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1.
Phys Rev Lett ; 132(26): 261001, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38996294

RESUMO

Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of the deuteron (D) flux are presented. The measurements are based on 21×10^{6} D nuclei in the rigidity range from 1.9 to 21 GV collected from May 2011 to April 2021. We observe that over the entire rigidity range the D flux exhibits nearly identical time variations with the p, ^{3}He, and ^{4}He fluxes. Above 4.5 GV, the D/^{4}He flux ratio is time independent and its rigidity dependence is well described by a single power law ∝R^{Δ} with Δ_{D/^{4}He}=-0.108±0.005. This is in contrast with the ^{3}He/^{4}He flux ratio for which we find Δ_{^{3}He/^{4}He}=-0.289±0.003. Above ∼13 GV we find a nearly identical rigidity dependence of the D and p fluxes with a D/p flux ratio of 0.027±0.001. These unexpected observations indicate that cosmic deuterons have a sizable primarylike component. With a method independent of cosmic ray propagation, we obtain the primary component of the D flux equal to 9.4±0.5% of the ^{4}He flux and the secondary component of the D flux equal to 58±5% of the ^{3}He flux.

2.
Stat Med ; 43(6): 1256-1270, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38258898

RESUMO

Allocating patients to treatment arms during a trial based on the observed responses accumulated up to the decision point, and sequential adaptation of this allocation, could minimize the expected number of failures or maximize total benefits to patients. In this study, we developed a Bayesian response-adaptive randomization (RAR) design targeting the endpoint of organ support-free days (OSFD) for patients admitted to the intensive care units. The OSFD is a mixture of mortality and morbidity assessed by the number of days of free of organ support within a predetermined post-randomization time-window. In the past, researchers treated OSFD as an ordinal outcome variable where the lowest category is death. We propose a novel RAR design for a composite endpoint of mortality and morbidity, for example, OSFD, by using a Bayesian mixture model with a Markov chain Monte Carlo sampling to estimate the posterior probability distribution of OSFD and determine treatment allocation ratios at each interim. Simulations were conducted to compare the performance of our proposed design under various randomization rules and different alpha spending functions. The results show that our RAR design using Bayesian inference allocated more patients to the better performing arm(s) compared to other existing adaptive rules while assuring adequate power and type I error rate control across a range of plausible clinical scenarios.


Assuntos
Projetos de Pesquisa , Humanos , Distribuição Aleatória , Teorema de Bayes , Probabilidade , Morbidade
3.
Alzheimer Dis Assoc Disord ; 38(2): 152-159, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38748688

RESUMO

BACKGROUND: Identifying potentially modifiable risk factors associated with MCI in different ethnoracial groups could reduce MCI burden and health inequity in the population. METHODS: Among 2845 adults aged 65+ years, we investigated potential risk exposures including education, physical and mental health, lifestyle, and sensory function, and their cross-sectional associations with MCI. We compared proportions of exposures between Black and White participants and explored relationships among race, MCI, and exposures. Logistic regression modeled MCI as a function of each exposure in the overall sample adjusting for age, sex, educational level, and race, and investigating race*exposure interactions. RESULTS: Compared with White participants, Black participants had greater odds of MCI (OR 1.53; 95% CI, 1.13 to 2.06) and were more likely to report depressive symptoms, diabetes, and stroke, to have high blood pressure and BMI, and to be APOE - 4 carriers. Exposures associated with higher odds of MCI were diabetes, stroke, lifetime smoking, sleep disturbances, social isolation, loneliness, depression and anxiety symptoms, and vision and hearing loss. There were no significant interactions between race and any exposure. CONCLUSIONS: Black participants had 53% higher odds of MCI adjusting for age, sex, and education. The same exposures were associated with MCI in Black and White participants.


