Journal of Postgraduate Medicine
 Open access journal indexed with Index Medicus & ISI's SCI  
Users online: 1342  
Home | Subscribe | Feedback | Login 
About Latest Articles Back-Issues Article Submission Resources Sections Etcetera Contact
 
  NAVIGATE Here 
  Search
 
  
 RESOURCE Links
 ::  Similar in PUBMED
 ::  Search Pubmed for
 ::  Search in Google Scholar for
 ::Related articles
 ::  Article in PDF (357 KB)
 ::  Citation Manager
 ::  Access Statistics
 ::  Reader Comments
 ::  Email Alert *
 ::  Add to My List *
* Registration required (free) 

  IN THIS Article
 ::  Abstract
 :: Introduction
 :: Conclusion
 ::  References
 ::  Article Tables

 Article Access Statistics
    Viewed2409    
    Printed58    
    Emailed0    
    PDF Downloaded22    
    Comments [Add]    

Recommend this journal


 


 
  Table of Contents     
REVIEW ARTICLE
Year : 2016  |  Volume : 62  |  Issue : 4  |  Page : 242-248

Can angiotensin-converting enzyme inhibitors impact cognitive decline in early stages of Alzheimer's disease? An overview of research evidence in the elderly patient population


Department of Family Practice, Medical University of Silesia (SUM), Katowice-Zabrze, 3 Maja St. 13/15, 41-800 Zabrze, Poland

Date of Submission28-Dec-2015
Date of Decision03-Feb-2016
Date of Acceptance27-Jun-2016
Date of Web Publication20-Oct-2016

Correspondence Address:
Dr. K Rygiel
Department of Family Practice, Medical University of Silesia (SUM), Katowice-Zabrze, Poland 3 Maja St. 13/15, 41-800 Zabrze
Poland
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0022-3859.188553

Rights and Permissions


 :: Abstract 

Alzheimer's disease (AD) is a neurodegenerative disease, in which an accumulation of toxic amyloid beta in the brain precedes the emergence of clinical symptoms. AD spectrum consists of presymptomatic, early symptomatic, and symptomatic phase of dementia. At present, no pharmacotherapy exists to modify or reverse a course of AD, and only symptomatic treatments are available. Many elderly patients, diagnosed with multiple medical conditions (such as cardiovascular diseases, Type 2 diabetes mellitus, and cerebrovascular diseases) are at increased risk of the development of mild cognitive impairment (MCI), AD, and vascular dementia. Studies have revealed reduced rates of cognitive decline, in elderly patients, who were treated with centrally active angiotensin-converting enzyme inhibitors (ACE-Is) (that have an ability to cross the blood–brain barrier). This article reviews recently published literature, focused on possible protective influence of the centrally active ACE-Is, in the elderly population, at risk for cognitive decline.


Keywords: Alzheimer's disease, angiotensin.converting enzyme inhibitors, mild cognitive impairment, renin.angiotensin system


How to cite this article:
Rygiel K. Can angiotensin-converting enzyme inhibitors impact cognitive decline in early stages of Alzheimer's disease? An overview of research evidence in the elderly patient population. J Postgrad Med 2016;62:242-8

How to cite this URL:
Rygiel K. Can angiotensin-converting enzyme inhibitors impact cognitive decline in early stages of Alzheimer's disease? An overview of research evidence in the elderly patient population. J Postgrad Med [serial online] 2016 [cited 2019 Aug 25];62:242-8. Available from: http://www.jpgmonline.com/text.asp?2016/62/4/242/188553



