| 1. |
- Larsson, Susanna C., et al.
(författare)
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Does Treating Vascular Risk Factors Prevent Dementia and Alzheimer's Disease? A Systematic Review and Meta-Analysis.
- 2018
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Ingår i: Journal of Alzheimer's Disease. - Stockholm : Karolinska Institutet, Institute of Environmental Medicine. - 1387-2877 .- 1875-8908. ; 64:2, s. 657-668
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Epidemiological evidence has associated Alzheimer's disease (AD) with vascular risk factors (VRFs), but whether treatment of VRFs reduces the incidence of dementia and AD is uncertain.OBJECTIVE: To conduct a systematic review and meta-analysis to summarize available data on the impact of treatment of VRFs on dementia and AD incidence.METHODS: Pertinent studies published until 1 January 2018 were identified from PubMed. Both randomized controlled trials (RCT) and prospective studies that investigated the impact of treatment of VRFs on dementia or AD incidence were included.RESULTS: Eight RCTs and 52 prospective studies were identified. Antihypertensive treatment was associated with a non-significant reduced risk of dementia in RCTs (n = 5; relative risk [RR], 0.84; 95% confidence interval [CI], 0.69-1.02) and prospective studies (n = 3; RR, 0.77; 95% CI, 0.58-1.01) and with reduced AD risk in prospective studies (n = 5; RR = 0.78; 95% CI, 0.66-0.91). In prospective studies, treatment of hyperlipidemia with statins, but not nonstatin lipid-lowering agents, was associated with reduced risk of dementia (n = 17; RR, 0.77; 95% CI, 0.63-0.95) and AD (n = 13; RR, 0.86; 95% CI, 0.80-0.92). The single RCT on statins and dementia incidence showed no association. Data from one RCT and six prospective studies did not support a beneficial impact of antidiabetic drugs or insulin therapy on dementia risk.CONCLUSION: Current evidence indicates that antihypertensives and statins might reduce the incidence of dementia and AD. Further trials to determine the effect of VRF on AD are needed.
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| 2. |
- Tan, Edwin C. K., et al.
(författare)
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Anticholinergic Burden and Risk of Stroke and Death in People with Different Types of Dementia
- 2018
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Ingår i: Journal of Alzheimer's Disease. - Stockholm : Karolinska Institutet, Dept of Neurobiology, Care Sciences and Society. - 1387-2877 .- 1875-8908. ; 65:2, s. 589-596
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Tidskriftsartikel (refereegranskat)abstract
- Background: Anticholinergic burden is associated with poorer cognitive and functional outcomes in people with dementia. However, the impact of anticholinergics on significant adverse outcomes such as stroke has not been studied previously.Objective: To investigate the association between total anticholinergic cognitive burden (ACB) and risk of stroke and death in people with different dementia subtypes.Methods: This was a cohort study of 39,107 people with dementia and no prior history of stroke registered in the Swedish Dementia Registry (SveDem) from 2008-2014. Data were extracted from the Swedish Prescribed Drug Register, the Swedish National Patient Register, and the Swedish Total Population Register. Competing risk regression models were used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between time-varying ACB score and risk of stroke and all-cause mortality.Results: During a mean follow-up period of 2.31 (standard deviation 1.66) years, 11,224 (28.7%) individuals had a stroke or died. Compared with non-users of anticholinergic medications, ACB score of 1 (HR 1.09, 95% CI 1.04-1.14) and ACB score of >= 2 (HR 1.20, 95% CI 1.14-1.26) increased the risk of developing the composite outcome of stroke and death. When stratifying by dementia disorder, the association remained significant in Alzheimer's disease, mixed dementia, and vascular dementia.Conclusions: The use of anticholinergic medicines may be associated with an increased risk of stroke and death in people with dementia. A dose-response relationship was observed. Careful consideration should be made when prescribing medications with anticholinergic properties to people with dementia.
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| 3. |
- Agholme, Lotta, et al.
