Blood pressure, cardiac biomarkers and cognitive function in old age

With the increase in life expectancy, the prevalence of cognitive disorders is expected to rise the coming years. In this thesis we studied the association between blood pressure, cardiac biomarkers and cognitive function in 5800 people with mean age of 75 years. Furthermore, we investigated the feasibility to use smartphone technology to measure home blood pressure in 151 people during a 6 months follow-up period. We show that higher variability in blood pressure is associated with increased microdamage of the brain and worse cognitive function, independent of average blood pressure and use of blood pressure lowering medication. Furthermore, increased levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT), both markers of cardiac disease, are associated with worse cognitive function and steeper cognitive decline, independent of cardiovascular diseases or risks. Finally, we show that smartphone-based technology is a reliable and promising method with good adherence to measure blood pressure at home. This provides a possibility for implementation in large-scale studies and can potentially contribute to blood pressure reduction, eventually helping to prevent cognitive impairment.Alzheimer-Nederland Netherlands Consortium for Healthy AgeingLUMC / Geneeskund

SUBCLINICAL THYROID DISORDERS AND COGNITIVE DECLINE IN OLD AGE: RESULTS FROM THE PROSPER STUDY

Pathophysiology, epidemiology and therapy of agein

Association of visit-to-visit variability in blood pressure with cognitive function in old age: prospective cohort study

<p>Objective To investigate the association between visit-to-visit variability in blood pressure and cognitive function in old age (>70 years).</p> <p>Design Prospective cohort study.</p> <p>etting PROSPER (PROspective Study of Pravastatin in the Elderly at Risk) study, a collaboration between centres in Ireland, Scotland, and the Netherlands.</p> <p>Participants 5461 participants, mean age 75.3 years, who were at risk of cardiovascular disease. Blood pressure was measured every three months during an average of 3.2 years. Visit-to-visit variability in blood pressure was defined as the standard deviation of blood pressure measurements between visits.</p> <p>Main outcome measures Four domains of cognitive function, testing selective attention, processing speed, and immediate and delayed memory. In a magnetic resonance imaging substudy of 553 participants, structural brain volumes, cerebral microbleeds, infarcts, and white matter hyperintensities were measured.</p> <p>Results Participants with higher visit-to-visit variability in systolic blood pressure had worse performance on all cognitive tests: attention (mean difference high versus low thirds) 3.08 seconds (95% confidence interval 0.85 to 5.31), processing speed −1.16 digits coded (95% confidence interval −1.69 to −0.63), immediate memory −0.27 pictures remembered (95% confidence interval −0.41 to −0.13), and delayed memory −0.30 pictures remembered (95% confidence interval −0.49 to −0.11). Furthermore, higher variability in both systolic and diastolic blood pressure was associated with lower hippocampal volume and cortical infarcts, and higher variability in diastolic blood pressure was associated with cerebral microbleeds (all P<0.05). All associations were adjusted for average blood pressure and cardiovascular risk factors.</p> Conclusion Higher visit-to-visit variability in blood pressure independent of average blood pressure was associated with impaired cognitive function in old age

NT-proBNP, blood pressure, and cognitive decline in the oldest old The Leiden 85-plus Study

Neuro Imaging Researc

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Blood pressure, cardiac biomarkers and cognitive function in old age

With the increase in life expectancy, the prevalence of cognitive disorders is expected to rise the coming years. In this thesis we studied the association between blood pressure, cardiac biomarkers and cognitive function in 5800 people with mean age of 75 years. Furthermore, we investigated the feasibility to use smartphone technology to measure home blood pressure in 151 people during a 6 months follow-up period. We show that higher variability in blood pressure is associated with increased microdamage of the brain and worse cognitive function, independent of average blood pressure and use of blood pressure lowering medication. Furthermore, increased levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT), both markers of cardiac disease, are associated with worse cognitive function and steeper cognitive decline, independent of cardiovascular diseases or risks. Finally, we show that smartphone-based technology is a reliable and promising method with good adherence to measure blood pressure at home. This provides a possibility for implementation in large-scale studies and can potentially contribute to blood pressure reduction, eventually helping to prevent cognitive impairment.</p

