Dataset Information

Non-linear relationships of cerebrospinal fluid biomarker levels with cognitive function: an observational study.

ABSTRACT:

Introduction

Levels of cerebrospinal fluid (CSF) ?-amyloid (A?) and Tau proteins change in Alzheimer's disease (AD). We tested if the relationships of these biomarkers with cognitive impairment are linear or non-linear.

Methods

We assessed cognitive function and assayed CSF A? and Tau biomarkers in 95 non-demented volunteers and 97 AD patients. We then tested non-linearities in their inter-relations.

Results

CSF biomarkers related to cognitive function in the non-demented range of cognition, but these relations were weak or absent in the patient range; A?1-40's relationship was biphasic.

Conclusions

Major biomarker changes precede clinical AD and index cognitive impairment in AD poorly, if at all.

SUBMITTER: Williams JH

PROVIDER: S-EPMC3109414 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature

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Publications

Non-linear relationships of cerebrospinal fluid biomarker levels with cognitive function: an observational study.

Williams Jonathan H JH Wilcock Gordon K GK Seeburger Jeffrey J Dallob Aimee A Laterza Omar O Potter William W Smith A David AD

Alzheimer's research & therapy 20110217 1

<h4>Introduction</h4>Levels of cerebrospinal fluid (CSF) β-amyloid (Aβ) and Tau proteins change in Alzheimer's disease (AD). We tested if the relationships of these biomarkers with cognitive impairment are linear or non-linear.<h4>Methods</h4>We assessed cognitive function and assayed CSF Aβ and Tau biomarkers in 95 non-demented volunteers and 97 AD patients. We then tested non-linearities in their inter-relations.<h4>Results</h4>CSF biomarkers related to cognitive function in the non-demented r ...[more]

PMID: 21329517

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Project description:Age-related cognitive decline among older individuals with normal cognition is a complex trait that potentially derives from processes of aging, inherited vulnerabilities, environmental factors, and common latent diseases that can progress to cause dementia, such as Alzheimer disease and vascular brain injury.To use cerebrospinal fluid (CSF) biomarkers to gain insight into this complex trait.Secondary analyses of an academic multicenter cross-sectional (n?=?315) and longitudinal (n?=?158) study of 5 neuropsychological tests (Immediate Recall, Delayed Recall, Trail Making Test Parts A and B, and Category Fluency) in cognitively normal individuals aged 21 to 100 years.To investigate the association of these cognitive function test results with age, sex, educational level, inheritance of the ?4 allele of the apolipoprotein E gene, and CSF concentrations of ?-amyloid 42 (A?42) and tau (biomarkers of Alzheimer disease) as well as F2-isoprostanes (measures of free radical injury).Age and educational level were broadly predictive of cross-sectional cognitive performance; of the genetic and CSF measures, only greater CSF F2-isoprostane concentration was significantly associated with poorer executive function (adjusted R2 ?0.31). Longitudinal measures of cognitive abilities, except Category Fluency, also were associated broadly with age; of the genetic and CSF measures, only lower baseline CSF A?42 concentration was associated with longitudinal measures of immediate and delayed recall (marginal R2 ?0.31).Our results suggest that age and educational level accounted for a substantial minority of variance in cross-sectional or longitudinal cognitive test performance in this large group of cognitively normal adults. Latent Alzheimer disease and other diseases that produce free radical injury, such as vascular brain injury, accounted for a small amount of variation in cognitive test performance across the adult human life span. Additional genetic and environmental factors likely contribute substantially to age-related cognitive decline.

Project description:BACKGROUND:Alzheimer's disease (AD) biomarkers are emerging as critically important for disease detection and monitoring. Most biomarkers are obtained through invasive, resource-intense procedures. A cognitive marker, intra-individual cognitive variability (IICV) may provide an alternative or adjunct marker of disease risk for individuals unable or disinclined to undergo lumbar puncture. OBJECTIVE:To contrast risk of incident AD and mild cognitive impairment (MCI) associated with IICV to risk associated with well-established biomarkers: cerebrospinal fluid (CSF) phosphorylated tau protein (p-tau181) and amyloid-? 42 (A?42) peptide. METHODS:Dispersion in cognitive performance, IICV, was estimated with a published algorithm, and included Trail Making Test A and B, Rey Auditory Verbal Learning Test (RAVLT), and the American National Adult Reading Test (ANART). CSF biomarkers were expressed as a ratio: p-tau181/A?42, wherein high values signified pathognomonic profiles. Logistic regression models included longitudinal data from 349 Alzheimer's Disease Neuroimaging Initiative (ADNI) participants who completed lumbar puncture. All subjects were cognitively healthy (n?=?105) or diagnosed with MCI (n?=?244) at baseline. We examined odds of conversion associated with baseline elevations in IICV and/or ratio of CSF p-tau181/A?42. RESULTS:When included in models alone or in combination with CSF p-tau181/A?42, one standard IICV unit higher was associated with an estimated odds ratio for incident AD or MCI of 2.81 (95% CI: 1.83-4.33) in the most inclusive sample, and an odds ratio of 3.41 (95% CI: 2.03-5.73) when restricted to participants with MCI. Iterative analyses suggested that IICV independently improved model fit even when individual index components were included in comparative models. CONCLUSIONS:These analyses provide preliminary support for IICV as a marker of incident AD and MCI. This easily-disseminated, non-invasive marker compared favorably to well-established CSF biomarkers.

