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Povova J, Ambroz P, Bar M, Pavukova V, Sery O, Tomaskova H, Janout V. Epidemiological of and risk factors for Alzheimer's disease: A review. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2012; 156:108-14. [DOI: 10.5507/bp.2012.055] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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Johnson ML, Parikh N, Kunik ME, Schulz PE, Patel JG, Chen H, Aparasu RR, Morgan RO. Antihypertensive drug use and the risk of dementia in patients with diabetes mellitus. Alzheimers Dement 2012; 8:437-44. [DOI: 10.1016/j.jalz.2011.05.2414] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 04/20/2011] [Accepted: 05/20/2011] [Indexed: 10/28/2022]
Affiliation(s)
- Michael L. Johnson
- Department of Clinical Sciences and Administration; Division of Pharmacy Administration and Public Health; University of Houston; College of Pharmacy; Houston TX USA
- Houston Center for Quality of Care & Utilization Studies; Veterans Affairs Medical Center; Houston TX USA
| | - Niraj Parikh
- Department of Clinical Sciences and Administration; Division of Pharmacy Administration and Public Health; University of Houston; College of Pharmacy; Houston TX USA
| | - Mark E. Kunik
- Houston Center for Quality of Care & Utilization Studies; Veterans Affairs Medical Center; Houston TX USA
- Menninger Department of Psychiatry and Behavioral Sciences; Baylor College of Medicine; Houston TX USA
- Veterans Affairs South Central Mental Illness Research; Education and Clinical Center; Houston TX USA
| | - Paul E. Schulz
- Department of Neurology; The Mischer Neuroscience Institute at The University of Texas Health Science Center; Memorial Hermann Hospital; Houston TX USA
| | - Jeetvan G. Patel
- Department of Clinical Sciences and Administration; Division of Pharmacy Administration and Public Health; University of Houston; College of Pharmacy; Houston TX USA
| | - Hua Chen
- Department of Clinical Sciences and Administration; Division of Pharmacy Administration and Public Health; University of Houston; College of Pharmacy; Houston TX USA
| | - Rajender R. Aparasu
- Department of Clinical Sciences and Administration; Division of Pharmacy Administration and Public Health; University of Houston; College of Pharmacy; Houston TX USA
| | - Robert O. Morgan
- Houston Center for Quality of Care & Utilization Studies; Veterans Affairs Medical Center; Houston TX USA
- School of Public Health; Division of Management; Policy and Community Health at The University of Texas Health Science Center; Houston TX USA
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Béjot Y, Giroud M, Touzé E. Pressione arteriosa e cervello. Neurologia 2012. [DOI: 10.1016/s1634-7072(12)60701-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Kennelly SP, Abdullah L, Paris D, Parish J, Mathura V, Mullan M, Crawford F, Lawlor BA, Kenny RA. Demonstration of safety in Alzheimer's patients for intervention with an anti-hypertensive drug Nilvadipine: results from a 6-week open label study. Int J Geriatr Psychiatry 2011; 26:1038-45. [PMID: 21905098 DOI: 10.1002/gps.2638] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Accepted: 09/03/2010] [Indexed: 11/11/2022]
Abstract
BACKGROUND Nilvadipine may lower rates of conversion from mild-cognitive impairment to Alzheimer's disease (AD), in hypertensive patients. However, it remains to be determined whether treatment with nilvadipine is safe in AD patients, given the higher incidence of orthostatic hypotension (OH) in this population, who may be more likely to suffer from symptoms associated with the further exaggeration of a drop in BP. OBJECTIVE The aim of this study was to investigate the safety and tolerability of nilvadipine in AD patients. METHODS AD patients in the intervention group (n = 56) received nilvadipine 8 mg daily over 6-weeks, compared to the control group (n = 30) who received no intervention. Differences in systolic (SBP) and diastolic (DBP) blood pressure, before and after intervention, was assessed using automated sphygmomanometer readings and ambulatory BP monitors (ABP), and change in OH using a finometer. Reporting of adverse events was monitored throughout the study. RESULTS There was a significant reduction in the SBP of treated patients compared to non-treated patients but no significant change in DBP. Individuals with higher initial blood pressure (BP) had greater reduction in BP but individuals with normal BP did not experience much change in their BP. While OH was present in 84% of the patients, there was no further drop in BP recorded on active stand studies. There were no significant differences in adverse event reporting between groups. CONCLUSION Nilvadipine was well tolerated by patients with AD. This study supports further investigation of its efficacy as a potential treatment for AD.
