Obstructive Sleep Apnea and Cerebral Small Vessel disease in Community-based Older People: An ASPREE Imaging Substudy.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) may increase risk of dementia. A potential pathway for this risk is through cerebral small vessel disease (CSVD). In the context of an existing randomized trial of aspirin for primary prevention, we aimed to investigate OSA's impact on CSVD imaging measures and explore whether aspirin effects these measures over 3 years that differ in the presence or absence of OSA. METHODS: A sub-study of the ASPirin in Reducing Events in the Elderly randomized placebo-controlled trial of low-dose aspirin. Community-dwelling participants aged 70 years and above, without cognitive impairment, cardiovascular disease or known OSA completed an unattended limited-channel sleep study that calculated the oxygen desaturation index and apnea-hypopnea index. At baseline and 3 years later, volumes of white matter hyperintensities (WMH) and silent brain infarctions (SBI) were measured on 1.5 Tesla brain magnetic resonance imaging, and retinal vessel calibers were calculated from retinal vascular imaging. RESULTS: Mild and moderate/severe OSA was detected in 48.9% and 29.9%, respectively, of the 311 participants, who had a mean age of 73.7 years (SD 3.4 years), 38.6% female. OSA of any severity did not associate with WMH volumes, SBI, nor with retinal vessel calibers at baseline, nor with change in these measures in the 277 participants with repeated measures acquired after 3 years. OSA of any severity did not interact with aspirin on change in these measures over 3 years. CONCLUSION: In healthy older adults undiagnosed OSA was not associated with retinal vascular calibers and neuroimaging measures of CSVD.

Low-Dose Aspirin and Progression of Age-Related Hearing Loss: A Secondary Analysis of the ASPREE Randomized Clinical Trial.

Importance: Age-related hearing loss is common in an aging population, affecting communication and contributing to a worsened quality of life. It occurs as a result of cochlear degeneration and may be further exacerbated by inflammation and microvascular changes, as observed in animal models. Objective: To compare the effect of daily low-dose aspirin vs placebo on the progression of age-related hearing loss in healthy older adults. Design, Setting, and Participants: A prespecified secondary analysis was conducted of the Aspirin in Reducing Events in the Elderly (ASPREE) randomized clinical trial. Participants were 279 healthy community-dwelling individuals living in Australia who were aged 70 years or older and free of overt cardiovascular diseases, dementia, and life-limiting illnesses. Participants were recruited between January 1, 2010, and December 31, 2014, and followed up over 3 years. Statistical analysis was completed from June to December 2023. Intervention: A 100-mg daily dose of enteric-coated aspirin or matching placebo. Main Outcomes and Measures: Hearing measures were air conduction audiometry and binaural speech perception in noise. Assessments were conducted at baseline, 18 months, and 3 years. The change from baseline hearing measures were analyzed using an intention to treat approach. Aspirin and placebo were compared using mixed linear regression models adjusting for age, sex, diabetes, and smoking. Results: Of 279 participants, 154 (55%) were male, and the median age at baseline was 73.1 years (IQR, 71.5-76.2 years). A total of 98 of 138 participants (71%) in the aspirin group and 94 of 141 participants (67%) in the placebo group reported experiencing hearing loss at baseline. Compared with placebo, aspirin did not affect the changes in mean (SD) 4-frequency average hearing threshold from baseline to year 3 (aspirin: baseline, 27.8 [13.3] dB; year 3, 30.7 [13.7] dB; difference, 3.3 [3.9] dB; placebo: baseline, 27.5 [12.6] dB; year 3, 30.9 [13.8] dB; difference, 3.0 [4.8] dB; P = .55) nor any other tested frequencies. An increase in air conduction threshold indicates a deterioration in hearing. Similarly, for the mean (SD) speech reception threshold, there was no significant difference observed between the aspirin and placebo group at the year 3 follow-up assessment (aspirin: baseline, -9.9 [3.8] dB; year 3, -9.1 [3.8] dB; difference, 0.9 [2.9] dB; placebo: baseline, -10.5 [7.1] dB; year 3, -9.6 [4.1] dB; difference, 0.9 [5.9] dB; P = .86). The findings were consistent across sex, age groups, diabetic and smoking status. Conclusions and Relevance: In this secondary analysis of the ASPREE randomized clinical trial, low-dose aspirin did not affect the progression of age-related hearing loss. More investigation is warranted on whether a longer follow-up or the use of a more powerful anti-inflammatory agent might prove beneficial. Trial Registration: anzctr.org.au Identifier: ACTRN12614000496617.