Project description:Alzheimer's disease (AD) is a progressive neurodegenerative disorder with clinical, biological, and pathological features occurring along a continuum from normal to end-stage disease. Currently, the diagnosis of AD depends on clinical assessments and post-mortem neuropathology, which is unbenefited early diagnosis and progressive monitoring. In recent years, clinical studies have reported that the level of cerebrospinal fluid (CSF) and blood neurogranin (Ng) are closely related to the occurrence and subsequent progression of AD. Therefore, the study used meta-analysis to identify the CSF and blood Ng levels for the development of diagnosis biomarker of patients with AD and mild cognitive impairment (MCI). We searched the Pubmed, Embase, Cochrane Library, and Web of Science databases. A total of 24 articles eligible for inclusion and exclusion criteria were assessed, including 4661 individuals, consisting of 1518 AD patients, 1501 MCI patients, and 1642 healthy control subjects. The level of CSF Ng significantly increased in patients with AD and MCI compared with healthy control subjects (SMD: 0.84 [95% CI: 0.70-0.98], P?<?0.001; SMD: 0.53 [95% CI: 0.40-0.66], P?=?0.008), and higher in AD patients than in MCI patients (SMD: 0.18 [95% CI: 0.07-0.30], P?=?0.002), and CSF Ng level of patients with MCI-AD who progressed from MCI to AD was significantly higher than that of patients with stable MCI (sMCI) (SMD: 0.71 [95% CI: 0.25-1.16], P?=?0.002). Moreover, the concentration of Ng in blood plasma exosomes of patients with AD and MCI was lower than that of healthy control subjects (SMD: -6.657 [95% CI: -10.558 to -2.755], P?=?0.001; and SMD: -3.64 [95% CI: -6.50 to -0.78], P?=?0.013), and which in patients with AD and MCI-AD were also lower than those in patients with sMCI (P?<?0.001). Furthermore, regression analysis showed a negative relationship between MMSE scores and CSF Ng levels in MCI patients (slope?=?-0.249 [95% CI: -0.003 to -0.495], P?=?0.047). Therefore, the Ng levels increased in CSF, but decreased in blood plasma exosomes of patients with AD and MCI-AD, and highly associated with cognitive declines. These findings provide the clinical evidence that CSF and blood exosomes Ng can be used as a cognitive biomarker for AD and MCI-AD, and further studies are needed to define the specific range of Ng values for diagnosis at the different stages of AD.

Project description:IntroductionAlzheimer's disease (AD) is characterized by the deposition of tau and amyloid in the brain. Although the core cerebrospinal fluid (CSF) AD biomarkers amyloid β peptide 1-42 (Aβ1-42), total tau (t-tau) and phosphorylated tau 181 (p-tau181) show good diagnostic sensitivity and specificity, additional biomarkers that can aid in preclinical diagnosis or better track disease progression are needed. Activation of the complement system, a pivotal part of inflammation, occurs at very early stages in the AD brain. Therefore, CSF levels of complement proteins that could be linked to cognitive and structural changes in AD may have diagnostic and prognostic value.MethodsUsing xMAP® technology based assays we measured complement 3 (C3) and factor H (FH) in the CSF of 110 controls (CN), 187 mild cognitive impairment (MCI) and 92 AD subjects of the AD Neuroimaging Initiative (ADNI) at baseline. All ADNI participants underwent clinical follow-up at 12 month intervals and MCI subjects had additional visits at 6 and 18 months. The association between CSF biomarkers and different outcome measures were analyzed using Cox proportional hazard models (conversion from MCI to AD), logistic regression models (classification of clinical groups) and mixed-effects models adjusted for age, gender, education, t-tau/Aβ1-42 and APOE ϵ4 presence (baseline and longitudinal association between biomarkers and cognitive scores).ResultsAlthough no association was found between the complement proteins and clinical diagnosis or cognitive measures, lower levels of C3 (β = -0.12, p = 0.041) and FH (β = -0.075, p = 0.041) were associated with faster cognitive decline in MCI subjects as measured by the AD Assessment Scale-cognitive subscale (ADAS-Cog) test. Furthermore, lower FH levels were associated with larger lateral ventricular volume (p = 0.024), which is indicative of brain atrophy.ConclusionsOur study confirms a lack of suitability of CSF C3 and FH as diagnostic biomarkers of AD, but points to their modest potential as prognostic biomarkers and therapeutic targets in cognitively impaired patients.

Dataset Information

Non-linear relationships of cerebrospinal fluid biomarker levels with cognitive function: an observational study.

Introduction

Methods

Results

Conclusions

Publications

Non-linear relationships of cerebrospinal fluid biomarker levels with cognitive function: an observational study.

Similar Datasets

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