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Calcium channel blocking as a therapeutic strategy for Alzheimer's disease: the case for isradipine. Biochim Biophys Acta Mol Basis Dis 2011; 1812:1584-90. [PMID: 21925266 DOI: 10.1016/j.bbadis.2011.08.013] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 08/12/2011] [Accepted: 08/30/2011] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease is the most devastating neurodegenerative disorder in the elderly, yet treatment options are severely limited. The drug development effort to modify Alzheimer's disease pathology by intervention at beta amyloid production sites has been largely ineffective or inconclusive. The greatest challenge has been to identify and define downstream mechanisms reliably predictive of clinical symptoms. Beta amyloid accumulation leads to dysregulation of intracellular calcium by plasma membrane L-type calcium channels located on neuronal somatodendrites and axons in the hippocampus and cortex. Paradoxically, L-type calcium channel subtype Ca(v)1.2 also promotes synaptic plasticity and spatial memory. Increased intracellular calcium modulates amyloid precursor protein processing and affects multiple downstream pathways including increased hyperphosphorylated tau and suppression of autophagy. Isradipine is a Federal Drug Administration-approved dihydropyridine calcium channel blocker that binds selectively to Ca(v)1.2 in the hippocampus. Our studies have shown that isradipine in vitro attenuates beta amyloid oligomer toxicity by suppressing calcium influx into cytoplasm and by suppressing Ca(v)1.2 expression. We have previously shown that administration of isradipine to triple transgenic animal model for Alzheimer's disease was well-tolerated. Our results further suggest that isradipine became bioavailable, lowered tau burden, and improved autophagy function in the brain. A better understanding of brain pharmacokinetics of calcium channel blockers will be critical for designing new experiments with appropriate drug doses in any future clinical trials for Alzheimer's disease. This review highlights the importance of Ca(v)1.2 channel overexpression, the accumulation of hyperphosphorylated tau and suppression of autophagy in Alzheimer's disease and modulation of this pathway by isradipine.
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Gorelick PB, Scuteri A, Black SE, Decarli C, Greenberg SM, Iadecola C, Launer LJ, Laurent S, Lopez OL, Nyenhuis D, Petersen RC, Schneider JA, Tzourio C, Arnett DK, Bennett DA, Chui HC, Higashida RT, Lindquist R, Nilsson PM, Roman GC, Sellke FW, Seshadri S. Vascular contributions to cognitive impairment and dementia: a statement for healthcare professionals from the american heart association/american stroke association. Stroke 2011; 42:2672-713. [PMID: 21778438 PMCID: PMC3778669 DOI: 10.1161/str.0b013e3182299496] [Citation(s) in RCA: 2538] [Impact Index Per Article: 195.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND PURPOSE This scientific statement provides an overview of the evidence on vascular contributions to cognitive impairment and dementia. Vascular contributions to cognitive impairment and dementia of later life are common. Definitions of vascular cognitive impairment (VCI), neuropathology, basic science and pathophysiological aspects, role of neuroimaging and vascular and other associated risk factors, and potential opportunities for prevention and treatment are reviewed. This statement serves as an overall guide for practitioners to gain a better understanding of VCI and dementia, prevention, and treatment. METHODS Writing group members were nominated by the writing group co-chairs on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council Scientific Statement Oversight Committee, the Council on Epidemiology and Prevention, and the Manuscript Oversight Committee. The writing group used systematic literature reviews (primarily covering publications from 1990 to May 1, 2010), previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and, when appropriate, formulate recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. After peer review by the American Heart Association, as well as review by the Stroke Council leadership, Council on Epidemiology and Prevention Council, and Scientific Statements Oversight Committee, the statement was approved by the American Heart Association Science Advisory and Coordinating Committee. RESULTS The construct of VCI has been introduced to capture the entire spectrum of cognitive disorders associated with all forms of cerebral vascular brain injury-not solely stroke-ranging from mild cognitive impairment through fully developed dementia. Dysfunction of the neurovascular unit and mechanisms regulating cerebral blood flow are likely to be important components of the pathophysiological processes underlying VCI. Cerebral amyloid angiopathy is emerging as an important marker of risk for Alzheimer disease, microinfarction, microhemorrhage and macrohemorrhage of the brain, and VCI. The neuropathology of cognitive impairment in later life is often a mixture of Alzheimer disease and microvascular brain damage, which may overlap and synergize to heighten the risk of cognitive impairment. In this regard, magnetic resonance imaging and other neuroimaging techniques play an important role in the definition and detection of VCI and provide evidence that subcortical forms of VCI with white matter hyperintensities and small deep infarcts are common. In many cases, risk markers for VCI are the same as traditional risk factors for stroke. These risks may include but are not limited to atrial fibrillation, hypertension, diabetes mellitus, and hypercholesterolemia. Furthermore, these same vascular risk factors may be risk markers for Alzheimer disease. Carotid intimal-medial thickness and arterial stiffness are emerging as markers of arterial aging and may serve as risk markers for VCI. Currently, no specific treatments for VCI have been approved by the US Food and Drug Administration. However, detection and control of the traditional risk factors for stroke and cardiovascular disease may be effective in the prevention of VCI, even in older people. CONCLUSIONS Vascular contributions to cognitive impairment and dementia are important. Understanding of VCI has evolved substantially in recent years, based on preclinical, neuropathologic, neuroimaging, physiological, and epidemiological studies. Transdisciplinary, translational, and transactional approaches are recommended to further our understanding of this entity and to better characterize its neuropsychological profile. There is a need for prospective, quantitative, clinical-pathological-neuroimaging studies to improve knowledge of the pathological basis of neuroimaging change and the complex interplay between vascular and Alzheimer disease pathologies in the evolution of clinical VCI and Alzheimer disease. Long-term vascular risk marker interventional studies beginning as early as midlife may be required to prevent or postpone the onset of VCI and Alzheimer disease. Studies of intensive reduction of vascular risk factors in high-risk groups are another important avenue of research.
