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BACKGROUND: Alzheimer's disease (AD) prevention research requires methods for measurement of disease progression not yet revealed by symptoms. Preferably, such measurement should encompass multiple disease markers. OBJECTIVES: Evaluate an item response theory (IRT) model-based latent variable Alzheimer Progression Score (APS) that uses multi-modal disease markers to estimate pre-clinical disease progression. DESIGN: Estimate APS scores in the BIOCARD observational study, and in the parallel PREVENT-AD Cohort and its sister INTREPAD placebo-controlled prevention trial. Use BIOCARD data to evaluate whether baseline and early APS trajectory predict later progression to MCI/dementia. Similarly, use longitudinal PREVENT-AD data to assess test measurement invariance over time. Further, assess portability of the PREVENT-AD IRT model to baseline INTREPAD data, and explore model changes when CSF markers are added or withdrawn. SETTING: BIOCARD was established in 1995 and participants were followed up to 20 years in Baltimore, USA. The PREVENT-AD and INTREPAD trial cohorts were established between 2011-2015 in Montreal, Canada, using nearly identical entry criteria to enroll high-risk cognitively normal persons aged 60+ then followed for several years. PARTICIPANTS: 349 cognitively normal, primarily middle-aged participants in BIOCARD, 125 high-risk participants aged 60+ in PREVENT-AD, and 217 similar subjects in INTREPAD. 106 INTREPAD participants donated up to four serial CSF samples. MEASUREMENTS: Global cognitive assessment and multiple structural, functional, and diffusion MRI metrics, sensori-neural tests, and CSF concentrations of tau, Aß42 and their ratio. RESULTS: Both baseline values and early slope of APS scores in BIOCARD predicted later progression to MCI or AD. Presence of CSF variables strongly improved such prediction. A similarly derived APS in PREVENT-AD showed measurement invariance over time and portability to the parallel INTREPAD sample. CONCLUSIONS: An IRT-based APS can summarize multimodal information to provide a longitudinal measure of pre-clinical AD progression, and holds promise as an outcome for AD prevention trials.
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We describe events spanning over 20 years that have shaped our approach to identification of interventions that may delay symptoms in Alzheimer's disease (AD). These events motivated the development of a new Centre for Studies on Prevention of AD that includes an observational cohort of cognitively normal high-risk persons and INTREPAD, a nested two-year randomized placebo-controlled trial of the non-steroidal anti-inflammatory drug naproxen sodium. INTREPAD enrolled 217 persons and will follow 160 in a modified intent-to-treat analysis of persons who remained on-protocol through at least one follow-up evaluation. The trial employs dual endpoints: 1) a composite global cognitive score generated by a battery of 12 psychometric tests organized into five subscales; and 2) a summary Alzheimer's Progression Score derived from latent variable modeling of multiple biomarker data from several modalities. The dual endpoints will be analyzed by consideration of their joint probability under the null hypothesis of no treatment effect, after allowing appropriately for their lack of independence. We suggest that such an approach can be used economically to generate preliminary data regarding the efficacy of potential prevention strategies, thereby increasing the chances of finding one or more interventions that successfully prevent symptoms.
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OBJECTIVE: Progression from cognitive impairment (CI) to dementia is predicted by several factors, but their relative importance and interaction are unclear. METHOD: We investigated numerous such factors in the AgeCoDe study, a longitudinal study of general practice patients aged 75+. We used recursive partitioning analysis (RPA) to identify hierarchical patterns of baseline covariates that predicted dementia-free survival. RESULTS: Among 784 non-demented patients with CI, 157 (20.0%) developed dementia over a follow-up interval of 4.5 years. RPA showed that more severe cognitive compromise, revealed by a Mini-Mental State Examination (MMSE) score < 27.47, was the strongest predictor of imminent dementia. Dementia-free survival time was shortest (mean 2.4 years) in such low-scoring patients who also had impaired instrumental activities of daily living (iADL) and subjective memory impairment with related worry (SMI-w). Patients with identical characteristics but without SMI-w had an estimated mean dementia-free survival time of 3.8 years, which was still shorter than in patients who had subthreshold MMSE scores but intact iADL (4.2-5.2 years). CONCLUSION: Hierarchical patterns of readily available covariates can predict dementia-free survival in older general practice patients with CI. Although less widely appreciated than other variables, iADL impairment appears to be an especially noteworthy predictor of progression to dementia.