A CCG expansion in ABCD3 causes oculopharyngodistal myopathy in individuals of European ancestry.

Oculopharyngodistal myopathy (OPDM) is an inherited myopathy manifesting with ptosis, dysphagia and distal weakness. Pathologically it is characterised by rimmed vacuoles and intranuclear inclusions on muscle biopsy. In recent years CGG • CCG repeat expansion in four different genes were identified in OPDM individuals in Asian populations. None of these have been found in affected individuals of non-Asian ancestry. In this study we describe the identification of CCG expansions in ABCD3, ranging from 118 to 694 repeats, in 35 affected individuals across eight unrelated OPDM families of European ancestry. ABCD3 transcript appears upregulated in fibroblasts and skeletal muscle from OPDM individuals, suggesting a potential role of over-expression of CCG repeat containing ABCD3 transcript in progressive skeletal muscle degeneration. The study provides further evidence of the role of non-coding repeat expansions in unsolved neuromuscular diseases and strengthens the association between the CGG • CCG repeat motif and a specific pattern of muscle weakness.

Cognitive status correlates of subclinical action tremor in female carriers of FMR1 premutation.

Background: There is evidence for a significant excess of kinetic upper limb tremor in non-FXTAS female FMR1 premutation carriers. The present study explores the possibility that this tremor is associated with various other features reminiscent of those occurring in syndromic FXTAS. Sample/methods: This study analyzed the data from an Australian cohort of 48 asymptomatic premutation women. We utilized spiral drawings from CRST, representing action tremor; the CRST total tremor; and ICARS- kinetic tremors/cerebellar ataxia scales. Cognitive tests (involving executive functioning) included SDMT, TMT, two subtests of the WAIS-III: MR and Similarities. Spearman Rank correlations assessed the relationships between the above measures, and the Chi-square tested hypothesis about the association between the white matter hyperintensities (wmhs) in the splenium of corpus callosum assessed from MR images and spiral drawings scores. Results: The spiral drawing scores were significantly correlated with all three non-verbal cognitive test scores, and with the CRST scores; the latter correlated with all four cognitive test measures. Similarities (verbal) scores correlated with CRST, ICARS, and with the remaining cognitive scores. Ordered spiral scores' categories were significantly associated with the degree of splenium involvement. Conclusion: This study showed that, in non-FXTAS premutation female carriers, sub-symptomatic forms of kinetic tremor were associated with a broader motor, and cognitive (especially executive) dysfunction.

Effect of Low-Dose Aspirin on the Course of Age-Related Macular Degeneration: A Secondary Analysis of the ASPREE Randomized Clinical Trial.