Cognitive Testing in People at Increased Risk of Dementia Using a Smartphone App: The iVitality Proof-of-Principle Study

Contains fulltext : 175959.pdf (publisher's version ) (Open Access)BACKGROUND: Smartphone-assisted technologies potentially provide the opportunity for large-scale, long-term, repeated monitoring of cognitive functioning at home. OBJECTIVE: The aim of this proof-of-principle study was to evaluate the feasibility and validity of performing cognitive tests in people at increased risk of dementia using smartphone-based technology during a 6 months follow-up period. METHODS: We used the smartphone-based app iVitality to evaluate five cognitive tests based on conventional neuropsychological tests (Memory-Word, Trail Making, Stroop, Reaction Time, and Letter-N-Back) in healthy adults. Feasibility was tested by studying adherence of all participants to perform smartphone-based cognitive tests. Validity was studied by assessing the correlation between conventional neuropsychological tests and smartphone-based cognitive tests and by studying the effect of repeated testing. RESULTS: We included 151 participants (mean age in years=57.3, standard deviation=5.3). Mean adherence to assigned smartphone tests during 6 months was 60% (SD 24.7). There was moderate correlation between the firstly made smartphone-based test and the conventional test for the Stroop test and the Trail Making test with Spearman rho=.3-.5 (P<.001). Correlation increased for both tests when comparing the conventional test with the mean score of all attempts a participant had made, with the highest correlation for Stroop panel 3 (rho=.62, P<.001). Performance on the Stroop and the Trail Making tests improved over time suggesting a learning effect, but the scores on the Letter-N-back, the Memory-Word, and the Reaction Time tests remained stable. CONCLUSIONS: Repeated smartphone-assisted cognitive testing is feasible with reasonable adherence and moderate relative validity for the Stroop and the Trail Making tests compared with conventional neuropsychological tests. Smartphone-based cognitive testing seems promising for large-scale data-collection in population studies

Evaluation of the Use of Home Blood Pressure Measurement Using Mobile Phone-Assisted Technology: The iVitality Proof-of-Principle Study

Pathophysiology, epidemiology and therapy of agein

User preferences and usability of iVitality: optimizing an innovative online research platform for home-based health monitoring

Background: The iVitality online research platform has been developed to gain insight into the relationship between early risk factors (ie, poorly controlled hypertension, physical or mental inactivity) and onset and possibly prevention of dementia. iVitality consists of a website, a smartphone application, and sensors that can monitor these indicators at home. Before iVitality can be implemented, it should fit the needs and preferences of users, ie, offspring of patients with dementia. This study aimed to explore users’ motivation to participate in home-based health monitoring research, to formulate requirements based on users’ preferences to optimize iVitality, and to test usability of the smartphone application of iVitality. Methods: We recruited 13 participants (aged 42–64 years, 85% female), who were offspring of patients with dementia. A user-centered methodology consisting of four iterative phases was used. Three semistructured interviews provided insight into motivation and acceptance of using iVitality (phase 1). A focus group with six participants elaborated on expectations and preferences regarding iVitality (phase 2). Findings from phase 1 and 2 were triangulated by two semistructured interviews (phase 3). Four participants assessed the usability of the smartphone application (phase 4) using a think aloud procedure and a questionnaire measuring ease and efficiency of use (scale 1–7; higher scores indicated better usability). Results: All participants were highly motivated to contribute to dementia research. However, the frequency of home-based health monitoring should not be too high. Participants preferred to receive feedback about their measurements and information regarding the relationship between these measurements and dementia. Despite minor technical errors, iVitality was considered easy and efficient to use (mean score 5.50, standard deviation 1.71). Conclusion: Offspring of patients with dementia are motivated to contribute to home-based monitoring research by using iVitality and are able to use the smartphone application. The formulated requirements will be embedded to optimize iVitality

NT-proBNP, blood pressure, and cognitive decline in the oldest old The Leiden 85-plus Study

Neuro Imaging Researc