scholarly journals Long-Term Blood Pressure Variability Across the Clinical and Biomarker Spectrum of Alzheimer’s Disease

2020 ◽  
Vol 77 (4) ◽  
pp. 1655-1669
Author(s):  
Isabel J. Sible ◽  
Daniel A. Nation ◽  
Keyword(s):  
Alzheimer’S Disease ◽  
Blood Pressure ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Systolic Blood Pressure ◽  
Blood Pressure Variability ◽  
Cognitively Normal ◽  
Systolic Blood Pressure Variability

Background: Elevated blood pressure is linked to cognitive impairment and Alzheimer’s disease (AD) biomarker abnormality. However, blood pressure levels vary over time. Less is known about the role of long-term blood pressure variability in cognitive impairment and AD pathophysiology. Objective: Determine whether long-term blood pressure variability is elevated across the clinical and biomarker spectrum of AD. Methods: Alzheimer’s Disease Neuroimaging Initiative participants (cognitively normal, mild cognitive impairment, AD [n = 1,421]) underwent baseline exam, including blood pressure measurement at 0, 6, and 12 months. A subset (n = 318) underwent baseline lumbar puncture to determine cerebrospinal fluid amyloid-β and phosphorylated tau levels. Clinical groups and biomarker-confirmed AD groups were compared on blood pressure variability over 12 months. Results: Systolic blood pressure variability was elevated in clinically diagnosed AD dementia (VIM: F2,1195 = 6.657, p = 0.001, η2 = 0.01) compared to cognitively normal participants (p = 0.001), and in mild cognitive impairment relative to cognitively normal participants (p = 0.01). Findings were maintained in biomarker-confirmed AD (VIM: F2,850 = 5.216, p = 0.006, η2 = 0.01), such that systolic blood pressure variability was elevated in biomarker-confirmed dementia due to AD relative to cognitively normal participants (p = 0.005) and in biomarker-confirmed mild cognitive impairment due to AD compared to cognitively normal participants (p = 0.04). Conclusion: Long-term systolic blood pressure variability is elevated in cognitive impairment due to AD. Blood pressure variability may represent an understudied aspect of vascular dysfunction in AD with potential clinical implications.

Long-Term Exposure to PM10 and in vivo Alzheimer’s Disease Pathologies

2021 ◽  
Author(s):  
Jun Ho Lee ◽  
Min Soo Byun ◽  
Dahyun Yi ◽  
Kang Ko ◽  
So Yeon Jeon ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Amyloid Β ◽  
Aerodynamic Diameter ◽  
Cognitively Normal ◽  
Study Population

Background: Previous studies indicated an association between Alzheimer’s disease (AD) dementia and air particulate matter (PM) with aerodynamic diameter <10 μm (PM10), as well as smaller PM. Limited information, however, is available for the neuropathological links underlying such association. Objective: This study aimed to investigate the relationship between long-term PM10 exposure and in vivo pathologies of AD using multimodal neuroimaging. Methods: The study population consisted of 309 older adults without dementia (191 cognitively normal and 118 mild cognitive impairment individuals), who lived in Republic of Korea. Participants underwent comprehensive clinical assessments, 11C-Pittsburg compound B (PiB) positron emission tomography (PET), and magnetic resonance imaging scans. A subset of 78 participants also underwent 18F-AV-1451 tau PET evaluation. The mean concentration of PM with aerodynamic diameter <10 μm over the past 5 years (PM10mean) collected from air pollution surveillance stations were matched to each participant’s residence. Results: In this non-demented study population, of which 62% were cognitively normal and 38% were in mild cognitive impairment state, exposure to the highest tertile of PM10mean was associated with increased risk of amyloid-β (Aβ) positivity (odds ratio 2.19, 95% confidence interval 1.13 to 4.26) even after controlling all potential confounders. In contrast, there was no significant associations between PM10mean exposure and tau accumulation. AD signature cortical thickness and white matter hyperintensity volume were also not associated with PM10mean exposure. Conclusion: The findings suggest that long-term exposure to PM10 may contribute to pathological Aβ deposition.

Long-Term Exposure to PM10 and in vivo Alzheimer’s Disease Pathologies

2020 ◽  
Vol 78 (2) ◽  
pp. 745-756
Author(s):  
Jun Ho Lee ◽  
Min Soo Byun ◽  
Dahyun Yi ◽  
Kang Ko ◽  
So Yeon Jeon ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Aerodynamic Diameter ◽  
Cognitively Normal ◽  
Increased Risk ◽  
Study Population