Importance: Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in old age. There is no proven intervention to prevent AMD and, apart from lifestyle, nutritional, and supplement advice, there is no intervention to delay its progression. Objective: To determine the impact of long-term low-dose aspirin on the incidence and progression of AMD. Design, Setting and Participants: The Aspirin in Reducing Events in the Elderly-AMD (ASPREE-AMD) study was an Australian-based substudy of the ASPREE trial, a multicenter, international, randomized, double-masked, placebo-clinical trial investigating the efficacy of low-dose aspirin in prolonging disability-free survival among older individuals. Retinal photography was conducted at baseline from March 2010 to January 2015, then 3 and 5 years after randomization. AMD status was determined using color retinal images and treatment records. Australian participants in ASPREE aged 70 years and older without dementia, independence-limiting physical disability, cardiovascular disease, or chronic illness limiting 5-year survival and with gradable retinal images at baseline were included. Data were analyzed from December 2022 to December 2023. Interventions: Aspirin (100 mg daily, enteric coated) or placebo. Main Outcomes and Measures: Incidence of AMD and progression from early/intermediate to late AMD. Outcomes were analyzed by modified intention-to-treat analysis. Results: A total of 4993 participants were enrolled in this substudy. Baseline characteristics were similar between groups. At the time of sponsor-determined trial termination, retinal follow-up data were available for 3208 participants, 3171 of whom were analyzed for AMD incidence and progression, with a median (IQR) age of 73.5 (71.5-76.4) years and even sex distribution (1619 [51%] female). Median (IQR) follow-up time was 3.1 (3.0-3.5) years. Cumulative AMD incidence was 195 of 1004 (19.4%) in the aspirin group and 187 of 979 (19.1%) in the placebo group (relative risk [RR], 1.02; 95% CI, 0.85-1.22; P = .86). Cumulative progression from early/intermediate AMD to late AMD was observed in 14 of 615 (2.3%) participants in the aspirin group and 18 of 573 (3.1%) in the placebo group (RR, 0.72; 95% CI, 0.36-1.44; P = .36). Conclusions and Relevance: In this trial, low-dose aspirin administered for 3 years did not affect the incidence of AMD. The evidence was weaker for progression of AMD due to low number of progressed cases. Overall, these results do not support suggestion that low-dose daily aspirin prevents the development or progression of AMD. Trial Registration: anzctr.org Identifier: ACTRN12613000755730.

Normative Data for Single-Letter Controlled Oral Word Association Test in Older White Australians and Americans, African-Americans, and Hispanic/Latinos.

Background: The Controlled Oral Word Association Test (COWAT) is a commonly used measure of verbal fluency. While a normal decline in verbal fluency occurs in late adulthood, significant impairments may indicate brain injury or diseases such as Alzheimer's disease. Normative data is essential to identify when test performance falls below expected levels based on age, gender, and education level. Objective: This study aimed to establish normative performance data on single-letter COWAT for older community-dwelling adults. Methods: Over 19,000 healthy men and women, without a diagnosis of dementia or a Modified Mini-Mental State Examination score below 77/100, were recruited for the ASPREE trial. Neuropsychological assessments, including the COWAT with letter F, were administered at study entry. Results: Median participant age was 75 years (range 65-98), with 56.5% being women. The majority of participants had 9-11 years of education in Australia and over 12 years in the U.S. The COWAT performance varied across ethno-racial groups and normative data were thus presented separately for 16,335 white Australians, 1,084 white Americans, 896 African-Americans, and 316 Hispanic/Latinos. Women generally outperformed men in the COWAT, except for Hispanic/Latinos. Higher education levels consistently correlated with better COWAT performance across all groups, while the negative association with age was weaker. Conclusions: This study provides comprehensive normative data for the COWAT stratified by ethno-racial groups in Australia and the U.S., considering age, gender, and education level. These norms can serve as reference standards for screening cognitive impairments in older adults in both clinical and research settings.

Validation of newly derived polygenic risk scores for dementia in a prospective study of older individuals.

INTRODUCTION: Recent genome-wide association studies identified new dementia-associated variants. We assessed the performance of updated polygenic risk scores (PRSs) using these variants in an independent cohort. METHODS: We used Cox models and area under the curve (AUC) to validate new PRSs (PRS-83SNP, PRS-SBayesR, and PRS-CS) compared with an older PRS-23SNP in 12,031 initially-healthy participants ≥70 years of age. Dementia was rigorously adjudicated according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria. RESULTS: PRS-83SNP, PRS-SBayesR, and PRS-CS were associated with incident dementia, with fully adjusted (including apolipoprotein E [APOE] ε4) hazard ratios per standard deviation (SD) of 1.35 (1.23-1.47), 1.37 (1.25-1.50), and 1.42 (1.30-1.56), respectively. The AUC of a model containing conventional/non-genetic factors and APOE was 74.7%. This was improved to 75.7% (p = 0.007), 76% (p = 0.004), and 76.1% (p = 0.003) with addition of PRS-83SNP, PRS-SBayesR, and PRS-CS, respectively. The PRS-23SNP did not improve AUC (74.7%, p = 0.95). CONCLUSION: New PRSs for dementia significantly improve risk-prediction performance, but still account for less risk than APOE genotype overall.

