The relationship between blood pressure and dementia: a review

Prevalence and associated factors of mild cognitive impairment among middle-aged and older adults: Results of the first phase of Ardakan Cohort Study on Aging

Background and Aims

Data on mild cognitive impairment (MCI) in low- to middle-income countries are still being determined, despite the fact that most future older adults are expected to reside in these regions. This study aimed to investigate the prevalence and associated factors of MCI in Iran.

Methods

A cross-sectional study was conducted on 4938 community-dwelling subjects aged 50 years or above in the first wave of the Ardakan Cohort Study on Aging. MCI was evaluated using the Mini-Mental State Examination (MMSE) and the Abbreviated Mental Test Score (AMTS) in literate and illiterate individuals. The relationship between factors associated with the odds of MCI was assessed through logistic regression.

Results

The prevalence of MCI among all participants, the literates and illiterates, was 15.8%, 6.3%, and 36.4%, respectively. It was found that failure to accomplish any of the MMSE or AMTS items was significantly related to MCI (p < 0.001). Age ([odds ratio (OR): 1.05; p < 0.001 in the literates], [OR: 1.06; p < 0.001 in the illiterates]), sex (OR: 0.13; p < 0.001 in the illiterates), history of stroke ([OR: 2.86; p = 0.006 in the literates], [OR: 2.04; p = 0.045 in the illiterates]), and depression ([OR: 1.87; p < 0.001 in the literates], [OR: 1.41; p = 0.008 in the illiterates]) were significantly associated with MCI.

Conclusion

This study highlights the significant associations between age, education, depression, stroke, and MCI in Iranian participants. These findings emphasize the need for targeted interventions in low-literacy populations, mental health screening, and stroke prevention strategies to mitigate the burden of MCI and enhance cognitive health.

Effects of Hypertension on Alzheimer's Disease and Related Disorders

PURPOSE OF REVIEW

To review the pathophysiology of hypertension in Alzheimer's disease and related dementias and explore the current landscape of clinical trials involving treatment of hypertension to improve cognition.

RECENT FINDINGS

Hypertension is increasingly recognized as a contributor to cognitive impairment. Clinical trials that explore blood pressure reductions with cognitive outcomes have been promising. Various antihypertensives have been evaluated in clinical trials, with growing interest in those agents that impact the renin-angiotensin-aldosterone system due to its own association with cognitive impairment. No antihypertensive agent has been found to be superior to others in reducing cognitive impairment risk or conferring neuroprotective benefits. In this review, the pathophysiology of and clinical trial data involving hypertension and dementia will be explored. Hypertension is a significant risk factor for the development of neurodegenerative dementias, and clinical trials have been overall favorable in improving cognition by reductions in blood pressure using antihypertensive agents.

Effect of Heart Rate Reserve on Prefrontal Cortical Activation While Dual-Task Walking in Older Adults

Hypertension is considered a risk factor for cardiovascular health and non-amnestic cognitive impairment in older adults. While heart rate reserve (HRR) has been shown to be a risk factor for hypertension, how impaired HRR in older adults can lead to cognitive impairment is still unclear. The objective of this study was to examine the effects of HRR on prefrontal cortical (PFC) activation under varying dual-task demands in older adults. Twenty-eight older adults (50-82 years of age) were included in this study and divided into higher (n = 14) and lower (n = 14) HRR groups. Participants engaged in the cognitive task which was the Modified Stroop Color Word Test (MSCWT) on a self-paced treadmill while walking. Participants with higher HRR demonstrated increased PFC activation in comparison to lower HRR, even after controlling for covariates in analysis. Furthermore, as cognitive task difficulty increased (from neutral to congruent to incongruent to switching), PFC activation increased. In addition, there was a significant interaction between tasks and HRR group, with older adults with higher HRR demonstrating increases in PFC activation, faster gait speed, and increased accuracy, relative to those with lower HRR, when going from neutral to switching tasks. These results provide evidence of a relationship between HRR and prefrontal cortical activation and cognitive and physical performance, suggesting that HRR may serve as a biomarker for cognitive health of an older adult with or without cardiovascular risk.