(författare)
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Amyloid-β Secretion, Generation, and Lysosomal Sequestration in Response to Proteasome Inhibition : Involvement of Autophagy
- 2012
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Ingår i: Journal of Alzheimer's Disease. - : I O S Press. - 1387-2877 .- 1875-8908. ; 31:2, s. 343-358
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Tidskriftsartikel (refereegranskat)abstract
- The proteasome is important for degradation of worn out and misfolded proteins. Decreased proteasome activity has been implicated in Alzheimer's disease (AD). Proteasome inhibition induces autophagy, but it is still unknown whether autophagy is beneficial or deleterious to AD neurons, as the autophagosome has been suggested as a site of amyloid-β (Aβ) generation. In this study, we investigated the effect of proteasome inhibition on Aβ accumulation and secretion, as well as the processing of amyloid-β protein precursor (AβPP) in AβPPSwe transfected SH-SY5Y neuroblastoma cells. We show that proteasome inhibition resulted in autophagy-dependent accumulation of Aβ in lysosomes, and increased levels of intracellular and secreted Aβ. The enhanced levels of Aβ could not be explained by increased amounts of AβPP. Instead, reduced degradation of the C-terminal fragment of AβPP (C99) by the proteasome makes C99 available for γ-secretase cleavage, leading to Aβ generation. Inhibition of autophagy after proteasome inhibition led to reduced levels of intracellular, but not secreted Aβ, and tended to further increase the C99 to AβPP ratio, supporting involvement of the autophagosome in Aβ generation. Furthermore, proteasome inhibition caused a reduction in cellular viability, which was reverted by inhibition of autophagy. Dysfunction of the proteasome could cause lysosomal accumulation of Aβ, as well as increased generation and secretion of Aβ, which is partly facilitated by autophagy. As a decrease in cellular viability was also detected, it is possible that upregulation of autophagy is an unsuccessful rescue mechanism, which instead of being protective, contributes to AD pathogenesis.
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| 4. |
- Almkvist, Ove, et al.
(författare)
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Subcortical and Cortical Regions of Amyloid-β Pathology Measured by C-11-PiB PET Are Differentially Associated with Cognitive Functions and Stages of Disease in Memory Clinic Patients
- 2021
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 81:4, s. 1613-1624
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Tidskriftsartikel (refereegranskat)abstract
- Background: The effect of regional brain amyloid-beta (A beta) pathology on specific cognitive functions is incompletely known.Objective: The relationship between A beta and cognitive functions was investigated in this cross-sectional multicenter study of memory clinic patients.Methods: The participants were patients diagnosed with Alzheimer's disease (AD, n = 83), mild cognitive impairment (MCI, n = 60), and healthy controls (HC, n = 32), who had been scanned by C-11-PiB PET in 13 brain regions of both hemispheres and who had been assessed by cognitive tests covering seven domains.Results: Hierarchic multiple regression analyses were performed on each cognitive test as dependent variable, controlling for demographic characteristics and APOE status (block 1) and PiB measures in 13 brain regions (block 2) as independent variables. The model was highly significant for each cognitive test and most strongly for tests of episodic memory (learning and retention) versus PiB in putamen, visuospatially demanding tests (processing and retention) versus the occipital lobe, semantic fluency versus the parietal lobe, attention versus posterior gyrus cinguli, and executive function versus nucleus accumbens. In addition, education had a positively and APOE status a negatively significant effect on cognitive tests.Conclusion: Five subcortical and cortical regions with A beta pathology are differentially associated with cognitive functions and stages of disease in memory clinic patients.
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| 5. |
- Andersson, Carl-Henrik, et al.
(författare)
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A Genetic Variant of the Sortilin 1 Gene isAssociated with Reduced Risk ofAlzheimer's Disease
- 2016
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 53:4, s. 1353-1363
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is a neurodegenerative disorder represented by the accumulation of intracellular tau protein and extracellular deposits of amyloid-β (Aβ) in the brain. The gene sortilin 1 (SORT1) has previously been associated with cardiovascular disease in gene association studies. It has also been proposed to be involved in AD pathogenesis through facilitating Aβ clearance by binding apoE/Aβ complexes prior to cellular uptake. However, the neuropathological role of SORT1 in AD is not fully understood. To evaluate the associations between gene variants of SORT1 and risk of AD, we performed genetic analyses in a Swedish case-control cohort. Ten single nucleotide polymorphisms (SNPs), covering the whole SORT1 gene, were selected and genotyped in 620 AD patients and 1107 controls. The SNP rs17646665, located in a non-coding region of the SORT1 gene, remained significantly associated with decreased risk of AD after multiple testing (pc=0.0061). In addition, other SNPs were found to be nominally associated with risk of AD, as well as altered cognitive function and the CSF biomarker Aβ42, but these associations did not survive correction for multiple testing. The fact that SORT1 has been strongly associated with risk of cardiovascular disease is intriguing as cardiovascular disease is also regarded as a risk factor for AD. Finally, increased knowledge about SORT1 function has a potential to increase our understanding of APOE, the strongest risk factor for AD.
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| 6. |
- Atti, Anna Rita, et al.
