138 research outputs found
Late-onset epilepsy and 25-year cognitive change: The Atherosclerosis Risk in Communities (ARIC) study
Objective: To define the association between late-onset epilepsy (LOE) and 25-year change in cognitive performance. Methods: The Atherosclerosis Risk in Communities (ARIC) study is a multicenter longitudinal cohort study with participants from four U.S. communities. From linked Medicare claims, we identified cases of LOE, defined as ≥2 seizure-related diagnostic codes starting at age ≥67. The ARIC cohort underwent evaluation with in-person visits at intervals of 3-15 years. Cognition was evaluated 4 times over >25 years (including before the onset of seizures) using the Delayed Word Recall Test (DWRT), Digit Symbol Substitution Test (DSST), and Word Fluency Test (WFT); a global z-score was also calculated. We compared the longitudinal cognitive changes of participants with and without LOE, adjusting for demographics and LOE risk factors. Results: From 8033 ARIC participants with midlife cognitive testing and Medicare claims data available (4523 [56%] female, 1392 [17%] Black), we identified 585 cases of LOE. The rate of cognitive decline was increased on all measures in the participants who developed LOE compared to those without LOE. On the measure of global cognition, participants with LOE declined by −0.43 z-score points more over 25 years than did participants without epilepsy (95% confidence interval [CI] −0.59 to −0.27). Prior to the onset of seizures, cognitive decline was more rapid on the DWRT, DSST, and global z-scores in those who would later develop LOE than it was in non-LOE participants. Results were similar after excluding data from participants with dementia. Significance: Global cognition, verbal memory, executive function, and word fluency declined faster over time in persons developing LOE than without LOE. Declines in cognition preceding LOE suggest these are linked; it will be important to investigate causes for midlife cognitive declines associated with LOE
Association of Hospitalization, Critical Illness, and Infection with Brain Structure in Older Adults
Objectives: To examine the association between hospitalization, critical illness, and infection occurring during middle- and late-life and structural brain abnormalities in older adults. Design: Prospective cohort study. Setting: Atherosclerosis Risk in Communities (ARIC) Study. Participants: A community sample of adults who were 44 to 66 years of age at study baseline. Measurements: Active surveillance of local hospitals and annual participant contact were used to gather hospitalization information (including International Classification of Diseases, Ninth Revision, codes) on all participants over a 24-year surveillance period. Subsequently, a subset of participants underwent 3-Tesla brain magnetic resonance imaging (MRI) to quantify total and regional brain volumes, white matter hyperintensity (WMH) volume, and white matter microstructural integrity (fractional anisotropy (FA) and mean diffusivity (MD) as measured using diffusion tensor imaging (DTI)). Results: Of the 1,689 participants included (mean age at MRI 76±5), 72% were hospitalized, 14% had a major infection, and 4% had a critical illness during the surveillance period. Using covariate-adjusted regression, hospitalization was associated with 0.12–standard deviation (SD) greater WMH volume (95% confidence interval (CI)=0.00–0.24) and poorer white matter microstructural integrity (0.17-SD lower FA, 95% CI=–0.27 to –0.06; 0.16-SD greater MD, 95% CI=0.07–0.25) than no hospitalization. There was a dose-dependent relationship between number of hospitalizations, smaller brain volumes, and lower white matter integrity (p-trends ≤.048). In hospitalized participants, critical illness was associated with smaller Alzheimer's disease (AD) signature region (–1.64 cm3, 95% CI=–3.16 to –0.12); major infection was associated with smaller AD signature region (–1.28 cm3, 95% CI=–2.21 to –0.35) and larger ventricular volume (3.79 cm3, 95% CI= 0.81–6.77). Conclusions: Whereas all-cause hospitalization was primarily associated with lower white matter integrity, critical illness and major infection were associated with smaller brain volume, particularly within regions implicated in AD
Depressive symptoms, cardiac structure and function, and risk of incident heart failure with preserved ejection fraction and heart failure with reduced ejection fraction in late life
