151
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Kuller LH, Margolis KL, Gaussoin SA, Bryan NR, Kerwin D, Limacher M, Wassertheil-Smoller S, Williamson J, Robinson JG. Relationship of hypertension, blood pressure, and blood pressure control with white matter abnormalities in the Women's Health Initiative Memory Study (WHIMS)-MRI trial. J Clin Hypertens (Greenwich) 2010; 12:203-12. [PMID: 20433539 DOI: 10.1111/j.1751-7176.2009.00234.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper evaluates the relationship of blood pressure (BP) levels at Women's Health Initiative (WHI) baseline, treatment of hypertension, and white matter abnormalities among women in conjugated equine estrogen (CEE) and medroxyprogesterone acetate and CEE-alone arms. The WHI Memory Study-Magnetic Resonance Imaging (WHIMS-MRI) trial scanned 1424 participants. BP levels at baseline were significantly positively related to abnormal white matter lesion (WML) volumes. Participants treated for hypertension but who had BP > or = 140/90 mm Hg had the greatest amount of WML volumes. Women with untreated BP > or = 140/90 mm Hg had intermediate WML volumes. Abnormal WML volumes were related to hypertension in most areas of the brain and were greater in the frontal lobe than in the occipital, parietal, or temporal lobes. Level of BP at baseline was strongly related to amount of WML volumes. The results of the study reinforce the relationship of hypertension and BP control and white matter abnormalities in the brain. The evidence to date supports tight control of BP levels, especially beginning at younger and middle age as a possible and perhaps only way to prevent dementia.
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Affiliation(s)
- Lewis H Kuller
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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152
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Reitz C, Tang MX, Schupf N, Manly JJ, Mayeux R, Luchsinger JA. A summary risk score for the prediction of Alzheimer disease in elderly persons. ACTA ACUST UNITED AC 2010; 67:835-41. [PMID: 20625090 DOI: 10.1001/archneurol.2010.136] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
OBJECTIVE To develop a simple summary risk score for the prediction of Alzheimer disease in elderly persons based on their vascular risk profiles. DESIGN A longitudinal, community-based study. SETTING New York, New York. Patients One thousand fifty-one Medicare recipients aged 65 years or older and residing in New York who were free of dementia or cognitive impairment at baseline. MAIN OUTCOME MEASURES We separately explored the associations of several vascular risk factors with late-onset Alzheimer disease (LOAD) using Cox proportional hazards models to identify factors that would contribute to the risk score. Then we estimated the score values of each factor based on their beta coefficients and created the LOAD vascular risk score by summing these individual scores. RESULTS Risk factors contributing to the risk score were age, sex, education, ethnicity, APOE epsilon4 genotype, history of diabetes, hypertension or smoking, high-density lipoprotein levels, and waist to hip ratio. The resulting risk score predicted dementia well. According to the vascular risk score quintiles, the risk to develop probable LOAD was 1.0 for persons with a score of 0 to 14 and increased 3.7-fold for persons with a score of 15 to 18, 3.6-fold for persons with a score of 19 to 22, 12.6-fold for persons with a score of 23 to 28, and 20.5-fold for persons with a score higher than 28. CONCLUSIONS While additional studies in other populations are needed to validate and further develop the score, our study suggests that this vascular risk score could be a valuable tool to identify elderly individuals who might be at risk of LOAD. This risk score could be used to identify persons at risk of LOAD, but can also be used to adjust for confounders in epidemiologic studies.
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Affiliation(s)
- Christiane Reitz
- The Gertrude H. Sergievsky Center, Columbia University, New York, NY 10032, USA.
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153
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Abstract
Promoting successful cognitive aging is a topic of major importance to individuals and the field of public health. This review presents a coherent framework not only for evaluating factors, protective activities, and enhancing agents that have already been proposed, but also ones that will be put forward in the future. The promotion of successful cognitive aging involves the dual goals of preventing loss of information processing capacity and cognitive reserve, and enhancing brain capacity and cognitive reserve. Four major lines of evidence are available for evaluating whether a proposed factor promotes successful cognitive aging: 1) epidemiologic/cohort studies; 2) animal/basic science studies; 3) human "proof-of-concept" studies; and 4) human intervention studies. Each line of evidence has advantages and limitations that will be discussed. Through illustrative examples, we trace the ways in which each method informs us about the potential value of several proposed factors. Currently, lines of converging evidence allow the strongest case to be made for physical and cognitively stimulating activities. Although epidemiological data seem to favor the use of statins to lower the risk of dementia, more definitive recommendations await further randomized controlled studies. There is presently no clear evidence that antioxidants or Ginkgo biloba promote successful cognitive aging. The impact of resveratrol, fish oil, and a long list of other proposed agents needs to be determined. Clinicians remain well-positioned to identify and aggressively treat vascular risk factors, diabetes, sleep disorders, and other conditions that may reduce brain capacity, and to encourage activities that can build cognitive reserve.
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Affiliation(s)
- Kirk R Daffner
- Brigham Behavioral Neurology Group, Division of Cognitive and Behavioral Neurology, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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154
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Uranga RM, Bruce-Keller AJ, Morrison CD, Fernandez-Kim SO, Ebenezer PJ, Zhang L, Dasuri K, Keller JN. Intersection between metabolic dysfunction, high fat diet consumption, and brain aging. J Neurochem 2010; 114:344-61. [PMID: 20477933 PMCID: PMC2910139 DOI: 10.1111/j.1471-4159.2010.06803.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Deleterious neurochemical, structural, and behavioral alterations are a seemingly unavoidable aspect of brain aging. However, the basis for these alterations, as well as the basis for the tremendous variability in regards to the degree to which these aspects are altered in aging individuals, remains to be elucidated. An increasing number of individuals regularly consume a diet high in fat, with high-fat diet consumption known to be sufficient to promote metabolic dysfunction, although the links between high-fat diet consumption and aging are only now beginning to be elucidated. In this review we discuss the potential role for age-related metabolic disturbances serving as an important basis for deleterious perturbations in the aging brain. These data not only have important implications for understanding the basis of brain aging, but also may be important to the development of therapeutic interventions which promote successful brain aging.
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Affiliation(s)
- Romina M. Uranga
- Pennington Biomedical Research Center/Louisiana State University System, Baton Rouge, LA, USA
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Bahía Blanca, Argentina
| | | | - Christopher D. Morrison
- Pennington Biomedical Research Center/Louisiana State University System, Baton Rouge, LA, USA
| | - Sun Ok Fernandez-Kim
- Pennington Biomedical Research Center/Louisiana State University System, Baton Rouge, LA, USA
| | - Philip J. Ebenezer
- Pennington Biomedical Research Center/Louisiana State University System, Baton Rouge, LA, USA
| | - Le Zhang
- Pennington Biomedical Research Center/Louisiana State University System, Baton Rouge, LA, USA
| | - Kalavathi Dasuri
- Pennington Biomedical Research Center/Louisiana State University System, Baton Rouge, LA, USA
| | - Jeffrey N. Keller
- Pennington Biomedical Research Center/Louisiana State University System, Baton Rouge, LA, USA
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155
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Launer LJ, Hughes T, Yu B, Masaki K, Petrovitch H, Ross GW, White LR. Lowering midlife levels of systolic blood pressure as a public health strategy to reduce late-life dementia: perspective from the Honolulu Heart Program/Honolulu Asia Aging Study. Hypertension 2010; 55:1352-9. [PMID: 20404223 PMCID: PMC3241740 DOI: 10.1161/hypertensionaha.109.147389] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Accepted: 03/23/2010] [Indexed: 11/16/2022]
Abstract
To estimate the potential benefits of lowering systolic blood pressure (SBP) toward preventing late-life dementia, we estimated the population-attributable risk of elevated SBP for dementia. Analyses are based on the cohort of 8006 Japanese American men (born 1900-1919) followed since 1965 as a part of the Honolulu Heart Program, continued as the Honolulu Asia Aging Study. Midlife cardiovascular risk factors and late-life brain function are well described. We estimated the population-attributable risk of dementia cases attributed to midlife SBP, grouped by the seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure criteria (<120, 120 to <140, and > or =140 mm Hg), taking into account treatment history, confounding factors, and competitive risk for death. The analysis is based on 7878 subjects, including 491 cases of dementia, with a mean interval of 25 years between measurement of blood pressure and dementia diagnosis. Compared with those with SBP <120 mm Hg, untreated, and <50 years of age at baseline, 17.7% (95% CI: 4.6% to 29.1%) of the cases were attributable to prehypertensive levels (SBP: 120 to <140 mm Hg) of SBP, translating into 11 excess cases per 1000. Among those who did not report taking antihypertensive medication in midlife, 27% (95% CI: 8.9% to 42.1%) of dementia cases can be attributed to systolic BP > or =120 mm Hg, translating into 17 excess cases per 1000. Although population-attributable risk estimates for population subgroups may differ by relative risk for dementia or prevalence of elevated levels of blood pressure, these data suggest that reducing midlife systolic BP is an effective prevention strategy to reduce risk for late-life dementia.