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Actividades Cotidianas , Disfunción Cognitiva/psicología , Demencia/psicología , Síntomas Prodrómicos , Factores de Edad , Anciano , Anciano de 80 o más Años , Progresión de la Enfermedad , Femenino , Humanos , Estudios Longitudinales , Masculino , Trastornos de la Memoria/psicología , Escala del Estado Mental , Factores de Riesgo , Índice de Severidad de la EnfermedadRESUMEN
The Alzheimer's Disease Anti-inflammatory Prevention Trial was a placebo-controlled three-arm pharmaco-prevention trial of the non-steroidal anti-inflammatory drugs naproxen sodium and celecoxib for prevention of incident Alzheimer's disease (AD) dementia in older (aged 70 and over) adults. Although subjects were at increased risk of symptoms because of a firstdegree family history, they were meant to be cognitively healthy at enrollment. ADAPT encountered several problems that resulted in the termination of its treatments after only two years on average. Interim results were complex but potentially interesting. In the end, however, the results were null. We describe the complications that prevented ADAPT from achieving conclusive results, and suggest that these could have been avoided if the trial design and execution had been better guided by preliminary data. We believe such data should be available before beginning further ambitious phase III trials of this sort, and we suggest a broad method by which such data can be accumulated with reasonable economy.
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OBJECTIVE: The use of psychotropic medications in Alzheimer's disease (AD) has been associated with both deleterious and potentially beneficial outcomes. We examined the longitudinal association of psychotropic medication use with cognitive, functional, and neuropsychiatric symptom (NPS) trajectories among community-ascertained incident AD cases from the Cache County Dementia Progression Study. METHODS: A total of 230 participants were followed for a mean of 3.7 years. Persistency index (PI) was calculated for all antidepressants, selective serotonin reuptake inhibitors (SSRIs), antipsychotics (atypical and typical), and benzodiazepines as the proportion of observed time of medication exposure. Mixed-effects models were used to examine the association between PI for each medication class and Mini-Mental State Exam (MMSE), Clinical Dementia Rating Sum of Boxes (CDR-Sum), and Neuropsychiatric Inventory - Total (NPI-Total) trajectories, controlling for appropriate demographic and clinical covariates. RESULTS: At baseline, psychotropic medication use was associated with greater severity of dementia and poorer medical status. Higher PI for all medication classes was associated with a more rapid decline in MMSE. For antidepressant, SSRI, benzodiazepine, and typical antipsychotic use, a higher PI was associated with a more rapid increase in CDR-Sum. For SSRIs, antipsychotics, and typical antipsychotics, a higher PI was associated with more rapid increase in NPI-Total. CONCLUSIONS: Psychotropic medication use was associated with more rapid cognitive and functional decline in AD, and not with improved NPS. Clinicians may tend to prescribe psychotropic medications to AD patients at risk of poorer outcomes, but one cannot rule out the possibility of poorer outcomes being caused by psychotropic medications.
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Enfermedad de Alzheimer/tratamiento farmacológico , Antidepresivos/uso terapéutico , Antipsicóticos/uso terapéutico , Benzodiazepinas/uso terapéutico , Cognición/efectos de los fármacos , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/psicología , Trastornos del Conocimiento/tratamiento farmacológico , Trastornos del Conocimiento/psicología , Progresión de la Enfermedad , Femenino , Humanos , Estudios Longitudinales , Masculino , Pruebas Neuropsicológicas , Escalas de Valoración PsiquiátricaRESUMEN
OBJECTIVES: Observational and experimental studies suggest that nonsteroidal anti-inflammatory drugs (NSAIDs) may protect against Alzheimer disease (AD); however, clinical trials and other observational studies, including the Adult Changes in Thought (ACT) study, show no protection or promotion of AD. The objective of this study is to determine the relationship between common dementia-associated pathologies and mid- to late-life NSAID exposure. METHODS: We examined the association of mid- to late-life NSAID use with neuropathologic findings on 257 autopsies from ACT, a population-based study of brain aging and incident dementia. Cumulative standard daily doses (SDD) of nonselective NSAIDs were determined from ≥10 years of computerized pharmacy dispensing data. Analyses were adjusted for selection bias to broaden generalizability of results to 3,026 eligible participants in the ACT cohort. Seven pathologic indices were evaluated: intermediate or frequent score for neuritic plaques, Braak stages V or VI for neurofibrillary tangles, >2 cerebral microinfarcts, the presence of any neocortical Lewy bodies, any macroscopic infarcts, any amyloid angiopathy, and moderate or severe atherosclerosis. RESULTS: Of the neuropathologic indices evaluated, only neuritic plaque score was significantly increased in participants with greater use of nonselective NSAIDs (p = 0.065), specifically in those with high levels of cumulative use: 1,000-2,000 SDD (adjusted relative risk [RR] 2.16, 95% confidence interval [CI] 1.02-4.25, compared to light/nonuse [<60 SDD]) and >2,000 SDD (adjusted RR 2.37, 95% CI 1.24-4.67). CONCLUSIONS: Increased neuritic plaque accumulation may explain the association between heavy use of nonselective NSAIDs and increased risk of dementia among ACT participants.