Cognitive trajectories and incident dementia after a cardiovascular event in older adults.

INTRODUCTION: Cardiovascular disease (CVD) is a recognized risk factor for dementia. Here we determined the extent to which an incident CVD event modifies the trajectory of cognitive function and risk of dementia. METHODS: 19,114 adults (65+) without CVD or dementia were followed prospectively over 9 years. Incident CVD (fatal coronary heart disease, nonfatal myocardial infarction [MI], stroke, hospitalization for heart failure) and dementia (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria) were adjudicated by experts. RESULTS: Nine hundred twenty-two participants had incident CVD, and 44 developed dementia after CVD (4.9% vs. 4.4% for participants without CVD). Following a CVD event there was a short-term drop in processing speed (-1.97, 95% confidence interval [CI]: -2.57 to -1.41), but there was no significant association with longer-term processing speed. In contrast, faster declines in trajectories of global function (-0.56, 95% CI: -0.76 to -0.36), episodic memory (-0.10, 95% CI: -0.16 to -0.04), and verbal fluency (-0.19, 95% CI: -0.30 to -0.01) were observed. DISCUSSION: Findings highlight the importance of monitoring cognition after a CVD event.

Grip strength, gait speed, and trajectories of cognitive function in community-dwelling older adults: A prospective study.

Introduction: This study investigated whether grip strength and gait speed predict cognitive aging trajectories and examined potential sex-specific associations. Methods: Community-dwelling older adults (n = 19,114) were followed for up to 7 years, with regular assessment of global function, episodic memory, psychomotor speed, and executive function. Group-based multi-trajectory modeling identified joint cognitive trajectories. Multinomial logistic regression examined the association of grip strength and gait speed at baseline with cognitive trajectories. Results: High performers (14.3%, n = 2298) and low performers (4.0%, n = 642) were compared to the average performers (21.8%, n = 3492). Grip strength and gait speed were positively associated with high performance and negatively with low performance (P-values < 0.01). The association between grip strength and high performance was stronger in women (interaction P < 0.001), while gait speed was a stronger predictor of low performance in men (interaction P < 0.05). Discussion: Grip strength and gait speed are associated with cognitive trajectories in older age, but with sex differences. Highlights: There is inter-individual variability in late-life cognitive trajectories.Grip strength and gait speed predicted cognitive trajectories in older age.However, sex-specific associations were identified.In women, grip strength strongly predicted high, compared to average, trajectory.In men, gait speed was a stronger predictor of low cognitive performance trajectory.

The association between sex hormones and the change in brain-predicted age difference in older women.

OBJECTIVE: The role of circulating sex hormones on structural brain ageing is yet to be established. This study explored whether concentrations of circulating sex hormones in older women are associated with the baseline and longitudinal changes in structural brain ageing, defined by the brain-predicted age difference (brain-PAD). DESIGN: Prospective cohort study using data from NEURO and Sex Hormones in Older Women; substudies of the ASPirin in Reducing Events in the Elderly clinical trial. PATIENTS: Community-dwelling older women (aged 70+ years). MEASUREMENTS: Oestrone, testosterone, dehydroepiandrosterone (DHEA), and sex-hormone binding globulin (SHBG) were quantified from plasma samples collected at baseline. T1-weighted magnetic resonance imaging was performed at baseline, 1 and 3 years. Brain age was derived from whole brain volume using a validated algorithm. RESULTS: The sample comprised of 207 women not taking medications known to influence sex hormone concentrations. A statistically higher baseline brain-PAD (older brain age relative to chronological age) was seen for women in the highest DHEA tertile compared with the lowest in the unadjusted analysis (p = .04). This was not significant when adjusted for chronological age, and potential confounding health and behavioural factors. Oestrone, testosterone and SHBG were not associated with brain-PAD cross-sectionally, nor were any of the examined sex hormones or SHBG associated with brain-PAD longitudinally. CONCLUSION: No strong evidence of an association between circulating sex hormones and brain-PAD. Given there is prior evidence to suggests sex hormones may be important for brain ageing, further studies of circulating sex hormones and brain health in postmenopausal women are warranted.