Assuntos
Disfunção Cognitiva , População Branca , Humanos , Masculino , Feminino , Idoso , Disfunção Cognitiva/etnologia , População Branca/estatística & dados numéricos , População Branca/psicologia , Estudos Transversais , Fatores de Risco , Negro ou Afro-Americano/psicologia , Negro ou Afro-Americano/estatística & dados numéricos , Idoso de 80 Anos ou mais , Depressão/etnologia
4.
Int Psychogeriatr ; 36(2): 142-148, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37231775

RESUMO

OBJECTIVES: Older adults commonly take benzodiazepines (BZDs) that may have long-term adverse cognitive effects. We investigated whether BZD use was related to developing mild cognitive impairment (MCI) or dementia in cognitively normal older adults in the community. SETTING/PARTICIPANTS: A population-based cohort (n = 1959) of adults aged 65 and over, recruited from communities of low socioeconomic status. MEASUREMENTS: BZD use, Clinical Dementia Rating (CDR), anxiety symptoms, depression symptoms, sleep difficulties, and APOE genotype. DESIGN: We examined time from study entry to MCI (CDR = 0.5) and time from study entry to dementia (CDR ≥ 1) in participants who were cognitively normal at baseline (CDR = 0). We used survival analysis (Cox model), adjusted for age, sex, education, sleep, anxiety, and depression. For all the models, we included an interaction term between BZD use and APOE*4. RESULTS: Taking BZDs was significantly associated with higher risk of developing MCI, but not of developing dementia. The effect was not affected by APOE genotype. CONCLUSIONS: In a population-based sample of cognitively normal older adults, BZD use is associated with developing MCI, but not dementia. BZD use may be a potentially modifiable risk factor for MCI.


Assuntos
Disfunção Cognitiva , Demência , Humanos , Idoso , Benzodiazepinas/efeitos adversos , Disfunção Cognitiva/diagnóstico , Modelos de Riscos Proporcionais , Demência/psicologia , Apolipoproteínas E , Fatores de Risco
5.
Alzheimers Dement ; 20(6): 4199-4211, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38753951

RESUMO

INTRODUCTION: Plasma biomarkers of Alzheimer's disease and related dementias predict global cognitive performance and decline over time; it remains unclear how they associate with changes in different dementia syndromes affecting distinct cognitive domains. METHODS: In a prospective study with repeated assessments of a randomly selected population-based cohort (n = 787, median age 73), we evaluated performance and decline in different cognitive domains over up to 8 years in relation to plasma concentrations of amyloid beta 42/40 (Aß42/40) ratio, phosphorylated tau181 (p-tau181), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP). RESULTS: Cross-sectionally, memory showed the strongest associations with p-tau181, and attention, executive, and visuospatial functions with NfL. Longitudinally, memory decline was distinguishable with all biomarker profiles dichotomized according to data-driven cutoffs, most efficiently with Aß42/40. GFAP and Aß42/40 were the best discriminators of decline patterns in language and visuospatial functions, respectively. DISCUSSION: These relatively non-invasive tests may be beneficial for clinical screening after replication in other populations and validation through neuroimaging or cerebrospinal fluid analysis. HIGHLIGHTS: We performed a prospective study with up to 8 years of repeated domain-specific cognitive assessments and baseline plasma Alzheimer's disease and related dementias biomarker measurements in a randomly selected population-based cohort. We considered distinct growth curves of trajectories of different cognitive domains and survival bias induced by missing data by adding quadratic time and applying joint modeling technique. Cross-sectionally, memory showed the strongest associations with plasma phosphorylated tau181, while attention, executive, and visuospatial functions were most strongly associated with neurofilament light chain. Longitudinally, memory and visuospatial declines were most efficiently distinguished by dichotomized amyloid beta 42/40 profile among all plasma biomarkers, while language was by dichotomized glial fibrillary acidic protein. These relatively non-invasive tests may be beneficial for clinical screening; however, they will need replication in other populations and validation through neuroimaging and/or cerebrospinal fluid assessments.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Biomarcadores , Disfunção Cognitiva , Proteínas de Neurofilamentos , Proteínas tau , Humanos , Biomarcadores/sangue , Feminino , Masculino , Doença de Alzheimer/sangue , Idoso , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Proteínas tau/sangue , Proteínas tau/líquido cefalorraquidiano , Disfunção Cognitiva/sangue , Estudos Prospectivos , Estudos Transversais , Proteínas de Neurofilamentos/sangue , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/líquido cefalorraquidiano , Proteína Glial Fibrilar Ácida/sangue , Estudos Longitudinais , Testes Neuropsicológicos/estatística & dados numéricos , Pessoa de Meia-Idade , Cognição/fisiologia , Idoso de 80 Anos ou mais
6.
Phys Rev Lett ; 131(15): 151002, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37897756