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Enfermedad de Alzheimer/patología , Antiinflamatorios no Esteroideos/farmacología , Encéfalo/efectos de los fármacos , Ovillos Neurofibrilares/efectos de los fármacos , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/genética , Antiinflamatorios no Esteroideos/uso terapéutico , Apolipoproteínas E/genética , Encéfalo/patología , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Ovillos Neurofibrilares/patología , Características de la Residencia , Estudios RetrospectivosRESUMEN
BACKGROUND: Commonly used organophosphate and organochlorine pesticides inhibit acetylcholinesterase at synapses in the somatic, autonomic, and central nervous systems and may therefore have lasting effects on the nervous system. Few studies have examined the relationship of pesticide exposure and risk of dementia or Alzheimer disease (AD). We sought to examine the association of occupational pesticide exposure and the risk of incident dementia and AD in later life. METHODS: Residents of the agricultural community of Cache County, UT, who were aged 65 years and older as of January 1995, were invited to participate in the study. At baseline, participants completed detailed occupational history questionnaires that included information about exposures to various types of pesticides. Cognitive status was assessed at baseline and after 3, 7, and 10 years. Standardized methods were used for detection and diagnosis of dementia and AD. Cox proportional hazards survival analyses were used to evaluate the risk of incident dementia and AD associated with pesticide exposure. RESULTS: Among 3,084 enrollees without dementia, more men than women reported pesticide exposure (p < 0.0001). Exposed individuals (n = 572) had more years of education (p < 0.01) but did not differ from others in age. Some 500 individuals developed incident dementia, 344 with AD. After adjustment for baseline age, sex, education, APOE epsilon4 status, and baseline Modified Mini-Mental State Examination scores, Cox proportional hazards models showed increased risks among pesticide-exposed individuals for all-cause dementia, with hazard ratio (HR) 1.38 and 95% confidence interval (CI) 1.09-1.76, and for AD (HR 1.42, 95% CI 1.06-1.91). The risk of AD associated with organophosphate exposure (HR 1.53, 95% CI 1.05-2.23) was slightly higher than the risk associated with organochlorines (HR 1.49, 95% CI 0.99-2.24), which was nearly significant. CONCLUSIONS: Pesticide exposure may increase the risk of dementia and Alzheimer disease in late life.
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Enfermedades de los Trabajadores Agrícolas/inducido químicamente , Enfermedad de Alzheimer/inducido químicamente , Encéfalo/efectos de los fármacos , Exposición Profesional/efectos adversos , Plaguicidas/efectos adversos , Anciano , Anciano de 80 o más Años , Enfermedades de los Trabajadores Agrícolas/epidemiología , Enfermedad de Alzheimer/epidemiología , Apolipoproteína E4/genética , Encéfalo/patología , Encéfalo/fisiopatología , Análisis Mutacional de ADN , Femenino , Pruebas Genéticas , Genotipo , Humanos , Incidencia , Masculino , Pruebas Neuropsicológicas , Modelos de Riesgos Proporcionales , Medición de Riesgo , Factores de Riesgo , Distribución por Sexo , Encuestas y Cuestionarios , Tiempo , Utah/epidemiologíaRESUMEN
AIM: Little is known about the concordance rate in twins for dementia with Lewy bodies (DLB). The rate of agreement between clinical and pathological diagnoses for DLB is typically low, necessitating confirmation of the diagnosis neuropathologically. METHODS: Participants were 17 twin pairs enrolled in the Duke Twins Study of Memory in Aging in which at least one member of the pair had an autopsy confirmed diagnosis of DLB, Alzheimer's disease (AD) with Lewy bodies or frontotemporal dementia with Lewy bodies. The characteristics of those with dementia were assessed and rates of concordance for pathological confirmed dementia were examined. RESULTS: Four monozygotic twin pairs had a proband with neuropathologically confirmed pure DLB; all remained discordant for dementia for periods up to 16 years or more. Five of 13 pairs in which the proband had AD plus DLB were concordant for dementia but only one pair was concordant for AD plus DLB, while the co-twins in the other four pairs had other types of dementia. CONCLUSIONS: The present study indicates that even among twins, a diagnosis of DLB in one twin does not predict the same diagnosis in the other twin. Neuropathological discordance in type of dementia among monozygotic pairs hints at environmental or epigenetic factors playing a role in Lewy body pathology.