Cognitive impairment in myocardial infarction and heart failure

Myocardial infarction (MI) occurs when coronary blood flow is decreased due to an obstruction/occlusion of the vessels, leading to myocardial death and progression to heart failure (HF). Cognitive impairment, anxiety, depression and memory loss are the most frequent mental health problems among patients with HF. The most common cause of cognitive decline is cardiac systolic dysfunction, which leads to reduced cerebral perfusion. Several in vivo and clinical studies provide information regarding the underlying mechanisms of HF in brain pathology. Neurohormonal activation, oxidative stress, inflammation, glial activation, dendritic spine loss and brain programmed cell death are all proposed as contributors of cognitive impairment in HF. Furthermore, several investigations into the effects of various medications on brain pathology utilizing MI models have been reported. In this review, potential mechanisms involving HF-associated cognitive impairment, as well as neuroprotective interventions in HF models, are discussed and summarized. In addition, gaps in the surrounding knowledge, including the types of brain cell death and the effects of cell death inhibitors in HF, are presented and discussed. This review provides valuable information that will suggest the potential therapeutic strategies for cognitive impairment in patients with HF.

Alzheimer's Disease: The Link Between Amyloid-β and Neurovascular Dysfunction

While prevailing evidence supports that the amyloid cascade hypothesis is a key component of Alzheimer's disease (AD) pathology, many recent studies indicate that the vascular system is also a major contributor to disease progression. Vascular dysfunction and reduced cerebral blood flow (CBF) occur prior to the accumulation and aggregation of amyloid-β (Aβ) plaques and hyperphosphorylated tau tangles. Although research has predominantly focused on the cellular processes involved with Aβ-mediated neurodegeneration, effects of Aβ on CBF and neurovascular coupling are becoming more evident. This review will describe AD vascular disturbances as they relate to Aβ, including chronic cerebral hypoperfusion, hypertension, altered neurovascular coupling, and deterioration of the blood-brain barrier. In addition, we will describe recent findings about the relationship between these vascular defects and Aβ accumulation with emphasis on in vivo studies utilizing rodent AD models.

Does Gender Influence the Relationship Between High Blood Pressure and Dementia? Highlighting Areas for Further Investigation

BACKGROUND

Gender differences have been noted in studies linking blood pressure to all-cause dementia, and the two most common forms of dementia: Alzheimer's disease (AD) and vascular dementia (VaD). However, how gender modifies the relationship between blood pressure and dementia remains unclear.

OBJECTIVE

To review evidence for a gender modifying effect on the link between blood pressure and all-cause dementia.

METHODS

A systematic review was conducted according to PRISMA guidelines. Sixteen out of 256 reviewed articles met inclusion criteria.

RESULTS

For women, higher midlife systolic blood pressure (SBP) and hypertension were both associated with greater risk of all-cause dementia, AD, and VaD, in six out of seven studies. Two of these studies reported higher midlife SBP/hypertension were associated with greater risk for all-cause dementia in women, but not men. One study reported higher midlife SBP associated with greater AD risk in women, but not men. However, another study reported that midlife hypertension associated with AD risk in men, but not women. No clear gender differences were reported in the relationship between late-life high blood pressure/hypertension with all-cause dementia or AD.

CONCLUSION

Studies rarely, and inconsistently, analyzed or reported gender effects. Therefore, interpretation of available evidence regarding the role of gender in blood pressure associated dementia was difficult. Several studies indicated higher midlife SBP was associated with greater risk of all-cause dementia for women, compared to men. Future studies should evaluate women-specific aging processes that occur in midlife when considering the association between blood pressure and dementia risk.

Cerebrovascular Disease Is a Risk for Getting Lost Behavior in Prodromal Dementia

Cerebrovascular disease (CVD) contributes to spatial navigation deficits; however, the everyday outcomes of this association remain unexplored. We investigated whether CVD was a risk for getting lost behavior (GLB) in elderly with mild cognitive impairment (MCI) and mild Alzheimer disease (AD). Getting lost behavior was assessed using a semistructured clinical interview and was associated with white matter lesions (WMLs) in patients with MCI. Specifically, right occipital WMLs increased the odds of GLB by 12 times (P = .03) and right temporal WMLs increased the odds of GLB by 4 times (P = .01), regardless of age, gender, global cognitive impairment, and occipital or medial temporal gray matter atrophy. Hypertension increased the risk of GLB in MCI by contributing to the burden of WMLs. White matter lesions were not associated with GLB in mild AD. Our findings suggest that interventions aimed at reducing GLB in prodromal dementia may involve preventing WMLs by optimizing hypertension control.