 :: Introduction Top


Alzheimer's disease (AD) is a neurodegenerative disease, in which an accumulation of toxic amyloid beta in the brain precedes the emergence of clinical symptoms by 10–20 years, and its spectrum consists of different phases of dementia, such as presymptomatic, early symptomatic, and symptomatic (mild, moderate, and severe). Many individuals, who begin to display symptoms of cognitive decline can be categorized as having mild cognitive impairment (MCI), including its amnestic or nonamnestic form. MCI represents the earliest stage, during which a person's most complex mental abilities are compromised, but his/her activities of daily living (ADL) or instrumental ADL can still be spared.[1] MCI often “sets the stage” for AD or vascular dementia, and typically patients with an amnestic type of MCI are almost seven times more likely to develop AD.[1] Although the role of amyloid beta in the progression of AD pathophysiologic changes has been well documented, the exact influence of amyloid beta load on the mental and functional performance of the afflicted patients, and their other AD biomarkers, is still not precisely determined.[2] Furthermore, many elderly patients, who have been diagnosed with multiple chronic medical conditions, have a greater risk of the development of MCI or vascular dementia. It has been shown that in the elderly, inadequately controlled common comorbid conditions (such as arterial hypertension, Type 2 diabetes mellitus, cardiovascular diseases [CVDs], and cerebrovascular diseases), as well as an inactive lifestyle, inappropriate nutrition, and multiple medication use play a significant role in progressive cognitive decline that may lead to the development of AD or vascular dementia.[3] Vascular cognitive impairment is relevant to the impact of cerebrovascular diseases (e.g., stroke) on cognition, leading to vascular dementia.[4] A meta-analysis by Valenti et al. showed evidence suggesting that the vascular risk factors play an important role in the pathogenesis of AD, and epidemiological studies have also confirmed the association.[5] Arterial hypertension represents an important risk factor for dementia, and it has been noted that certain antihypertensive medications, such as angiotensin-converting enzyme inhibitors (ACE-Is), independently from blood pressure regulation, might be protective against dementia, and thus, could lead to improved cognitive outcomes.[6] These include centrally active ACE-Is (a subclass of ACE-Is), such as captopril, fosinopril, lisinopril, perindopril, ramipril, and trandolapril, which are lipid soluble and have an ability to cross the blood–brain barrier and penetrate cerebral tissues. They thus exert an effect on cognition via possible anti-inflammatory mechanisms independent of their blood pressure-lowering action.[6] In contrast, noncentrally active ACE-Is (without these cerebral properties), including benazepril, enalapril, moexipril, and quinapril, which work mainly by lowering blood pressure, do not have such an effect on cognitive functions.[6] Since AD has been associated with chronic inflammation in the brain, the centrally active ACE-Is may likely target the inflammatory processes, and in this way, impact cognitive decline.[6] In addition, the brain renin-angiotensin system (RAS) regulates cerebral blood flow (independently from the peripheral RAS), and plays a key role in linking arterial hypertension to cognitive functions.[7] It thus appears that the central actions of angiotensins are beyond their “traditional” physiologic roles and can be related to learning and memory processes. It is conceivable that some pharmacological manipulation of angiotensin ligands may translate to the possible management of cognitive deterioration in AD.[7] In the brain, angiotensin II activates two types of receptors: Type 1 that leads to vasoconstriction, endothelial dysfunction, and vascular remodeling and Type 2 that leads to vasodilatation, neuronal differentiation, decreased inflammation, and axonal regeneration.[8] Angiotensin receptor blockers (ARBs) block the Type 1, but not Type 2, whereas centrally active ACE-Is decrease activation of both receptors.[8] A study by Ohrui et al. has shown that the adequate blood pressure control, achieved by pharmacotherapy, based on brain-penetrating ACE-Is, has been associated with protection against cognitive decline and slowing down the progression of AD.[9] However, it is still unknown which treatment regimen: Centrally active ACE-Is or ARBs would have a superior impact on cerebral hemodynamics and cognitive or executive brain functions. At present, for AD, only symptomatic treatments that consist mostly of acetyl-cholinesterase inhibitors (including donepezil, galantamine, and rivastigmine) and the N-methyl-D-aspartate receptor antagonist memantine are available.[10] Although the above medications might exert some modest effects on the disease course, they do not prevent the AD progression, and thus, additional approaches aimed at slowing cognitive decline have been investigated.

This article reviews published literature (over the last 15 years) on the antihypertensive medications, associated with a possible influence on cognitive status, focusing on the role of centrally active ACE-Is in the reduction of the cognitive decline in early AD stages and MCI. In preparing of this review, a PubMed search of English language medical literature was performed using the keywords: “Alzheimer's disease,” “mild cognitive impairment,” “angiotensin-converting enzyme inhibitors,” and “renin-angiotensin system.” The main search timeframe was set up for the last 10 years, in relevance to the elderly patient population, with common comorbidities, including arterial hypertension. This search was supplemented with some data from cross references, addressing the effects of centrally active ACE-Is on cognitive status (beyond their blood pressure controlling actions), in patients with early stages of AD.