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Affiliation(s)
- Lenore J Launer
- Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, Bethesda, MD 20892, USA.
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156
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Dickstein DL, Walsh J, Brautigam H, Stockton SD, Gandy S, Hof PR. Role of vascular risk factors and vascular dysfunction in Alzheimer's disease. ACTA ACUST UNITED AC 2010; 77:82-102. [PMID: 20101718 DOI: 10.1002/msj.20155] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Recent findings indicate that vascular risk factors and neurovascular dysfunction play integral roles in the pathogenesis of Alzheimer's disease. In addition to aging, the most common risk factors for Alzheimer's disease are apolipoprotein e4 allele, hypertension, hypotension, diabetes, and hypercholesterolemia. All of these can be characterized by vascular pathology attributed to conditions such as cerebral amyloid angiopathy and subsequent blood-brain barrier dysfunction. Many epidemiological, clinical, and pharmacotherapeutic studies have assessed the associations between such risk factors and Alzheimer's disease and have found positive associations between hypertension, hypotension, and diabetes mellitus. However, there are still many conflicting results from these population-based studies, and they should be interpreted carefully. Recognition of these factors and the mechanisms by which they contribute to Alzheimer's disease will be beneficial in the current treatment regimens for Alzheimer's disease and in the development of future therapies. Here we discuss vascular factors with respect to Alzheimer's disease and dementia and review the factors that give rise to vascular dysfunction and contribute to Alzheimer's disease.
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Affiliation(s)
- Dara L Dickstein
- Department of Neuroscience and Kastor Neurobiology of Aging Laboratories, Mount Sinai School of Medicine, New York, NY, USA.
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157
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Knopman DS. Invited commentary: Albuminuria and microvascular disease of the brain--a shared pathophysiology. Am J Epidemiol 2010; 171:287-9; author reply 290-1. [PMID: 20061365 DOI: 10.1093/aje/kwp429] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
This commentary considers the implications of the association between albuminuria and cognitive decline described by Jassal et al. in this issue of the Journal (Am J Epidemiol. 2010;171(3):290-291). The authors report that men with albuminuria had a greater likelihood than men without albuminuria of experiencing declines in cognitive function over a 6.6-year period. Albuminuria is the result of endothelial damage in the kidney, which, in turn, is the result of microvascular disease. If one of the key mechanisms of brain microvascular disease is leakage of serum proteins into the brain extracellular space, in a fashion parallel to albuminuria that occurs in nephrosclerosis, several facets of cerebrovascular disease and cognitive decline are explained. First, brain microvascular disease would not be recognized by traditional clinical features of cerebrovascular disease because brain microvascular disease occurs gradually and insidiously. Second, the extravasation of serum proteins as a result of brain microvascular disease would account for the perivascular distribution of white matter hyperintensities on magnetic resonance imaging. Albuminuria might be a useful screening test for generalized microvascular disease and, if detected, might reasonably prompt brain imaging and more intensive therapeutic efforts to forestall further endothelial dysfunction in the kidney, brain, and elsewhere.
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Affiliation(s)
- David S Knopman
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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158
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Abstract
There is growing clinical and neuropathologic evidence suggesting that cognitive decline in early Alzheimer's disease (AD) is aggravated by a synergistic relationship between AD and cerebrovascular disease associated with cardiovascular risk factors such as diabetes and hypertension. Here we used the stereologic "Space Balls" method to investigate the relationships between AD pathology and cardiovascular risk factors in postmortem human brains of patients with hypertension and diabetes in two groups - one consisting of cases with AD diagnosis and one of cases without. Hippocampal CA1 and CA3 microvasculature length density estimates were generated to characterize quantitatively the contribution of cardiovascular risk factors to the severity of neuropathologic changes. Our main finding is that the mean and variance of length density values in the AD group were significantly increased from the non-AD group, regardless of the absence or presence of a cardiovascular risk factor. An additional finding is that in the AD group without a risk factor, dementia severity correlated with amount of length density change in the CA1 field-this correlation did not exist in the AD groups with risk factors. Our findings suggest a role for cardiovascular risk factors in quantifiable change of hippocampal CA1 field microvasculature, as well as suggest a possible role of cardiovascular risk factors in altering microvasculature pathology in the presence of AD.
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159
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Hendrie HC, Albert MS, Butters MA, Gao S, Knopman DS, Launer LJ, Yaffe K, Cuthbert BN, Edwards E, Wagster MV. The NIH Cognitive and Emotional Health Project. Report of the Critical Evaluation Study Committee. Alzheimers Dement 2009; 2:12-32. [PMID: 19595852 DOI: 10.1016/j.jalz.2005.11.004] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Accepted: 11/29/2005] [Indexed: 12/29/2022]
Abstract
BACKGROUND The Cognitive and Emotional Health Project (CEHP) seeks to identify the demographic, social, and biological determinants of cognitive and emotional health in the older adult. As part of the CEHP, a critical evaluation study committee was formed to assess the state of epidemiological research on demographic, social, and biological determinants of cognitive and emotional health. METHODS Criteria for inclusion in the survey were large cohort studies, longitudinal in design, participants predominantly 65 years or older, with measurements of both cognition and emotion, and information on a wide variety of demographic, psychosocial, and biological factors. North American and European studies, which met these criteria, were selected for the review. Outcome measures included cognition, cognitive decline, and cognitive function. For emotion, symptoms included depression and anxiety, positive and negative affect, subjective well being, mastery, and resilience. RESULTS Ninety-six papers were identified that addressed cognitive and emotional outcomes. A large variety of risk factors were consistently identified with cognitive outcomes, particularly those previously associated with increased risk of cardiovascular disease. There was considerable overlap between risk factors for cognitive and emotional outcomes. CONCLUSION This review identifies a large number of lifestyle and health behaviors that alter the risk for maintenance of cognitive and emotional health. Large longitudinal cohort studies are a unique source to explore factors associated with cognitive and emotional health. Secondary analyses of these studies should be encouraged as should the development of standardized questionnaires to measure cognitive and emotional health. Future research in this field should study cognitive and emotional health simultaneously.
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Affiliation(s)
- Hugh C Hendrie
- Indiana University Center for Aging Research, Indianapolis, IN, USA.
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160
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Wang LY, Larson EB, Sonnen JA, Shofer JB, McCormick W, Bowen JD, Montine TJ, Li G. Blood pressure and brain injury in older adults: findings from a community-based autopsy study. J Am Geriatr Soc 2009; 57:1975-81. [PMID: 19793158 DOI: 10.1111/j.1532-5415.2009.02493.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To examine correlations between blood pressure (BP) and dementia-related pathological brain changes in a community-based autopsy sample. DESIGN Prospective cohort study. SETTING A large health maintenance organization in Seattle, Washington. PARTICIPANTS A cohort of 250 participants aged 65 and older and cognitively normal at time of enrollment in the Adult Changes in Thought (ACT) Study and who underwent autopsy. MEASUREMENTS BP and history of antihypertensive treatment were taken at enrollment. A linear regression model was used to examine the relationship between BP (systolic (SBP) and diastolic (DBP)) at enrollment and pathological changes in the cerebrum (cystic macroscopic infarcts, microinfarcts, neuritic plaques, neurofibrillary tangles, and cortical Lewy bodies). RESULTS The presence of more than 2 microinfarcts, but not any other pathological change, was independently associated with SBP in younger participants (65-80, n=137) but not in older participants (>80, n=91). The relative risk (RR) for more than two microinfarcts with each 10-mmHg increase in SBP was 1.15 (95% confidence interval (CI)=1.00-1.33) in the younger participants, adjusted for age at entry, sex, and time to death. This RR was particularly strong in younger participants not taking antihypertensive medications (RR=1.48, 95% CI=1.21, 1.81); significant associations were not observed in participants treated for hypertension. Findings for DBP were negative. CONCLUSION The association between high SBP and cerebrovascular damage in untreated older adults (65-80) suggests that adequate hypertension treatment may reduce dementia risk by minimizing microvascular injury to cerebrum.
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Affiliation(s)
- Lucy Y Wang
- Mental Illness Research and Education Clinical Center, Veterans Affairs Puget Sound Healthcare System, Seattle, Washington 98108, USA.