Low Cerebrospinal Fluid Aβ42 and Aβ40 are Related to White Matter Lesions in Cognitively Normal Elderly

Background:

Low cerebrospinal fluid (CSF) levels of Aβ₄₂ may be the earliest manifestation of Alzheimer’s disease (AD). Knowledge on how CSF Aβ interacts with different brain pathologies early in the disease process is limited. We examined how CSF Aβ markers relate to brain atrophy and white matter lesions (WMLs) in octogenarians with and without dementia to explore the earliest pathogenetic pathways of AD in the oldest old.

Objective:

To study CSF amyloid biomarkers in relation to brain atrophy and WMLs in 85-year-olds with and without dementia.

Methods:

53 octogenarians took part in neuropsychiatric examinations and underwent both a lumbar puncture and a brain CT scan. CSF levels of Aβ₄₂ and Aβ₄₀ were examined in relation to cerebral atrophy and WMLs. Dementia was diagnosed.

Results:

In 85-year-olds without dementia, lower levels of both CSF Aβ₄₂ and CSF Aβ₄₀ were associated with WMLs. CSF Aβ₄₂ also correlated with measures of central atrophy, but not with cortical atrophy. In participants with dementia, lower CSF levels of Aβ₄₂ were related to frontal, temporal, and parietal cortical atrophy but not to WMLs.

Conclusions:

Our findings may suggest that there is an interrelationship between Aβ and subcortical WMLs in older persons without dementia. After onset of dementia, low CSF Aβ₄₂, probably representing amyloid deposition in plaques, is associated with cortical atrophy. WMLs may be an earlier manifestation of Aβ deposition than cortical degeneration.

Association Between Late-Life Blood Pressure and the Incidence of Cognitive Impairment: A Community-Based Prospective Cohort Study

OBJECTIVES

To investigate the association between late-life blood pressure and the incidence of cognitive impairment in older adults.

DESIGN

Prospective cohort study.

SETTING

Community-living older adults from 22 provinces in China.

PARTICIPANTS

We included 12,281 cognitively normal [Mini-Mental State Examination (MMSE) ≥ 24] older adults (median age: 81 years) from the Chinese Longitudinal Healthy Longevity Survey. Eligible participants must have baseline blood pressure data and have 1 or more follow-up cognitive assessments.

MEASUREMENTS

Baseline systolic (SBP) and diastolic blood pressure (DBP) were measured by trained internists. Cognitive function was evaluated by MMSE. We considered mild/moderate/severe cognitive impairment (MMSE <24, and MMSE decline ≥3) as the primary outcome.

RESULTS

The participants with hypertension had a significantly higher risk of mild/moderate/severe cognitive impairment (hazard ratio [HR] 1.17, 95% confidence interval [CI] 1.10-1.24). Overall, the associations with cognitive impairment seem to be hockey stick-shaped for SBP and linear for DBP, though the estimated effects for low SBP/DBP were less precise. High SBP was associated with a gradual increase in the risk of mild/moderate/severe cognitive impairment (P trend < .001). Compared with SBP 120 to 129 mmHg, the adjusted HR was 1.17 (95% CI 1.07-1.29) for SBP 130 to 139 mmHg, increased to 1.54 (95% CI 1.35-1.75) for SBP ≥180 mmHg. Analyses for high DBP showed the same increasing pattern, with an adjusted HR of 1.09 (95% CI 1.01-1.18) for DBP 90 to 99 mmHg and 1.19 (95% CI 1.02-1.38) for DBP ≥110 mmHg, as compared with DBP 70 to 79 mmHg.

CONCLUSION

Late-life high blood pressure was independently associated with cognitive impairment in cognitively normal Chinese older adults. Prevention and management of high blood pressure may have substantial benefits for cognition among older adults in view of the high prevalence of hypertension in this rapidly growing population.

Associations of centrally acting ACE inhibitors with cognitive decline and survival in Alzheimer's disease

BACKGROUND

Cognitive improvement has been reported in patients receiving centrally acting angiotensin-converting enzyme inhibitors (C-ACEIs).

AIMS

To compare cognitive decline and survival after diagnosis of Alzheimer's disease between people receiving C-ACEIs, non-centrally acting angiotensin-converting enzyme inhibitors (NC-ACEIs), and neither.

