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1.
Stat Methods Med Res ; : 9622802241262526, 2024 Jul 25.
Article de Anglais | MEDLINE | ID: mdl-39053566

RÉSUMÉ

The cause-specific hazard Cox model is widely used in analyzing competing risks survival data, and the partial likelihood method is a standard approach when survival times contain only right censoring. In practice, however, interval-censored survival times often arise, and this means the partial likelihood method is not directly applicable. Two common remedies in practice are (i) to replace each censoring interval with a single value, such as the middle point; or (ii) to redefine the event of interest, such as the time to diagnosis instead of the time to recurrence of a disease. However, the mid-point approach can cause biased parameter estimates. In this article, we develop a penalized likelihood approach to fit semi-parametric cause-specific hazard Cox models, and this method is general enough to allow left, right, and interval censoring times. Penalty functions are used to regularize the baseline hazard estimates and also to make these estimates less affected by the number and location of knots used for the estimates. We will provide asymptotic properties for the estimated parameters. A simulation study is designed to compare our method with the mid-point partial likelihood approach. We apply our method to the Aspirin in Reducing Events in the Elderly (ASPREE) study, illustrating an application of our proposed method.

2.
BMC Med Res Methodol ; 24(1): 158, 2024 Jul 23.
Article de Anglais | MEDLINE | ID: mdl-39044195

RÉSUMÉ

BACKGROUND: In randomized clinical trials, treatment effects may vary, and this possibility is referred to as heterogeneity of treatment effect (HTE). One way to quantify HTE is to partition participants into subgroups based on individual's risk of experiencing an outcome, then measuring treatment effect by subgroup. Given the limited availability of externally validated outcome risk prediction models, internal models (created using the same dataset in which heterogeneity of treatment analyses also will be performed) are commonly developed for subgroup identification. We aim to compare different methods for generating internally developed outcome risk prediction models for subject partitioning in HTE analysis. METHODS: Three approaches were selected for generating subgroups for the 2,441 participants from the United States enrolled in the ASPirin in Reducing Events in the Elderly (ASPREE) randomized controlled trial. An extant proportional hazards-based outcomes predictive risk model developed on the overall ASPREE cohort of 19,114 participants was identified and was used to partition United States' participants by risk of experiencing a composite outcome of death, dementia, or persistent physical disability. Next, two supervised non-parametric machine learning outcome classifiers, decision trees and random forests, were used to develop multivariable risk prediction models and partition participants into subgroups with varied risks of experiencing the composite outcome. Then, we assessed how the partitioning from the proportional hazard model compared to those generated by the machine learning models in an HTE analysis of the 5-year absolute risk reduction (ARR) and hazard ratio for aspirin vs. placebo in each subgroup. Cochran's Q test was used to detect if ARR varied significantly by subgroup. RESULTS: The proportional hazard model was used to generate 5 subgroups using the quintiles of the estimated risk scores; the decision tree model was used to generate 6 subgroups (6 automatically determined tree leaves); and the random forest model was used to generate 5 subgroups using the quintiles of the prediction probability as risk scores. Using the semi-parametric proportional hazards model, the ARR at 5 years was 15.1% (95% CI 4.0-26.3%) for participants with the highest 20% of predicted risk. Using the random forest model, the ARR at 5 years was 13.7% (95% CI 3.1-24.4%) for participants with the highest 20% of predicted risk. The highest outcome risk group in the decision tree model also exhibited a risk reduction, but the confidence interval was wider (5-year ARR = 17.0%, 95% CI= -5.4-39.4%). Cochran's Q test indicated ARR varied significantly only by subgroups created using the proportional hazards model. The hazard ratio for aspirin vs. placebo therapy did not significantly vary by subgroup in any of the models. The highest risk groups for the proportional hazards model and random forest model contained 230 participants each, while the highest risk group in the decision tree model contained 41 participants. CONCLUSIONS: The choice of technique for internally developed models for outcome risk subgroups influences HTE analyses. The rationale for the use of a particular subgroup determination model in HTE analyses needs to be explicitly defined based on desired levels of explainability (with features importance), uncertainty of prediction, chances of overfitting, and assumptions regarding the underlying data structure. Replication of these analyses using data from other mid-size clinical trials may help to establish guidance for selecting an outcomes risk prediction modelling technique for HTE analyses.


Sujet(s)
Acide acétylsalicylique , Apprentissage machine , Modèles des risques proportionnels , Humains , Acide acétylsalicylique/usage thérapeutique , Sujet âgé , Femelle , Mâle , Résultat thérapeutique , États-Unis , Appréciation des risques/méthodes , Appréciation des risques/statistiques et données numériques , Modèles statistiques , Essais contrôlés randomisés comme sujet/méthodes , Essais contrôlés randomisés comme sujet/statistiques et données numériques , Arbres de décision , /méthodes , /statistiques et données numériques
3.
JAMA Netw Open ; 7(7): e2424373, 2024 Jul 01.
Article de Anglais | MEDLINE | ID: mdl-39052288

RÉSUMÉ

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.