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Bachmeier C, Beaulieu-Abdelahad D, Mullan M, Paris D. Selective dihydropyiridine compounds facilitate the clearance of β-amyloid across the blood-brain barrier. Eur J Pharmacol 2011; 659:124-9. [PMID: 21497592 DOI: 10.1016/j.ejphar.2011.03.048] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 03/07/2011] [Accepted: 03/28/2011] [Indexed: 12/11/2022]
Abstract
Increasing evidence suggests that the soluble form of the β-amyloid peptide (Aβ) plays a critical role in the pathogenesis of Alzheimer's disease. Previously, we reported that treatment with certain antihypertensive dihydropyridine (DHP) compounds can mitigate Aβ production in whole cells and reduce brain Aβ burden in a mouse model of Alzheimer's disease. As Aβ clearance across the blood-brain barrier (BBB) is a key regulatory step in the deposition of Aβ in the brain, we examined the effect of DHP treatment on Aβ brain clearance. Treatment with certain DHP compounds significantly increased Aβ(1-42) transcytosis across the BBB in an in vitro model. The rank order of these compounds was nitrendipine>nicardipine=cilnidipine=lercanidipine>nimodipine>azelnidipine=nilvadipine. Conversely, amlodipine, felodipine, isradipine, and nifedipine had no effect on Aβ(1-42) BBB transcytosis. In an in vivo paradigm of Aβ clearance across the BBB, peripheral administration of nitrendipine, cilnidipine, and nilvadipine to wild-type animals facilitated the brain clearance of centrally administered exogenous Aβ(1-42), whereas with amlodipine, there was no effect. We also observed improved cognitive function in mice treated with nilvadipine following central Aβ(1-42) insult. Thus, in addition to the effect of certain DHP compounds on Aβ production, we demonstrate that certain DHP compounds also facilitate the clearance of Aβ across the BBB. This dual mechanism of action may be particularly effective in attenuating Aβ brain burden in Alzheimer's disease and could open the door to a new class of therapies for the treatment of this disease.
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Affiliation(s)
- Corbin Bachmeier
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA.
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Paris D, Bachmeier C, Patel N, Quadros A, Volmar CH, Laporte V, Ganey J, Beaulieu-Abdelahad D, Ait-Ghezala G, Crawford F, Mullan MJ. Selective antihypertensive dihydropyridines lower Aβ accumulation by targeting both the production and the clearance of Aβ across the blood-brain barrier. Mol Med 2011; 17:149-62. [PMID: 21170472 PMCID: PMC3060987 DOI: 10.2119/molmed.2010.00180] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 12/16/2010] [Indexed: 11/06/2022] Open
Abstract
Several large population-based or clinical trial studies have suggested that certain dihydropyridine (DHP) L-type calcium channel blockers (CCBs) used for the treatment of hypertension may confer protection against the development of Alzheimer disease (AD). However, other studies with drugs of the same class have shown no beneficial clinical effects. To determine whether certain DHPs are able to impact underlying disease processes in AD (specifically the accumulation of the Alzheimer Aβ peptide), we investigated the effect of several antihypertensive DHPs and non-DHP CCBs on Aβ production. Among the antihypertensive DHPs tested, a few, including nilvadipine, nitrendipine and amlodipine inhibited Aβ production in vitro, whereas others had no effect or raised Aβ levels. In vivo, nilvadipine and nitrendipine acutely reduced brain Aβ levels in a transgenic mouse model of AD (Tg PS1/APPsw) and improved Aβ clearance across the blood-brain barrier (BBB), whereas amlodipine and nifedipine were ineffective showing that the Aβ-lowering activity of the DHPs is independent of their antihypertensive activity. Chronic oral treatment with nilvadipine decreased Aβ burden in the brains of Tg APPsw (Tg2576) and Tg PS1/APPsw mice, and also improved learning abilities and spatial memory. Our data suggest that the clinical benefit conferred by certain antihypertensive DHPs against AD is unrelated to their antihypertensive activity, but rely on their ability to lower brain Aβ accumulation by affecting both Aβ production and Aβ clearance across the BBB.