Antihypertensive medications and their possible beneficial impact on cognitive functions in elderly patients – insights from research studies

According to research evidence [Table 1], the antihypertensive medications associated with reduced risk of developing cognitive decline or dementia include: centrally active ACE-Is, for example, perindopril;[6],[11],[13] calcium channel blockers (CCBs), for example, nilvadipine;[12] diuretics, for example, indapamide;[13] and ARBs, for example, candesartan.[14] In general, the results of studies related to the potential role of antihypertensive agents (in particular brain-penetrating ACE-Is) in older individuals with prodromal AD or MCI appear promising. Evidence from the Perindopril Protection against Recurrent Stroke Study demonstrated that a combination of perindopril (a centrally active ACE-I) and indapamide (adiuretic) was associated with a significant reduction in the incidence of stroke and cognitive decline, compared to placebo, among patients with cerebrovascular disease.[13] Concurrently, the antihypertensives and vascular, endothelial, and cognitive function trial, conducted in elderly hypertensives with early cognitive impairment, supported the notion that the centrally active ACE-Is and ARBs might lower dementia risk, independently of their blood pressure lowering properties.[14] Likewise, the Systolic Hypertension in Europe study has found that the combination of nitrendipine (CCB), enalapril (ACE-I), and/or hydrochlorothiazide (diuretic) reduced the incidence of dementia by 55% compared with placebo.[15] Similarly, in the Study on Cognition and Prognosis in the Elderly, a monotherapy with the ARB, candesartan, showed modest cognitive effects.[16] It should be highlighted that in the Cardiovascular Health Study cognition trial, a large group of elderly patients with hypertension (treated pharmacologically) was followed to determine whether the cumulative exposure to ACE-Is (as a class and by central activity), compared with other antihypertensive agents, was associated with a lower risk of incident dementia, cognitive decline, or incident disability.[6] Although the observational data from the Cardiovascular Health Study have revealed that the centrally active ACE-Is were associated with 65% less cognitive decline per year of exposure (this effect was mostly related to their properties of cerebral tissues penetration), these findings would have to be confirmed by further large-scale, randomized controlled, clinical trials (RCTs).[6] In addition, it has been considered that the difference in the impact on cognitive status between centrally active ACE-Is and noncentrally active ACE-Is is not due to their antihypertensive mechanism of action but rather to their effect on the brain's intrinsic RAS, which is involved in memory and cognition.[6] In addition, the results of an observational study that involved patients with AD, vascular dementia, or mixed dementia have suggested that the centrally active ACE-Is may reduce the rate of cognitive decline in patients with dementia, regardless of blood pressure levels.[17] Based on this study reports, the cognitive improvement had been most evident in the initial 6 months, during which the patients with dementia had been started on therapy with one of the centrally active ACE-Is (e.g., captopril, fosinopril, lisinopril, prinivil, perindopril, ramipril, or trandolapril).[17] There is a growing body of research showing that the centrally active ACE-Is slow down the cognitive deterioration in patients with AD, by almost 30% a year, compared with the other antihypertensive agents or with the ACE-Is that do not exhibit the central mechanism of action.[17],[18] Furthermore, centrally active ACE-Is may also improve exercise tolerance in functionally impaired older adults with normal cognition.[18] In agreement with the above findings, in the French cohort study, involving older adults with AD, it has been reported that the use of centrally active ACE-Is was associated with a slower cognitive decline, independent from the antihypertensive effect.[19] Moreover, an analysis of a large, prospective US cohort, involving mostly elderly male patients, has revealed that the ARBs alone or in combination with ACE-Is were associated with a significant reduction in the incidence, and progression of AD or other types of dementia, compared with ACE-Is alone, or other antihypertensive medications.[20] However, not all studies have shown cognitive benefits with the RAS-related antihypertensive agents. In particular, two large-scale parallel studies, the Ongoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial and Telmisartan Randomized Assessment Study in ACE Intolerant Subjects with CVD, have found that the centrally active ACE-Is did not reveal measurable effects on cognition.[21]
Table 1: Research studies evaluating the effects of antihypertensive medications on cognition in elderly patients with hypertension, Alzheimer's disease, or risk factors for dementia