Relationships of Motor Changes with Cognitive and Neuropsychiatric Features in FMR1 Male Carriers Affected with Fragile X-Associated Tremor/Ataxia Syndrome.

The premutation expansion of the Fragile X Messenger Ribonucleoprotein 1 (FMR1) gene on the X chromosome has been linked to a range of clinical and subclinical features. Nearly half of men with FMR1 premutation develop a neurodegenerative disorder; Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS). In this syndrome, cognitive executive decline and psychiatric changes may co-occur with major motor features, and in this study, we explored the interrelationships between these three domains in a sample of adult males affected with FXTAS. A sample of 23 adult males aged between 48 and 80 years (mean = 62.3; SD = 8.8), carrying premutation expansions between 45 and 118 CGG repeats, and affected with FXTAS, were included in this study. We employed a battery of cognitive assessments, two standard motor rating scales, and two self-reported measures of psychiatric symptoms. When controlling for age and/or educational level, where appropriate, there were highly significant correlations between motor rating score for ICARS gait domain, and the scores representing global cognitive decline (ACE-III), processing speed (SDMT), immediate memory (Digit Span), and depression and anxiety scores derived from both SCL90 and DASS instruments. Remarkably, close relationships of UPDRS scores, representing the contribution of Parkinsonism to FXTAS phenotypes, were exclusive to psychiatric scores. Highly significant relationships between CGG repeat size and most scores for three phenotypic domains suggest a close tracking with genetic liability. These findings of relationships between a constellation of phenotypic domains in male PM carriers with FXTAS are reminiscent of other conditions associated with disruption to cerebro-cerebellar circuits.

Combination of gait speed and grip strength to predict cognitive decline and dementia.

Introduction: To determine whether slowed gait and weakened grip strength independently, or together, better identify risk of cognitive decline or dementia. Methods: Time to walk 3 meters and grip strength were measured in a randomized placebo-controlled clinical trial involving community-dwelling, initially cognitively healthy older adults (N = 19,114). Results: Over a median 4.7 years follow-up, slow gait and weak grip strength at baseline were independently associated with risk of incident dementia (hazard ratio [HR] = 1.44, 95% confidence interval [CI]: 1.19-1.73; and 1.24, 95% CI: 1.04-1.50, respectively) and cognitive decline (HR = 1.38, 95% CI: 1.26-1.51; and 1.04, 95% CI: 0.95-1.14, respectively) and when combined, were associated with 79% and 43% increase in risk of dementia and cognitive decline, respectively. Annual declines in gait and in grip over time showed similar results. Discussion: Gait speed and grip strength are low-cost markers that may be useful in the clinical setting to help identify and manage individuals at greater risk, or with early signs, of dementia, particularly when measured together. Highlights: Grip strength and gait speed are effective predictors and markers of dementia.Dementia risk is greater than cognitive decline risk with declines in gait or grip.Decline in gait speed, more so than in grip strength, predicts greater dementia risk.Greater risk prediction results from combining grip strength and gait speed.

Potential modifiable factors associated with late-life cognitive trajectories.