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161
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Role of Hypertension in Aggravating Abeta Neuropathology of AD Type and Tau-Mediated Motor Impairment. Cardiovasc Psychiatry Neurol 2009; 2009:107286. [PMID: 19936102 PMCID: PMC2775676 DOI: 10.1155/2009/107286] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 06/19/2009] [Accepted: 07/02/2009] [Indexed: 11/17/2022] Open
Abstract
Epidemiological evidence suggests that hypertension may accelerate the onset and progression of Alzheimer's disease (AD). In this study, we explored the role of hypertension in the neurodegenerative changes associated with Abeta and tau aggregation. We induced hypertension in APP(swe) Tg2576 and P301L-tauTg mouse models. In Tg2576 mice, experimental hypertension was associated with a significant increase of the accumulation of Amyloid-beta (Abeta) peptides in brain tissue and a significant reduction of Abeta peptides in serum (P < .05). These results indicate that hypertension may promote AD-type Abeta neuropathology in Tg2576. In P301L-tauTg mice we found that the presence of hypertension was significantly associated with aggravated motor function assessed by hindlimb extension test (P = .01). These results suggest that hypertension may play a role in accelerating the progression of motor dysfunction associated with tau-related alterations. Our studies suggest that the management of blood pressure (BP) may alleviate AD-type Abeta neuropathology and neurological disorders associated with abnormal tau metabolism.
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162
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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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163
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Beeri MS, Ravona-Springer R, Silverman JM, Haroutunian V. The effects of cardiovascular risk factors on cognitive compromise. DIALOGUES IN CLINICAL NEUROSCIENCE 2009. [PMID: 19585955 PMCID: PMC3093131 DOI: 10.31887/dcns.2009.11.2/msbeeri] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
As life expectancy in the United States continues to increase, the projected numbers of elderly people who will develop dementia will grow rapidly. This paper reviews four well-established cardiovascular risk factors (type 2 diabetes, hypertension, cholesterol, and inflammation), for which there is longitudinal epidemiological evidence of increased risk of dementia, Alzheimer's disease, mild cognitive impairment, and cognitive decline. These risk factors are of special interest because of their potential modif lability, which may affect the course of cognitive compromise. Diabetes is the cardiovascular risk factor (CvRF) most consistently associated with cognition. Hypertension in midlife is consistently associated with cognition, but its associations with late-life hypertension are less clear. Total cholesterol is not consistently associated with cognition, interleukin-6 and C-reactive protein are inflammatory markers relatively consistently associated with cognition. Composites of the CvRFs increase the risk for dementia in a dose-dependent fashion, suggesting a cumulative effect of these factors on neuronal stress. In the relatively few studies that have reported interactions of risk factors, they potentiate each other. The effect of each of these risk factors varies according to apolipoprotein E genotype, it may be that the effect of these risk factors varies according to the presence of the others, and these complex relationships underlie the biological mechanisms of cognitive compromise. This may be crucial for understanding the effects on cognition of druqs and other approaches, such as lifestyle chanqe, for treatinq these risk factors.
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164
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Mueller SG, Weiner MW. Selective effect of age, Apo e4, and Alzheimer's disease on hippocampal subfields. Hippocampus 2009; 19:558-64. [PMID: 19405132 DOI: 10.1002/hipo.20614] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Histopathological studies and animal models suggest that different physiological and pathophysiological processes exert different subfield specific effects on the hippocampus. High-resolution images at 4T depict details of the internal structure of the hippocampus allowing for in vivo volumetry of hippocampal subfields. The aims of this study were (1) to determine patterns of hippocampal subfield volume loss due to normal aging and Apo e4 carrier state, (2) to determine subfield specific volume losses due to preclinical (MCI) and clinical Alzheimer's disease (AD) and their modification due to age and Apo e4 carrier state. One hundred fifty seven subjects (119 cognitively healthy elderly controls, 20 MCI and 18 AD) were studied with a high resolution T2 weighted imaging sequence obtained at 4T aimed at the hippocampus. Apo e4 carrier state was known in 95 subjects (66 controls, 14 MCI, 15 AD). Subiculum (SUB), CA1, CA1-CA2 transition zone (CA1-2 transition), CA3- dentate gyrus (CA3&DG) were manually marked. Multiple linear regression analysis was used to test for effects of age, Apo e4 carrier state and effects of MCI and AD on different hippocampal subfields. Age had a significant negative effect on CA1 and CA3&DG volumes in controls (P < 0.05). AD had significantly smaller volumes of SUB, CA1, CA1-2 transition, and MCI had smaller CA1-2 transition volumes than controls (P < 0.05). Apo e4 carrier state was associated with volume loss in CA3&DG compared to non-Apo e4 carriers in healthy controls and AD. Based on these findings, we conclude that subfield volumetry provides regional selective information that allows to distinguish between different normal and pathological processes affecting the hippocampus and thus for an improved differential diagnosis of neurodegenerative diseases affecting the hippocampus.
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Affiliation(s)
- Susanne G Mueller
- Center for Imaging of Neurodegenerative Diseases, Department of Veterans Affairs Medical Center, San Francisco, California 94121, USA.
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165
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Stephan BC, Matthews FE, Khaw KT, Dufouil C, Brayne C. Beyond mild cognitive impairment: vascular cognitive impairment, no dementia (VCIND). ALZHEIMERS RESEARCH & THERAPY 2009; 1:4. [PMID: 19674437 PMCID: PMC2719105 DOI: 10.1186/alzrt4] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Identifying the causes of dementia is important in the search for effective preventative and treatment strategies. The concept of mild cognitive impairment (MCI), as prodromal dementia, has been useful but remains controversial since in population-based studies it appears to be a limited predictor of progression to dementia. Recognising the relative contribution of neurodegenerative and vascular causes, as well as their interrelationship, may enhance predictive accuracy. The concept of vascular cognitive impairment (VCI) has been introduced to describe the spectrum of cognitive change related to vascular causes from early cognitive decline to dementia. A recent review of this concept highlighted the need for diagnostic criteria that encompass the full range of the VCI construct. However, very little is known regarding the mildest stage of VCI, generally termed 'vascular cognitive impairment, no dementia' (VCIND). Whether mild cognitive change in the context of neurodegenerative pathologies is distinct from that in the context of cerebrovascular diseases is not known. This is key to the definition of VCIND and whether it is possible to identify this state. Distinguishing between vascular (that is, VCIND) and non-vascular (that is, MCI) cognitive disorders and determining how well each might predict dementia may not be possible due to the overlap in pathologies observed in the older population. Here, we review the concept of VCIND in an effort to identify recent developments and areas of controversy in nosology and the application of VCIND for screening individuals at increased risk of dementia secondary to vascular disease and its risk factors.
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Affiliation(s)
- Blossom Cm Stephan
- Department of Public Health and Primary Care, Institute of Public Health, The University of Cambridge, Forvie Site, Robinson Way, Cambridge, CB2 0SR, UK.
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166
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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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167
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Abstract
The amyloid hypothesis has been the basis for most work on the pathogenesis of Alzheimer's disease. Recent clinical trials based on this hypothesis have been inconclusive. In this article I review the current status of the hypothesis and suggest that a major scientific need is to understand the normal function of amyloid-beta precursor protein (APP) and think how this may relate to the cell death in the disease process.
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Affiliation(s)
- John Hardy
- Reta Lilla Weston Institute and Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK.
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168
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Hughes TF, Ganguli M. Modifiable Midlife Risk Factors for Late-Life Cognitive Impairment and Dementia. CURRENT PSYCHIATRY REVIEWS 2009; 5:73-92. [PMID: 19946443 PMCID: PMC2782871 DOI: 10.2174/157340009788167347] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The baby boom generation is approaching the age of greatest risk for cognitive impairment and dementia. There is growing interest in strategies to modify the environment in midlife to increase the probability of maintaining cognitive health in late life. Several potentially modifiable risk factors have been studied in relation to cognitive impairment and dementia in late life, but methodological limitations of observational research have resulted in some inconsistencies across studies. The most promising strategies are maintaining cardiovascular health, engagement in mental, physical, and social activities, using alcohol in moderation, abstaining from tobacco use, and following a heart-healthy diet. Other factors that may influence cognitive health are occupational attainment, depression, personality, exposure to general anesthesia, head injury, postmenopausal hormone therapy, non-steroidal anti-inflammatory medications, and nutritional supplements such as antioxidants. Some long-term observational studies initiated in midlife or earlier, and some randomized controlled trials, have examined the effects of specific cognitive health promotion behaviors in midlife on the risk of cognitive impairment in late life. Overall, these studies provide limited support for risk reduction at this time. Recommendations and challenges for developing effective strategies to reduce the burden of cognitive impairment and dementia in the future are discussed.