RESUMO

We present the precision measurements of 11 years of daily cosmic positron fluxes in the rigidity range from 1.00 to 41.9 GV based on 3.4×10^{6} positrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The positron fluxes show distinctly different time variations from the electron fluxes at short and long timescales. A hysteresis between the electron fluxes and the positron fluxes is observed with a significance greater than 5σ at rigidities below 8.5 GV. On the contrary, the positron fluxes and the proton fluxes show similar time variation. Remarkably, we found that positron fluxes are modulated more than proton fluxes with a significance greater than 5σ for rigidities below 7 GV. These continuous daily positron fluxes, together with AMS daily electron, proton, and helium fluxes over an 11-year solar cycle, provide unique input to the understanding of both the charge-sign and mass dependencies of cosmic rays in the heliosphere.

7.
Phys Rev Lett ; 130(21): 211002, 2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37295095

RESUMO

We report the properties of primary cosmic-ray sulfur (S) in the rigidity range 2.15 GV to 3.0 TV based on 0.38×10^{6} sulfur nuclei collected by the Alpha Magnetic Spectrometer experiment (AMS). We observed that above 90 GV the rigidity dependence of the S flux is identical to the rigidity dependence of Ne-Mg-Si fluxes, which is different from the rigidity dependence of the He-C-O-Fe fluxes. We found that, similar to N, Na, and Al cosmic rays, over the entire rigidity range, the traditional primary cosmic rays S, Ne, Mg, and C all have sizeable secondary components, and the S, Ne, and Mg fluxes are well described by the weighted sum of the primary silicon flux and the secondary fluorine flux, and the C flux is well described by the weighted sum of the primary oxygen flux and the secondary boron flux. The primary and secondary contributions of the traditional primary cosmic-ray fluxes of C, Ne, Mg, and S (even Z elements) are distinctly different from the primary and secondary contributions of the N, Na, and Al (odd Z elements) fluxes. The abundance ratio at the source for S/Si is 0.167±0.006, for Ne/Si is 0.833±0.025, for Mg/Si is 0.994±0.029, and for C/O is 0.836±0.025. These values are determined independent of cosmic-ray propagation.


Assuntos
Carbono , Magnésio , Neônio , Enxofre , Fenômenos Magnéticos
8.
Phys Rev Lett ; 130(16): 161001, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37154630

RESUMO

We present the precision measurements of 11 years of daily cosmic electron fluxes in the rigidity interval from 1.00 to 41.9 GV based on 2.0×10^{8} electrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The electron fluxes exhibit variations on multiple timescales. Recurrent electron flux variations with periods of 27 days, 13.5 days, and 9 days are observed. We find that the electron fluxes show distinctly different time variations from the proton fluxes. Remarkably, a hysteresis between the electron flux and the proton flux is observed with a significance of greater than 6σ at rigidities below 8.5 GV. Furthermore, significant structures in the electron-proton hysteresis are observed corresponding to sharp structures in both fluxes. This continuous daily electron data provide unique input to the understanding of the charge sign dependence of cosmic rays over an 11-year solar cycle.

9.
J Int Neuropsychol Soc ; 29(1): 1-11, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36630994

RESUMO

OBJECTIVE: Emerging evidence suggests low vision may be a modifiable risk factor for cognitive decline. We examined effects of baseline visual acuity (VA) on level of, and change in, cognitive test performance over 9 years. METHOD: A population-based sample of 1,621 participants (average age 77 years) completed a comprehensive neuropsychological evaluation and VA testing at baseline and reassessed at nine subsequent annual visits. Linear regression modeled the association between baseline VA and concurrent cognitive test performance. Joint modeling of a longitudinal sub-model and a survival sub-model to adjust for attrition were used to examine associations between baseline VA and repeated cognitive test performance over time. RESULTS: Better baseline VA was associated cross-sectionally with younger age, male sex, greater than high school education, and higher baseline neuropsychological test scores on both vision-dependent (B coefficient range -0.163 to -0.375, p = .006 to <.001) and vision-independent tests (-0.187 to -0.215, p = .003 to .002). In longitudinal modeling, better baseline VA was associated with slower decline in vision-dependent tests (B coefficient range -0.092 to 0.111, p = .005 to <.001) and vision-independent tests (-0.107 to 0.067, p = .007 to <.001). CONCLUSIONS: Higher VA is associated with higher concurrent cognitive abilities and slower rates of decline over 9 years in both vision-dependent and vision-independent tests of memory, language, and executive functioning. Findings are consistent with emerging literature supporting vision impairment in aging as a potentially modifiable risk factor for cognitive decline. Clinicians should encourage patient utilization of vision assessment and correction with the added aim of protecting cognition.