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Enfermedad por Cuerpos de Lewy/genética , Edad de Inicio , Anciano , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/psicología , Apolipoproteínas E/genética , Encéfalo/patología , Educación , Femenino , Genotipo , Humanos , Enfermedad por Cuerpos de Lewy/patología , Enfermedad por Cuerpos de Lewy/psicología , Masculino , Persona de Mediana Edad , Gemelos Dicigóticos , Gemelos MonocigóticosRESUMEN
BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) may prevent Alzheimer dementia (AD). METHODS: We analyzed the association of prior NSAID exposure with incident dementia and AD in the Adult Changes in Thought population-based cohort aged > or = 65 years (median 74.8) at enrollment. Participants were members of Group Health, which provided computerized pharmacy dispensing records from 1977 onward. We studied 2,736 dementia-free enrollees with extensive prior pharmacy data, following them biennially for up to 12 years to identify dementia and AD. Cox proportional hazards regression assessed association of dementia or AD with NSAID use graded in standard daily doses (SDD) dispensed over 2 years (e.g., heavy use = 500 + SDD), with some analyses also adding consecutive biennial self-reports of NSAID use. RESULTS: Pharmacy records identified 351 participants (12.8%) with history of heavy NSAID use at enrollment. Another 107 became heavy users during follow-up. Some 476 individuals developed incident dementia, 356 with AD (median onset ages 83.5 and 83.8 years). Contrary to the hypothesis that NSAIDs protect against AD, pharmacy-defined heavy NSAID users showed increased incidence of dementia and AD, with adjusted hazard ratios of 1.66 (95% confidence interval, 1.24-2.24) and 1.57 (95% confidence interval, 1.10-2.23). Addition of self-reported exposure data did not alter these results. CONCLUSIONS: These findings differ from those of other studies with younger cohorts. The results observed elsewhere may reflect delayed onset of Alzheimer dementia (AD) in nonsteroidal anti-inflammatory drug (NSAID) users. Conceivably, such delay could result in increased AD incidence in late old age. The relation of NSAID use and AD pathogenesis needs further investigation.
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Envejecimiento/fisiología , Enfermedad de Alzheimer/inducido químicamente , Enfermedad de Alzheimer/epidemiología , Antiinflamatorios no Esteroideos/efectos adversos , Encéfalo/efectos de los fármacos , Distribución por Edad , Factores de Edad , Edad de Inicio , Anciano , Anciano de 80 o más Años , Encéfalo/patología , Encéfalo/fisiopatología , Causalidad , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de Riesgo , TiempoRESUMEN
BACKGROUND: Evidence suggests that cardiovascular medications, including statins and antihypertensive medications, may delay cognitive decline in patients with Alzheimer dementia (AD). We examined the association of cardiovascular medication use and rate of functional decline in a population-based cohort of individuals with incident AD. METHODS: In the Dementia Progression Study of the Cache County Study on Memory, Health, and Aging, 216 individuals with incident AD were identified and followed longitudinally with in-home visits for a mean of 3.0 years and 2.1 follow-up visits. The Clinical Dementia Rating (CDR) was completed at each follow-up. Medication use was inventoried during in-home visits. Generalized least-squares random-effects regression was performed with CDR Sum of Boxes (CDR-Sum) as the outcome and cardiovascular medication use as the major predictors. RESULTS: CDR-Sum increased an average of 1.69 points annually, indicating a steady decline in functioning. After adjustment for demographic variables and the baseline presence of cardiovascular conditions, use of statins (p = 0.03) and beta-blockers (p = 0.04) was associated with a slower annual rate of increase in CDR-Sum (slower rate of functional decline) of 0.75 and 0.68 points respectively, while diuretic use was associated with a faster rate of increase in CDR-Sum (p = 0.01; 0.96 points annually). Use of calcium-channel blockers, angiotensin-converting enzyme inhibitors, digoxin, or nitrates did not affect the rate of functional decline. CONCLUSIONS: In this population-based study of individuals with incident AD, use of statins and beta-blockers was associated with delay of functional decline. Further studies are needed to confirm these results and to determine whether treatment with these medications may help delay AD progression.