Click here to view


Relations between angiotensin-converting enzyme, the accumulation of amyloid beta, and inflammatory process in the brain of patients with Alzheimer's disease – ”setting the stage” for angiotensin-converting enzyme inhibitors

According to the AD amyloid hypothesis, patients with AD have abnormal cleavage of amyloid precursor protein resulting in a pathological accumulation of amyloid beta in the brain.[22] The relationship between ACE and the accumulation of amyloid beta in the brain is very complex and not fully explained.[22] The results of the large meta-analysis by Lehmann et al. suggest that the ACE insertion-deletion polymorphism can be considered a marker of AD, indicating the elevated risk of developing AD.[23] Since ACE plays a central role in the regulation of blood pressure, this enzyme is commonly targeted by medications such as ACE-Is, especially in elderly patients, suffering from arterial hypertension. It should be noted that based on a long-term retrospective survey of neuropathological reports, ACE-Is had been one of the first antihypertensives studied in AD.[24] In addition, genetic, pathological, and biochemical studies have also associated ACE with AD and suggested that the ACE activity is increased in AD, proportionally to the cerebral load of amyloid beta.[25] It appears that the RAS might also contribute to a possible connection between the blood vessel functional condition and AD pathology. This concept has been supported by a higher ACE activity (a component of the intrinsic cerebral RAS) in the cortical areas, including hippocampus, parahippocampal gyrus, frontal cortex, and caudate nucleus that are particularly responsible for memory, cognitive, and executive functions, which are primarily affected in patients with AD.[26] Furthermore, higher ACE levels were also documented in autopsies of the AD brain tissue in direct relation to the parenchymal amyloid beta load.[27] A recent meta-analysis by Ye et al. evaluated the exact role of RAS-targeting antihypertensive agents (such as centrally active ACE-Is) in terms of slowing down cognitive decline in patients with AD.[28] It has been indicated that the RAS-targeting antihypertensive medications might serve as a potential treatment for reducing the incidence and progression of AD beyond just blood pressure controlling properties.[28] Moreover, a meta-analysis by Ligthart et al.[29] provided evidence that the adequate management of cardiovascular risk factors, in particular, blood pressure control, with centrally active antihypertensive medications, might not only optimize cerebral perfusion but also decrease inflammatory processes and reduce amyloid beta accumulation in the brain. This is convergent with some reports concerning the effects of antihypertensive therapy on the reduction of cognitive decline rate in AD.[30] It should be emphasized that the recommendations from the National Institute on Aging-Alzheimer's Association include antihypertensive therapies in the preclinical stages of AD.[31]

Potential risks of centrally active angiotensin-converting enzyme inhibitors

There is a concern that in some patients, centrally active ACE-Is can interfere with degradation of amyloid beta that in turn might contribute to its higher accumulation in the brain. Since AD is a very heterogeneous disease, it is possible that in certain patients, the accumulation of the amyloid plaques plays a more prominent role in the AD pathology than the inflammatory process.[17] It appears that beneficial effects of the centrally active ACE-Is (in particular perindopril, which has a strong ability of cerebral tissue penetration) are related to their lipophilic properties rather than to their hypotensive mechanism of action.[17] At present, it remains unclear how the centrally active ACE-Is slow down the cognitive decline in AD patients. One possible suggestion relates to the concept that AD represents a chronic inflammatory process in the brain. Since centrally active ACE-Is can possibly exert some anti-inflammatory effects, they may counteract this cerebral proinflammatory state.[17] On the other hand, a stimulation of the cerebral RAS can potentially mediate activation of proinflammatory cytokines, which could influence neurodegenerative processes, leading to dementia. Evidence from the AD Centers' Uniform Data Set revealed that the treatment with RAS-acting antihypertensive medications decreased AD incidence, among individuals without dementia,[32] and also improved cognitive performance, among the ones with AD,[9] in comparison to the therapy with non-RAS-acting medications or RAS-acting medications that do not cross the blood–brain barrier. These benefits have been reported independently from changes in blood pressure.[32] However, more clinical trials are needed to fully explain whether the RAS-acting medications (such as the centrally active ACE-Is) can effectively impact cognitive functions or influence the disease conversion from its prodromal stage or MCI to more advanced AD stages. Answers to these questions are important for a possible further implementation of targeted therapies with the centrally active ACE-Is, early in the disease process to reduce the amyloid beta toxicity and in consequence to slow down the development of AD pathology in the brain.