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Affiliation(s)
- Daniel Paris
- The Roskamp Institute, Sarasota, Florida 34243, United States of America.
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Piau A, Nourhashémi F, Hein C, Caillaud C, Vellas B. Progress in the development of new drugs in Alzheimer's disease. J Nutr Health Aging 2011; 15:45-57. [PMID: 21267520 DOI: 10.1007/s12603-011-0012-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is an age-related neurodegenerative disease with a global prevalence estimated at 26.55 million in 2006. During the past decades, several agents have been approved that enhance cognition of AD patients. However, the effectiveness of these treatments are limited or controversial and they do not modify disease progression. Recent advances in understanding AD pathogenesis have led to the development of numerous compounds that might modify the disease process. AD is mainly characterized neuropathologically by the presence of two kinds of protein aggregates: extracellular plaques of Abeta-peptide and intracellular neurofibrillary tangles. Abeta and tau could interfere in an original way contributing to a cascade of events leading to neuronal death and transmitter deficits. Investigation for novel therapeutic approaches targeting the presumed underlying pathogenic mechanisms is major focus of research. Antiamyloid agents targeting production, accumulation, clearance, or toxicity associated with Abeta peptide, are some approaches under investigation to limit extracellular plaques of Abeta-peptide accumulation. We can state as an example: Abeta passive and active immunization, secretases modulation, Abeta degradation enhancement, or antiaggregation and antifibrillization agents. Tau-related therapies are also under clinical investigation but few compounds are available. Another alternative approach under development is neuroprotective agents such as antioxidants, anti-inflammatory drugs, compounds acting against glutamate mediated neurotoxicity. Neurorestorative approaches through neurotrophin or cell therapy also represent a minor avenue in AD research. Finally, statins, receptor for advanced glycation end products inhibitors, thiazolidinediones, insulin, and hormonal therapies are some other ways of research for a therapeutic approach of Alzheimer's disease. Taking into account AD complexity, it becomes clear that polypharmacology with drugs targeting different sites could be the future treatment approach and a majority of the recent drugs under evaluation seems to act on multiple targets. This article exposes general classes of disease-modifying therapies under investigation.
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Does use of antihypertensive drugs affect the incidence or progression of dementia? A systematic review. ACTA ACUST UNITED AC 2010; 7:250-61. [PMID: 19948301 DOI: 10.1016/j.amjopharm.2009.11.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2009] [Indexed: 11/23/2022]
Abstract
BACKGROUND Hypertension appears to contribute to the development of dementia. Antihypertensive drugs may play an important role in altering the incidence or progression of dementia, particularly dementia of the vascular type; however, the neuroprotective effects of these agents in other types of dementia are not well characterized. OBJECTIVES The main aims of this review were to examine the relationship between use of antihypertensive agents and the incidence and progression of Alzheimer's dementia (AD), vascular dementia (VaD), and unspecified dementia, and to consider whether these agents may be neuroprotective. METHODS A search of the English-language literature (January 1996-August 2009) was conducted using PubMed, Ovid MEDLINE, EBSCO MEDLINE, and the Cochrane Database of Systematic Reviews for publications mentioning both antihypertensive drugs and dementia. A combination of searches was performed using the following terms: antihypertensive drugs, dementia, cognitive impairment, Alzheimer's dementia, vascular dementia, progression of cognitive impairment, severity of cognitive impairment, severity of dementia, prevalence, and incidence. Searches were also performed using the names of antihypertensive drug classes. The bibliographies of all retrieved articles were reviewed for additional relevant publications. The focus was on randomized controlled trials, cohort studies, and case-control studies, excluding studies in animals, patients aged <45 years, drugs other than antihypertensive agents, and the role in cognition of hormones, receptors, and enzymes. RESULTS Sixty-five potentially relevant articles were identified from the 536 publications retrieved by the literature search. After application of the exclusion criteria, 12 original studies were included in the review, all published between 1999 and 2008 and most involving patients with AD or VaD. The most frequently studied antihypertensive agents were calcium channel blockers (7 studies), diuretics (6 studies), and angiotensin-converting enzyme (ACE) inhibitors (6 studies). Overall, these medications appeared to be beneficial in dementia, but only ACE inhibitors and diuretics significantly reduced the risk for and progression of dementia in the majority of studies. CONCLUSIONS Antihypertensive medications-particularly ACE inhibitors and diuretics-may be helpful in reducing the risk for and progression of dementia. Large randomized clinical trials are warranted to further explore the relationship between antihypertensive drugs and dementia.