Objective: There is variability across individuals in cognitive aging. To investigate the associations of several modifiable factors with high and low cognitive performance. Methods: Data came from 17,724 community-dwelling individuals aged 65-98 years. Global cognition, verbal fluency, episodic memory, and psychomotor speed were assessed over up to seven years. Group-based multi-trajectory modeling identified distinct cognitive trajectories. Structural equation modeling examined the direct/indirect associations of social/behavioral factors and several chronic conditions with cognitive trajectories. Results: Seven trajectory subgroups were identified. In the structural equation modeling we compared two subgroups-participants with the highest (14.2%) and lowest (4.1%) cognitive performance with the average subgroup. Lower education, never alcohol intake, and frailty directly predicted increased risk of low performance, and decreased likelihood of high performance. Hypertension (RR: 0.69, 95%CI: 0.60-0.80), obesity (RR: 0.84, 95%CI: 0.73-0.97), diabetes (RR: 0.69, 95%CI: 0.56-0.86) and depression (RR: 0.68, 95%CI: 0.54-0.85) only predicted lower likelihood of high cognitive performance, while dyslipidemia was only associated with low performance (RR: 1.30, 95%CI: 1.07-1.57). Living alone predicted increased risk of low cognitive performance and several comorbidities. Smoking did not predict cognitive trajectories but was associated with increased risk of diabetes, obesity and frailty. Findings were similar when examining the direct associations between modifiable risk factors and all seven cognitive subgroups. Conclusions: Although several modifiable factors were associated with high performance, and reversely with low performance, this was not observed for obesity, hypertension and dyslipidemia. Further, health behaviors may affect cognitive function indirectly, via geriatric conditions. This indicates that strategies to promote healthy cognitive aging, may be distinct from those targeting dementia prevention.

Clinical impact of whole-genome sequencing in patients with early-onset dementia.

BACKGROUND: In the clinical setting, identification of the genetic cause in patients with early-onset dementia (EOD) is challenging due to multiple types of genetic tests required to arrive at a diagnosis. Whole-genome sequencing (WGS) has the potential to serve as a single diagnostic platform, due to its superior ability to detect common, rare and structural genetic variation. METHODS: WGS analysis was performed in 50 patients with EOD. Point mutations, small insertions/deletions, as well as structural variants (SVs) and short tandem repeats (STRs), were analysed. An Alzheimer's disease (AD)-related polygenic risk score (PRS) was calculated in patients with AD. RESULTS: Clinical genetic diagnosis was achieved in 7 of 50 (14%) of the patients, with a further 8 patients (16%) found to have established risk factors which may have contributed to their EOD. Two pathogenic variants were identified through SV analysis. No expanded STRs were found in this study cohort, but a blinded analysis with a positive control identified a C9orf72 expansion accurately. Approximately 37% (7 of 19) of patients with AD had a PRS equivalent to >90th percentile risk. DISCUSSION: WGS acts as a single genetic test to identify different types of clinically relevant genetic variations in patients with EOD. WGS, if used as a first-line clinical diagnostic test, has the potential to increase the diagnostic yield and reduce time to diagnosis for EOD.

Cognitive Trajectories in Community-Dwelling Older Adults and Incident Dementia, Disability and Death: A 10-Year Longitudinal Study.

Objective: The inter-individual variability in cognitive changes may be early indicators of major health events. We aimed to determine whether late-life cognitive trajectories were associated with incident dementia, persistent physical disability and all-cause mortality. Methods: Data came from a cohort of older community-dwelling individuals aged 70 years or above in Australia and the United States. Global cognition, verbal fluency, episodic memory and psychomotor speed were assessed regularly at up to seven waves between 2010 and 2017. Dementia, disability in activities of daily living, and death were adjudicated between 2017 and 2020. Latent classes of cognitive trajectories over seven years were determined using group-based trajectory modeling. Multivariable logistic regression was used for the prospective associations between cognitive trajectories and these outcomes. Results: Cognitive trajectories were defined for 16,174 participants (mean age: 78.9 years; 56.7% female) who were alive and without incident dementia or disability by 2017, among which 14,655 participants were included in the association analysis. Between three and five trajectory classes were identified depending on the cognitive test. Cognitive trajectories were strongly associated with the risk of dementia. For example, compared to those in the highest-functioning trajectory, the worst performers of episodic memory had a 37-fold increased risk of dementia (95% CI: 17.23-82.64). The lowest trajectories of both global cognition and episodic memory also predicted increased mortality risk (OR: 1.80, 95% CI: 1.28-2.52; OR: 1.61, 95% CI: 1.09-2.36, respectively), while only slow psychomotor speed was marginally associated with physical disability (OR: 2.39, 95% CI: 0.99-5.77). Conclusions: In older individuals, cognitive trajectories appear to be early indicators of clinically relevant health outcomes. Systematic cognitive assessments as part of routine geriatric evaluation may facilitate early identification and interventions for those individuals at highest risk.