Predictors of conversion from mild cognitive impairment to Alzheimer's disease

The main factors that are helpful in predicting the likelihood of progression from MCI to AD include: (1) whole brain and hippocampal volume on magnetic resonance imaging (MRI) and computed tomography (CT) (at present, CT and MRI scans are mostly used to rule out coexisting cerebral pathologies),[33] (2) apolipoprotein E (APOE) status-the APOE epsilon4 allele is associated with incident MCI among community-dwelling older persons (this genetic test it is highly informative in providing AD risk evaluation; however, it is not recommended for routine clinical use [34]), and (3) the severity of memory impairment (evaluated via psychometric tests and neuropsychological testing).[35] It should be highlighted that emerging technologies of amyloid imaging scans have a tremendous impact on the early diagnosis of AD; however, they are not yet accessible in clinical practice. For instance, the positron emission tomography (PET) scan, using a radioactive glucose tracer, reveals some findings characteristic for early-stage AD, and the amyloid-based PET scan reflects a relative amyloid load in the brain that is also associated with the early, often asymptomatic AD stage.[36]

Future research directions for angiotensin-converting enzyme inhibitors in patients with elevated Alzheimer's disease risk

In the future, clinical trials examining the impact of blood–brain barrier crossing RAS-acting medications on the biomarkers of AD, in prodromal and mild AD stages, or MCI are merited. In particular, this includes trials using neuroimaging, and cerebrospinal fluid analysis, since they could elucidate the relation between AD and RAS, especially among patients in early AD stages.[37] Further clinical studies in patient groups with or without hypertension, and with elevated risk of AD (due to genetic predispositions, early onset of cognitive impairment, cardiovascular comorbidities, or ethnicity) should be conducted to explore whether the RAS-modifying medications, including centrally acting ACE-Is, should be considered for repurposing for AD indications in high-risk for dementia older patient populations.[37] It should be highlighted that outside of the large-scale clinical trials, there are only limited reports on the effects of centrally active ACE-Is on the rate of cognitive decline in elderly patients with dementia or its risk factors. Therefore, further prospective, long-term trials, conducted in a “real world” setting would be helpful for medical providers managing such patients. Finally, to test the hypothesis that the centrally active ACE-Is has protective effects on cognition (beyond the effects of blood-pressure control) it would be necessary to conduct a large-scale RCT, randomizing older adults with hypertension to centrally active ACE-Is versus noncentrally active ACE-Is. In addition, further prospective RCTs, in elderly patients with early AD stage or MCI, naive to ACE-Is, with one arm receiving centrally active ACE-Is and the other arm receiving standard medical treatment (not containing centrally active ACE-Is), followed for at least a year, would be helpful to address whether this treatment could be another potential therapeutic option for prevention of cognitive decline in a growing population of geriatric patients suffering from AD or MCI (often associated with cardiovascular, cerebral, and metabolic comorbidities).


 :: Conclusion Top


Treatment options for AD are limited, and therefore the potential approaches to intervene at the earliest possible AD stage are necessary to fulfill the unmet needs of a growing population of elderly patients, who are at risk of cognitive decline. Identifying such patients, establishing an early diagnosis of AD or MCI, and designing an individualized therapy plan, including the safe and effective treatment for comorbidities (that often accompany MCI and AD), represent important priorities for physicians involved in the management of elderly patients. In conclusion, it should be emphasized that the centrally active ACE-Is (in contrast, noncentrally active ones) can impact cognitive functions (e.g., reduce risk for cognitive decline or dementia) via a possible anti-inflammatory or cerebral RAS-related actions and not by a blood pressure-lowering.[37],[38] Unquestionably, long-term prospective RCTs of centrally-active ACE-Is versus a noncentrally active ACE-Is would be warranted to establish further recommendations for centrally active ACE-Is as possible additional options to be adopted in the therapy of early AD stages or MCI. However, such evidence is not available yet and in the meantime, possible practical implications for many older patients at risk for dementia who have medical indications for the ACE-Is use (due to comorbidities, such as arterial hypertension, congestive heart failure, status post myocardial infarction, diabetes mellitus, or chronic kidney disease) might include a preferred choice of a centrally active ACE-I (e.g., captopril, fosinopril, lisinopril, perindopril, ramipril, or trandolapril) rather than a noncentrally active one.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
 :: References Top