METHOD

Routine Mini-Mental State Examination (MMSE) scores were extracted in 5260 patients receiving acetylcholinesterase inhibitors and analysed against C-/NC-ACEI exposure at the time of Alzheimer's disease diagnosis.

RESULTS

In the 9 months after Alzheimer's disease diagnosis, MMSE scores significantly increased by 0.72 and 0.19 points per year in patients on C-ACEIs and neither respectively, but deteriorated by 0.61 points per year in those on NC-ACEIs. There were no significant group differences in score trajectories from 9 to 36 months and no differences in survival.

CONCLUSIONS

In people with Alzheimer's disease receiving acetylcholinesterase inhibitors, those also taking C-ACEIs had stronger initial improvement in cognitive function, but there was no evidence of longer-lasting influence on dementia progression.

DECLARATION OF INTEREST

R.S. has received research funding from Pfizer, Lundbeck, Roche, Janssen and GlaxoSmithKline.

COPYRIGHT AND USAGE

© The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.

Macroarray analysis in the hypertrophic left ventricle of renin-dependent hypertensive rats: identification of target genes for renin

Introduction The aim of this work was to identify new renin target genes in left ventricular hypertrophy during hypertension.

Materials and methods We compared left ventricle gene expression from four transgenic TGR(mRen2)27 (TG+/-) rats and four non-transgenic littermates (TG-/-) using cDNA macroarray. Hybridisation signals were quantified with a phosphorimager, and normalised to an external scale. Data analysis was performed with Statistical Analysis for Microarrays (SAM 1.21) software. The mRNA levels of candidate genes were determined by semi-quantitative RT-PCR in three different hypertensive rats: TG+/-, spontaneously hypertensive (SHR) and genetically Lyon hypertensive (LH) rats, compared to their respective controls (TG-/-, Wistar-Kyoto, Lyon low blood pressure rats).

Results Out of 1,200 genes present on the macroarray, 233 were reliably measured and only three were overexpressed (Biglycan, β1-adenosine monophosphate-activated protein kinase [AMPK] and amyloid precursor like protein 2 [APLP2]) and 19 were underexpressed in the left ventricle of TG+/compared with TG-/-. APLP2 is a member of the amyloid precursor protein (APP) family. APLP2 and APP mRNA levels were increased in TGR(mRen2)27 but significantly decreased in LH rats, while only APP was increased in SHR rats.

Conclusions We report new genes associated with renin-dependent left ventricular hypertrophy. Moreover, this work shows for the first time that the APP family gene expression could be altered in response to high renin activity and this effect is independent of cardiac remodelling and hypertension.

Cerebral microbleeds: different prevalence, topography, and risk factors depending on dementia diagnosis—the Karolinska Imaging Dementia Study

BACKGROUND AND PURPOSE

Cerebral microbleeds are thought to represent cerebral amyloid angiopathy when in lobar regions of the brain and hypertensive arteriopathy when in deep and infratentorial locations. By studying cerebral microbleeds, their topography, and risk factors, we aimed to gain an insight into the vascular and amyloid pathology of dementia diagnoses and increase the understanding of cerebral microbleeds in dementia.

MATERIALS AND METHODS

We analyzed 1504 patients (53% women; mean age, 63 ± 10 years; 10 different dementia diagnoses) in this study. All patients underwent MR imaging as part of the dementia investigation, and all their clinical parameters were recorded.

RESULTS

Among the 1504 patients with dementia, 22% had cerebral microbleeds. Cerebral microbleed topography was predominantly lobar (P = .01) and occipital (P = .007) in Alzheimer disease. Patients with cerebral microbleeds were significantly older (P < .001), were more frequently male (P < .001), had lower cognitive scores (P = .006), and more often had hypertension (P < .001). Risk factors for cerebral microbleeds varied depending on the dementia diagnosis. Odds ratios for having cerebral microbleeds increased with the number of risk factors (hypertension, hyperlipidemia, diabetes, male sex, and age 65 and older) in the whole patient group and increased differently in the separate dementia diagnoses.

CONCLUSIONS

Prevalence, topography, and risk factors of cerebral microbleeds vary depending on the dementia diagnosis and reflect the inherent pathology of different dementia diagnoses. Because cerebral microbleeds are seen as possible predictors of intracerebral hemorrhage, their increasing prevalence with an increasing number of risk factors, as shown in our study, may require taking the number of risk factors into account when deciding on anticoagulant therapy in dementia.