Sujet(s)
Acide acétylsalicylique , Évolution de la maladie , Presbyacousie , Humains , Acide acétylsalicylique/usage thérapeutique , Acide acétylsalicylique/administration et posologie , Mâle , Femelle , Sujet âgé , Presbyacousie/traitement médicamenteux , Australie , Anti-inflammatoires non stéroïdiens/administration et posologie , Anti-inflammatoires non stéroïdiens/usage thérapeutique , Sujet âgé de 80 ans ou plus , Perte d'audition/prévention et contrôle , Méthode en double aveugle , Perception de la parole/effets des médicaments et des substances chimiques
4.
BMC Med ; 22(1): 306, 2024 Jul 29.
Article de Anglais | MEDLINE | ID: mdl-39075484

RÉSUMÉ

BACKGROUND: The net benefit of aspirin cessation in older adults remains uncertain. This study aimed to use observational data to emulate a randomized trial of aspirin cessation versus continuation in older adults without cardiovascular disease (CVD). METHODS: Post hoc analysis using a target trial emulation framework applied to the immediate post-trial period (2017-2021) of a study of low-dose aspirin initiation in adults aged ≥ 70 years (ASPREE; NCT01038583). Participants from Australia and the USA were included if they were free of CVD at the start of the post-trial intervention period (time zero, T0) and had been taking open-label or randomized aspirin immediately before T0. The two groups in the target trial were as follows: aspirin cessation (participants who were taking randomized aspirin immediately before T0; assumed to have stopped at T0 as instructed) versus aspirin continuation (participants on open-label aspirin at T0 regardless of their randomized treatment; assumed to have continued at T0). The outcomes after T0 were incident CVD, major adverse cardiovascular events (MACE), all-cause mortality, and major bleeding during 3, 6, and 12 months (short-term) and 48 months (long-term) follow-up. Hazard ratios (HRs) comparing aspirin cessation to continuation were estimated from propensity-score (PS) adjusted Cox proportional-hazards regression models. RESULTS: We included 6103 CVD-free participants (cessation: 5427, continuation: 676). Over both short- and long-term follow-up, aspirin cessation versus continuation was not associated with elevated risk of CVD, MACE, and all-cause mortality (HRs, at 3 and 48 months respectively, were 1.23 and 0.73 for CVD, 1.11 and 0.84 for MACE, and 0.23 and 0.79 for all-cause mortality, p > 0.05), but cessation had a reduced risk of incident major bleeding events (HRs at 3 and 48 months, 0.16 and 0.63, p < 0.05). Similar findings were seen for all outcomes at 6 and 12 months, except for a lowered risk of all-cause mortality in the cessation group at 12 months. CONCLUSIONS: Our findings suggest that deprescribing prophylactic aspirin might be safe in healthy older adults with no known CVD.


Sujet(s)
Acide acétylsalicylique , Maladies cardiovasculaires , Humains , Acide acétylsalicylique/administration et posologie , Acide acétylsalicylique/usage thérapeutique , Sujet âgé , Mâle , Femelle , Maladies cardiovasculaires/prévention et contrôle , Sujet âgé de 80 ans ou plus , Antiagrégants plaquettaires/administration et posologie , Australie , États-Unis , Hémorragie/induit chimiquement
6.
Alzheimers Res Ther ; 16(1): 111, 2024 05 18.
Article de Anglais | MEDLINE | ID: mdl-38762556

RÉSUMÉ

BACKGROUND: Cognitive impairment is common after stroke, and a large proportion of stroke patients will develop dementia. However, there have been few large prospective studies which have assessed cognition both prior to and after stroke. This study aims to determine the extent to which incident stroke impacts different domains of cognitive function in a longitudinal cohort of older community-dwelling individuals. METHODS: 19,114 older individuals without cardiovascular disease or major cognitive impairment were recruited and followed over a maximum 11 years. Stroke included ischaemic and haemorrhagic stroke and was adjudicated by experts. Cognitive function was assessed regularly using Modified Mini-Mental State Examination (3MS), Hopkins Verbal Learning Test-Revised (HVLT-R), Symbol Digit Modalities Test (SDMT), and Controlled Oral Word Association Test (COWAT). Linear mixed models were used to investigate the change in cognition at the time of stroke and decline in cognitive trajectories following incident stroke. RESULTS: During a median follow-up period of 8.4 [IQR: 7.2, 9.6] years, 815 (4.3%) participants experienced a stroke. Over this time, there was a general decline observed in 3MS, HVLT-R delayed recall, and SDMT scores across participants. However, for individuals who experienced a stroke, there was a significantly greater decline across all cognitive domains immediately after the event immediately after the event (3MS: -1.03 [95%CI: -1.45, -0.60]; HVLT-R: -0.47 [-0.70, -0.24]; SDMT: -2.82 [-3.57, -2.08]; COWAT: -0.67 [-1.04, -0.29]) and a steeper long-term decline for three of these domains (3MS -0.62 [-0.88, -0.35]; COWAT: -0.30 [-0.46, -0.14]); HVLT-R: -0.12 [95%CI, -0.70, -0.24]). However individuals with stroke experienced no longer-term decline in SDMT compared to the rest of the participants. CONCLUSIONS: These findings highlight the need for comprehensive neuropsychology assessments for ongoing monitoring of cognition following incident stroke; and potential early intervention.