Assuntos
Disfunção Cognitiva , Humanos , Masculino , Idoso , Estudos Longitudinais , Cognição , Envelhecimento , Testes Neuropsicológicos , Acuidade Visual
10.
Alzheimer Dis Assoc Disord ; 37(1): 20-27, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36706325

RESUMO

OBJECTIVE: We investigated whether anticholinergic drug use was related to developing mild cognitive impairment (MCI) or dementia in older adults at the population level. METHODS: We used an Anticholinergic Rating (ACR) scale, Clinical Dementia Rating, APOE genotype, and number of prescription medications. We examined time to incident MCI and incident dementia in a population-based cohort (n=1959). We assessed whether developing MCI or dementia was associated with (1) any anticholinergic drug use, (2) total ACR score, or (3) number of anticholinergic drugs taken. RESULTS: Taking any anticholinergic drug was significantly associated with higher risk of developing MCI; however, higher ACR score or higher number of anticholinergic drugs, compared with lower, were not associated with greater risk of developing MCI. We found no significant relationship between anticholinergic use and developing dementia. The relationship between anticholinergic use and cognitive outcome was not affected by APOE genotype. CONCLUSIONS: Among cognitively normal older adults in a population-based sample, anticholinergic drug use is independently associated with subsequently developing MCI, but not dementia. Thus, anticholinergic drug use may influence risk of MCI that is nonprogressive to dementia and potentially be a modifiable risk factor for MCI.


Assuntos
Antagonistas Colinérgicos , Disfunção Cognitiva , Humanos , Idoso , Estudos de Coortes , Antagonistas Colinérgicos/efeitos adversos , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/genética , Genótipo , Apolipoproteínas E/genética , Fatores de Risco
11.
Alzheimer Dis Assoc Disord ; 37(1): 13-19, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36706321

RESUMO

BACKGROUND: Changes in physical health and cognition during aging can result in some older adults to stop driving. In this population-based longitudinal study, we describe potential predictors of driving cessation in older adults. METHODS: Age-stratified random population cohort of 1982 adults aged 65 years and older drawn from voter registration lists. Participant characteristics were measured using demographics, physical and self-rated health, sleeping habits, driving status, cognitive screening, modified Center for Epidemiologic Studies-Depression scale, clinical dementia rating, and mini-mental state examination. RESULTS: Over 12 years of follow-up, 390 participants stopped driving. These individuals were older, more likely to be women and to have a clinical dementia rating score ≥1, had worse self-reported health, and more symptoms of depression, compared with those who were still driving. In addition, individuals with lower test performance in all cognitive domains, loss of visual acuity and fields, and bilateral hearing loss were more likely to stop driving. CONCLUSIONS: Age, sex, cognitive impairments, physical health, and depressive symptoms were associated with driving cessation in this cohort. By identifying potential driving cessation predictors, health care providers and families may better recognize these risk factors and begin the driving cessation discussion early.


Assuntos
Condução de Veículo , Disfunção Cognitiva , Humanos , Feminino , Idoso , Masculino , Estudos Longitudinais , Condução de Veículo/psicologia , Cognição , Envelhecimento/psicologia
12.
BMC Infect Dis ; 23(1): 30, 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36658543