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McGuinness B, Todd S, Passmore P, Bullock R. Blood pressure lowering in patients without prior cerebrovascular disease for prevention of cognitive impairment and dementia. Cochrane Database Syst Rev 2009; 2009:CD004034. [PMID: 19821318 PMCID: PMC7163274 DOI: 10.1002/14651858.cd004034.pub3] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND This is an update of a previous review (McGuinness 2006).Hypertension and cognitive impairment are prevalent in older people. Hypertension is a direct risk factor for vascular dementia (VaD) and recent studies have suggested hypertension impacts upon prevalence of Alzheimer's disease (AD). Therefore does treatment of hypertension prevent cognitive decline? OBJECTIVES To assess the effects of blood pressure lowering treatments for the prevention of dementia and cognitive decline in patients with hypertension but no history of cerebrovascular disease. SEARCH STRATEGY The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group, The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS as well as many trials databases and grey literature sources were searched on 13 February 2008 using the terms: hypertens$ OR anti-hypertens$. SELECTION CRITERIA Randomized, double-blind, placebo controlled trials in which pharmacological or non-pharmacological interventions to lower blood pressure were given for at least six months. DATA COLLECTION AND ANALYSIS Two independent reviewers assessed trial quality and extracted data. The following outcomes were assessed: incidence of dementia, cognitive change from baseline, blood pressure level, incidence and severity of side effects and quality of life. MAIN RESULTS Four trials including 15,936 hypertensive subjects were identified. Average age was 75.4 years. Mean blood pressure at entry across the studies was 171/86 mmHg. The combined result of the four trials reporting incidence of dementia indicated no significant difference between treatment and placebo (236/7767 versus 259/7660, Odds Ratio (OR) = 0.89, 95% CI 0.74, 1.07) and there was considerable heterogeneity between the trials. The combined results from the three trials reporting change in Mini Mental State Examination (MMSE) did not indicate a benefit from treatment (Weighted Mean Difference (WMD) = 0.42, 95% CI 0.30, 0.53). Both systolic and diastolic blood pressure levels were reduced significantly in the three trials assessing this outcome (WMD = -10.22, 95% CI -10.78, -9.66 for systolic blood pressure, WMD = -4.28, 95% CI -4.58, -3.98 for diastolic blood pressure). Three trials reported adverse effects requiring discontinuation of treatment and the combined results indicated no significant difference (OR = 1.01, 95% CI 0.92, 1.11). When analysed separately, however, more patients on placebo in Syst Eur 1997 were likely to discontinue treatment due to side effects; the converse was true in SHEP 1991. Quality of life data could not be analysed in the four studies. Analysis of the included studies in this review was problematic as many of the control subjects received antihypertensive treatment because their blood pressures exceeded pre-set values. In most cases the study became a comparison between the study drug against a usual antihypertensive regimen. AUTHORS' CONCLUSIONS There is no convincing evidence from the trials identified that blood pressure lowering in late-life prevents the development of dementia or cognitive impairment in hypertensive patients with no apparent prior cerebrovascular disease. There were significant problems identified with analysing the data, however, due to the number of patients lost to follow-up and the number of placebo patients who received active treatment. This introduced bias. More robust results may be obtained by conducting a meta-analysis using individual patient data.
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Affiliation(s)
- Bernadette McGuinness
- Queen's University BelfastDepartment of Geriatric MedicineWhitla Medical Building97 Lisburn RoadBelfastUKBT9 7BL
| | - Stephen Todd
- Queen's University BelfastDepartment of Geriatric MedicineWhitla Medical Building97 Lisburn RoadBelfastUKBT9 7BL
| | - Peter Passmore
- Queen's University BelfastDepartment of Geriatric MedicineWhitla Medical Building97 Lisburn RoadBelfastUKBT9 7BL
| | - Roger Bullock
- Kingshill Research Centre, Victoria HospitalOkus RoadSwindonUKSN4 4HZ
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Abstract
Cumulative evidence implicates hypertension in the pathogenesis of Alzheimer disease. Although it may not presently be possible to completely differentiate the effects of treatment and control of hypertension itself from those of the medication used to achieve such treatment goals, efforts directed at the treatment and control of hypertension can have significant public health impact.
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Affiliation(s)
- Thomas Olabode Obisesan
- Division of Geriatrics, Department of Medicine, Howard University Hospital, 2041 Georgia Avenue, NW, Washington, DC 20060, USA.