BACKGROUND: Depressive symptoms are associated with heightened risk of heart failure (HF), but their association with cardiac function and with HF with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF) in late life is un-clear. We aimed to determine the prevalence of depression in HFpEF and in HFrEF in late life, and the association of depressive symptoms with cardiac function and incident HFpEF and HFrEF. METHODS AND RESULTS: We studied 6025 participants (age, 75.3±5.1 years; 59% women; 20% Black race) in the ARIC (Atherosclerosis Risk in Communities) study at visit 5 who underwent echocardiography and completed the Center for Epidemiologic Studies Depression Scale questionnaire. Among HF-free participants (n=5086), associations of Center for Epidemiologic Studies Depression Scale score with echocardiography and incident adjudicated HFpEF and HFrEF were assessed using multivariable linear and Cox proportional hazards regression. Prevalent HFpEF, but not HFrEF, was associated with a higher prevalence of depression compared with HF-free participants (P0.05). Over 5.5-year follow-up, higher Center for Epidemiologic Studies Depression Scale score was associated with heightened risk of incident HFpEF (hazard ratio [HR] [95% CI], 1.06 [1.04–1.12]; P=0.02), but not HFrEF (HR [95% CI], 1.02 [0.96–1.08]; P=0.54), independent of echocardiographic measures, NT-proBNP (N-terminal pro-B-type natriuretic peptide), troponin, and hs-CRP (high-sensitivity C-reactive protein) (HR [95% CI], 1.06 [1.00–1.12]; P=0.04). CONCLUSIONS: Worse depressive symptoms predict incident HFpEF in late life, independent of common comorbidities, cardiac structure and function, and prognostic biomarkers. Further studies are necessary to understand the mechanisms linking depression to risk of HFpEF
Is an MRI-derived anatomical measure of dementia risk also a measure of brain aging?
Machine learning methods have been applied to estimate measures of brain aging from neuroimages. However, only rarely have these measures been examined in the context of biologic age. Here, we investigated associations of an MRI-based measure of dementia risk, the Alzheimer’s disease pattern similarity (AD-PS) scores, with measures used to calculate biological age. Participants were those from visit 5 of the Atherosclerosis Risk in Communities Study with cognitive status adjudication, proteomic data, and AD-PS scores available. The AD-PS score estimation is based on previously reported machine learning methods. We evaluated associations of the AD-PS score with all-cause mortality. Sensitivity analyses using only cognitively normal (CN) individuals were performed treating CNS-related causes of death as competing risk. AD-PS score was examined in association with 32 proteins measured, using a Somalogic platform, previously reported to be associated with age. Finally, associations with a deficit accumulation index (DAI) based on a count of 38 health conditions were investigated. All analyses were adjusted for age, race, sex, education, smoking, hypertension, and diabetes. The AD-PS score was significantly associated with all-cause mortality and with levels of 9 of the 32 proteins. Growth/differentiation factor 15 (GDF-15) and pleiotrophin remained significant after accounting for multiple-testing and when restricting the analysis to CN participants. A linear regression model showed a significant association between DAI and AD-PS scores overall. While the AD-PS scores were created as a measure of dementia risk, our analyses suggest that they could also be capturing brain aging
Central arterial stiffness is associated with structural brain damage and poorer cognitive performance: The ARIC study
Background Central arterial stiffening and increased pulsatility, with consequent cerebral hypoperfusion, may result in structural brain damage and cognitive impairment. Methods and Results We analyzed a cross‐sectional sample of ARIC‐NCS(Atherosclerosis Risk in Communities–Neurocognitive Study) participants (aged 67–90 years, 60% women) with measures of cognition (n=3703) and brain magnetic resonance imaging (n=1255). Central arterial hemodynamics were assessed as carotid‐femoral pulse wave velocity and pressure pulsatility (central pulse pressure). We derived factor scores for cognitive domains. Brain magnetic resonance imaging using 3‐Tesla scanners quantified lacunar infarcts; cerebral microbleeds; and volumes of white matter hyperintensities, total brain, and the Alzheimer disease signature region. We used logistic regression, adjusted for demographics, apolipoprotein E ɛ4, heart rate, mean arterial pressure, and select cardiovascular risk factors, to estimate the odds of lacunar infarcts or cerebral microbleeds. Linear regression, additionally adjusted for intracranial volume, estimated the difference in log‐transformed volumes of white matter hyperintensities, total brain, and the Alzheimer diseasesignature region. We estimated the mean difference in cognitive factor scores across quartiles of carotid‐femoral pulse wave velocity or central pulse pressure using linear regression. Compared