RESUMO

BACKGROUND: The Procalcitonin Antibiotic Consensus Trial (ProACT) found provision of a procalcitonin antibiotic prescribing guideline to hospital-based clinicians did not reduce antibiotic use. Possible reasons include clinician reluctance to follow the guideline, with an observed 64.8% adherence rate. In this study we sought to determine the threshold adherence rate for reduction in antibiotic use, and to explore opportunities to increase adherence. METHODS: This study is a retrospective analysis of ProACT data. ProACT randomized 1656 patients presenting to 14 U.S. hospitals with suspected lower respiratory tract infection to usual care or provision of procalcitonin assay results and an antibiotic prescribing guideline to the treating clinicians. We simulated varying adherence to guideline recommendations for low procalcitonin levels and determined which threshold adherence rate could have resulted in rejection of the null hypothesis of no difference between groups at alpha = 0.05. We also performed sensitivity analyses within specific clinical settings and grouped patients initially prescribed antibiotics despite low procalcitonin into low, medium, and high risk of illness severity or bacterial infection. RESULTS: Our primary outcome was number of antibiotic-days by day 30 using an intention-to-treat approach and a null hypothesis of no difference in antibiotic use. We determined that an 84% adherence rate in the hospital setting (emergency department and inpatient) for low procalcitonin could have allowed rejection of the null hypothesis (3.7 vs 4.3 antibiotic-days, p = 0.048). The threshold adherence rate was 76% for continued guideline adherence after discharge. Even 100% adherence in the emergency department alone failed to reduce antibiotic-days. Of the 218 patients prescribed antibiotics in the emergency department despite low procalcitonin, 153 (70.2%) were categorized as low or medium risk. CONCLUSIONS: High adherence in the hospital setting to a procalcitonin antibiotic prescribing guideline is necessary to reduce antibiotic use in suspected lower respiratory tract infection. Continued guideline adherence after discharge and withholding of antibiotics in low and medium risk patients with low procalcitonin may offer impactful potential opportunities for antibiotic reduction. Trial registration Procalcitonin Antibiotic Consensus Trial (ProACT), ClinicalTrials.gov Identifier: NCT02130986. First posted May 6, 2014.


Assuntos
Pró-Calcitonina , Infecções Respiratórias , Humanos , Antibacterianos/uso terapêutico , Calcitonina , Estudos Retrospectivos , Biomarcadores , Infecções Respiratórias/tratamento farmacológico , Fidelidade a Diretrizes
13.
Crit Care ; 27(1): 61, 2023 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-36797793

RESUMO

BACKGROUND: Whether surrogate decision makers regret decisions about the use of life support for incapacitated, critically ill patients remain uncertain. We sought to determine the prevalence of decision regret among surrogates of adult ICU patients and identify factors that influence regret. METHODS: We conducted a secondary analysis of data from the PARTNER 2 trial, which tested a family support intervention for surrogates of critically ill adults. At 6-month follow-up, surrogates rated their regret about life support decisions using the Decision Regret Scale (DRS), scored from 0 to 100, with higher scores indicating more regret. We used multiple linear regression to identify covariates associated with decision regret based on a psychological construct of regret. We constructed two models using the full cohort; model 1 included patient outcomes; model 2 focused on covariates known at the time of ICU decision-making. Subgroup analyses were also conducted based on patient survival status at hospital discharge and 6-month follow-up. RESULTS: 748 of 848 surrogates had complete DRS data. The median (IQR) DRS score was 15 (0, 25). Overall, 54% reported mild regret (DRS 5-25), 19% moderate-strong regret (DRS 30-100), and 27% no regret (DRS 0). Poor patient outcome at 6 months (death or severe functional dependence) was associated with more regret in model 1 (ß 10.1; 95% C.I. 3.2, 17.0). In model 2, palliative care consultation (3.0; 0.1, 5.9), limitations in life support (LS) prior to death (6.3; 3.1, 9.4) and surrogate black race (6.3; 0.3, 12.3) were associated with more regret. Other modulators of regret in subgroup analyses included surrogate age and education level, surrogate-patient relationship, death in hospital (compared to the post-discharge period), and code status at time of ICU admission. CONCLUSIONS: One in five ICU surrogate decision makers experience moderate to strong regret about life support decisions in ICU. Poor patient outcomes are linked to more regret. Decisions to limit life support prior to patient death may also increase regret. Future studies are needed to understand how regret relates to decision quality and how to lessen lasting regret.


Assuntos
Estado Terminal , Tomada de Decisões , Adulto , Humanos , Estado Terminal/epidemiologia , Estado Terminal/terapia , Prevalência , Assistência ao Convalescente , Unidades de Terapia Intensiva , Alta do Paciente
14.
Int J Geriatr Psychiatry ; 38(3): e5899, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36855309