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Louis ED, Benito-León J, Bermejo-Pareja F. Antihypertensive agents and risk of Parkinson's disease, essential tremor and dementia: a population-based prospective study (NEDICES). Neuroepidemiology 2009; 33:286-92. [PMID: 19696520 PMCID: PMC2826448 DOI: 10.1159/000235641] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Accepted: 06/29/2009] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Recent interest in antihypertensive agents, especially calcium channel blockers, has been sparked by the notion that these medications may be neuroprotective. A modest literature, with mixed results, has examined whether these medications might lower the odds or risk of Parkinson's disease (PD) or dementia. There are no data for essential tremor (ET). OBJECTIVE To examine the association between antihypertensive use (defined broadly and by individual subclasses) and ET, PD and dementia. For each disorder, we used cross-sectional data (association with prevalent disease) and prospective data (association with incident disease). METHODS Prospective population-based study in Spain enrolling 5,278 participants at baseline. RESULTS Use of antihypertensive medications (aside from beta-blockers) was similar in prevalent ET cases and controls. Baseline use of antihypertensive agents was not associated with reduced risk of incident ET. Antihypertensive medication use was not associated with prevalent or incident PD. Calcium channel blocker use was marginally reduced in prevalent dementia cases (OR(adjusted) = 0.63, p = 0.06) but was not associated with reduced risk of incident dementia (RR(adjusted) = 1.02, p = 0.95). CONCLUSIONS We did not find evidence of a protective effect of antihypertensive medications in these three neurodegenerative disorders.
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Affiliation(s)
- Elan D Louis
- Department of Neurology, GH Sergievsky Center, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
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Qiu C, Kivipelto M, von Strauss E. Epidemiology of Alzheimer's disease: occurrence, determinants, and strategies toward intervention. DIALOGUES IN CLINICAL NEUROSCIENCE 2009. [PMID: 19585947 PMCID: PMC3181909 DOI: 10.31887/dcns.2009.11.2/cqiu] [Citation(s) in RCA: 625] [Impact Index Per Article: 41.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
More than 25 million people in the world today are affected by dementia, most suffering from Alzheimer's disease. In both developed and developing nations, Alzheimer's disease has had tremendous impact on the affected individuals, caregivers, and society. The etiological factors, other than older age and genetic susceptibility, remain to be determined. Nevertheless, increasing evidence strongly points to the potential risk roles of vascular risk factors and disorders (eg, cigarette smoking, midlife high blood pressure and obesity, diabetes, and cerebrovascular lesions) and the possible beneficial roles of psychosocial factors (eg, high education, active social engagement, physical exercise, and mentally stimulating activity) in the pathogenetic process and clinical manifestation of the dementing disorders. The long-term multidomain interventions toward the optimal control of multiple vascular risk factors and the maintenance of socially integrated lifestyles and mentally stimulating activities are expected to reduce the risk or postpone the clinical onset of dementia, including Alzheimer's disease.
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Affiliation(s)
- Chengxuan Qiu
- Aging Research Center, Karolinska Institutet-Stockholm, Sweden.
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Kennelly SP, Lawlor BA, Kenny RA. Blood pressure and dementia - a comprehensive review. Ther Adv Neurol Disord 2009; 2:241-60. [PMID: 21179532 PMCID: PMC3002634 DOI: 10.1177/1756285609103483] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD) and vascular dementia (VaD) are important causes of cognitive decline in the elderly. As a result of an ageing population worldwide, the incidence of dementia is expected to rise exponentially over the coming decades. Vascular risk factors are implicated in the pathogenesis of both AD and VaD. Hypertension in midlife is particularly associated with an increased risk of developing dementia. One might hope the treatment of high blood pressure in midlife would reduce the risk of developing dementia, as it does the risk of stroke. Divergent results have been reported in studies examining this effect, with the evidence suggesting that certain antihypertensives confer benefits beyond others. This implies that certain drugs may have neuroprotective properties separate to their blood pressure lowering capabilities. Recent trials have added to our understanding of these relationships.
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Coley N, Andrieu S, Gardette V, Gillette-Guyonnet S, Sanz C, Vellas B, Grand A. Dementia Prevention: Methodological Explanations for Inconsistent Results. Epidemiol Rev 2008; 30:35-66. [PMID: 18779228 DOI: 10.1093/epirev/mxn010] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Casado Naranjo I, Ramírez Moreno JM. Hipertensión arterial y función cognitiva. Med Clin (Barc) 2008; 130:542-52. [DOI: 10.1157/13119721] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Green KN, Smith IF, Laferla FM. Role of calcium in the pathogenesis of Alzheimer's disease and transgenic models. Subcell Biochem 2007; 45:507-21. [PMID: 18193650 DOI: 10.1007/978-1-4020-6191-2_19] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder of the elderly that is characterized by memory loss. Neuropathologically, the AD brain is marked by an increased AP burden, hyperphosphorylated tau aggregates, synaptic loss, and inflammatory responses. Disturbances in calcium homeostasis are also one of the earliest molecular changes that occur in AD patients, alongside alterations in calcium-dependent enzymes in the post-mortem brain. The sum of these studies suggests that calcium dyshomeostasis is an integral part of the pathology, either influencing AP production, mediating its effects or both. Increasing evidence from in vitro studies demonstrates that the AP peptide could modulate a number of ion channels increasing calcium influx, including voltage-gated calcium and potassium channels, the NMDA receptor, the nicotinic receptor, as well as forming its own calcium-conducting pores. In vivo evidence has shown that A3 impairs both LTP and cognition, whereas all of these ion channels cluster at the synapse and underlie synaptic transmission and hence cognition. Here we consider the evidence that AP causes cognitive deficits through altering calcium homeostasis at the synapse, thus impairing synaptic transmission and LTP. Furthermore, this disruption appearr to occur without overt or extensive neuronal loss, as it is observed in transgenic mouse models of AD, but may contribute to the synaptic loss, which is an early event that correlates best with cognitive decline.