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Affiliation(s)
- Tiffany F. Hughes
- From the Departments of Psychiatry (T.F.H., M.G.) and Neurology (M.G.), School of Medicine, and the Department of Epidemiology (M.G.), Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mary Ganguli
- From the Departments of Psychiatry (T.F.H., M.G.) and Neurology (M.G.), School of Medicine, and the Department of Epidemiology (M.G.), Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
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169
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Fourteen-year longitudinal study of vascular risk factors, APOE
genotype, and cognition: The ARIC MRI Study. Alzheimers Dement 2009; 5:207-14. [DOI: 10.1016/j.jalz.2009.01.027] [Citation(s) in RCA: 171] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 01/23/2009] [Accepted: 01/27/2009] [Indexed: 11/17/2022]
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170
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Kennelly SP, Lawlor B, Kenny R. Blood pressure and the risk for dementia: a double edged sword. Ageing Res Rev 2009; 8:61-70. [PMID: 19063999 DOI: 10.1016/j.arr.2008.11.001] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Revised: 11/13/2008] [Accepted: 11/13/2008] [Indexed: 11/24/2022]
Abstract
Alzheimer's disease (AD) and vascular dementia (VaD) are important causes of cognitive decline in the elderly. As a result of the aging population, the incidence of dementia is expected to increase substantially over the coming decades. Many studies have identified that vascular risk factors are implicated in the pathogenesis of both AD and VaD. Longitudinal studies have suggested that high blood pressure in midlife is associated with a higher incidence of both AD and VaD in later life. The association appears weaker for hypertension in later life. Some studies also suggest that hypotension; especially low diastolic blood pressure in late-life is also associated with an increased risk of AD. Long-standing hypertension may lead to severe atherosclerosis and impaired cerebrovascular autoregulation. A decline in blood pressure in later life may contribute to diminished cerebral perfusion. The subsequent ischaemic state may lead to increased cerebral beta-amyloid accumulation.
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171
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Hoffman LB, Schmeidler J, Lesser GT, Beeri MS, Purohit DP, Grossman HT, Haroutunian V. Less Alzheimer disease neuropathology in medicated hypertensive than nonhypertensive persons. Neurology 2009; 72:1720-6. [PMID: 19228583 DOI: 10.1212/01.wnl.0000345881.82856.d5] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE To test the hypothesis that use of antihypertensive medication is associated with lower Alzheimer disease (AD) neuropathology. METHODS This was a postmortem study of 291 brains limited to those with normal neuropathology or with uncomplicated AD neuropathology (i.e., without other dementia-associated neuropathology) in persons with or without hypertension (HTN) who were and were not treated with antihypertensive medications. Neuritic plaque (NP) and neurofibrillary tangle (NFT) densities, quantified in selected brain regions according to the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropathologic criteria, with additional cortical NP counts, yielded 24 neuropathologic regional measures or summaries. Medicated hypertension (HTN-med; n = 77), nonmedicated HTN (HTN-nomed; n = 42), and non-HTN (no-HTN; n = 172) groups were compared by analyses of variance. RESULTS The HTN-med group had significantly less neuropathology than the no-HTN group. The no-HTN group averaged over 50% higher mean NP and NFT ratings, and double the mean NP count, of the HTN-med group. The HTN-nomed group had significantly more neuropathology than the HTN-med group, but not significantly less than the no-HTN group. CONCLUSIONS There was substantially less Alzheimer disease (AD) neuropathology in the medicated hypertension group than the nonhypertensive group, which may reflect a salutary effect of antihypertensive medication against AD-associated neuropathology.
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Affiliation(s)
- L B Hoffman
- Department of Psychiatry, Mount Sinai School of Medicine, New York, USA.
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172
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Lopez OL, Mackell JA, Sun Y, Kassalow LM, Xu Y, McRae T, Li H. Effectiveness and safety of donepezil in Hispanic patients with Alzheimer's disease: a 12-week open-label study. J Natl Med Assoc 2008; 100:1350-8. [PMID: 19024233 DOI: 10.1016/s0027-9684(15)31515-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND Hispanics represent 10% of the U.S. population and are the fastest growing group. Studies show a higher prevalence and incidence of Alzheimer's disease (AD) in Hispanics than in the non-Hispanic white population, with an earlier age of onset. Among the currently estimated 200,000 Hispanics with AD, a significant number remain undiagnosed and untreated, and Hispanic participation in AD clinical trials has been historically low. This study evaluated the efficacy and safety of donepezil hydrochloride (donepezil) in Hispanics with mild-to-moderate AD. METHODS In this multicenter, open-label, 12-week study conducted in the United States, subjects were Hispanic men or women aged > or =50 years with a diagnosis of mild-to-moderate AD (DSMV-IV and NINCDS/ADRDA criteria), with Mini-Mental State Examination (MMSE) scores of 10-26 (inclusive) at screening. Subjects were treated with donepezil 5 mg/day for 6 weeks followed by 10 mg/day for 6 weeks. Clinical evaluation was performed at baseline, week 6 and week 12. Cognitive improvement was measured using the MMSE, Fuld Object Memory Evaluation (FOME) and Symbol Digit Modality Test (SDMT). Behavioral symptoms and associated caregiver distress were assessed with the Neuropsychiatric Inventory (NPI). RESULTS One-hundred-six patients with mild-to-moderate AD (mean age 68.6 years) were enrolled (intent to treat, n=97); most chose to have assessments conducted in Spanish. With 12 weeks of treatment, subjects showed statistically significant improvement from baseline on MMSE (P<0.0001), FOME retrieval (P=0.0042), FOME repeated retrieval (P=0.0020) and SDMT correct scores (P<0.0001). The NPI subdomain "apathy/indifference" showed statistically significant improvement (P=0.0010).The NPI Caregiver Distress scale (NPI-D) total score was statistically significantly improved (P=0.0500), suggesting a positive impact on relieving caregivers' burden associated with patient behavior. Most patients tolerated the treatment well, with only 2 discontinuing because of adverse events. The most common (>5%) adverse events were insomnia (9.5%), dizziness (7.6%), diarrhea (5.7%) and nausea (5.7%). CONCLUSION The cognitive improvement and safety results from this study were consistent with those reported for donepezil in the general population. Increased awareness of AD in the Hispanic population will help more Hispanics with AD to benefit from early diagnosis and effective treatment.
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Affiliation(s)
- Oscar L Lopez
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
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173
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Affiliation(s)
- Lenore J Launer
- Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, Bethesda, MD 20892, USA.
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174
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Atherosclerosis risk factors in American Indians with Alzheimer disease: preliminary findings. Alzheimer Dis Assoc Disord 2008; 22:245-8. [PMID: 18580594 DOI: 10.1097/wad.0b013e318169d701] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Factors predisposing to and associated with atherosclerosis may impact the onset and progression of Alzheimer disease (AD). The high prevalence of atherosclerosis and associated risk factors in American Indians makes them ideal subjects to test this association. We compared frequency of history of hypertension, myocardial infarction, stroke, diabetes, and high cholesterol in 34 American Indians with AD with 34 age-matched American Indian controls, and 34 age-matched whites with probable AD. We also measured waist size, height, and weight, and acquired blood for determination of plasma homocysteine and apolipoprotein E genotype. The 3 groups did not differ significantly in age or sex. History of hypertension and diabetes was significantly more common among American Indian AD patients than Indian controls or whites with AD. The 3 groups did not differ in history of stroke or myocardial infarction. Body mass index was significantly greater in both Indian groups than the white AD group. Plasma homocysteine levels were greater, but not significantly so, in the Indian AD than the Indian control group. Thus, there is preliminary evidence of a modest association between history of hypertension and diabetes and AD in a small sample of American Indians. This suggests that changes in lifestyle factors could influence the expression of AD in American Indians.