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Antagonistas Adrenérgicos beta/uso terapéutico , Enfermedad de Alzheimer/psicología , Enfermedades Cardiovasculares/tratamiento farmacológico , Demencia/psicología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/prevención & control , Estudios de Cohortes , Demencia/prevención & control , Femenino , Evaluación Geriátrica , Humanos , Modelos Lineales , Estudios Longitudinales , Masculino , Análisis Multivariante , Pruebas Neuropsicológicas , Escalas de Valoración Psiquiátrica , Reproducibilidad de los Resultados , Factores de Riesgo , Índice de Severidad de la EnfermedadRESUMEN
INTRODUCTION: Observational studies show reduced incidence of Alzheimer dementia (AD) in users of nonsteroidal anti-inflammatory drugs (NSAIDs). One hypothesis holds that the subset of NSAIDs known as selective A beta(42)-lowering agents (SALAs) is responsible for this apparent reduction in AD risk. METHODS: We pooled individual-level data from six prospective studies to obtain a sufficient sample to examine AD risk in users of SALA vs non-SALA NSAIDs. RESULTS: Of 13,499 initially dementia-free participants (70,863 person-years), 820 developed incident AD. Users of NSAIDs (29.6%) showed reduced risk of AD (adjusted hazard ratio [aHR] 0.77, 95% CI 0.65-0.91). The point estimates were similar for SALAs (aHR 0.87, CI 0.72-1.04) and non-SALAs (aHR 0.75, CI 0.56-1.01). Because 573 NSAID users (14.5%) reported taking both a SALA and non-SALA, we examined their use alone and in combination. Resulting aHRs were 0.82 (CI 0.67-0.99) for SALA only, 0.60 (CI 0.40-0.90) for non-SALA only, and 0.87 (CI 0.57-1.33) for both NSAIDs (Wald test for differences, p = 0.32). The 40.7% of participants who used aspirin also showed reduced risk of AD, even when they used no other NSAIDs (aHR 0.78, CI 0.66-0.92). By contrast, there was no association with use of acetaminophen (aHR 0.93, CI 0.76-1.13). CONCLUSIONS: In this pooled dataset, nonsteroidal anti-inflammatory drug (NSAID) use reduced the risk of Alzheimer dementia (AD). However, there was no apparent advantage in AD risk reduction for the subset of NSAIDs shown to selectively lower A beta(42), suggesting that all conventional NSAIDs including aspirin have a similar protective effect in humans.
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Enfermedad de Alzheimer/prevención & control , Péptidos beta-Amiloides/metabolismo , Antiinflamatorios no Esteroideos/uso terapéutico , Fármacos Neuroprotectores/uso terapéutico , Fragmentos de Péptidos/metabolismo , Acetaminofén/uso terapéutico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Analgésicos no Narcóticos/uso terapéutico , Aspirina/uso terapéutico , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND: Epidemiologic and laboratory studies suggest that nonsteroidal antiinflammatory drugs (NSAIDs) reduce risk of Alzheimer disease (AD). We therefore investigated the association between use of NSAIDs, aspirin, and the non-NSAID analgesic acetaminophen with incidence of dementia and AD. METHODS: Participants in the Cardiovascular Health Cognition Study included 3,229 individuals aged 65 or older, free of dementia at baseline, with information on medication use. We used Cox proportional hazards regression to estimate the association of medication use with incident all-cause dementia, AD, and vascular dementia (VaD). Additional analyses considered the NSAID-AD relationship as a function of age, presence of at least one epsilon 4 allele at APOE, race, and individual NSAIDs' reported ability to reduce production of the amyloid-beta peptide variant A beta(42). RESULTS: Use of NSAIDs was associated with a lower risk of dementia (adjusted hazard ratio or aHR 0.76, 95% CI or CI 0.60-0.96) and, in particular, AD (aHR 0.63, CI 0.45-0.88), but not VaD (aHR 0.92, CI 0.65-1.28). No similar trends were observed with acetaminophen (aHR 0.99, CI 0.79-1.24). Closer examination suggested AD risk reduction with NSAIDs only in participants having an APOE epsilon 4 allele (aHR 0.34, CI 0.18-0.65; aHR for others 0.88, CI 0.59-1.32). There was no advantage in AD risk reduction with NSAIDs reported to selectively reduce A beta(42). CONCLUSIONS: Results were consistent with previous cohort studies showing reduced risk of AD in NSAID users, but this association was found only in those with an APOE epsilon 4 allele, and there was no advantage for A beta(42)-lowering NSAIDs.