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Affiliation(s)
- K N Green
- Department of Neurobiology and Behavior, University of California, Irvine CA 92697-4545, USA
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71
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Staessen JA, Richart T, Birkenhäger WH. Less Atherosclerosis and Lower Blood Pressure for a Meaningful Life Perspective With More Brain. Hypertension 2007; 49:389-400. [PMID: 17283254 DOI: 10.1161/01.hyp.0000258151.00728.d8] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Jan A Staessen
- Studies Coordinating Centre, Division of Hypertension and Cardiovascular Rehabilitation, Department of Cardiovascular Diseases, University of Leuven, Leuven, Belgium.
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72
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Abstract
Dementia is one of the commonest neurological disorders in the elderly population. In regards to the increasing longevity of populations worldwide, prevention of dementia has become a major public health challenge. There has been an intense research in the identification of modifiable risk factors for dementia. These risk factors could then be used as targets for intervention, pharmacologic or non-pharmacologic. Numerous reports of the relation between cardiovascular risk factors and cognitive decline and dementia have been published over the past years. This review focuses on the cardiovascular risk factors hypertension, hyperlipidemia and diabetes mellitus as targets for prevention of cognitive decline, overall dementia and Alzheimer's disease. Observational studies and clinical trials regarding the association between antihypertensive, lipid lowering and antidiabetic medications and the risk of impaired cognition, dementia or Alzheimer's disease are reviewed. Based on these data, we propose that early interventions at reducing these cardiovascular risk factors may have an impact on future incidence and prevalence of cognitive deficits of many etiologies including Alzheimer's disease.
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Affiliation(s)
- Christine Bergmann
- Alzheimer Disease Research Center of Mount Sinai School of Medicine, NYC, James J Peters VAMC, Bronx, NY 10468, USA
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73
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Vogel T, Benetos A, Verreault R, Kaltenbach G, Kiesmann M, Berthel M. Facteurs de risque de la maladie d’Alzheimer: vers une prévention? Presse Med 2006; 35:1309-16. [PMID: 16969326 DOI: 10.1016/s0755-4982(06)74810-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Recent longitudinal studies have highlighted associations between Alzheimer's disease (AD) and several factors, especially some cardiovascular risk factors, including hypertension, diabetes, diet, obesity, and elevated levels of homocysteine and lipids in the blood. The strongest associations are with hypertension and diabetes. Moderate alcohol consumption also appears to be associated with a decreased risk of incident AD. Studies of the effect of interventions to control these risk factors on the onset and course of dementia report encouraging results about antihypertensive agents and statins. Benefits from other drug therapies such as nonsteroidal antiinflammatory drugs and antioxidants remain uncertain, and initial hopes for hormonal replacement therapy for postmenopausal women have not been confirmed. Physical, cognitive and leisure activities seem to provide protection against incident AD. Cautious interpretation is necessary in view of the possible biases in these studies (confounding factors as well as survival, regression dilution, and indication biases). These epidemiologic data raise questions about the diagnostic boundaries between AD and vascular dementia. Additional studies are needed to validate these concepts and to confirm the possible benefits of preventive measures.
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Affiliation(s)
- Thomas Vogel
- Pôle de Gériatrie, Hôpital de la Robertsau, Strasbourg.
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74
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Popović M, Caballero-Bleda M, Popović N, Puelles L, van Groen T, Witter MP. Verapamil prevents, in a dose-dependent way, the loss of ChAT-immunoreactive neurons in the cerebral cortex following lesions of the rat nucleus basalis magnocellularis. Exp Brain Res 2005; 170:368-75. [PMID: 16328269 DOI: 10.1007/s00221-005-0219-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Accepted: 09/01/2005] [Indexed: 12/23/2022]
Abstract
In the present study we analysed the neuroprotective effect of the L-type voltage-dependent calcium channel antagonist verapamil on cholineacetyltransferase (ChAT)-immunoreactive neurons in the cerebral cortex of rats with bilateral electrolytic lesions of the nucleus basalis magnocellularis (NBM). Treatment with verapamil (1.0, 2.5, 5.0 and 10.0 mg/kg/12 h i.p.) started 24 h after NBM lesions and lasted 8 days. Animals were sacrificed on day 21 after NBM-lesions. The bilateral NBM-lesions produced significant loss of ChAT-immunoreactive neurons in frontal, parietal and temporal cortex. Although the number of ChAT-positive neurons was significantly higher in NBM-lesioned animals treated with verapamil at a dose of 2.5, 5.0 and 10.0 mg/kg than in saline treated ones, the most significant effect was obtained at a dose of 5 mg/kg. This is, to our knowledge, the first report showing an inverted U-shape mode of neuroprotective action of the calcium antagonist verapamil, at morphological level in this particular model of brain damage. The demonstrated beneficial effect of verapamil treatment suggests that the regulation of calcium homeostasis during the early period after NBM lesions might be a possible treatment to prevent neurodegenerative processes in the rat cerebral cortex.