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175
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Fillit H, Nash DT, Rundek T, Zuckerman A. Cardiovascular risk factors and dementia. ACTA ACUST UNITED AC 2008; 6:100-18. [DOI: 10.1016/j.amjopharm.2008.06.004] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2008] [Indexed: 12/19/2022]
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176
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Lange-Asschenfeldt C, Kojda G. Alzheimer's disease, cerebrovascular dysfunction and the benefits of exercise: from vessels to neurons. Exp Gerontol 2008; 43:499-504. [PMID: 18474414 DOI: 10.1016/j.exger.2008.04.002] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 03/14/2008] [Accepted: 04/01/2008] [Indexed: 01/14/2023]
Abstract
Exercise training promotes extensive cardiovascular changes and adaptive mechanisms in both the peripheral and cerebral vasculature, such as improved organ blood flow, induction of antioxidant pathways, and enhanced angiogenesis and vascular regeneration. Clinical studies have demonstrated a reduction of morbidity and mortality from cardiovascular disease among exercising individuals. However, evidence from recent large clinical trials also suggests a substantial reduction of dementia risk - particularly regarding Alzheimer's disease (AD) - with regular exercise. Enhanced neurogenesis and improved synaptic plasticity have been implicated in this beneficial effect. However, recent research has revealed that vascular and specifically endothelial dysfunction is essentially involved in the disease process and profoundly aggravates underlying neurodegeneration. Moreover, vascular risk factors (VRFs) are probably determinants of incidence and course of AD. In this review, we emphasize the interconnection between AD and VRFs and the impact of cerebrovascular and endothelial dysfunction on AD pathophysiology. Furthermore, we describe the molecular mechanisms of the beneficial effects of exercise on the vasculature such as activation of the vascular nitric oxide (NO)/endothelial NO synthase (eNOS) pathway, upregulation of antioxidant enzymes, and angiogenesis. Finally, recent prospective clinical studies dealing with the effect of exercise on the risk of incident AD are briefly reviewed. We conclude that, next to upholding neuronal plasticity, regular exercise may counteract AD pathophysiology by building a vascular reserve.
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Affiliation(s)
- Christian Lange-Asschenfeldt
- Klinik für Psychiatrie und Psychotherapie, Abteilung Gerontopsychiatrie, Bergische Landstr. 2, Düsseldorf 40629, Germany
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177
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Bondi MW, Jak AJ, Delano-Wood L, Jacobson MW, Delis DC, Salmon DP. Neuropsychological contributions to the early identification of Alzheimer's disease. Neuropsychol Rev 2008. [PMID: 18347989 DOI: 10.1007/s11065‐008‐9054‐1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A wealth of evidence demonstrates that a prodromal period of Alzheimer's disease (AD) exists for some years prior to the appearance of significant cognitive and functional declines required for the clinical diagnosis. This prodromal period of decline is characterized by a number of different neuropsychological and brain changes, and reliable identification of individuals prior to the development of significant clinical symptoms remains a top priority of research. In this review we provide an overview of those neuropsychological changes. In particular, we examine specific domains of cognition that appear to be negatively affected during the prodromal period of AD, and we review newer analytic strategies designed to examine cognitive asymmetries or discrepancies between higher-order cognitive functions versus fundamental skills. Finally, we provide a critical examination of the clinical concept of Mild Cognitive Impairment and offer suggestions for an increased focus on the impact of cerebrovascular disease (CVD) and CVD risk during the prodromal period of AD.
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Affiliation(s)
- Mark W Bondi
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA.
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178
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Montine TJ, Quinn J, Kaye J, Morrow JD. F(2)-isoprostanes as biomarkers of late-onset Alzheimer's disease. J Mol Neurosci 2008; 33:114-9. [PMID: 17901555 DOI: 10.1007/s12031-007-0044-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 11/27/2022]
Abstract
Alzheimer's disease (AD) is a syndrome caused by a few uncommon mutations that lead to early-onset disease, occurs in adults with Down's syndrome, but is by far most commonly seen as a late-onset disease with multiple risk factors but no causative factors yet identified. Emerging data suggests a chronic disease model for AD with latency, prodrome, and dementia stages together lasting decades. Free radical damage to lipids in brain is one pathogenic process of AD that may be quantified with F(2)-isoprostanes (IsoPs). Whereas brain and cerebrospinal fluid (CSF) F(2)-IsoPs are reproducibly elevated in AD patients at both dementia and prodromal stages of disease, plasma and urine F(2)-IsoPs are not reproducibly increased in AD patients. CSF F(2)-IsoPs may be used to assist in diagnosis and aid in objective assessment of disease progression and response to therapeutics in patients with AD.
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Affiliation(s)
- Thomas J Montine
- Department of Pathology, University of Washington, Seattle, WA 98104, USA.
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179
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Bondi MW, Jak AJ, Delano-Wood L, Jacobson MW, Delis DC, Salmon DP. Neuropsychological contributions to the early identification of Alzheimer's disease. Neuropsychol Rev 2008; 18:73-90. [PMID: 18347989 PMCID: PMC2882236 DOI: 10.1007/s11065-008-9054-1] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2008] [Accepted: 01/27/2008] [Indexed: 01/22/2023]
Abstract
A wealth of evidence demonstrates that a prodromal period of Alzheimer's disease (AD) exists for some years prior to the appearance of significant cognitive and functional declines required for the clinical diagnosis. This prodromal period of decline is characterized by a number of different neuropsychological and brain changes, and reliable identification of individuals prior to the development of significant clinical symptoms remains a top priority of research. In this review we provide an overview of those neuropsychological changes. In particular, we examine specific domains of cognition that appear to be negatively affected during the prodromal period of AD, and we review newer analytic strategies designed to examine cognitive asymmetries or discrepancies between higher-order cognitive functions versus fundamental skills. Finally, we provide a critical examination of the clinical concept of Mild Cognitive Impairment and offer suggestions for an increased focus on the impact of cerebrovascular disease (CVD) and CVD risk during the prodromal period of AD.
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Affiliation(s)
- Mark W Bondi
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA.
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180
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Obisesan TO, Obisesan OA, Martins S, Alamgir L, Bond V, Maxwell C, Gillum RF. High blood pressure, hypertension, and high pulse pressure are associated with poorer cognitive function in persons aged 60 and older: the Third National Health and Nutrition Examination Survey. J Am Geriatr Soc 2008; 56:501-9. [PMID: 18179496 DOI: 10.1111/j.1532-5415.2007.01592.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To test the hypothesis that hypertension, high blood pressure, and high pulse pressure (PP) are independently associated with lower cognitive function. DESIGN Cross-sectional study of persons examined in 1988 to 1994. SETTING U.S. noninstitutionalized population. PARTICIPANTS Six thousand one hundred sixty-three men and women aged 60 and older who participated in the Third National Health and Nutrition Examination Survey (NHANES III). MEASUREMENTS Measurements included blood pressure, short-portable Mini-Mental State Examination (sp-MMSE), self-reported history of hypertension, diagnosis, and treatment. RESULTS In the initial bivariate analysis within age groups of 60 to 64, 65 to 69, and 70 to 74, optimal blood pressure (< 120/80 mmHg) was associated with best cognitive performance; the severe hypertension group had the poorest performance in all age groups except the very old (> or = 80), where the pattern was reversed, showing poorest performance in the optimal blood pressure group and best in the group with moderate hypertension. This pattern changed slightly in multiple regression analyses modeling sp-MMSE as the outcome variable. Higher stage of hypertension according to the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure and higher PP were associated with worse cognitive performance than normal blood pressure at ages 70 to 79 and 80 and older. No significant negative association was seen in subjects aged 60 to 69. Subjects with treated but uncontrolled hypertension had significantly lower sp-MMSE scores than those without hypertension or with controlled hypertension after controlling for age, sex, ethnicity, income, and PP. CONCLUSION At age 70 and older, high blood pressure, hypertension, and uncontrolled blood pressure are associated with poorer cognitive function than normal blood pressure. Optimal control of blood pressure may be useful in preserving neurocognitive loss as the population ages.
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Affiliation(s)
- Thomas Olabode Obisesan
- Department of Medicine, Division of Geriatrics, Howard University Hospital, 2041 Georgia Ave, NW, Washington, DC 20060, USA.
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181
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Dai W, Lopez OL, Carmichael OT, Becker JT, Kuller LH, Gach HM. Abnormal regional cerebral blood flow in cognitively normal elderly subjects with hypertension. Stroke 2008; 39:349-54. [PMID: 18174483 DOI: 10.1161/strokeaha.107.495457] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The purpose of this study was to examine regional cerebral blood flow (rCBF) in normal cognitive-performing subjects with hypertension (HTN) using continuous arterial spin-labeled MRI. The most common explanation for the effect of blood pressure on cognition is that HTN increases the risk of cerebrovascular disease, and it may increase the risk for Alzheimer disease possibly through small vessel disease, ischemia, oxidative stress, and inflammation. However, few studies to date have examined the rCBF of cognitively normal subjects with HTN in population-based cohorts, and none have used continuous arterial spin-labeled MRI. This is a noninvasive technique that does not require either injections or ionizing radiation and can measure absolute rCBF rates over the entire brain. METHODS rCBF was measured at 1.5 T using continuous arterial spin-labeled MRI in 41 cognitively normal subjects who were participating in the Cardiovascular Health Study Cognition Study. A deformable atrophy-corrected registration method was used to warp the rCBF maps to the standard colin27 brain space. Image and cluster-based statistical analyses were performed between subject groups. RESULTS Cognitively normal subjects with HTN (n=19) had decreased rCBF in the putamen, globus pallidus, bilaterally, and in the left hippocampus compared with normotensives (n=22). In addition, decreased rCBF was observed in the right and left anterior cingulate gyrus with extension to the subcallosal region, left posterior cingulate gyrus and medial precuneus, left lateral inferior and superior frontal, and inferior parietal, left orbitofrontal, and left superior temporal cortices. CONCLUSIONS rCBF is affected in normal subjects with HTN, not only in the subcortical regions, but also in limbic and paralimbic structures. We hypothesize that the HTN creates a vulnerability state for the development of neurodegenerative disorders, especially Alzheimer disease.