Factors Influencing Change in Brain-Predicted Age Difference in a Cohort of Healthy Older Individuals.

Background: There is considerable variability in the rate at which we age biologically, and the brain is particularly susceptible to the effects of aging. Objective: We examined the test-retest reliability of brain age at one- and three-year intervals and identified characteristics that predict the longitudinal change in brain-predicted age difference (brain-PAD, defined by deviations of brain age from chronological age). Methods: T1-weighted magnetic resonance images were acquired at three timepoints from 497 community-dwelling adults (73.8±3.5 years at baseline, 48% were female). Brain age was estimated from whole brain volume, using a publicly available algorithm trained on an independent dataset. Linear mixed models were used, adjusting for sex, age, and age2. Results: Excellent retest reliability of brain age was observed over one and three years. We identified a significant sex difference in brain-PAD, where a faster rate of brain aging (worsening in brain age relative to chronological age) was observed in men, and this finding replicated in secondary analyses. The effect size, however, was relatively weak, equivalent to 0.16 years difference per year. A higher score in physical health related quality of life and verbal fluency were associated with a faster rate of brain aging, while depression was linked to a slower rate of brain aging, but these findings were not robust. Conclusion: Our study provides consistent evidence that older men have slightly faster brain atrophy than women. Given the sparsity of longitudinal research on brain age in older populations, future prospective studies are needed to confirm our findings.

Association of Dual Decline in Cognition and Gait Speed With Risk of Dementia in Older Adults.

Importance: Dual decline in gait speed and cognition has been found to be associated with increased dementia risk in previous studies. However, it is unclear if risks are conferred by a decline in domain-specific cognition and gait. Objective: To examine associations between dual decline in gait speed and cognition (ie, global, memory, processing speed, and verbal fluency) with risk of dementia. Design, Setting, and Participants: This cohort study used data from older adults in Australia and the US who participated in a randomized clinical trial testing low-dose aspirin between 2010 and 2017. Eligible participants in the original trial were aged 70 years or older, or 65 years or older for US participants identifying as African American or Hispanic. Data analysis was performed between October 2020 and November 2021. Exposures: Gait speed, measured at 0, 2, 4, and 6 years and trial close-out in 2017. Cognitive measures included Modified Mini-Mental State examination (3MS) for global cognition, Hopkins Verbal Learning Test-Revised (HVLT-R) for memory, Symbol Digit Modalities (SDMT) for processing speed, and Controlled Oral Word Association Test (COWAT-F) for verbal fluency, assessed at years 0, 1, 3, 5, and close-out. Participants were classified into 4 groups: dual decline in gait and cognition, gait decline only, cognitive decline only, and nondecliners. Cognitive decline was defined as membership of the lowest tertile of annual change. Gait decline was defined as a decline in gait speed of 0.05 m/s or greater per year across the study. Main Outcomes and Measures: Dementia (using Diagnostic and Statistical Manual of Mental Disorders [Fourth Edition] criteria) was adjudicated by an expert panel using cognitive tests, functional status, and clinical records. Cox proportional hazard models were used to estimate risk of dementia adjusting for covariates, with death as competing risk. Results: Of 19 114 randomized participants, 16 855 (88.2%) had longitudinal gait and cognitive data for inclusion in this study (mean [SD] age, 75.0 [4.4] years; 9435 women [56.0%], 7558 participants [44.8%] with 12 or more years of education). Compared with nondecliners, risk of dementia was highest in the gait plus HVLT-R decliners (hazard ratio [HR], 24.7; 95% CI, 16.3-37.3), followed by the gait plus 3MS (HR, 22.2; 95% CI, 15.0-32.9), gait plus COWAT-F (HR, 4.7; 95% CI, 3.5-6.3), and gait plus SDMT (HR, 4.3; 95% CI, 3.2-5.8) groups. Dual decliners had a higher risk of dementia than those with either gait or cognitive decline alone for 3MS and HVLT-R. Conclusions and Relevance: Of domains examined, the combination of decline in gait speed with memory had the strongest association with dementia risk. These findings support the inclusion of gait speed in dementia risk screening assessments.