(författare)
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Cognitive Impairment after Age 60 : clinical and Social Correlates in the "Faenza Project"
- 2010
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 21:4, s. 1325-1334
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Tidskriftsartikel (refereegranskat)abstract
- A total of 7,389 dementia-free elderly (60–102 years old) enrolled in the "Faenza Project" (Northern Italy) were clinically evaluated by nurses and physicians with the aim of detecting the independent and combined association of medical and social factors with cognitive status. Cognitive Impairment No Dementia (CIND) was defined for MMSE scores ⩽ 2 standard deviations than the age- and education-corrected mean score obtained by the non-demented persons of the Faenza cohort. Logistic Regression analysis was used to estimate Odds Ratios and 95% Confidence Intervals (OR, 95%CI) for CIND. The diagnostic procedure identified 402 (5.4%) CIND cases. Diabetes (OR, 95%CI=1.6, 1.2–2.2), stroke (OR, 95%CI=1.9, 1.4–2.6), and depressive symptoms (OR, 95%CI=1.9, 1.4–2.7) emerged as the most relevant medical comorbidities of CIND. Low education (OR, 95%CI=1.8, 1.1–2.9), low Socio Economic Status (SES) (OR, 95%CI=1.5, 1.1–2.1), and unmarried status (OR, 95%CI=1.7, 1.2–2.5) were associated with CIND. Medical and social factors were independently related to CIND occurrence. In comparison to subjects without any of the above mentioned conditions, subjects with one medical and one social factor had an OR, 95%CI for CIND equal to 6.0, 2.9–12.4. The strength of the association increased when more of those conditions occurred in combination, suggesting a synergistic effect. Despite some methodological limitations, data from this cross-sectional population-based Italian study show that low education, low SES, unmarried status together with diabetes, stroke, and depressive symptoms are related to cognitive impairment in the general population. The interaction of medical and social factors further increases the probability of CIND.
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| 7. |
- Barbera, Mariagnese, et al.
(författare)
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Designing an Internet-Based Multidomain Intervention for the Prevention of Cardiovascular Disease and Cognitive Impairment in Older Adults : The HATICE Trial
- 2018
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 62:2, s. 649-663
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Tidskriftsartikel (refereegranskat)abstract
- Background: Many dementia and cardiovascular disease (CVD) cases in older adults are attributable to modifiable vascular and lifestyle-related risk factors, providing opportunities for prevention. In the Healthy Aging Through Internet Counselling in the Elderly (HATICE) randomized controlled trial, an internet-based multidomain intervention is being tested to improve the cardiovascular risk (CVR) profile of older adults. Objective: To design a multidomain intervention to improve CVR, based on the guidelines for CVR management, and administered through a coach-supported, interactive, platform to over 2500 community-dwellers aged 65+ in three European countries. Methods: A comparative analysis of national and European guidelines for primary and secondary CVD prevention was performed. Results were used to define the content of the intervention. Results: The intervention design focused on promoting awareness and self-management of hypertension, dyslipidemia, diabetes mellitus, and overweight, and supporting smoking cessation, physical activity, and healthy diet. Overall, available guidelines lacked specific recommendations for CVR management in older adults. The comparative analysis of the guidelines showed general consistency for lifestyle-related recommendations. Key differences, identified mostly in methods used to assess the overall CVR, did not hamper the intervention design. Minor country-specific adaptations were implemented to maximize the intervention feasibility in each country. Conclusion: Despite differences inCVRmanagement within the countries considered, itwas possible to design and implement the HATICE multidomain intervention. The study can help define preventative strategies for dementia and CVD that are applicable internationally.
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| 8. |
- Beam, Christopher R., et al.
(författare)
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Estimating Likelihood of Dementia in the Absence of Diagnostic Data : A Latent Dementia Index in 10 Genetically Informed Studies
- 2022
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 90:3, s. 1187-1201
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Epidemiological research on dementia is hampered by differences across studies in how dementia is classified, especially where clinical diagnoses of dementia may not be available. OBJECTIVE: We apply structural equation modeling to estimate dementia likelihood across heterogeneous samples within a multi-study consortium and use the twin design of the sample to validate the results. METHODS: Using 10 twin studies, we implement a latent variable approach that aligns different tests available in each study to assess cognitive, memory, and functional ability. The model separates general cognitive ability from components indicative of dementia. We examine the validity of this continuous latent dementia index (LDI). We then identify cut-off points along the LDI distributions in each study and align them across studies to distinguish individuals with and without probable dementia. Finally, we validate the LDI by determining its heritability and estimating genetic and environmental correlations between the LDI and clinically diagnosed dementia where available. RESULTS: Results indicate that coordinated estimation of LDI across 10 studies has validity against clinically diagnosed dementia. The LDI can be fit to heterogeneous sets of memory, other cognitive, and functional ability variables to extract a score reflective of likelihood of dementia that can be interpreted similarly across studies despite diverse study designs and sampling characteristics. Finally, the same genetic sources of variance strongly contribute to both the LDI and clinical diagnosis. CONCLUSION: This latent dementia indicator approach may serve as a model for other research consortia confronted with similar data integration challenges.