Sujet(s)
Dysfonctionnement cognitif , Tests neuropsychologiques , Accident vasculaire cérébral , Humains , Femelle , Mâle , Sujet âgé , Accident vasculaire cérébral/complications , Accident vasculaire cérébral/psychologie , Accident vasculaire cérébral/épidémiologie , Études longitudinales , Dysfonctionnement cognitif/épidémiologie , Dysfonctionnement cognitif/étiologie , Dysfonctionnement cognitif/diagnostic , Incidence , Sujet âgé de 80 ans ou plus , Cognition/physiologie , Études prospectives
7.
JAMA Oncol ; 10(7): 989, 2024 Jul 01.
Article de Anglais | MEDLINE | ID: mdl-38814615
8.
JAMA Ophthalmol ; 142(7): 627-635, 2024 Jul 01.
Article de Anglais | MEDLINE | ID: mdl-38780931

RÉSUMÉ

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.


Sujet(s)
Acide acétylsalicylique , Évolution de la maladie , Humains , Acide acétylsalicylique/administration et posologie , Mâle , Femelle , Sujet âgé , Méthode en double aveugle , Sujet âgé de 80 ans ou plus , Australie/épidémiologie , Incidence , Dégénérescence maculaire/prévention et contrôle , Acuité visuelle/physiologie , Études de suivi , Relation dose-effet des médicaments , Antiagrégants plaquettaires/administration et posologie , Antiagrégants plaquettaires/usage thérapeutique , Résultat thérapeutique
9.
Int J Eat Disord ; 57(6): 1337-1349, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38469971

RÉSUMÉ

Randomized controlled trials can be used to generate evidence on the efficacy and safety of new treatments in eating disorders research. Many of the trials previously conducted in this area have been deemed to be of low quality, in part due to a number of practical constraints. This article provides an overview of established and more innovative clinical trial designs, accompanied by pertinent examples, to highlight how design choices can enhance flexibility and improve efficiency of both resource allocation and participant involvement. Trial designs include individually randomized, cluster randomized, and designs with randomizations at multiple time points and/or addressing several research questions (master protocol studies). Design features include the use of adaptations and considerations for pragmatic or registry-based trials. The appropriate choice of trial design, together with rigorous trial conduct, reporting and analysis, can establish high-quality evidence to advance knowledge in the field. It is anticipated that this article will provide a broad and contemporary introduction to trial designs and will help researchers make informed trial design choices for improved testing of new interventions in eating disorders. PUBLIC SIGNIFICANCE: There is a paucity of high quality randomized controlled trials that have been conducted in eating disorders, highlighting the need to identify where efficiency gains in trial design may be possible to advance the eating disorder research field. We provide an overview of some key trial designs and features which may offer solutions to practical constraints and increase trial efficiency.


Sujet(s)
Troubles de l'alimentation , Essais contrôlés randomisés comme sujet , Plan de recherche , Humains , Troubles de l'alimentation/thérapie
10.
Stat Med ; 43(9): 1708-1725, 2024 Apr 30.
Article de Anglais | MEDLINE | ID: mdl-38382112

RÉSUMÉ

In studies that assess disease status periodically, time of disease onset is interval censored between visits. Participants who die between two visits may have unknown disease status after their last visit. In this work, we consider an additional scenario where diagnosis requires two consecutive positive tests, such that disease status can also be unknown at the last visit preceding death. We show that this impacts the choice of censoring time for those who die without an observed disease diagnosis. We investigate two classes of models that quantify the effect of risk factors on disease outcome: a Cox proportional hazards model with death as a competing risk and an illness death model that treats disease as a possible intermediate state. We also consider four censoring strategies: participants without observed disease are censored at death (Cox model only), the last visit, the last visit with a negative test, or the second last visit. We evaluate the performance of model and censoring strategy combinations on simulated data with a binary risk factor and illustrate with a real data application. We find that the illness death model with censoring at the second last visit shows the best performance in all simulation settings. Other combinations show bias that varies in magnitude and direction depending on the differential mortality between diseased and disease-free subjects, the gap between visits, and the choice of the censoring time.