with participants in the lowest carotid‐femoral pulse wave velocity quartile, participants in the highest quartile of carotid‐femoral pulse wave velocity had a greater burden of white matter hyperintensities (P=0.007 for trend), smaller total brain volumes (−18.30 cm 3 ; 95% CI, −27.54 to −9.07 cm 3 ), and smaller Alzheimer disease signature region volumes (−1.48 cm 3 ; 95% CI, −2.27 to −0.68 cm 3 ). These participants also had lower scores in executive function/processing speed (β=−0.04 z score; 95% CI, −0.07 to −0.01 z score) and general cognition (β=−0.09 z score; 95% CI, −0.15 to −0.03 z score). Similar results were observed for central pulse pressure. Conclusions Central arterial hemodynamics were associated with structural brain damage and poorer cognitive performance among older adults
Orbital anastomoses of the anterior deep temporal artery
The anterior deep temporal artery may provide a major collateral pathway to the intracranial circulation through anastomoses with branches of the ophthalmic artery. Review of carotid angiograms in 26 patients with internal carotid artery occlusive disease revealed anterior deep temporal to ophthalmic artery anastomoses in 16 cases. This route of collateral blood flow was associated in most instances with total occlusion of the cervical portion of the internal carotid artery. Three cases demonstrating the angiographic anatomy of the anterior deep temporal artery and its potential anastomoses with branches of the ophthalmic artery are presented. L'artère temporale profonde antérieure peut être à l'origine de circulation colatérale grâce à ses anastomoses avec l'artère ophtalmique. Une telle anastomose a été constatée 16 fois sur 26 cas de thrombose de l'artère carotide interne. Über die A. temporalis anterior ist über Anastomosen zu den Ästen der A. ophthalmica ein Kollateral-Kreislauf zu den intracraniellen Gefäßabschnitten möglich. Bei 26 Patienten mit einem A. carotis interna-Verschluß zeigte sich dieser Kreislauf in 16 Fällen. Es wird über 3 Fälle ausführlich berichtet, bei denen die angiographische Anatomie der A. temporalis anterior und die möglichen Anastomosen mit Ästen der A. ophthalmica besprochen wird.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46672/1/234_2004_Article_BF00335020.pd
Heart Failure Stages among Older Adults in the Community: The Atherosclerosis Risk in Communities Study
Background: Although heart failure (HF) disproportionately affects older adults, little data exist regarding the prevalence of American College of Cardiology/American Heart Association HF stages among older individuals in the community. Additionally, the role of contemporary measures of longitudinal strain and diastolic dysfunction in defining HF stages is unclear. Methods: HF stages were classified in 6118 participants in the Atherosclerosis Risk in Communities study (67-91 years of age) at the fifth study visit as follows: A (asymptomatic with HF risk factors but no cardiac structural or functional abnormalities), B (asymptomatic with structural abnormalities, defined as left ventricular hypertrophy, dilation or dysfunction, or significant valvular disease), C1 (clinical HF without prior hospitalization), and C2 (clinical HF with earlier hospitalization). Results: Using the traditional definitions of HF stages, only 5% of examined participants were free of HF risk factors or structural heart disease (Stage 0), 52% were categorized as Stage A, 30% Stage B, 7% Stage C1, and 6% Stage C2. Worse HF stage was associated with a greater risk of incident HF hospitalization or death at a median follow-up of 608 days. Left ventricular (LV) ejection fraction was preserved in 77% and 65% in Stages C1 and C2, respectively. Incorporation of longitudinal strain and diastolic dysfunction into the Stage B definition reclassified 14% of the sample from Stage A to B and improved the net reclassification index (P=0.028) and integrated discrimination index (P=0.016). Abnormal LV structure, systolic function (based on LV ejection fraction and longitudinal strain), and diastolic function (based on e', E/e', and left atrial volume index) were each independently and additively associated with risk of incident HF hospitalization or death in Stage A and B participants. Conclusions: The majority of older adults in the community are at risk for HF (Stages A or B), appreciably more compared with previous reports in younger community-based samples. LV ejection fraction is robustly preserved in at least two-thirds of older adults with prevalent HF (Stage C), highlighting the burden of HF with preserved LV ejection fraction in the elderly. LV diastolic function and longitudinal strain provide incremental prognostic value beyond conventional measures of LV structure and LV ejection fraction in identifying persons at risk for HF hospitalization or death