RESUMO

OBJECTIVE: To investigate the relationship between anxiety and mild cognitive impairment (MCI), and whether it is mediated by perceived stress, at the population level. METHOD AND DESIGN: In a longitudinal study of 368 adults aged 65+ from a population-based cohort, we annually assessed anxiety symptoms (GAD-7), perceived stress (PSS-4), and ratings on the Clinical Dementia Rating (CDR®), where CDR = 0.5 was operationalized as MCI. Examining data from three consecutive assessment waves, we first determined the associations between anxiety at the first wave with MCI at the third wave, and vice versa. We then used mediation analyses to determine whether the pathways in both directions were mediated by perceived stress at the second wave, adjusting for demographics and other relevant covariates. RESULTS: We confirmed significant bidirectional longitudinal associations between anxiety and MCI. Perceived stress was detected as a significant mediator for both pathways between anxiety and MCI, explaining 37.1% of the total effect (TE) of anxiety on incident MCI while conversely explaining 27.1% of the TE of MCI on anxiety. CONCLUSIONS: A bidirectional relationship with a 2-year lag between anxiety and MCI was mediated through perceived stress. Clinicians should be sensitive both to potential consequent anxiety when patients present with cognitive impairment, and to potential incipient MCI when the presenting complaint is anxiety. Managing stress may help mitigate adverse outcomes.


Assuntos
Ansiedade , Disfunção Cognitiva , Humanos , Estudos Longitudinais , Ansiedade/epidemiologia , Transtornos de Ansiedade , Disfunção Cognitiva/epidemiologia , Testes de Estado Mental e Demência
15.
Clin Radiol ; 78(4): 254-264, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35773096

RESUMO

Neurological interventions have taken on a significant role in interventional radiology (IR) practice. Indications fall under three main categories: (1) intraprocedural pain management, (2) cancer pain palliation, and (3) chronic non-cancer pain control. Short-term regional anaesthesia can be achieved with local anaesthetics, while longer-term pain control can be attained with radiofrequency neuromodulation (pulsed or otherwise) or thermal/chemical neurolysis. This review article summarises the therapeutic options, applications, and techniques of commonly used peripheral nerve and plexus interventions in IR.


Assuntos
Dor Crônica , Bloqueio Nervoso , Humanos , Manejo da Dor/métodos , Analgésicos Opioides , Radiologia Intervencionista , Bloqueio Nervoso/métodos
16.
Alzheimers Dement ; 19(10): 4507-4519, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-36876954

RESUMO

INTRODUCTION: Plasma biomarkers-cost effective, non-invasive indicators of Alzheimer's disease (AD) and related disorders (ADRD)-have largely been studied in clinical research settings. Here, we examined plasma biomarker profiles and their associated factors in a population-based cohort to determine whether they could identify an at-risk group, independently of brain and cerebrospinal fluid biomarkers. METHODS: We measured plasma phosphorylated tau181 (p-tau181), neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and amyloid beta (Aß)42/40 ratio in 847 participants from a population-based cohort in southwestern Pennsylvania. RESULTS: K-medoids clustering identified two distinct plasma Aß42/40 modes, further categorizable into three biomarker profile groups: normal, uncertain, and abnormal. In different groups, plasma p-tau181, NfL, and GFAP were inversely correlated with Aß42/40, Clinical Dementia Rating, and memory composite score, with the strongest associations in the abnormal group. DISCUSSION: Abnormal plasma Aß42/40 ratio identified older adult groups with lower memory scores, higher dementia risks, and higher ADRD biomarker levels, with potential implications for population screening. HIGHLIGHTS: Population-based plasma biomarker studies are lacking, particularly in cohorts without cerebrospinal fluid or neuroimaging data. In the Monongahela-Youghiogheny Healthy Aging Team study (n = 847), plasma biomarkers associated with worse memory and Clinical Dementia Rating (CDR), apolipoprotein E ε4, and greater age. Plasma amyloid beta (Aß)42/40 ratio levels allowed clustering participants into abnormal, uncertain, and normal groups. Plasma Aß42/40 correlated differently with neurofilament light chain, glial fibrillary acidic protein, phosphorylated tau181, memory composite, and CDR in each group. Plasma biomarkers can enable relatively affordable and non-invasive community screening for evidence of Alzheimer's disease and related disorders pathophysiology.