Sujet(s)
Modèles des risques proportionnels , Humains , Simulation numérique , Facteurs de risque
11.
Ophthalmology ; 131(8): 880-891, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38307466

RÉSUMÉ

PURPOSE: A recent genome-wide association study of age-related macular degeneration (AMD) identified new AMD-associated risk variants. These variants now can be incorporated into an updated polygenic risk score (PRS). This study aimed to assess the performance of an updated PRS, PRS2023, in an independent cohort of older individuals with retinal imaging data and to compare performance with an older PRS, PRS2016. DESIGN: Cross-sectional study. PARTICIPANTS: A total of 4175 participants of European ancestry, 70 years of age or older, with genotype and retinal imaging data. METHODS: We used logistic regression models and area under the receiver operating characteristic curve (AUC) to assess the performance of PRS2023 compared with PRS2016. AMD status and severity were graded using color fundus photography. MAIN OUTCOME MEASURES: Association of PRS2023 and PRS2016 with AMD risk at baseline. RESULTS: At enrollment among 4175 participants, 2605 participants (62.4%) had no AMD and 853 participants (20.4%), 671 participants (16.1%), and 46 participants (1.1%) had early, intermediate, and late-stage AMD, respectively. More than 27% of the participants with a high PRS2023 (top quartile) had intermediate or late-stage AMD, compared with < 15% for those in the middle 2 quartiles and less than 13% for those in the lowest quartile. Both PRS2023 and PRS2016 were associated significantly with AMD after adjustment for age, sex, smoking status, and lipid levels, with increasing odds ratios (ORs) for worsening AMD grades. PRS2023 outperformed PRS2016 (P = 0.03 for all AMD and P = 0.03 for late AMD, DeLong test comparing AUC). PRS2023 was associated with late-stage AMD with an adjusted OR of 5.05 (95% confidence interval [CI], 3.41-7.47) per standard deviation. The AUC of a model containing conventional or nongenetic risk factors and PRS2023 was 91% (95% CI, 87%-95%) for predicting late-stage AMD, which improved 12% over the model without the PRS (AUC, 79%; P < 0.001 for difference). CONCLUSIONS: A new PRS, PRS2023, for AMD outperforms a previous PRS and predicts increasing risk for late-stage AMD (with stronger association for more severe imaging-confirmed AMD grades). Our findings have clinical implications for the improved prediction and risk stratification of AMD. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.


Sujet(s)
Étude d'association pangénomique , Dégénérescence maculaire , Courbe ROC , Humains , Mâle , Femelle , Sujet âgé , Études transversales , Facteurs de risque , Dégénérescence maculaire/génétique , Dégénérescence maculaire/diagnostic , Sujet âgé de 80 ans ou plus , Polymorphisme de nucléotide simple , Aire sous la courbe , Appréciation des risques/méthodes , Prédisposition génétique à une maladie , Hérédité multifactorielle , Valeur prédictive des tests , Génotype ,
12.
J Am Geriatr Soc ; 72(4): 1023-1034, 2024 Apr.
Article de Anglais | MEDLINE | ID: mdl-38243627

RÉSUMÉ

BACKGROUND: This study examined the associations of body mass index (BMI) and waist circumference (WC), as well as their short- and long-term changes over time, with incident dementia in older individuals. METHODS: Data came from 18,837 community-dwelling individuals aged 65+ years from Australia and the United States, who were relatively healthy without major cognitive impairment at enrolment. Anthropometric measures were prospectively assessed at baseline, as well as change and variability from baseline to year two (three time-points). In a subgroup (n = 11,176), self-reported weight at age 18 and 70+ years was investigated. Dementia cases satisfied DSM-IV criteria. Cox regression was used to examine the associations between anthropometric measures and incident risk of dementia. RESULTS: Compared to normal weight, an overweight (HR: 0.67, 95%CI: 0.57-0.79, p < 0.001) or obese BMI (HR: 0.73, 95%CI: 0.60-0.89, p = 0.002), or a larger WC (elevated, HR: 0.71, 95%CI: 0.58-0.86, p < 0.001; highly elevated, HR: 0.65, 95%CI: 0.55-0.78, p < 0.001; relative to low) at baseline was associated with lower dementia risk. In contrast, substantial increases in BMI (>5%) over 2 years after baseline were associated with higher dementia risk (HR: 1.49, 95% CI: 1.17-1.91, p = 0.001). Increased dementia risk was also seen with an underweight BMI at baseline and a 2-year BMI decrease (>5%), but these associations appeared only in the first 4 years of follow-up. Compared to normal weight at both age 18 and 70+ years, being obese at both times was associated with increased dementia risk (HR: 2.27, 95%CI: 1.22-4.24, p = 0.01), while obesity only at age 70+ years was associated with decreased risk (HR: 0.70, 95%CI: 0.51-0.95, p = 0.02). CONCLUSIONS: Our findings suggest that long-term obesity and weight gain in later life may be risk factors for dementia. Being underweight or having substantial weight loss in old age may be early markers of pre-clinical dementia.