Sleep-disordered breathing was associated with lower health-related quality of life and cognitive function in a cross-sectional study of older adults.

BACKGROUND AND OBJECTIVE: The clinical significance of sleep-disordered breathing (SDB) in older age is uncertain. This study determined the prevalence and associations of SDB with mood, daytime sleepiness, quality of life (QOL) and cognition in a relatively healthy older Australian cohort. METHODS: A cross-sectional analysis was conducted from the Study of Neurocognitive Outcomes, Radiological and retinal Effects of Aspirin in Sleep Apnoea. Participants completed an unattended limited channel sleep study to measure the oxygen desaturation index (ODI) to define mild (ODI 5-15) and moderate/severe (ODI ≥ 15) SDB, the Centre for Epidemiological Studies Scale, the Epworth Sleepiness Scale, the 12-item Short-Form for QOL and neuropsychological tests. RESULTS: Of the 1399 participants (mean age 74.0 years), 36% (273 of 753) of men and 25% (164 of 646) of women had moderate/severe SDB. SDB was associated with lower physical health-related QOL (mild SDB: beta coefficient [ß] -2.5, 95% CI -3.6 to -1.3, p < 0.001; moderate/severe SDB: ß -1.8, 95% CI -3.0 to -0.6, p = 0.005) and with lower global composite cognition (mild SDB: ß -0.1, 95% CI -0.2 to 0.0, p = 0.022; moderate/severe SDB: ß -0.1, 95% CI -0.2 to 0.0, p = 0.032) compared to no SDB. SDB was not associated with daytime sleepiness nor depression. CONCLUSION: SDB was associated with lower physical health-related quality of life and cognitive function. Given the high prevalence of SDB in older age, assessing QOL and cognition may better delineate subgroups requiring further management, and provide useful treatment target measures for this age group.

Test-Retest Reliability and Minimal Detectable Change of Four Cognitive Tests in Community-Dwelling Older Adults.

BACKGROUND: Cognitive test-retest reliability measures can be used to evaluate meaningful changes in scores. OBJECTIVE: This analysis aimed to develop a comprehensive set of test-retest reliability values and minimal detectable change (MDC) values for a cognitive battery for community-dwelling older individuals in Australia and the U.S., for use in clinical practice. METHODS: Cognitive scores collected at baseline and year 1, in the ASPirin in Reducing Events in the Elderly clinical trial were used to calculate intraclass correlation coefficients (ICC) for four tests: Modified Mini-Mental State examination (3MS), Hopkins Verbal Learning Test-Revised (HVLT-R), single-letter Controlled Oral Word Association Test (COWAT-F), and Symbol Digit Modalities Test (SDMT). 16,956 participants aged 70 years and over (65 years and over for U.S. minorities) were included. ICCs were used to calculate MDC values for eight education and ethno-racial subgroups. RESULTS: All four cognitive tests had moderate (ICC > 0.5) to good (ICC > 0.7) test-retest reliability. ICCs ranged from 0.53 to 0.63 (3MS), 0.68 to 0.77 (SDMT), 0.56 to 0.64 (COWAT-F), 0.57 to 0.69 (HVLT-R total recall), and 0.57 to 0.70 (HVLT-R delayed recall) across the subgroups. MDC values ranged from 6.60 to 9.95 (3MS), 12.42 to 15.61 (SDMT), 6.34 to 8.34 (COWAT-F), 8.13 to 10.85 (HVLT-R total recall), and 4.00 to 5.62 (HVLT-R delayed recall). CONCLUSION: This large cohort of older individuals provides test-retest reliability and MDC values for four widely employed tests of cognitive function. These results can aid interpretation of cognitive scores and decline instead of relying on cross-sectional normative data alone.