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Affiliation(s)
- Weiying Dai
- Department of Computer Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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182
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Reitz C, Tang MX, Manly J, Mayeux R, Luchsinger JA. Hypertension and the risk of mild cognitive impairment. ACTA ACUST UNITED AC 2008; 64:1734-40. [PMID: 18071036 DOI: 10.1001/archneur.64.12.1734] [Citation(s) in RCA: 226] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To explore whether hypertension is associated with the risk of mild cognitive impairment (MCI), an intermediate stage of dementia, because there are conflicting data relating hypertension to the risk of Alzheimer disease. DESIGN AND SETTING Prospective community-based cohort study conducted in northern Manhattan. Multivariate proportional hazards regression analyses were used, relating hypertension to incident all-cause MCI, amnestic MCI, and nonamnestic MCI in 918 persons without prevalent MCI at baseline followed up for a mean of 4.7 years. RESULTS There were 334 cases of incident MCI, 160 cases of amnestic MCI, and 174 cases of nonamnestic MCI during 4337 person-years of follow-up. Hypertension was associated with an increased risk of all-cause MCI (hazard ratio, 1.40; 95% confidence interval, 1.06-1.77; P = .02) and nonamnestic MCI (hazard ratio, 1.70; 95% confidence interval, 1.13-2.42; P = .009) after adjusting for age and sex. Both associations were slightly attenuated in models additionally adjusting for stroke and other vascular risk factors. There was no association between hypertension and the risk of amnestic MCI (hazard ratio, 1.10; 95% confidence interval, 0.79-1.63; P = .49). Consistent with this association, hypertension was related with the slope of change in an executive ability score, but not with memory or language score. There was no effect modification of the association between hypertension and MCI by APOEepsilon4 genotype or use of antihypertensive medication. CONCLUSIONS A history of hypertension is related to a higher risk of MCI. The association seems to be stronger with the nonamnestic than the amnestic type of MCI in the elderly. These findings suggest that prevention and treatment of hypertension may have an important impact in lowering the risk of cognitive impairment.
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Affiliation(s)
- Christiane Reitz
- The Gertrude H Sergievsky Center, Columbia University Medical Center, Columbia University, New York, NY 10706, USA
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183
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Hermann B, Seidenberg M, Sager M, Carlsson C, Gidal B, Sheth R, Rutecki P, Asthana S. Growing old with epilepsy: the neglected issue of cognitive and brain health in aging and elder persons with chronic epilepsy. Epilepsia 2007; 49:731-40. [PMID: 18031544 DOI: 10.1111/j.1528-1167.2007.01435.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The purpose of this review is to examine what is known about cognitive and brain aging in elders with chronic epilepsy. We contend that much remains to be learned about the ultimate course of cognition and brain structure in persons with chronic epilepsy and concern appears warranted. Individuals with chronic epilepsy are exposed to many risk factors demonstrated to be associated with abnormal cognitive and brain aging in the general population, with many of these risk factors present in persons with chronic epilepsy as early as midlife. We suggest that a research agenda be developed to systematically identify and treat known modifiable risk factors in order to protect and promote cognitive and brain health in aging and elder persons with chronic epilepsy.
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Affiliation(s)
- Bruce Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA.
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184
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Berr C, Akbaraly TN, Nourashemi F, Andrieu S. Épidémiologie des démences. Presse Med 2007; 36:1431-41. [PMID: 17560760 DOI: 10.1016/j.lpm.2007.04.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Accepted: 04/17/2007] [Indexed: 11/29/2022] Open
Abstract
Dementia is a major public health problem and its burden will increase in the 30 years to come. Prevalence increases with age and incidence is slightly higher in women than men, especially after the age of 80 years. Survival after the onset of dementia is approximately 5 years. Lifestyle and health habits are a keystone for dementia: risk factors include physical, intellectual and social activity and nutritional habits. Data from well-conducted intervention studies are necessary to show whether better care for hypertension, diabetes, and dyslipidemia might decrease the incidence of dementia.
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Affiliation(s)
- Claudine Berr
- Inserm, U888, Université Montpellier 1, Montpellier (34).
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185
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Lanari A, Silvestrelli G, De Dominicis P, Tomassoni D, Amenta F, Parnetti L. Arterial hypertension and cognitive dysfunction in physiologic and pathologic aging of the brain. ACTA ACUST UNITED AC 2007; 16:158-64. [PMID: 17483667 DOI: 10.1111/j.1076-7460.2007.06502.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Arterial hypertension is the most important modifiable cerebrovascular risk factor; its relationship with cerebrovascular disease is continuous, consistent, and independent. Different and probably converging pathophysiologic mechanisms explain the role of arterial hypertension in causing cognitive dysfunction in pathologic aging of the brain, specifically, vascular dementia and Alzheimer's disease.
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Affiliation(s)
- Alessia Lanari
- Section of Neurology, University of Perugia, Perugia, Italy
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186
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Reitz C, Luchsinger JA. Relation of Blood Pressure to Cognitive Impairment and Dementia. Curr Hypertens Rev 2007; 3:166-176. [PMID: 22545032 DOI: 10.2174/157340207781386747] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Over the past decade several studies have assessed the relation of blood pressure with cognitive function and dementia. While some cross-sectional studies have shown an inverse association between blood pressure levels and cognitive performance or dementia, longitudinal studies yielded controversial results. Most studies relating blood pressure levels in mid-life with late-life risk of cognitive decline or dementia reported a harmful effect of higher blood pressure levels on cognitive function. Studies assessing the effect of late-life blood pressure levels reported that low diastolic and very high systolic levels may increase the risk. Observational studies and randomized cinical trials provide limited evidence for a protective effect of antihypertensive therapy. It seems that the older the person and the more advanced the disease process, the less harmful or even inverted the effect of blood pressure elevation on dementia risk. The reason for this may be that blood pressure declines with age-related pathology, such as vessel stiffening, weight loss, and changes in the autonomic regulation of blood flow.
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Affiliation(s)
- Christiane Reitz
- The Gertrude H. Sergievsky Center, Columbia University College of Physicians and Surgeons, New York, NY, USA
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187
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Eftekhari H, Uretsky S, Messerli FH. Blood pressure, cognitive dysfunction, and dementia. ACTA ACUST UNITED AC 2007; 1:135-44. [DOI: 10.1016/j.jash.2007.01.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Revised: 01/10/2007] [Accepted: 01/16/2007] [Indexed: 10/23/2022]
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188
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Reitz C, Patel B, Tang MX, Manly J, Mayeux R, Luchsinger JA. Relation between vascular risk factors and neuropsychological test performance among elderly persons with Alzheimer's disease. J Neurol Sci 2007; 257:194-201. [PMID: 17328914 PMCID: PMC2725022 DOI: 10.1016/j.jns.2007.01.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Vascular risk factors increase the risk of Alzheimer's disease (AD). The mechanisms for these associations are unclear, and may be due to misdiagnosis of a vascular dementia syndrome as AD. OBJECTIVE To examine differences in neuropsychological profile among persons diagnosed clinically with AD with and without vascular risk factors or stroke. METHODS Community based cohort study. Individual and composite scores of neuropsychological tests at the time of clinical diagnosis of incident AD were compared among 243 persons with and without vascular risk factors or stroke. RESULTS Among subjects with incident AD, diabetes was associated with lower performance in Delayed Recall of the Selective Reminding Test (SRT), while persons diagnosed with hypertension scored lower in consistent long term recall (CLTR) of the SRT and current smokers scored lower in Category Fluency. None of the risk factors was associated with differences in composite scores in memory, abstract/visuospatial or language domain, nor was the number of risk factors per person. Persons with stroke had a higher delayed recall score at the time of AD diagnosis. CONCLUSION The presence of vascular risk factors among persons with clinically diagnosed AD was associated with subtle differences in neuropsychological profile at the time of diagnosis. This study needs to be replicated in samples with brain imaging, a comprehensive executive abilities battery, and pathological diagnosis of AD.