Sujet(s)
Démence , Maigreur , Humains , Sujet âgé , Maigreur/complications , Maigreur/épidémiologie , Obésité/complications , Obésité/épidémiologie , Indice de masse corporelle , Facteurs de risque , Tour de taille , Démence/étiologie , Démence/complications
13.
Article de Anglais | MEDLINE | ID: mdl-38038339

RÉSUMÉ

BACKGROUND: The prognostic implication of cholesterol levels in older adults remains uncertain. This study aimed to examine the relationship between low-density-lipoprotein cholesterol (LDL-c) and mortality outcomes in older individuals. METHODS: This post hoc analysis examined the associations of LDL-c levels with mortality risks from all-cause, cardiovascular disease (CVD), cancer, and combined non-CVD/noncancer conditions in a cohort of individuals aged ≥65 years from the ASPirin in Reducing Events in the Elderly trial (NCT01038583). At baseline, participants had no diagnosed dementia, physical disability, or CVD, and were not taking lipid-lowering agents. Outcome analyses were performed using multivariable Cox models. RESULTS: We analyzed 12 334 participants (mean age: 75.2 years). Over a median 7-year follow-up, 1 250 died. Restricted cubic splines found a U-shaped relation for LDL-c and all-cause mortality, cancer mortality, and noncancer/non-CVE mortality (nadir: 3.3-3.4 mmol/L); the risk of CVD mortality was similar at LDL-c below 3.3 mmol/L and increased above 3.3 mmol/L. Similar trends were observed in analyses modeling LDL-c by quartiles. When modeling LDL-c as a continuous variable, the risk of all-cause mortality, cancer mortality, and noncancer/non-CVD mortality was decreased by 9%, 16%, and 18%, respectively, per 1-mmol/L higher LDL-c, and the risk of CVD mortality was increased by 19% per 1-mmol/L higher LDL-c. Reduced all-cause and non-CVD/noncancer mortality risks were only significant in males but not females (pinteraction < .05). CONCLUSIONS: There were U-shaped relationships between LDL-c and all-cause mortality, cancer mortality, and noncancer/non-CVD mortality in healthy older adults. Higher LDL-c levels were associated with an increased risk of CVD mortality. Future studies are warranted to confirm our results.


Sujet(s)
Maladies cardiovasculaires , Lipoprotéines , Tumeurs , Mâle , Sujet âgé , Humains , Cholestérol LDL , Cholestérol , Cholestérol HDL , Facteurs de risque
14.
J Hypertens ; 42(2): 244-251, 2024 Feb 01.
Article de Anglais | MEDLINE | ID: mdl-38009310

RÉSUMÉ

INTRODUCTION: In healthy older adults, the relationship between long-term, visit-to-visit variability in blood pressure (BP) and frailty is uncertain. METHODS: Secondary analysis of blood pressure variability (BPV) and incident frailty in >13 000 participants ≥65-70 years enrolled in the ASPirin in Reducing Events in the Elderly (ASPREE) trial and its observational follow-up (ASPREE-XT). Participants were without dementia, physical disability, or cardiovascular disease at baseline. BPV was estimated using standard deviation of mean BP from three annual visits (baseline through the second annual follow-up). Frailty was defined using Fried phenotype and a frailty deficit accumulation index (FDAI). Participants with frailty during the BPV estimation period were excluded from the main analysis. Adjusted Cox proportional hazards regression evaluated the association between BPV and incident frailty, and linear mixed models for change in frailty scores, through a maximum of 9 years of follow-up. RESULTS: Participants in the highest systolic BPV tertile were at higher risk of frailty compared to those in the lowest (referent) tertile of systolic BPV [Fried hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.04-1.31; FDAI HR 1.18, 95% CI 1.07-1.30]. Findings were consistent when adjusted for multiple covariates and when stratified by antihypertensive use. Linear mixed models showed that higher systolic BPV was associated with increasing frailty score over time. Diastolic BPV was not consistently associated. CONCLUSIONS: High systolic BPV, independent of mean BP, is associated with increased risk of frailty in healthy older adults. Variability of BP across visits, even in healthy older adults, can convey important risk information beyond mean BP. TRIAL REGISTRATION: ClinicalTrials.gov NCT01038583 and ISRCTN83772183.