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Antiinflamatorios no Esteroideos/uso terapéutico , Apolipoproteínas E/genética , Sistema Cardiovascular/efectos de los fármacos , Demencia , Factores de Riesgo , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/inmunología , Demencia/tratamiento farmacológico , Demencia/epidemiología , Demencia/genética , Femenino , Humanos , Incidencia , Masculino , Modelos de Riesgos Proporcionales , Estudios ProspectivosRESUMEN
BACKGROUND: Reduced brain insulin signaling and low CSF-to-plasma insulin ratios have been observed in patients with Alzheimer disease (AD). Furthermore, intracerebroventricular or IV insulin administration improve memory, alter evoked potentials, and modulate neurotransmitters, possibly by augmenting low brain levels. After intranasal administration, insulin-like peptides follow extracellular pathways to the brain within 15 minutes. OBJECTIVE: We tested the hypothesis that daily intranasal insulin treatment would facilitate cognition in patients with early AD or its prodrome, amnestic mild cognitive impairment (MCI). The proportion of verbal information retained after a delay period was the planned primary outcome measure. Secondary outcome measures included attention, caregiver rating of functional status, and plasma levels of insulin, glucose, beta-amyloid, and cortisol. METHODS: Twenty-five participants were randomly assigned to receive either placebo (n = 12) or 20 IU BID intranasal insulin treatment (n = 13) using an electronic atomizer, and 24 participants completed the study. Participants, caregivers, and all clinical evaluators were blinded to treatment assignment. Cognitive measures and blood were obtained at baseline and after 21 days of treatment. RESULTS: Fasting plasma glucose and insulin were unchanged with treatment. The insulin-treated group retained more verbal information after a delay compared with the placebo-assigned group (p = 0.0374). Insulin-treated subjects also showed improved attention (p = 0.0108) and functional status (p = 0.0410). Insulin treatment raised fasting plasma concentrations of the short form of the beta-amyloid peptide (A beta 40; p = 0.0471) without affecting the longer isoform (A beta 42), resulting in an increased A beta 40/42 ratio (p = 0.0207). CONCLUSIONS: The results of this pilot study support further investigation of the benefits of intranasal insulin for patients with Alzheimer disease, and suggest that intranasal peptide administration may be a novel approach to the treatment of neurodegenerative disorders.
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Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/efectos de los fármacos , Trastornos del Conocimiento/tratamiento farmacológico , Insulina/administración & dosificación , Placa Amiloide/efectos de los fármacos , Administración Intranasal , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/fisiopatología , Enfermedad de Alzheimer/psicología , Péptidos beta-Amiloides/sangre , Atención/efectos de los fármacos , Atención/fisiología , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/fisiopatología , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/fisiopatología , Progresión de la Enfermedad , Humanos , Fármacos Neuroprotectores/administración & dosificación , Pruebas Neuropsicológicas , Fragmentos de Péptidos/sangre , Fragmentos de Péptidos/efectos de los fármacos , Proyectos Piloto , Placa Amiloide/metabolismo , Resultado del Tratamiento , Conducta Verbal/efectos de los fármacos , Conducta Verbal/fisiologíaRESUMEN
The already considerable public health burden of Alzheimer's disease will likely worsen as populations around the world age. As a result, there is considerable motivation to develop effective strategies for preventing the disease. A wide variety of such strategies are under investigation and include pharmaceuticals, nutriceuticals, diet, physical activity and cognitive activity. We review here the most promising candidates and the epidemiologic evidence for their efficacy. Although none of these have yet to be definitively shown to prevent Alzheimer's disease, further research should help to clarify what role they may play in reducing the burden of this disease.
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Enfermedad de Alzheimer/prevención & control , Quimioterapia , Humanos , Inmunoterapia , Resistencia a la Insulina , Servicios Preventivos de Salud/provisión & distribución , Factores de RiesgoRESUMEN
BACKGROUND: While there is considerable epidemiologic evidence that cardiovascular risk factors increase risk of incident Alzheimer disease (AD), few studies have examined their effect on progression after an established AD diagnosis. OBJECTIVE: To examine the effect of vascular factors, and potential age modification, on rate of progression in a longitudinal study of incident dementia. METHODS: A total of 135 individuals with incident AD, identified in a population-based sample of elderly persons in Cache County, UT, were followed with in-home visits for a mean of 3.0 years (range: 0.8 to 9.5) and 2.1 follow-up visits (range: 1 to 5). The Clinical Dementia Rating (CDR) Scale and Mini-Mental State Examination (MMSE) were administered at each visit. Baseline vascular factors were determined by interview and physical examination. Generalized least-squares random-effects regression was performed with CDR Sum of Boxes (CDR-Sum) or MMSE as the outcome, and vascular index or individual vascular factors as independent variables. RESULTS: Atrial fibrillation, systolic hypertension, and angina were associated with more rapid decline on both the CDR-Sum and MMSE, while history of coronary artery bypass graft surgery, diabetes, and antihypertensive medications were associated with a slower rate of decline. There was an age interaction such that systolic hypertension, angina, and myocardial infarction were associated with greater decline with increasing baseline age. CONCLUSION: Atrial fibrillation, hypertension, and angina were associated with a greater rate of decline and may represent modifiable risk factors for secondary prevention in Alzheimer disease. The attenuated decline for diabetes and coronary artery bypass graft surgery may be due to selective survival. Some of these effects appear to vary with age.
