. Participants aged 70+ years (non-minorities) or 65+ years (U.S. minorities) were free of cardiovascular disease, dementia, or physical disability and without a contraindication to, or indication for, aspirin. Baseline data include physical and lifestyle, personal and family medical history, hemoglobin, fasting glucose, creatinine, lipid panel, urinary albumin:creatinine ratio, cognition (3MS, HVLT-R, COWAT, SDMT), mood (CES-D-10), physical function (gait speed, grip strength), Katz activities of daily living and quality of life (SF-12).

RESULTS

Recruitment ended in December 2014 with 16,703 Australian and 2,411 U.S. participants, a median age of 74 (range 65-98) years and 56% women. Approximately 55% of the U.S. cohort were from minority groups; 9% of the total cohort. Proportions with hypertension, overweight, and chronic kidney disease were similar to age-matched populations from both countries although lower percentages had diabetes, dyslipidemia, and osteoarthritis.

DISCUSSION

Findings from ASPREE will be generalizable to a healthier older population in both countries and will assess whether the broad benefits of daily low-dose aspirin in prolonging independent life outweigh the risks.

Ligand binding induces a conformational change in epidermal growth factor receptor dimers

The activation of the epidermal growth factor receptor (EGFR) kinase requires ligand binding to the extracellular domain (ECD). Previous reports demonstrate that the EGFR-ECD can be crystallized in two conformations - a tethered monomer or, in the presence of ligand, an untethered back-to-back dimer. We use Biosensor analysis to demonstrate that even in the monomeric state different C-terminal extensions of both truncated (EGFR(1-501))-ECD and full-length EGFR(1-621)-ECD can change the conformation of the ligand-binding site. The binding of a monoclonal antibody mAb806, which recognizes the dimer interface, to the truncated EGFR(1-501)-Fc fusion protein is reduced in the presence of ligand, consistent with a change in conformation. On the cell surface, the presence of erythroblastosis B2 (erbB2) increases the binding of mAb806 to the EGFR. The conformation of the erbB2: EGFR heterodimer interface changes when the cells are treated with epidermal growth factor (EGF). We propose that ligand induces kinase-inactive, pre-formed EGFR dimers and heterodimers to change conformation leading to kinase-active tetramers, where kinase activation occurs via an asymmetric interaction between EGFR dimers.

Predominance of activated EGFR higher-order oligomers on the cell surface

The epidermal growth factor receptor (EGFR) kinase is generally considered to be activated by either ligand-induced dimerisation or a ligand-induced conformational change within pre-formed dimers. We report the relationship between ligand-induced higher-order EGFR oligomerization and EGFR phosphorylation on the surface of intact cells. We have combined lifetime-detected Forster resonance energy transfer, as a probe of the receptor phosphorylation state and image correlation spectroscopy, to extract the relative association state of activated versus unactivated EGFR, to determine the ratio of the average number of receptors for active (phosphorylated) and inactive clusters. There are at least four times as many receptors in the ligand-induced active clusters than inactive clusters. Contrary to the prevailing view that the EGFR dimer is the predominant, active form, our data determine that higher-order EGFR oligomers are the dominant species associated with the ligand activated EGFR tyrosine kinase.

Ligand-induced Dimer-Tetramer Transition during the Activation of the Cell Surface Epidermal Growth Factor Receptor-A Multidimensional Microscopy Analysis

The epidermal growth factor receptor (EGFR) is a member of the erbB tyrosine kinase family of receptors. For many years it has been believed that receptor activation occurs via a monomer-dimer transition that is associated with a conformational change to activate the kinase. However, little is known about the quaternary state of the receptor at normal levels of expression (<10(5) receptors/cell). We employed multidimensional microscopy techniques to gain insight into the state of association of the human EGFR, in the absence and presence of ligand, on the surface of intact BaF/3 cells (50,000 receptors/cell). Image correlation microscopy of an EGFR-enhanced green fluorescent protein chimera was used to establish an average degree of aggregation on the submicron scale of 2.2 receptors/cluster in the absence of ligand increasing to 3.7 receptors/cluster in the presence of ligand. Energy transfer measurements between mixtures of fluorescein isothiocyanate-EGF and Alexa 555-EGF were performed using fluorescence lifetime imaging microscopy as a function of the donor: acceptor labeling ratio to gain insight into the spatial disposition of EGFR ligand binding sites on the nanometer scale. In the context of a two-state Förster resonance energy transfer (FRET)/non-FRET model, the data are consistent with a minimum transfer efficiency of 75% in the FRET population. The microscopy data are related to biophysical data on the EGFR in the A431 cell line and the three-dimensional structure of the ligated EGFR extracellular domain. In the context of a monomer-dimer-oligomer model, the biophysical data are consistent with a significant fraction of ligated EGFR tetramers comprising two dimers juxtaposed in a side-by-side (or slightly staggered) arrangement. Our data are consistent with a specific higher order association of the ligand-bound EGFR on the nanometer scale and indicate the existence of distinct signaling entities beyond the level of the EGFR dimer which could play an important role in receptor transactivation.

CR1/CR2 Interactions Modulate the Functions of the Cell Surface Epidermal Growth Factor Receptor

Recent crystallographic data on the isolated extracellular domain of the epidermal growth factor receptor (EGFR) have suggested a model for its activation by ligand. We have tested this model in the context of the full-length EGFR displayed at the cell surface, by introducing mutations in two regions (CR1 and CR2) of the extracellular domain thought to be critical for regulation of receptor activation. Mutations in the CR1 and CR2 domains have opposing effects on ligand binding affinity, receptor dimerization, tyrosine kinase activation, and signaling competence. Tyr(246) is a critical residue in the CR1 loop, which is implicated in the positioning and stabilization of the receptor dimer interface after ligand binding; mutations of Tyr(246) impair or abolish receptor function. Mutations in CR2, which weaken the interaction that restricts the receptor to the tethered (inactive) state, enhance responsiveness to EGF by increasing affinity for the ligand. However, weakening of the CR1/CR2 interaction does not result in spontaneous activation of the receptors' kinase. We have used an antibody (mAb 806), which recognizes a transition state of the EGF receptor between the negatively constrained, tethered state and the fully active back-to-back dimer conformation, to follow conformational changes in the wild-type and mutant EGF receptors after ligand binding. Our results suggest that EGFR on the cell surface can be untethered, but this form is inactive; thus, untethering of the receptor is not sufficient for activation, and ligand binding is essential for the correct positioning of the two receptor subunits to achieve kinase activation.