Sujet(s)
Pression sanguine , Fragilité , Sujet âgé , Humains , Antihypertenseurs/usage thérapeutique , Pression sanguine/physiologie , Fragilité/épidémiologie , Hypertension artérielle/traitement médicamenteux , Études de suivi
15.
Gerontology ; 70(2): 143-154, 2024.
Article de Anglais | MEDLINE | ID: mdl-37984339

RÉSUMÉ

INTRODUCTION: Risk factors for cardiovascular disease (CVD) also increase the risk of dementia. However, whether commonly used CVD risk scores are associated with dementia risk in older adults who do not have a history of CVD, and potential gender differences in this association, remains unclear. The aim of this study was to determine whether CVD risk scores are prospectively associated with cognitive decline and dementia in initially healthy older men and women. METHODS: A total of19,114 participants from a prospective cohort of individuals aged 65+ years without known CVD or dementia were recruited. The atherosclerotic cardiovascular disease risk score (ASCVDRS), Systematic Coronary Risk Evaluation 2-Older Persons (SCORE2-OP), and the Framingham risk score (FRS) were calculated at baseline. Risk of dementia (according to DSM-IV criteria) and cognitive decline (defined as a >1.5 standard deviation decline in global cognition, episodic memory, psychomotor speed, or verbal fluency from the previous year) were assessed using hazard ratio. RESULTS: Over a median follow-up of 6.4 years, 850 individuals developed dementia and 4,352 cognitive decline. Men and women in the highest ASCVDRS tertile had a 41% (95% CI 1.08, 1.85) and 45% (1.11, 1.89) increased risk of dementia compared to the lowest tertile, respectively. Likewise, men and women in the highest SCORE2-OP tertile had a 64% (1.24, 2.16) and 60% (1.22, 2.11) increased risk of dementia compared to the lowest tertile, respectively. Findings were similar, but the risk was slightly lesser when examining risk of cognitive decline for both ASCVDRS and SCORE2-OP. However, FRS was only associated with the risk of cognitive decline among women (highest vs. lowest tertiles: 1.13 [1.01-1.26]). CONCLUSION: These findings suggest the utility of the ASCVDRS and SCORE2-OP in clinical practice, to not only assess future risk of CVD, but also as potential early indicators of cognitive impairment, even in relatively healthy older men and women.


Sujet(s)
Maladies cardiovasculaires , Dysfonctionnement cognitif , Démence , Mâle , Humains , Femelle , Sujet âgé , Sujet âgé de 80 ans ou plus , Démence/diagnostic , Démence/épidémiologie , Démence/étiologie , Maladies cardiovasculaires/diagnostic , Maladies cardiovasculaires/épidémiologie , Maladies cardiovasculaires/étiologie , Études prospectives , Dysfonctionnement cognitif/diagnostic , Dysfonctionnement cognitif/épidémiologie , Dysfonctionnement cognitif/étiologie , Facteurs de risque , Facteurs de risque de maladie cardiaque
16.
Lancet Diabetes Endocrinol ; 12(2): 98-106, 2024 Feb.
Article de Anglais | MEDLINE | ID: mdl-38142708

RÉSUMÉ

BACKGROUND: Inflammation has been implicated in the pathogenesis of diabetes. This study investigated the randomised treatment effect of low-dose aspirin on incident type 2 diabetes and fasting plasma glucose (FPG) concentrations among older adults. METHODS: ASPREE was a double-blind, placebo-controlled trial of daily oral low-dose aspirin. The study population included community-dwelling individuals aged 70 years or older (≥65 years for US minority ethnic groups) in the USA and Australia who were free of cardiovascular disease, independence-limiting physical disability, or dementia. For the post-hoc analysis, we excluded participants with diabetes at baseline or with incomplete or missing incident diabetes data during follow-up. Participants were randomly assigned 1:1 to oral 100 mg daily enteric-coated aspirin or placebo. Incident diabetes was defined as self-reported diabetes, commencement of glucose-lowering medication, or a FPG concentration of 7·0 mmol/L or more assessed at annual follow-up visits among participants with no diabetes at baseline. We used Cox proportional hazards models and mixed-model repeated measures to assess the effect of aspirin on incident diabetes and FPG concentrations in the intention-to-treat population. We assessed major bleeding in participants who had taken at least one dose of study medication. FINDINGS: Between March 10, 2010, and Dec 24, 2014, a total of 16 209 participants were included (8086 [49·9%] randomly assigned to aspirin and 8123 [50·1%] randomly assigned to placebo). During a median follow-up of 4·7 years (IQR 3·6-5·7), 995 (in 6·1% individuals) incident cases of type 2 diabetes were recorded (459 in the aspirin group and 536 in the placebo group). Compared with placebo, the aspirin group had a 15% reduction in risk of incident diabetes (hazard ratio 0·85 [95% CI 0·75 to 0·97]; p=0·013) and a slower rate of increase in FPG concentration at year 5 (between-group difference estimate -0·048 mmol/L [95% CI -0·079 to -0·018]; p=0·0017). Major bleeding (major gastrointestinal bleeding, intracranial bleeding, and clinically significant bleeding at other sites) occurred in 510 (3·2%) of 16 104 participants (300 [3·7%] in the aspirin group and 210 [2·6%] in the placebo group). Compared with placebo, the aspirin group had a 44% increase in risk of major bleeding (hazard ratio 1·44 [95% CI 1·21 to 1·72]; p<0·0001). INTERPRETATION: Aspirin treatment reduced the incidence of type 2 diabetes and slowed the increase in FPG concentration but increased major bleeding among community-dwelling older adults. Given the increasing prevalence of type 2 diabetes among older adults, the potential for anti-inflammatory agents such as aspirin to prevent type 2 diabetes or improve glucose levels warrants further study with a comprehensive assessment of all potential safety events of interest. FUNDING: US National Institute on Aging, US National Cancer Institute, National Health and Medical Research Council of Australia, Monash University, and the Victorian Cancer Agency.