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| 9. |
- Bloniecki, Victor, et al.
(författare)
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Effects of Risperidone and Galantamine Treatment on Alzheimer's Disease Biomarker Levels in Cerebrospinal Fluid
- 2017
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 57:2, s. 387-393
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Treatment for neuropsychiatric symptoms (NPS) in dementia is insufficient. Antipsychotics and acetylcholinesterase inhibitors are used generating symptomatic improvements in behavior and cognition, but few studies have investigated their effect on Alzheimer's disease (AD) biomarkers in cerebrospinal fluid (CSF).OBJECTIVE: This is a secondary analysis based on an earlier clinical trial comparing the treatment effects on NPS. The aim of this study was to examine whether treatment with risperidone and galantamine affect levels of the biomarkers T-Tau, P-Tau, Aβ1-42, and Aβ42/40-ratio in CSF. The secondary aim was to test if baseline levels of these biomarkers are associated with the clinical course of NPS.METHODS: 83 patients (mean + SD 77.9.6±7.7 years) with dementia and NPS were randomized to galantamine (n = 44) or risperidone (n = 39) treatment. CSF samples were collected at baseline and after 12 weeks.RESULTS: Changes in levels of biomarkers between the two treatment groups did not differ significantly. Low baseline levels of Aβ1 - 42 was significantly associated with reduction of irritability at follow up. Low baseline levels of Aβ1-42, Aβ42/40, and P-Tau were significant correlates of reduction in appetite and eating disorders. CSF Aβ1-42 levels in patients treated with risperidone were significantly decreased at follow up, showing an 8% (40 pg/mL) reduction as compared with baseline (p = 0.03).CONCLUSIONS: Our results suggest that risperidone may affect the CSF profile of AD biomarkers indicating more amyloid pathology. Treatment with galantamine did not affect the CSF biomarkers in any direction. The AD CSF biomarkers displayed correlations with specific NPS suggesting potential research questions to be pursued.
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| 10. |
- Bogstedt, A., et al.
(författare)
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Development of Immunoassays for the Quantitative Assessment of Amyloid-β in the Presence of Therapeutic Antibody: Application to Pre-Clinical Studies
- 2015
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 46:4, s. 1091-1101
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Tidskriftsartikel (refereegranskat)abstract
- Utilizing decision making biomarkers in drug development requires thorough assay validation. Special considerations need to be taken into account when monitoring biomarkers using immunoassays in the presence of therapeutic antibodies. We have developed robust and sensitive assays to assess target engagement and proof of mechanism to support the clinical progression of a human monoclonal antibody against the neurotoxic amyloid-β (Aβ)42 peptide. Here we present the introduction of novel pre-treatment steps to ensure drug-tolerant immunoassays and describe the validation of the complete experimental procedures to measure total Aβ42 concentration (bound and unbound) in cerebrospinal fluid (CSF) and plasma, free Aβ42 concentration (unbound) in CSF, and Aβ40 concentration in CSF. The difference in composition of the matrices (CSF and plasma) and antigen levels therein, in combination with the hydrophobic properties of Aβ protein, adds to the complexity of validation. Monitoring pharmacodynamics of an Aβ42 specific monoclonal antibody in a non-human primate toxicology study using these assays, we demonstrated a 1500-fold and a 3000-fold increase in total Aβ42 in plasma, a 4-fold and 8-fold increase in total Aβ42 in CSF together with a 95% and 96% reduction of free Aβ42 in CSF following weekly intravenous injections of 10 mg/kg and 100 mg/kg, respectively. Levels of Aβ40 were unchanged. The accuracy of these data is supported by previous pre-clinical studies as well as predictive pharmacokinetic/pharmacodynamics modeling. In contrast, when analyzing the same non-human primate samples excluding the pre-treatment steps, we were not able to distinguish between free and total Aβ42. Our data clearly demonstrate the importance of thorough evaluation of antibody interference and appropriate validation to monitor different types of biomarkers in the presence of a therapeutic antibody. © 2015-IOS Press and the authors. All rights reserved.
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