1.
Boyle PA, Wilson RS, Aggarwal NT, Tang Y, Bennett DA. Mild cognitive impairment: Risk of Alzheimer disease and rate of cognitive decline. Neurology 2006;67:441-5.  Back to cited text no. 1
[PUBMED]    
2.
Petersen RC, Wiste HJ, Weigand SD, Rocca WA, Roberts RO, Mielke MM, et al. Association of elevated amyloid levels with cognition and biomarkers in cognitively normal people from the community. JAMA Neurol 2016;73:85-92.  Back to cited text no. 2
    
3.
Vassilaki M, Aakre JA, Cha RH, Kremers WK, St Sauver JL, Mielke MM, et al. Multimorbidity and risk of mild cognitive impairment. J Am Geriatr Soc 2015;63:1783-90.  Back to cited text no. 3
    
4.
Erkinjuntti T, Gauthier S. The concept of vascular cognitive impairment. Front Neurol Neurosci 2009;24:79-85.  Back to cited text no. 4
[PUBMED]    
5.
Valenti R, Pantoni L, Markus HS. Treatment of vascular risk factors in patients with a diagnosis of Alzheimer's disease: A systematic review. BMC Med 2014;12:160.  Back to cited text no. 5
[PUBMED]    
6.
Sink KM, Leng X, Williamson J, Kritchevsky SB, Yaffe K, Kuller L, et al. Angiotensin-converting enzyme inhibitors and cognitive decline in older adults with hypertension: Results from the Cardiovascular Health Study. Arch Intern Med 2009;169:1195-202.  Back to cited text no. 6
[PUBMED]    
7.
Ciobica A, Bild W, Hritcu L, Haulica I. Brain renin-angiotensin system in cognitive function: Pre-clinical findings and implications for prevention and treatment of dementia. Acta Neurol Belg 2009;109:171-80.  Back to cited text no. 7
[PUBMED]    
8.
Horiuchi M, Mogi M, Iwai M. The angiotensin II type 2 receptor in the brain. J Renin Angiotensin Aldosterone Syst 2010;11:1-6.  Back to cited text no. 8
[PUBMED]    
9.
Ohrui T, Tomita N, Sato-Nakagawa T, Matsui T, Maruyama M, Niwa K, et al. Effects of brain-penetrating ACE inhibitors on Alzheimer disease progression. Neurology 2004;63:1324-5.  Back to cited text no. 9
[PUBMED]    
10.
Sloane PD, Zimmerman S, Suchindran C, Reed P, Wang L, Boustani M, et al. The public health impact of Alzheimer's disease, 2000-2050: Potential implication of treatment advances. Annu Rev Public Health 2002;23:213-31.  Back to cited text no. 10
[PUBMED]    
11.
Rozzini L, Chilovi BV, Bertoletti E, Conti M, Del Rio I, Trabucchi M, et al. Angiotensin converting enzyme (ACE) inhibitors modulate the rate of progression of amnestic mild cognitive impairment. Int J Geriatr Psychiatry 2006;21:550-5.  Back to cited text no. 11
[PUBMED]    
12.
Kennelly S, Abdullah L, Kenny RA, Mathura V, Luis CA, Mouzon B, et al. Apolipoprotein E genotype-specific short-term cognitive benefits of treatment with the antihypertensive nilvadipine in Alzheimer's patients – An open-label trial. Int J Geriatr Psychiatry 2012;27:415-22.  Back to cited text no. 12
[PUBMED]    
13.
Tzourio C, Anderson C, Chapman N, Woodward M, Neal B, MacMahon S, et al. Effects of blood pressure lowering with perindopril and indapamide therapy on dementia and cognitive decline in patients with cerebrovascular disease. Arch Intern Med 2003;163:1069-75.  Back to cited text no. 13
[PUBMED]    
14.
Hajjar I, Hart M, Milberg W, Novak V, Lipsitz L. The rationale and design of the antihypertensives and vascular, endothelial, and cognitive function (AVEC) trial in elderly hypertensives with early cognitive impairment: Role of the renin angiotensin system inhibition. BMC Geriatr 2009;9:48.  Back to cited text no. 14
[PUBMED]    
15.
Forette F, Seux ML, Staessen JA, Thijs L, Babarskiene MR, Babeanu S, et al. The prevention of dementia with antihypertensive treatment: New evidence from the Systolic Hypertension in Europe (Syst-Eur) study. Arch Intern Med 2002;162:2046-52.  Back to cited text no. 15
[PUBMED]    
16.
Lithell H, Hansson L, Skoog I, Elmfeldt D, Hofman A, Olofsson B, et al. The Study on Cognition and Prognosis in the Elderly (SCOPE): Principal results of a randomized double-blind intervention trial. J Hypertens 2003;21:875-86.  Back to cited text no. 16
[PUBMED]    
17.
Gao Y, O'Caoimh R, Healy L, Kerins DM, Eustace J, Guyatt G, et al. Effects of centrally acting ACE inhibitors on the rate of cognitive decline in dementia. BMJ Open 2013;3. pii: E002881.  Back to cited text no. 17
    