Blood pressure and cognition among older adults: a meta-analysis

Hypertension has adverse effects on cognition, can alter cerebral vasculature integrity, and is associated with the pathogenesis of dementia. Using meta-analysis, we correlated blood pressure to multiple cognitive domains among older adults free of clinical stroke and dementia. We identified 230 studies indexed in PubMed and PsycINFO relating blood pressure and cognition. After applying exclusion criteria, we selected n = 12 articles with n = 4,076 participants (age range 43-91 years). Meta-analysis yielded an association between blood pressure and episodic memory (r = -.18, p < .001) and between blood pressure and global cognition (r = -.07, p < .001). When limiting analyses to studies adjusting for vascular covariates (n = 8, n = 2,141), blood pressure was modestly related to global cognition (r = -.11, p < .001), attention (r = .14, p = .002), and episodic memory (r = -.20, p < .001) with a trend for language (r = -.22, p = .07). Findings underscore the need to manage blood pressure as a key prevention method in minimizing abnormal cognitive aging prior to the onset of clinical dementia.

Does vascular burden contribute to the progression of mild cognitive impairment to dementia?

AIMS

To investigate the contribution of vascular risk factors (VRFs), vascular diseases (VDs) and white matter lesions (WMLs) to the progression of mild cognitive impairment (MCI) to dementia and Alzheimer's disease (AD).

METHODS

Two hundred forty-five consecutive subjects with MCI (age 74.09 ± 6.92 years) were followed for an average of 2.4 years. The Hachinski Ischemic Score and the Framingham Stroke Risk Profile were used to summarize VRFs and VDs. WMLs were graded using the Age-Related White Matter Changes Scale.

RESULTS

One hundred twenty-nine (52.6%) out of 245 subjects at risk converted to dementia, including 87 cases of AD. When hypertension occurred in MCI with deep WMLs, a 1.8-fold increased risk of dementia was observed (95% CI = 1.0-3.4). When deep WMLs occurred in MCI with high scores (≥4) on the Hachinski scale, a 3.5-fold (95% CI = 1.6-7.4) and 3.8-fold (95% CI = 1.2-11.5) risk of progression to dementia and AD was observed, respectively. Analogously, the joint effect of WMLs and high scores (≥14) on the Framingham scale nearly doubled the risk of dementia (hazard ratio = 1.9, 95% CI = 1.1-3.3).

CONCLUSIONS

Accelerated progression of MCI to dementia and AD is to be expected when VRFs and VDs occur together with WMLs.

A cottage model for eldercare

OBJECTIVE

An overview of medical, cognitive, and affective changes experienced by geriatric long-term care residents during a migration from traditional healthcare delivery to a cottage-based model.

BACKGROUND

New architectural models hold great promise for improving health and social outcomes for residents. New studies must explore the resident, family, and staff outcomes across transformations, as well as the business case for change.

METHODS

A longitudinal, quasi-experimental design was employed, with an emphasis on regularly acquired institutional data, including the Minimum Data Set, as well as commonly available survey instruments including the MOSES, the 2005 NSWHN, and Castle's Job Satisfaction Questionnaire. Descriptive statistics, McNemar's Exact Test, repeated measures ANOVA, and t-tests were used as well as narratives from families, staff, and management.

RESULTS

Staff perceived enhanced institutional respect (t(72) = 2.38, p = 0.02) and work environment, and families perceived more staff cooperation and a better bond between staff and residents. No changes were discerned in a resident's prevalence of pain (odds ratio 0.43, p = .34, 95% CI [0.07, 1.88]), mobility (odds ratio 0.50, p =.19, 95% CI [0.17, 1.32]), range of motion(odds ratio 0.57, p = .55, 95% CI [0.12, 2.25]), or depression and anxiety (odds ratio 2.33, p =.11,95% CI [0.84, 7.41]). A modest decline in residents' systolic (t(101) = 3.74, p < .001) and diastolic (t(101) = 2.870, p < .01) blood pressures was demonstrated. The rate at which a resident's Activities of Daily Living score declined was attenuated (t(57) = 3.37, p < .001). Operational costs remained constant across the move.

CONCLUSIONS

Cottage settings were aesthetically appealing to residents, family, and staff. Modest improvements in health outcomes were observed, and operational costs remained stable.