Assuntos
Doença de Alzheimer , Humanos , Idoso , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides , Proteína Glial Fibrilar Ácida , Apolipoproteína E4 , Biomarcadores , Proteínas tau
17.
Alzheimers Dement ; 19(9): 4073-4083, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37212597

RESUMO

INTRODUCTION: Cardiovascular fat is a novel risk factor that may link to dementia. Fat volume and radiodensity are measurements of fat quantity and quality, respectively. Importantly, high fat radiodensity could indicate healthy or adverse metabolic processes. METHODS: The associations of cardiovascular fat (including epicardial, paracardial, and thoracic perivascular adipose tissue [PVAT]) quantity and quality assessed at mean age of 51 with subsequent cognitive performance measured repeatedly over 16 years of follow-up were examined using mixed models among 531 women. RESULTS: Higher thoracic PVAT volume was associated with a higher future episodic memory (ß[standard error (SE)] = 0.08 [0.04], P = 0.033), while higher thoracic PVAT radiodensity with lower future episodic (ß[SE] = -0.06 [0.03], P = 0.045) and working (ß[SE] = -0.24 [0.08], P = 0.003) memories. The latter association is prominent at higher volume of thoracic PVAT. DISCUSSION: Mid-life thoracic PVAT may have a distinct contribution to future cognition possibly due to its distinct adipose tissue type (brown fat) and anatomical proximity to the brain circulation. HIGHLIGHTS: Higher mid-life thoracic perivascular adipose tissue (thoracic PVAT) volume is related to a better future episodic memory in women. Higher mid-life thoracic PVAT radiodensity is related to worse future working and episodic memories. Negative association of high thoracic PVAT radiodensity with working memory is prominent at higher thoracic PVAT volume. Mid-life thoracic PVAT is linked to future memory loss, an early sign of Alzheimer's disease. Mid-life women's epicardial and paracardial fat are not related to future cognition.


Assuntos
Tecido Adiposo , Feminino , Humanos , Pessoa de Meia-Idade , Tecido Adiposo/diagnóstico por imagem , Fatores de Risco
18.
Alzheimers Dement ; 19(11): 5114-5128, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37102417

RESUMO

INTRODUCTION: Previous meta-analyses have linked social connections and mild cognitive impairment, dementia, and mortality. However, these used aggregate data from North America and Europe and examined a limited number of social connection markers. METHODS: We used individual participant data (N = 39271, Mage  = 70.67 (40-102), 58.86% female, Meducation  = 8.43 years, Mfollow-up  = 3.22 years) from 13 longitudinal ageing studies. A two-stage meta-analysis of Cox regression models examined the association between social connection markers with our primary outcomes. RESULTS: We found associations between good social connections structure and quality and lower risk of incident mild cognitive impairment (MCI); between social structure and function and lower risk of incident dementia and mortality. Only in Asian cohorts, being married/in a relationship was associated with reduced risk of dementia, and having a confidante was associated with reduced risk of dementia and mortality. DISCUSSION: Different aspects of social connections - structure, function, and quality - are associated with benefits for healthy aging internationally. HIGHLIGHTS: Social connection structure (being married/in a relationship, weekly community group engagement, weekly family/friend interactions) and quality (never lonely) were associated with lower risk of incident MCI. Social connection structure (monthly/weekly friend/family interactions) and function (having a confidante) were associated with lower risk of incident dementia. Social connection structure (living with others, yearly/monthly/weekly community group engagement) and function (having a confidante) were associated with lower risk of mortality. Evidence from 13 longitudinal cohort studies of ageing indicates that social connections are important targets for reducing risk of incident MCI, incident dementia, and mortality. Only in Asian cohorts, being married/in a relationship was associated with reduced risk of dementia, and having a confidante was associated with reduced risk of dementia and mortality.


Assuntos
Disfunção Cognitiva , Demência , Humanos , Feminino , Idoso , Masculino , Estudos Longitudinais , Demência/epidemiologia , Demência/psicologia , Estudos de Coortes , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/psicologia , Envelhecimento/psicologia
19.
Zhonghua Xin Xue Guan Bing Za Zhi ; 51(11): 1137-1144, 2023 Nov 24.
Artigo em Zh | MEDLINE | ID: mdl-37963748