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Affiliation(s)
- Miroljub Popović
- Departamento de Anatomía Humana y Psicobiología, Facultad de Medicina, Campus Universitario de Espinardo, Universidad de Murcia, 30100 Murcia, Spain.
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75
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Qiu C, Winblad B, Fratiglioni L. The age-dependent relation of blood pressure to cognitive function and dementia. Lancet Neurol 2005; 4:487-99. [PMID: 16033691 DOI: 10.1016/s1474-4422(05)70141-1] [Citation(s) in RCA: 757] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The relation of blood pressure with cognitive function and dementia has, in recent years, received much attention from epidemiological research. Some cross-sectional studies have shown an inverse association between blood pressure and the prevalence of dementia and Alzheimer's disease, whereas longitudinal studies yield mixed results that largely depend on the age at which blood pressure is measured and the time interval between blood pressure and outcome assessments. Some studies suggest that midlife high blood pressure is a risk factor for late-life cognitive impairment and dementia, and that low diastolic pressure and very high systolic pressure in older adults may be associated with subsequent development of dementia and Alzheimer's disease. Observational studies and randomised clinical trials provide limited evidence for a protective effect of antihypertensive therapy against dementia and stroke-related cognitive decline. Atherosclerosis resulting from long-standing hypertension, and cerebral hypoperfusion secondary to severe atherosclerosis and to low blood pressure may be major biological pathways linking both high blood pressure in midlife and low blood pressure in late-life to cognitive decline and dementia.
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Affiliation(s)
- Chengxuan Qiu
- Aging Research Centre, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institute and Stockholm Gerontology Research Centre, Stockholm, Sweden.
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Blasko I, Kemmler G, Krampla W, Jungwirth S, Wichart I, Jellinger K, Tragl KH, Fischer P. Plasma amyloid beta protein 42 in non-demented persons aged 75 years: effects of concomitant medication and medial temporal lobe atrophy. Neurobiol Aging 2005; 26:1135-43. [PMID: 15917096 DOI: 10.1016/j.neurobiolaging.2005.03.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Revised: 02/09/2005] [Accepted: 03/08/2005] [Indexed: 10/25/2022]
Abstract
Plasma amyloid beta (Abeta42) levels increase with age and are elevated in some patients during the early stages of Alzheimer's disease (AD). Although plasma Abeta42 is not useful for diagnosis of AD, it might be a biological risk factor. In the elderly population a considerable variety of concomitant medication is used for the treatment of various disorders. How this co-medication might influence Abeta42 levels is still to be investigated. Through the Vienna Transdanube Aging study (VITA), the authors measured cross-sectional Abeta42 plasma levels during the initial examination of 526 individuals aged 75 years without dementia. The medication considered included: treatment with calcium channel blockers, digitalis, anticoagulants, antihistamines, ergotamine, histamine H(2) receptor antagonists, bronchodilators, pentoxyfilline, neuroleptics, insulin, oral antidiabetics, l-dopa, benzodiazepines, oestrogen, Gingko biloba, vitamins, piracetam, non-steroidal anti-inflammatory drugs (NSAIDs), and statins. Of the study population aged 75 years, 90% were users of some of the above-mentioned medication. Depending on their medial temporal lobe atrophy (MTA), users of insulin showed significantly increased levels of Abeta42, while users of gingko biloba for at least 2 years of drug intake had significantly decreased Abeta42 plasma levels, independent of their MTA. Users of NSAIDs showed a non-significant trend to reduced Abeta42 plasma levels, while users of biguanides showed an increase in Abeta42 plasma levels. In the multiple regression analysis considering possible interactions between various medications statin users showed a significant decrease of Abeta42; insulin users had again significantly higher and long-term gingko biloba users lower plasma Abeta42 levels. Persons with a low degree of MTA had significantly increased Abeta42 plasma levels. Considering the increase of Abeta42 plasma levels as a risk factor for AD, any changes induced by medication by long-term use in the peripheral and possibly also in the central compartment, could be of clinical relevance.
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Affiliation(s)
- Imrich Blasko
- Department of Psychiatry, Innsbruck Medical University, Austria
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