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Enfermedad de Alzheimer/epidemiología , Enfermedades Cardiovasculares/epidemiología , Distribución por Edad , Anciano , Anciano de 80 o más Años , Angina de Pecho/epidemiología , Antihipertensivos/uso terapéutico , Fibrilación Atrial/epidemiología , Estudios de Cohortes , Comorbilidad , Puente de Arteria Coronaria/estadística & datos numéricos , Diabetes Mellitus/epidemiología , Evaluación de la Discapacidad , Progresión de la Enfermedad , Femenino , Humanos , Hipertensión/epidemiología , Incidencia , Estudios Longitudinales , Masculino , Infarto del Miocardio/epidemiología , Pruebas Neuropsicológicas , Valor Predictivo de las Pruebas , Tasa de Supervivencia , Utah/epidemiologíaRESUMEN
BACKGROUND: Treatment with 3-hydroxy-3-methylglutaryl-coenzyme-A reductase inhibitors ("statins") has been associated in some epidemiologic studies with reduced risk of Alzheimer disease (AD). However, direct evidence of statin effects on neuropathologic markers of AD is lacking. We investigated whether antecedent statin exposure is associated with neuritic plaque (NP) or neurofibrillary tangle (NFT) burden in a population-based sample of human subjects. METHODS: Brain autopsies were performed on 110 subjects, ages 65 to 79 years, who were cognitively normal at enrollment into the Adult Changes in Thought Study. Neuropathologic findings were compared between statin users with > or =3 prescriptions of > or =15 pills of simvastatin, pravastatin, lovastatin, or atorvastatin vs nonusers, based on pharmacy dispensing records. RESULTS: After controlling for age at death, gender, cognitive function at study entry, brain weight, and presence of cerebral microvascular lesions, the odds ratio (OR) for each unit increase in Braak NFT stage in statin users vs nonusers was 0.44 (95% CI: 0.20 to 0.95). The OR for each unit increase in Consortium to Establish a Registry for Alzheimer's Disease (CERAD) staging of NPs did not deviate significantly from unity (OR 0.69; 95% CI: 0.32 to 1.52). However, the risk for typical AD pathology (Braak stage > or = IV and CERAD rating > or = moderate) was reduced in statin users (OR 0.20; 95% CI: 0.05 to 0.86). CONCLUSIONS: These findings demonstrate an association between antecedent statin use and neurofibrillary tangle burden at autopsy. Additional study is needed to examine whether statin use may be causally related to decreased development of Alzheimer disease-related neuropathologic changes.
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Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/patología , Encéfalo/efectos de los fármacos , Encéfalo/patología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Ovillos Neurofibrilares/efectos de los fármacos , Distribución por Edad , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/prevención & control , Atrofia/tratamiento farmacológico , Atrofia/patología , Atrofia/prevención & control , Encéfalo/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Masculino , Ovillos Neurofibrilares/patología , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Tamaño de los Órganos/efectos de los fármacos , Tamaño de los Órganos/fisiología , Placa Amiloide/efectos de los fármacos , Placa Amiloide/patología , Estudios Retrospectivos , Distribución por Sexo , Resultado del TratamientoRESUMEN
BACKGROUND: Epidemiologic studies have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) may be useful for the prevention of Alzheimer disease (AD). By contrast, clinical trials have not supported NSAID use to delay or treat AD. Few studies have evaluated cognitive trajectories of NSAID users over time. METHODS: Residents of Cache County, UT, aged 65 or older on January 1, 1995, were invited to participate in the study. At baseline, participants provided a detailed inventory of their medications and completed a revised Modified Mini-Mental State Examination (3MS). Participants (n = 3,383) who were cognitively normal at baseline were re-examined after 3 and 8 years. The association between NSAID use and 3MS scores over time was estimated using random effects modeling. RESULTS: Associations depended upon when NSAIDs were started and APOE genotype. In participants who started NSAID use prior to age 65, those with no APOE epsilon4 alleles performed similarly to nonusers (a difference of 0.10 points per year; p = 0.19), while those with one or more epsilon4 allele(s) showed more protection (0.40 points per year; p = 0.0005). Among participants who first used NSAIDs at or after age 65, those with one or more epsilon4 alleles had higher baseline scores (0.95 points; p = 0.03) but did not show subsequent difference in change in score over time (0.06 points per year; p = 0.56). Those without an epsilon4 allele who started NSAID use after age 65 showed greater decline than nonusers (-0.16 points per year; p = 0.02). CONCLUSIONS: Nonsteroidal anti-inflammatory drug use may help to prevent cognitive decline in older adults if started in midlife rather than late life. This effect may be more notable in those who have one or more APOE epsilon4 alleles.