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Affiliation(s)
- Christiane Reitz
- The Gertrude H. Sergievsky Center, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Bindu Patel
- The Gertrude H. Sergievsky Center, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Ming-Xix Tang
- The Gertrude H. Sergievsky Center, Columbia University College of Physicians and Surgeons, New York, NY, USA
- The Department of Biostatistics in the Mailman School of Public Health Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Jennifer Manly
- The Gertrude H. Sergievsky Center, Columbia University College of Physicians and Surgeons, New York, NY, USA
- The Department of Neurology, Columbia University College of Physicians and Surgeons, New York, NY, USA
- The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Richard Mayeux
- The Gertrude H. Sergievsky Center, Columbia University College of Physicians and Surgeons, New York, NY, USA
- The Department of Neurology, Columbia University College of Physicians and Surgeons, New York, NY, USA
- The Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY, USA
- The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Jose A. Luchsinger
- The Gertrude H. Sergievsky Center, Columbia University College of Physicians and Surgeons, New York, NY, USA
- The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, NY, USA
- The Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, USA
- Corresponding author. Department of Medicine, 630 West 168th Street, Columbia University, New York, NY 10032, USA. Tel.: +1 212 305 4730; fax: +1 212 305 9349. E-mail address: (J.A. Luchsinger)
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189
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Jellinger KA. The enigma of mixed dementia. Alzheimers Dement 2007; 3:40-53. [DOI: 10.1016/j.jalz.2006.09.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Accepted: 09/22/2006] [Indexed: 10/23/2022]
Affiliation(s)
- Kurt A. Jellinger
- Institute of Clinical Neurobiology; Kenyongasse 18, A-1070 Vienna Austria
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190
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Abstract
Several studies report that blood pressure is increased in victims of Alzheimer's disease (AD) decades before the onset of the disease. Years before onset of Alzheimer's disease, blood pressure start to decrease and continues to decrease during the disease process. High blood pressure has also been related to pathological manifestations of Alzheimer's disease (senile plaques, neurofibrillary tangles, hippocampal atrophy). The exact mechanism behind these associations is not clear. Hypertension is also a risk factor for stroke, ischemic white matter lesions, silent infarcts, general atherosclerosis, myocardial infarction and cardiovascular diseases, and often clusters with other vascular risk factors, including diabetes mellitus, obesity and hypercholesterolemia. Also these risk factors have been related to Alzheimer's disease. Hypertension may thus cause cerebrovascular disease that may increase the possibility for individuals with AD encephalopathy to express a dementia syndrome. Hypertension may also lead to vessel wall changes in the brain, leading to hypoperfusion, ischemia and hypoxia which may initiate the pathological process of AD. Finally, subclinical AD may lead to increased blood pressure, and similar biological mechanisms may be involved in the pathogenesis of both disorders. Hypertension is a common disorder and often untreated. Several observational studies have reported that use of antihypertensives decreases risk of AD. Even though hypertension only results in a moderately increased risk of AD, or overall dementia, better treatment of hypertension may have an immense effect on the total number of demented individuals.
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Affiliation(s)
- Ingmar Skoog
- Institute of Neuroscience and Physiology, Section of Psychiatry, Unite of Neuropsychiatric Epidemiology, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden.
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191
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Bain LJ. A review of the “State of the Art” on Mild Cognitive Impairment: The Fourth Annual Symposium. Alzheimers Dement 2006; 2:246-56. [DOI: 10.1016/j.jalz.2006.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Accepted: 04/06/2006] [Indexed: 10/24/2022]
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192
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Bennett DA. Commentary on “Vascular cognitive impairment: Today and tomorrow”. Alzheimers Dement 2006; 2:207-9. [DOI: 10.1016/j.jalz.2006.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Accepted: 04/10/2006] [Indexed: 10/24/2022]
Affiliation(s)
- David A. Bennett
- Rush Alzheimer's Disease CenterRush University Medical CenterChicagoILUSA
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193
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Gianaros PJ, Greer PJ, Ryan CM, Jennings JR. Higher blood pressure predicts lower regional grey matter volume: Consequences on short-term information processing. Neuroimage 2006; 31:754-65. [PMID: 16488626 PMCID: PMC2254305 DOI: 10.1016/j.neuroimage.2006.01.003] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Revised: 12/19/2005] [Accepted: 01/07/2006] [Indexed: 11/30/2022] Open
Abstract
Hypertension is a risk factor for diffuse brain atrophy. Yet, there is little evidence that higher blood pressure predicts focal brain atrophy, as indicated by a lower volume of regional brain tissue. This voxel-based morphometry study tested (a) whether higher blood pressure predicts lower regional grey or white matter volume and (b) whether a blood-pressure-related reduction in regional brain tissue volume predicts poorer neuropsychological test performance. Participants were 76 men (M age = 61.33, SD = 4.95 years) and 58 women (M age = 59.86, SD = 5.10 years) without a cardiovascular, cerebrovascular, or neuropsychiatric disease. Results showed that among men, higher resting systolic blood pressure predicted lower grey matter volume in the supplementary motor area and adjacent superior frontal gyrus, the anterior cingulate cortex, and middle temporal gyrus. Among men, lower grey matter volume in the supplementary motor area also predicted a slower time to complete the Trail Making Part B Test of executive control and a poorer recall of items from the Four-word Short-term Memory Test of working memory. These relationships were independent of age, total brain tissue volume, educational history, severity of carotid atherosclerosis, and the extent of periventricular and subcortical white matter lesions. Among women, no statistically significant relationships were found between blood pressure, regional brain tissue volume, and cognitive function. These findings suggest a functional relationship among men between higher blood pressure, lower regional grey matter volume, and poorer cognitive function that is independent of other risk factors and confounding medical conditions.
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Affiliation(s)
- Peter J Gianaros
- Department of Psychiatry, University of Pittsburgh, 3811 O'Hara Street, Pittsburgh, PA 15213, USA.
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194
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Luchsinger JA, Reitz C, Honig LS, Tang MX, Shea S, Mayeux R. Aggregation of vascular risk factors and risk of incident Alzheimer disease. Neurology 2006; 65:545-51. [PMID: 16116114 PMCID: PMC1619350 DOI: 10.1212/01.wnl.0000172914.08967.dc] [Citation(s) in RCA: 522] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The prevalence of Alzheimer disease (AD) is increasing in the elderly, and vascular risk factors may increase its risk. OBJECTIVE To explore the association of the aggregation of vascular risk factors with AD. METHODS The authors followed 1,138 individuals without dementia at baseline (mean age 76.2) for a mean of 5.5 years. The presence of vascular risk factors was related to incident possible and probable AD. RESULTS Four risk factors (diabetes, hypertension, heart disease, and current smoking) were associated with a higher risk of AD (p < 0.10) when analyzed individually. The risk of AD increased with the number of risk factors (diabetes + hypertension + heart disease + current smoking). The adjusted hazards ratio of probable AD for the presence of three or more risk factors was 3.4 (95% CI: 1.8, 6.3; p for trend < 0.0001) compared with no risk factors. Diabetes and current smoking were the strongest risk factors in isolation or in clusters, but hypertension and heart disease were also related to a higher risk of AD when clustered with diabetes, smoking, or each other. CONCLUSIONS The risk of Alzheimer disease (AD) increased with the number of vascular risk factors. Diabetes and current smoking were the strongest risk factors, but clusters including hypertension and heart disease also increased the risk of AD. These associations are unlikely to be explained by misclassification of the outcome, given strong associations when only probable AD is considered.
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Affiliation(s)
- J A Luchsinger
- Taub Institute for Research of Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA.
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195
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Zaccai J, Ince P, Brayne C. Population-based neuropathological studies of dementia: design, methods and areas of investigation--a systematic review. BMC Neurol 2006; 6:2. [PMID: 16401346 PMCID: PMC1397861 DOI: 10.1186/1471-2377-6-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Accepted: 01/09/2006] [Indexed: 11/25/2022] Open
Abstract
Background Prospective population-based neuropathological studies have a special place in dementia research which is under emphasised. Methods A systematic review of the methods of population-based neuropathological studies of dementia was carried out. These studies were assessed in relation to their representativeness of underlying populations and the clinical, neuropsychological and neuropathological approaches adopted. Results Six studies were found to be true population-based neuropathological studies of dementia in the older people: the Hisayama study (Japan); Vantaa 85+ study (Finland); CC75C study (Cambridge, UK); CFAS (multicentre, UK); Cache County study (Utah, USA); HAAS (Hawaï, USA). These differ in the core characteristics of their populations. The studies used standardised neuropathological methods which facilitate analyses on: clinicopathological associations and confirmation of diagnosis, assessing the validity of hierarchical models of neuropathological lesion burden; investigating the associations between neuropathological burden and risk factors including genetic factors. Examples of findings are given although there is too little overlap in the areas investigated amongst these studies to form the basis of a systematic review of the results. Conclusion Clinicopathological studies based on true population samples can provide unique insights in dementia. Individually they are limited in power and scope; together they represent a powerful source to translate findings from laboratory to populations.