Sujet(s)
Diabète de type 2 , Vie autonome , Humains , Sujet âgé , Diabète de type 2/traitement médicamenteux , Diabète de type 2/épidémiologie , Diabète de type 2/prévention et contrôle , Acide acétylsalicylique/usage thérapeutique , Hémorragie/traitement médicamenteux , Hémorragie/épidémiologie , Glucose , Méthode en double aveugle
17.
J Am Heart Assoc ; 12(21): e031459, 2023 11 07.
Article de Anglais | MEDLINE | ID: mdl-37929782

RÉSUMÉ

Background The risk of atherosclerotic cardiovascular disease (ASCVD) increases sharply with age. Some older individuals, however, remain unaffected despite high predicted risk. These individuals may carry cardioprotective genetic variants that contribute to resilience. Our aim was to assess whether asymptomatic older individuals without prevalent ASCVD carry cardioprotective genetic variants that contribute to ASCVD resilience. Methods and Results We performed a genome-wide association study using a 10-year predicted ASCVD risk score as a quantitative trait, calculated only in asymptomatic older individuals aged ≥70 years without prevalent ASCVD. Our discovery genome-wide association study of N=12 031 ASCVD event-free individuals from the ASPREE (Aspirin in Reducing Events in the Elderly) trial identified 2 independent variants, rs9939224 (P<5×10-8) and rs56156922 (P<10-6), in the CETP (cholesteryl ester transfer protein) gene. The CETP gene is a regulator of plasma high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and lipoprotein(a) levels, and it is a therapeutic drug target. The associations were replicated in the UK Biobank (subpopulation of N=13 888 individuals aged ≥69 years without prevalent ASCVD). Carriers of the identified CETP variants (versus noncarriers) had higher plasma high-density lipoprotein cholesterol levels, lower plasma low-density lipoprotein cholesterol levels, and reduced risk of incident ASCVD events during follow-up. Expression quantitative trait loci analysis predicted the identified CETP variants reduce CETP gene expression across various tissues. Previously reported associations between genetic CETP inhibition and increased risk of age-related macular degeneration were not observed among the 3917 ASPREE trial participants with retinal imaging and genetic data available. Conclusions Common genetic variants in the CETP gene region are associated with cardiovascular resilience during aging. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01038583.


Sujet(s)
Maladies cardiovasculaires , Étude d'association pangénomique , Sujet âgé , Humains , Maladies cardiovasculaires/génétique , Protéines de transfert des esters de cholestérol/génétique , Cholestérol HDL , Cholestérol LDL , Lipoprotéines HDL/métabolisme , Locus de caractère quantitatif , Facteurs de risque
18.
Neurology ; 101(22): e2288-e2299, 2023 Nov 27.
Article de Anglais | MEDLINE | ID: mdl-37879942