Background: Previous studies indicated an association between Alzheimer’s disease (AD) dementia and air particulate matter (PM) with aerodynamic diameter <10μm (PM10), as well as smaller PM. Limited information, however, is available for the neuropathological links underlying such association. Objective: This study aimed to investigate the relationship between long-term PM10 exposure and in vivo pathologies of AD using multimodal neuroimaging. Methods: The study population consisted of 309 older adults without dementia (191 cognitively normal and 118 mild cognitive impairment individuals), who lived in Republic of Korea. Participants underwent comprehensive clinical assessments, 11C-Pittsburg compound B (PiB) positron emission tomography (PET), and magnetic resonance imaging scans. A subset of 78 participants also underwent 18F-AV-1451 tau PET evaluation. The mean concentration of PM with aerodynamic diameter <10μm over the past 5 years (PM10mean) collected from air pollution surveillance stations were matched to each participant’s residence. Results: In this non-demented study population, of which 62% were cognitively normal and 38% were in mild cognitive impairment state, exposure to the highest tertile of PM10mean was associated with increased risk of amyloid-β (Aβ) positivity (odds ratio 2.19, 95% confidence interval 1.13 to 4.26) even after controlling all potential confounders. In contrast, there was no significant associations between PM10mean exposure and tau accumulation. AD signature cortical thickness and white matter hyperintensity volume were also not associated with PM10mean exposure. Conclusion: The findings suggest that long-term exposure to PM10 may contribute to pathological Aβ deposition.

Long term habitual vigorous physical activity is associated with lower visit-to-visit systolic blood pressure variability

2020 ◽  
Author(s):  
Xiaoyong Xu ◽  
Xianghong Meng ◽  
Shin-ichi Oka
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Standard Deviation ◽  
Systolic Blood Pressure ◽  
Blood Pressure Variability ◽  
Vigorous Physical Activity ◽  
Systolic Blood Pressure Variability ◽  
Average Real Variability ◽  
Post Hoc

Abstract Objective Our work aimed to investigate the association between vigorous physical activity and visit-to-visit systolic blood pressure variability (BPV). Methods We conducted a post hoc analysis of SPRINT (Systolic Blood Pressure Intervention Trial), a well-characterized cohort of participants randomized to intensive (&lt;120 mmHg) or standard (&lt;140 mmHg) SBP targets. We assessed whether patients with hypertension who habitually engage in vigorous physical activity would have lower visit-to-visit systolic BPV compared with those who do not engage in vigorous physical activity. Visit-to-visit systolic BPV was calculated by standard deviation (SD), average real variability (ARV), and standard deviation independent of the mean (SDIM) using measurements taken during the 1-, 2-, 3-, 6-, 9- and 12-month study visits. A medical history questionnaire assessed vigorous physical activity, which was divided into three categories according to the frequency of vigorous physical activity. Results A total of 7571 participants were eligible for analysis (34.8% female, mean age 67.9±9.3 years). During a follow-up of 1-year, vigorous physical activity could significantly reduce SD, ARV, and SDIM across increasing frequency of vigorous physical activity. There were negative linear trends between frequency of vigorous physical activity and visit-to-visit systolic BPV. Conclusions Long-term engagement in vigorous physical activity was associated with lower visit-to-visit systolic BPV.

scholarly journals Financial Capacity and Regional Cerebral Tau in Cognitively Normal Older Adults, Mild Cognitive Impairment, and Alzheimer’s Disease Dementia

2020 ◽  
pp. 1-10
Author(s):  
Christopher Gonzalez ◽  
Nicole S. Tommasi ◽  
Danielle Briggs ◽  
Michael J. Properzi ◽  
Rebecca E. Amariglio ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Early Stage ◽  
Cognitively Normal ◽  
Financial Capacity ◽  
Posterior Cingulate ◽  
Dorsolateral Prefrontal

Background: Financial capacity is often one of the first instrumental activities of daily living to be affected in cognitively normal (CN) older adults who later progress to amnestic mild cognitive impairment (MCI) and Alzheimer’s disease (AD) dementia. Objective: The objective of this study was to investigate the association between financial capacity and regional cerebral tau. Methods: Cross-sectional financial capacity was assessed using the Financial Capacity Instrument –Short Form (FCI-SF) in 410 CN, 199 MCI, and 61 AD dementia participants who underwent flortaucipir tau positron emission tomography from the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Linear regression models with backward elimination were used with FCI-SF total score as the dependent variable and regional tau and tau-amyloid interaction as predictors of interest in separate analyses. Education, age sex, Rey Auditory Verbal Learning Test Total Learning, and Trail Making Test B were used as covariates. Results: Significant associations were found between FCI-SF and tau regions (entorhinal: p <  0.001; inferior temporal: p <  0.001; dorsolateral prefrontal: p = 0.01; posterior cingulate: p = 0.03; precuneus: p <  0.001; and supramarginal gyrus: p = 0.005) across all participants. For the tau-amyloid interaction, significant associations were found in four regions (amyloid and dorsolateral prefrontal tau interaction: p = 0.005; amyloid and posterior cingulate tau interaction: p = 0.005; amyloid and precuneus tau interaction: p <  0.001; and amyloid and supramarginal tau interaction: p = 0.002). Conclusion: Greater regional tau burden was modestly associated with financial capacity impairment in early-stage AD. Extending this work with longitudinal analyses will further illustrate the utility of such assessments in detecting clinically meaningful decline, which may aid clinical trials of early-stage AD.