18.
O'Caoimh R, Healy L, Gao Y, Svendrovski A, Kerins DM, Eustace J, et al. Effects of centrally acting angiotensin converting enzyme inhibitors on functional decline in patients with Alzheimer's disease. J Alzheimers Dis 2014;40:595-603.  Back to cited text no. 18
    
19.
Soto ME, van Kan GA, Nourhashemi F, Gillette-Guyonnet S, Cesari M, Cantet C, et al. Angiotensin-converting enzyme inhibitors and Alzheimer's disease progression in older adults: Results from the Réseau sur la Maladie d'Alzheimer Français cohort. J Am Geriatr Soc 2013;61:1482-8.  Back to cited text no. 19
[PUBMED]    
20.
Li NC, Lee A, Whitmer RA, Kivipelto M, Lawler E, Kazis LE, et al. Use of angiotensin receptor blockers and risk of dementia in a predominantly male population: Prospective cohort analysis. BMJ 2010;340:b5465.  Back to cited text no. 20
[PUBMED]    
21.
Teo K, Yusuf S, Sleight P, Anderson C, Mookadam F, Ramos B, et al. Rationale, design, and baseline characteristics of 2 large, simple, randomized trials evaluating telmisartan, ramipril, and their combination in high-risk patients: The Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial/Telmisartan Randomized Assessment Study in ACE Intolerant Subjects with Cardiovascular Disease (ONTARGET/TRANSCEND) trials. Am Heart J 2004;148:52-61.  Back to cited text no. 21
[PUBMED]    
22.
Hardy J. The amyloid hypothesis for Alzheimer's disease: A critical reappraisal. J Neurochem 2009;110:1129-34.  Back to cited text no. 22
[PUBMED]    
23.
Lehmann DJ, Cortina-Borja M, Warden DR, Smith AD, Sleegers K, Prince JA, et al. Large meta-analysis establishes the ACE insertion-deletion polymorphism as a marker of Alzheimer's disease. Am J Epidemiol 2005;162:305-17.  Back to cited text no. 23
[PUBMED]    
24.
Brunnström H, Gustafson L, Passant U, Englund E. Prevalence of dementia subtypes: A 30-year retrospective survey of neuropathological reports. Arch Gerontol Geriatr 2009;49:146-9.  Back to cited text no. 24
    