RÉSUMÉ

BACKGROUND AND OBJECTIVES: It has been suggested that higher triglyceride levels were associated with a lower risk of Alzheimer disease. This study aimed to examine the association of triglycerides with dementia and cognition change in community-dwelling older adults. METHODS: This prospective longitudinal study used data from the Aspirin in Reducing Events in the Elderly (ASPREE) randomized trial of adults aged 65 years or older without dementia or previous cardiovascular events at enrollment. The main outcome was incident dementia. Other outcomes included changes in composite cognition and domain-specific cognition (global cognition, memory, language and executive function, and psychomotor speed). The association between baseline triglycerides and dementia risk was estimated using Cox proportional hazard models adjusting for relevant risk factors. Linear mixed models were used to investigate cognitive change. The analysis was repeated in a subcohort of participants with available APOE-ε4 genetic data with additional adjustment for APOE-ε4 carrier status and an external cohort (UK Biobank) with similar selection criteria applied. RESULTS: This study included 18,294 ASPREE participants and 68,200 UK Biobank participants (mean age: 75.1 and 66.9 years; female: 56.3% and 52.7%; median [interquartile range] triglyceride: 106 [80-142] mg/dL and 139 [101-193] mg/dL), with dementia recorded in 823 and 2,778 individuals over a median follow-up of 6.4 and 12.5 years, respectively. Higher triglyceride levels were associated with lower dementia risk in the entire ASPREE cohort (hazard ratio [HR] with doubling of triglyceride: 0.82, 95% CI 0.72-0.94). Findings were similar in the subcohort of participants with APOE-ε4 genetic data (n = 13,976) and in the UK Biobank cohort (HR was 0.82 and 0.83, respectively, all p ≤ 0.01). Higher triglycerides were also associated with slower decline in composite cognition and memory over time (p ≤ 0.05). DISCUSSION: Older adults with higher triglyceride levels within the normal to high-normal range had a lower dementia risk and slower cognitive decline over time compared with individuals with lower triglyceride levels. Higher triglyceride levels may be reflective of better overall health and/or lifestyle behaviors that would protect against dementia development. Future studies are warranted to investigate whether specific components within the total circulating pool of plasma triglycerides may promote better cognitive function, with the hope of informing the development of new preventive strategies.


Sujet(s)
Maladie d'Alzheimer , Dysfonctionnement cognitif , Sujet âgé , Humains , Femelle , Études prospectives , Études longitudinales , Triglycéride , Vie autonome , Maladie d'Alzheimer/génétique , Dysfonctionnement cognitif/prévention et contrôle , Cognition , Acide acétylsalicylique , Apolipoprotéines E
19.
BMC Geriatr ; 23(1): 646, 2023 10 11.
Article de Anglais | MEDLINE | ID: mdl-37821846

RÉSUMÉ

BACKGROUND: Unhealthy lifestyle behaviours such as smoking, high alcohol consumption, poor diet or low physical activity are associated with morbidity and mortality. Public health guidelines provide recommendations for adherence to these four factors, however, their relationship to the health of older people is less certain. METHODS: The study involved 11,340 Australian participants (median age 7.39 [Interquartile Range (IQR) 71.7, 77.3]) from the ASPirin in Reducing Events in the Elderly study, followed for a median of 6.8 years (IQR: 5.7, 7.9). We investigated whether a point-based lifestyle score based on adherence to guidelines for a healthy diet, physical activity, non-smoking and moderate alcohol consumption was associated with subsequent all-cause and cause-specific mortality. RESULTS: In multivariable adjusted models, compared to those in the unfavourable lifestyle group, individuals in the moderate lifestyle group (Hazard Ratio (HR) 0.73 [95% CI 0.61, 0.88]) and favourable lifestyle group (HR 0.68 [95% CI 0.56, 0.83]) had lower risk of all-cause mortality. A similar pattern was observed for cardiovascular related mortality and non-cancer/non-cardiovascular related mortality. There was no association of lifestyle with cancer-related mortality. CONCLUSIONS: In a large cohort of initially healthy older people, reported adherence to a healthy lifestyle is associated with reduced risk of all-cause and cause-specific mortality. Adherence to all four lifestyle factors resulted in the strongest protection.


Sujet(s)
Mode de vie sain , Mortalité , Sujet âgé , Humains , Australie/épidémiologie , Maladies cardiovasculaires/épidémiologie , Maladies cardiovasculaires/mortalité , Comportement en matière de santé , Mode de vie , Études prospectives , Facteurs de risque , Régime alimentaire sain/mortalité , Régime alimentaire sain/statistiques et données numériques , Exercice physique/statistiques et données numériques , Consommation d'alcool/épidémiologie , Consommation d'alcool/mortalité , Fumer/épidémiologie , Fumer/mortalité , Tumeurs/épidémiologie , Tumeurs/mortalité
20.
medRxiv ; 2023 Sep 14.
Article de Anglais | MEDLINE | ID: mdl-37745426

RÉSUMÉ

The ASPREE randomized controlled trial (2010-2017) of 19,114 community-dwelling older adults without cardiovascular disease and significant disability compared daily 100mg aspirin to placebo. A total of 16,317 (93%) of 17,546 surviving and non-withdrawn participants agreed to continue regular study follow-up visits in the post-trial phase, named ASPREE-XT (2017-2024). We present a statistical analysis plan to underpin three main papers to report aspirin effects through to the fourth post-trial ASPREE-XT study visit with focus areas of: (1) death, dementia, and disability, (2) CVD events and bleeding, and (3) cancer. The focus of the plan is to estimate long-term (entire timespan of RCT plus post-trial) and legacy (post-trial period only) effects of aspirin in the setting of primary prevention for older individuals. Preliminary insights to these effects are presented that are based on data that has been reported to the study's observational study monitoring board however formal data lock is not expected until October 2023.

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