scholarly journals 12-year prediction of mild cognitive impairment aided by Alzheimer’s brain signatures at mean age 56

2021 ◽  
Author(s):  
McKenna E Williams ◽  
Jeremy A Elman ◽  
Linda K McEvoy ◽  
Ole A Andreassen ◽  
Anders M Dale ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Mean Diffusivity ◽  
Area Under The Curve ◽  
Polygenic Risk Score ◽  
Age Difference ◽  
Cognitively Normal ◽  
Brain Age

Abstract Neuroimaging signatures based on composite scores of cortical thickness and hippocampal volume predict progression from mild cognitive impairment to Alzheimer’s disease. However, little is known about the ability of these signatures among cognitively normal adults to predict progression to mild cognitive impairment. Toward that end, a signature sensitive to microstructural changes that may predate macrostructural atrophy should be useful. We hypothesized that: 1) a validated MRI-derived Alzheimer’s disease signature based on cortical thickness and hippocampal volume in cognitively normal middle-aged adults would predict progression to mild cognitive impairment; and 2) a novel gray matter mean diffusivity signature would be a better predictor than the thickness/volume signature. This cohort study was part of the Vietnam Era Twin Study of Aging. Concurrent analyses compared cognitively normal and mild cognitive impairment groups at each of three study waves (ns = 246–367). Predictive analyses included 169 cognitively normal men at baseline (age = 56.1, range = 51–60). Our previously published thickness/volume signature derived from independent data, a novel mean diffusivity signature using the same regions and weights as the thickness/volume signature, age, and an Alzheimer’s disease polygenic risk score were used to predict incident mild cognitive impairment an average of 12 years after baseline (follow-up age = 67.2, range = 61–71). Additional analyses adjusted for predicted brain age difference scores (chronological age minus predicted brain age) to determine if signatures were Alzheimer-related and not simply aging-related. In concurrent analyses, individuals with mild cognitive impairment had higher (worse) mean diffusivity signature scores than cognitively normal participants, but thickness/volume signature scores did not differ between groups. In predictive analyses, age and polygenic risk score yielded an area under the curve of 0.74 (sensitivity = 80.00%; specificity = 65.10%). Prediction was significantly improved with addition of the mean diffusivity signature (area under the curve = 0.83; sensitivity = 85.00%; specificity = 77.85%; P=0.007), but not with addition of the thickness/volume signature. A model including both signatures did not improve prediction over a model with only the mean diffusivity signature. Results held up after adjusting for predicted brain age difference scores. The novel mean diffusivity signature was limited by being yoked to the thickness/volume signature weightings. An independently-derived mean diffusivity signature may thus provide even stronger prediction. The young age of the sample at baseline is particularly notable. Given that the brain signatures were examined when participants were only in their 50 s, our results suggest a promising step toward improving very early identification of Alzheimer’s disease risk and the potential value of mean diffusivity and/or multimodal brain signatures.

scholarly journals Visual Object Discrimination Impairment as an Early Predictor of Mild Cognitive Impairment and Alzheimer’s Disease

2019 ◽  
Vol 25 (7) ◽  
pp. 688-698 ◽  
Author(s):  
Leslie S. Gaynor ◽  
Rosie E. Curiel Cid ◽  
Ailyn Penate ◽  
Mónica Rosselli ◽  
Sara N. Burke ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Discrimination Task ◽  
Inverse Function ◽  
Visual Object ◽  
Object Discrimination ◽  
Cognitively Normal ◽  
Novel Object

AbstractObjective:Detection of cognitive impairment suggestive of risk for Alzheimer’s disease (AD) progression is crucial to the prevention of incipient dementia. This study was performed to determine if performance on a novel object discrimination task improved identification of earlier deficits in older adults at risk for AD.Method:In total, 135 participants from the 1Florida Alzheimer’s Disease Research Center [cognitively normal (CN), Pre-mild cognitive impairment (PreMCI), amnestic mild cognitive impairment (aMCI), and dementia] completed a test of object discrimination and traditional memory measures in the context of a larger neuropsychological and clinical evaluation.Results:The Object Recognition and Discrimination Task (ORDT) revealed significant differences between the PreMCI, aMCI, and dementia groups versus CN individuals. Moreover, relative risk of being classified as PreMCI rather than CN increased as an inverse function of ORDT score.Discussion:Overall, the obtained results suggest that a novel object discrimination task improves the detection of very early AD-related cognitive impairment, increasing the window for therapeutic intervention. (JINS, 2019,25, 688–698)

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