RESUMO

Objective: To investigate the relationship between obstructive sleep apnea (OSA), apnea hypopnea index (AHI) and vascular injury in hypertensive patients. Methods: This cross-sectional study enrolled patients admitted to the Hypertension Department of TEDA International Cardiovascular Hospital from April 2020 to April 2023, who finished portable sleep monitoring. Sleep monitoring indicators, flow-mediated vasodilation (FMD), carotid artery ultrasound, carotid intima-media thickness, cervical and femoral pulse wave conduction velocity (cfPWV), brachial and ankle pulse wave conduction velocity (baPWV) were analyzed. OSA was classified into mild (5 times/h≤AHI<15 times/h), moderate (15≤AHI<30 times/h), and severe (AHI≥30 times/h) based on AHI levels. FMD<6.0% was defined as vascular endothelial injury, and cfPWV>10 m/s and/or baPWV>18 m/s was defined as arterial stiffness. Multivariate logistic regression analysis was used to explore the correlation between AHI, OSA severity and vascular injury, and subgroup analysis was performed in young (age≤45 years) and middle-to-old patients (age>45 years). Sensitivity analysis was performed by excluding patients with diabetes, cerebrovascular disease and coronary heart disease. The correlation between AHI and vascular injury index was analyzed by restricted cubic spline. Results: A total of 555 adult hypertensive patients were included, the mean age was (39.7±9.2) years, 422 were males (76.0%), and the prevalence of OSA was 66.7% (370/555). Multivariate logistic regression analysis showed that moderate OSA (OR=2.83, P=0.019) and severe OSA (OR=3.40, P=0.016) were positively correlated with vascular endothelial injury after adjusting for age, sex, body mass index and mean arterial pressure. Subgroup analysis showed that log AHI (OR=1.99, P=0.035), moderate OSA (OR=4.83, P=0.010) and severe OSA (OR=4.64, P=0.015) were associated with vascular endothelial injury in young hypertensive patients. The results of sensitivity analysis were similar to the above results. The results of restricted cubic spline analysis showed that AHI was correlated with FMD (P=0.022), and the slope of the curve was the largest when AHI was between 0 and 10 times/h. There was no correlation between log AHI and OSA severity and carotid intima-media thickening and arterial stiffness (all P<0.05). Conclusions: OSA is associated with vascular endothelial injury in hypertensive patients, especially in young patients.


Assuntos
Hipertensão , Apneia Obstrutiva do Sono , Rigidez Vascular , Lesões do Sistema Vascular , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , Feminino , Espessura Intima-Media Carotídea , Estudos Transversais , Hipertensão/complicações , Apneia Obstrutiva do Sono/complicações , Artérias Carótidas
20.
Crit Care Med ; 50(6): 935-944, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35120041

RESUMO

OBJECTIVES: Whether metformin exposure is associated with improved outcomes in patients with type 2 diabetes mellitus and sepsis. DESIGN: Retrospective cohort study. SETTING: Patients admitted to ICUs in 16 hospitals in Pennsylvania from October 2008 to December 2014. PATIENTS: Adult critical ill patients with type 2 diabetes mellitus and sepsis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We conducted a retrospective cohort study to compare 90-day mortality in diabetic patients with sepsis with and without exposure to metformin during hospitalization. Data were obtained from the electronic health record of a large healthcare system in Pennsylvania from October 2008 to December 2014, on patients admitted to the ICU at any of the 16 hospitals within the system. The primary outcome was mortality at 90 days. The absolute and adjusted odds ratio (OR) with 95% CI were calculated in a propensity score-matched cohort. Among 14,847 patients with type 2 diabetes mellitus and sepsis, 682 patients (4.6%) were exposed to metformin during hospitalization and 14,165 (95.4%) were not. Within a total of 2,691 patients subjected to propensity score-matching at a 1:4 ratio, exposure to metformin (n = 599) was associated with decreased 90-day mortality (71/599, 11.9% vs 475/2,092, 22.7%; OR, 0.46; 95% CI, 0.35-0.60), reduced severe acute kidney injury (50% vs 57%; OR, 0.75; 95% CI, 0.62-0.90), less Major Adverse Kidney Events at 1 year (OR, 0.27; 95% CI, 0.22-0.68), and increased renal recovery (95% vs 86%; OR, 6.43; 95% CI, 3.42-12.1). CONCLUSIONS: Metformin exposure during hospitalization is associated with a decrease in 90-day mortality in patients with type 2 diabetes mellitus and sepsis.


Assuntos
Diabetes Mellitus Tipo 2 , Metformina , Sepse , Adulto , Estado Terminal , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hospitalização , Humanos , Metformina/uso terapêutico , Estudos Retrospectivos , Sepse/complicações , Sepse/tratamento farmacológico
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