25.
Zou K, Michikawa M. Angiotensin-converting enzyme as a potential target for treatment of Alzheimer's disease: Inhibition or activation? Rev Neurosci 2008;19:203-12.  Back to cited text no. 25
[PUBMED]    
26.
Savaskan E, Hock C, Olivieri G, Bruttel S, Rosenberg C, Hulette C, et al. Cortical alterations of angiotensin converting enzyme, angiotensin II and AT1 receptor in Alzheimer's dementia. Neurobiol Aging 2001;22:541-6.  Back to cited text no. 26
[PUBMED]    
27.
Miners JS, Ashby E, Van Helmond Z, Chalmers KA, Palmer LE, Love S, et al. Angiotensin-converting enzyme (ACE) levels and activity in Alzheimer's disease, and relationship of perivascular ACE-1 to cerebral amyloid angiopathy. Neuropathol Appl Neurobiol 2008;34:181-93.  Back to cited text no. 27
[PUBMED]    
28.
Ye R, Hu Y, Yao A, Yang Y, Shi Y, Jiang Y, et al. Impact of renin-angiotensin system-targeting antihypertensive drugs on treatment of Alzheimer's disease: A meta-analysis. Int J Clin Pract 2015;69:674-81.  Back to cited text no. 28
[PUBMED]    
29.
Ligthart SA, Moll van Charante EP, Van Gool WA, Richard E. Treatment of cardiovascular risk factors to prevent cognitive decline and dementia: A systematic review. Vasc Health Risk Manag 2010;6:775-85.  Back to cited text no. 29
[PUBMED]    
30.
Duron E, Rigaud AS, Dubail D, Mehrabian S, Latour F, Seux ML, et al. Effects of antihypertensive therapy on cognitive decline in Alzheimer's disease. Am J Hypertens 2009;22:1020-4.  Back to cited text no. 30
[PUBMED]    
31.
Sperling RA, Aisen PS, Beckett LA, Bennett DA, Craft S, Fagan AM, et al. Toward defining the preclinical stages of Alzheimer's disease: Recommendations from the National Institute on Aging-Alzheimer's Association workgroups on diagnostic guidelines for Alzheimer's disease. Alzheimers Dement 2011;7:280-92.  Back to cited text no. 31
[PUBMED]    
32.
Weintraub S, Salmon D, Mercaldo N, Ferris S, Graff-Radford NR, Chui H, et al. The Alzheimer's disease centers' Uniform Data Set (UDS): The neuropsychologic test battery. Alzheimer Dis Assoc Disord 2009;23:91-101.  Back to cited text no. 32
[PUBMED]    
33.
Risacher SL, Saykin AJ, West JD, Shen L, Firpi HA, McDonald BC; Alzheimer's disease neuroimaging initiative (ADNI). Baseline MRI predictors of conversion from MCI to probable AD in the ADNI cohort. Curr Alzheimer Res 2009;6:347-61.  Back to cited text no. 33
    
34.
Boyle PA, Buchman AS, Wilson RS, Kelly JF, Bennett DA. The APOE epsilon4 allele is associated with incident mild cognitive impairment among community-dwelling older persons. Neuroepidemiology 2010;34:43-9.  Back to cited text no. 34
[PUBMED]    
35.
Cummings JL, Isaacson RS, Schmitt FA, Velting DM. A practical algorithm for managing Alzheimer's disease: What, when, and why? Ann Clin Transl Neurol 2015;2:307-23.  Back to cited text no. 35
[PUBMED]    
36.
Mountz JM, Laymon CM, Cohen AD, Zhang Z, Price JC, Boudhar S, et al. Comparison of qualitative and quantitative imaging characteristics of [11C] PiB and [18F] flutemetamol in normal control and Alzheimer's subjects. Neuroimage Clin 2015;9:592-8.  Back to cited text no. 36
[PUBMED]    
37.
Wharton W, Goldstein FC, Zhao L, Steenland K, Levey AI, Hajjar I, et al. Modulation of renin-angiotensin system may slow conversion from mild cognitive impairment to Alzheimer's Disease. J Am Geriatr Soc 2015;63:1749-56.  Back to cited text no. 37
    
38.
de Oliveira FF, Bertolucci PH, Chen ES, Smith MC. Brain-penetrating angiotensin-converting enzyme inhibitors and cognitive change in patients with dementia due to Alzheimer's disease. J Alzheimers Dis 2014;42 Suppl 3:S321-4.  Back to cited text no. 38
[PUBMED]    



 
 
    Tables

  [Table 1]



 

Top
Print this article  Email this article
 
Online since 12th February '04
2004 - Journal of Postgraduate Medicine
Official Publication of the Staff Society of the Seth GS Medical College and KEM Hospital, Mumbai, India
Published by Wolters Kluwer - Medknow