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Affiliation(s)
- Julia Zaccai
- Department of Public Health and Primary Care, University of Cambridge, Robinson Way, Cambridge CB2 2SR, UK
| | - Paul Ince
- Academic Unit of Neuropathology, University of Sheffield, 'E' Floor, Royal Hallamshire Hospital, Glossop Road, Sheffield S10 2JF, UK
| | - Carol Brayne
- Department of Public Health and Primary Care, University of Cambridge, Robinson Way, Cambridge CB2 2SR, UK
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196
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Abstract
Arterial hypertension (AH) is considered to be an important risk factor for vascular cognitive impairment and probably for Alzheimer's disease, too. In the current review we provide an overview of the major prospective clinical trials on this issue. With respect to the inconsistent findings of these studies one must state that the interrelations between AH and dementia are still incompletely understood. Regarding therapy there thus is a simple rule: AH should be treated until normal blood pressure values are reached. As long as the hypothesis of a J-curve between blood pressure and cognitive dysfunction has not been disproved, overaggressive blood pressure lowering cannot be recommended. Regarding the aim of preventing dementia, there is no evidence for the superiority of a specific antihypertensive treatment regimen.
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Affiliation(s)
- R Scheid
- Tagesklinik für kognitive Neurologie, Max-Planck-Institut für Kognitions- und Neurowissenschaften, Universität Leipzig, 04103 Leipzig.
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197
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Zhao Z, Ho L, Wang J, Qin W, Festa ED, Mobbs C, Hof P, Rocher A, Masur S, Haroutunian V, Pasinetti GM. Connective tissue growth factor (CTGF) expression in the brain is a downstream effector of insulin resistance‐associated promotion of Alzheimer's disease β‐amyloid neuropathology. FASEB J 2005; 19:2081-2. [PMID: 16186174 DOI: 10.1096/fj.05-4359fje] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The goal of this study was to further explore potential mechanisms through which diabetogenic dietary conditions that result in promotion of insulin resistance (IR), a feature of non-insulin dependant diabetes mellitus (type-2 diabetes), may influence Alzheimer's disease (AD). Using genome-wide array technology, we found that connective tissue growth factor (CTGF), a gene product described previously for its involvement in diabetic fibrosis, is elevated in brain tissue in an established mouse model of diet-induced IR. With this evidence we continued to explore the regulation of CTGF in postmortem AD brain tissue and found that CTGF expression correlated with the progression of AD clinical dementia and amyloid neuritic plaque (NP) neuropathology, but not neurofibrillary tangle (NFT) deposition. Consistent with this evidence, we also found that exposure of Tg2576 mice (a model AD-type amyloid neuropathology) to a diabetogenic diet that promotes IR results in a ~2-fold elevation in CTGF steady-state levels in the brain, coincident with a commensurate promotion of AD-type amyloid plaque burden. Finally, using in vitro cellular models of amyloid precursor protein (APP)-processing and Abeta generation/clearance, we confirmed that human recombinant (hr)CTGF may increase Abeta1-40 and Abeta1-42 peptide steady-state levels, possibly through a mechanism that involves gamma-secretase activation and decreased insulin-degrading enzyme (IDE) steady-state levels in a MAP kinase (MAPK)/ phosphatidylinositol 3-kinase (PI-3K)/protein kinase-B (AKT)1-dependent manner. The findings in this study tentatively suggest that increased CTGF expression in the brain might be a novel biological predicative factor of AD clinical progression and neuropathology in response to dietary regimens promoting IR conditions.
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Affiliation(s)
- Zhong Zhao
- Neuroinflammation Research Laboratories, Mount Sinai School of Medicine, New York, NY 10029, USA
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198
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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: 753] [Impact Index Per Article: 39.6] [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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199
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Vogel T, Verreault R, Kaltenbach G, Berthel M. L’hypertension artérielle est-elle associée à la maladie d’alzheimer ? Presse Med 2005; 34:809-12. [PMID: 16097385 DOI: 10.1016/s0755-4982(05)84049-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Case-control transversal studies have suggested the existence of an association between low blood pressure and Alzheimer's disease, although there is some doubt on the cause to effect relationship. A drop in blood pressure preceding the onset of dementia has been evoked but never confirmed. Longitudinal studies, with long term follow-up on the existence of hypertension during middle-age, have demonstrated a significant increase in the risk of developing Alzheimer's disease in cohorts of hypertensive patients compared to normotensive subjects. The potential benefit of preventive treatment with antihypertensive drugs in decreasing the risk of Alzheimer's disease has not been confirmed in clinical trials. The hypothesis of the formation of a cerebrovascular disease that would combine with the neuropathological lesions has been evoked, raising doubts on the diagnostic criteria used to define Alzheimer's disease. The novel concept that vascular risk factors could directly induce the formation of neuropathological lesions is interesting but warrants confirmation.
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Affiliation(s)
- Thomas Vogel
- Centre de Gérontologie, Hôpitaux Universitaires de Strasbourg, 83 rue Himmerich, 67091 Strasbourg.
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200
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DeCarli C, Massaro J, Harvey D, Hald J, Tullberg M, Au R, Beiser A, D'Agostino R, Wolf PA. Measures of brain morphology and infarction in the framingham heart study: establishing what is normal. Neurobiol Aging 2005; 26:491-510. [PMID: 15653178 DOI: 10.1016/j.neurobiolaging.2004.05.004] [Citation(s) in RCA: 490] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Revised: 05/26/2004] [Accepted: 05/28/2004] [Indexed: 12/31/2022]
Abstract
Numerous anatomical and brain imaging studies find substantial differences in brain structure between men and women across the span of human aging. The ability to extend the results of many of these studies to the general population is limited, however, due to the generally small sample size and restrictive health criteria of these studies. Moreover, little attention has been paid to the possible impact of brain infarction on age-related differences in regional brain volumes. Given the current lack of normative data on gender and aging related differences in regional brain morphology, particularly with regard to the impact of brain infarctions, we chose to quantify brain MRIs from more than 2200 male and female participants of the Framingham Heart Study who ranged in age from 34 to 97 years. We believe that MRI analysis of the Framingham Heart Study more closely represents the general population enabling more accurate estimates of regional brain changes that occur as the consequence of normal aging. As predicted, men had significantly larger brain volumes than women, but these differences were generally not significant after correcting for gender related differences in head size. Age explained approximately 50% of total cerebral brain volume differences, but age-related differences were generally small prior to age 50, declining substantially thereafter. Frontal lobe volumes showed the greatest decline with age (approximately 12%), whereas smaller differences were found for the temporal lobes (approximately 9%). Age-related differences in occipital and parietal lobe were modest. Age-related gender differences were generally small, except for the frontal lobe where men had significantly smaller lobar brain volumes throughout the age range studied. The prevalence of MRI infarction was common after age 50, increased linearly with age and was associated with significantly larger white matter hyperintensity (WMH) volumes beyond that associated with age-related differences in these measures. Amongst men, the presence of MRI infarction was associated with significant age-related reductions in total brain volume. Finally, statistically significant associations were found between the volume of MRI infarcts in cubic centimeters and all brain measures with the exception of parietal lobe volume for individuals where the volume of MRI infarctions was measured. These data serve to define age and gender differences in brain morphology for the Framingham Heart Study. To the degree participants of the Framingham Heart Study are representative the general population, these data can serve as norms for comparison with morphological brain changes associated with aging and disease. In this regard, these cross-sectional quantitative estimates suggest that age-related tissue loss differs quantitatively and qualitatively across brain regions with only minor differences between men and women. In addition, MRI evidence of cerebrovascular disease is common to the aging process and associated with smaller regional brain volumes for a given age, particularly for men. We believe quantitative MRI studies of the Framingham community enables exploration of numerous issues ranging from understanding normal neurobiology of brain aging to assessing the impact of various health factors, particularly those related to cerebrovascular disease, that appear important to maintaining brain health for the general population.
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Affiliation(s)
- Charles DeCarli
- Department of Neurology and Center for Neuroscience, 4860 Y Street, Suite 3700, Sacramento, CA 95817, USA.
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