Melanocortin-1 receptor, skin cancer and phenotypic characteristics (M-SKIP) project
Background: For complex diseases like cancer, pooled-analysis of individual data represents a powerful tool to investigate the joint contribution of genetic, phenotypic and environmental factors to the development of a disease. Pooled-analysis of epidemiological studies has many advantages over meta-analysis, and preliminary results may be obtained faster and with lower costs than with prospective consortia. Design and methods. Based on our experience with the study design of the Melanocortin-1 receptor (MC1R) gene, SKin cancer and Phenotypic characteristics (M-SKIP) project, we describe the most important steps in planning and conducting a pooled-analysis of genetic epidemiological studies. We then present the statistical analysis plan that we are going to apply, giving particular attention to methods of analysis recently proposed to account for between-study heterogeneity and to explore the joint contribution of genetic, phenotypic and environmental factors in the development of a disease. Within the M-SKIP project, data on 10,959 skin cancer cases and 14,785 controls from 31 international investigators were checked for quality and recoded for standardization. We first proposed to fit the aggregated data with random-effects logistic regression models. However, for the M-SKIP project, a two-stage analysis will be preferred to overcome the problem regarding the availability of different study covariates. The joint contribution of MC1R variants and phenotypic characteristics to skin cancer dev
Chronic neuropsychiatric sequelae of SARS‐CoV‐2: Protocol and methods from the Alzheimer's Association Global Consortium
Introduction
Coronavirus disease 2019 (COVID-19) has caused >3.5 million deaths worldwide and affected >160 million people. At least twice as many have been infected but remained asymptomatic or minimally symptomatic. COVID-19 includes central nervous system manifestations mediated by inflammation and cerebrovascular, anoxic, and/or viral neurotoxicity mechanisms. More than one third of patients with COVID-19 develop neurologic problems during the acute phase of the illness, including loss of sense of smell or taste, seizures, and stroke. Damage or functional changes to the brain may result in chronic sequelae. The risk of incident cognitive and neuropsychiatric complications appears independent from the severity of the original pulmonary illness. It behooves the scientific and medical community to attempt to understand the molecular and/or systemic factors linking COVID-19 to neurologic illness, both short and long term.
Methods
This article describes what is known so far in terms of links among COVID-19, the brain, neurological symptoms, and Alzheimer's disease (AD) and related dementias. We focus on risk factors and possible molecular, inflammatory, and viral mechanisms underlying neurological injury. We also provide a comprehensive description of the Alzheimer's Association Consortium on Chronic Neuropsychiatric Sequelae of SARS-CoV-2 infection (CNS SC2) harmonized methodology to address these questions using a worldwide network of researchers and institutions.
Results
Successful harmonization of designs and methods was achieved through a consensus process initially fragmented by specific interest groups (epidemiology, clinical assessments, cognitive evaluation, biomarkers, and neuroimaging). Conclusions from subcommittees were presented to the whole group and discussed extensively. Presently data collection is ongoing at 19 sites in 12 countries representing Asia, Africa, the Americas, and Europe.
Discussion
The Alzheimer's Association Global Consortium harmonized methodology is proposed as a model to study long-term neurocognitive sequelae of SARS-CoV-2 infection
Calibration of the LIGO gravitational wave detectors in the fifth science run
The Laser Interferometer Gravitational Wave Observatory (LIGO) is a network of three detectors built to detect local perturbations in the space–time metric from astrophysical sources. These detectors, two in Hanford, WA and one in Livingston, LA, are power-recycled Fabry-Perot Michelson interferometers. In their fifth science run (S5), between November 2005 and October 2007, these detectors accumulated one year of triple coincident data while operating at their designed sensitivity. In this paper, we describe the calibration of the instruments in the S5 data set, including measurement techniques and uncertainty estimation.United States. National Aeronautics and Space AdministrationCarnegie TrustLeverhulme TrustDavid & Lucile Packard FoundationResearch CorporationAlfred P. Sloan Foundatio
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