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Antiinflamatorios no Esteroideos/uso terapéutico , Trastornos del Conocimiento/epidemiología , Trastornos del Conocimiento/prevención & control , Anciano , Anciano de 80 o más Años , Trastornos del Conocimiento/psicología , Femenino , Humanos , Estudios Longitudinales , Masculino , Fármacos Neuroprotectores/uso terapéutico , Pruebas Neuropsicológicas , Utah/epidemiologíaRESUMEN
OBJECTIVE: We prospectively examined associations between intakes of antioxidants (vitamins C, vitamin E, and carotene) and cognitive function and decline among elderly men and women of the Cache County Study on Memory and Aging in Utah. PARTICIPANTS AND DESIGN: In 1995, 3831 residents 65 years of age or older completed a baseline survey that included a food frequency questionnaire and cognitive assessment. Cognitive function was assessed using an adapted version of the Modified Mini-Mental State examination (3MS) at baseline and at three subsequent follow-up interviews spanning approximately 7 years. Multivariable-mixed models were used to estimate antioxidant nutrient effects on average 3MS score over time. RESULTS: Increasing quartiles of vitamin C intake alone and combined with vitamin E were associated with higher baseline average 3MS scores (p-trend = 0.013 and 0.02 respectively); this association appeared stronger for food sources compared to supplement or food and supplement sources combined. Study participants with lower levels of intake of vitamin C, vitamin E and carotene had a greater acceleration of the rate of 3MS decline over time compared to those with higher levels of intake. CONCLUSION: High antioxidant intake from food and supplement sources of vitamin C, vitamin E, and carotene may delay cognitive decline in the elderly.
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Antioxidantes/administración & dosificación , Ácido Ascórbico/administración & dosificación , Carotenoides/administración & dosificación , Trastornos del Conocimiento/prevención & control , Cognición/efectos de los fármacos , Vitamina E/administración & dosificación , Anciano , Trastornos del Conocimiento/etiología , Escolaridad , Conducta Alimentaria , Femenino , Humanos , Estudios Longitudinales , Masculino , Estudios Prospectivos , Pruebas Psicológicas , Encuestas y Cuestionarios , UtahRESUMEN
OBJECTIVE: To evaluate the efficacy and safety of naproxen and celecoxib for the primary prevention of Alzheimer disease (AD). METHODS: Randomized, placebo-controlled, double-masked clinical trial conducted at six US dementia research clinics. Volunteers aged 70+ years, with cognitive screening scores above designated cut-offs and a family history of AD, were randomly assigned to celecoxib 200 mg BID, naproxen sodium 220 mg BID, or placebo. Enrollment began in early 2001. The main outcome measure was diagnosis of AD after randomization. RESULTS: On December 17, 2004, treatments were suspended. Events while on treatment yielded hazard ratios vs placebo of 1.99 (95% CI 0.80 to 4.97; p = 0.14) for celecoxib and 2.35 (0.95 to 5.77; p = 0.06) for naproxen. Imperfect screening measures led to enrollment of 7 individuals with dementia and 46 others with milder cognitive syndromes. Their (prevalent) illness was detected at enrollment and diagnosed within 6 months following randomization. Secondary analyses that excluded the 7 cases of prevalent dementia showed increased hazard ratios for AD with both treatments. Neither treatment produced a notable effect on the incidence of milder cognitive syndromes. CONCLUSIONS: These results do not support the hypothesis that celecoxib or naproxen prevent Alzheimer dementia, at least within the early years after initiation of treatment. Masked long-term follow-up of these participants will be essential.