Therapeutic approaches to age-associated neurocognitive disorders

The United Nations projects that the number of individuals with dementia in developed countries alone will be approximately 36,7 million by the year 2050. International recognition of the significant emotional and economic burden of Alzheimer's disease has been matched by a dramatic increase in the development of pharmacological and nonpharmacological approaches to this illness in the past decade. Changing demographics have underscored the necessity to develop similar approaches for the remediation of the cognitive impairment associated with more benign syndromes, such as mild cognitive impairment (MCI) and age-associated cognitive decline (AACD). The present article aims to provide an overview of the most current therapeutic approaches to age-associated neurocognitive disorders. Additionally, it discusses the conceptual and methodological issues that surround the design, implementation, and interpretation of such approaches.

Occurrence and risk factors of mild cognitive impairment in the older Chinese population: a 3-year follow-up study

OBJECTIVE

To investigate the occurrence and risk factors of mild cognitive impairment (MCI) and the conversion rates to dementia in Chinese people over 80 years of age.

METHODS

Two hundred and two participants (>80 years old) without dementia were assessed clinically using neuropsychological tests; they were re-assessed at 1, 2, and 3 years.

RESULTS

The results revealed that 30.2% of the study population was classified as having MCI at baseline. Multivariate linear regression analysis showed that coronary heart disease, hypertension, and stroke were risk factors of MCI. During the 3 years follow-up, the occurrence of MCI increased, and 21.8% of the participants with MCI progressed to dementia.

CONCLUSIONS

These results suggest that in the older elderly, prevention and early treatment of cardiovascular and cerebrovascular diseases may be effective in lowering the risk of MCI. MCI is a high risk factor for dementia.

Cognitive enhancement following acute losartan in normotensive young adults

RATIONALE

Losartan, an angiotensin II receptor antagonist (AIIA), is an antihypertensive that has previously been suggested to have cognitive-enhancing potential for older adults. The objective indices for such effects are equivocal, however, and if these drugs do offer dual advantages of hypertension control plus cognitive-enhancing potential, there exists a clear need to establish this directly.

OBJECTIVES

This work examines the potential of losartan administered as a single dose to healthy young adults to improve cognitive performance alone or to reverse scopolamine-induced cognitive decrements.

METHODS

In two placebo-controlled, double-blind studies, participants completed a cognitive test battery once before and once after drug absorption. In experiment 1, participants were randomly allocated to receive placebo, losartan 50 mg or losartan 100 mg. In experiment 2, participants were randomly allocated to one of four treatment groups: placebo/placebo, placebo/scopolamine, losartan/scopolamine and losartan/placebo (50 mg losartan p.o. and 1.2 mg scopolamine hydrochloride p.o.).

RESULTS

Losartan 50 mg improved performance on a task of prospective memory when administered alone and reversed the detrimental effects of scopolamine both in a standard lexical decision paradigm (p < 0.01) and when the task incorporated a prospective memory component (p < 0.008).

CONCLUSIONS

The findings highlight a cognitive-enhancing potential for losartan on compromised cognitive systems and emphasise the potential of AIIAs to produce benefits over and above hypertension control.

Non-adherence to antihypertensive medication and impaired cognition: which comes first?

OBJECTIVE

Antihypertensive medications are important in the prevention of serious consequences of hypertension, such as stroke and heart failure. Up to one-third of elderly hypertensive patients, however, do not adhere to their medication. Adherence to medication decreases with increasing age, and with decreasing cognitive ability, thus elderly, cognitively-impaired patients have poorer control of blood pressure. Good control of blood pressure is associated with decreased prevalence of dementia and Alzheimer's disease. This study assessed the evidence that antihypertensive medications have effects on the prevalence or severity of mild cognitive impairment, dementia or Alzheimer's disease.

METHODS

The ISI Web of Knowledge database was searched; including replicates, the nine searches identified 14400 publications since 1952, of which 9.9% had been published in 2009. This review considers the 18 studies meeting the set criteria published in 2009 or later.

KEY FINDINGS

Not all antihypertensive medications are equivalent in their positive cognitive effects, with brain-penetrating angiotensin-converting-enzyme inhibitors and possibly angiotensin receptor antagonists being the most effective.

CONCLUSIONS

Based on evidence of blood-pressure control and cost, UK National Institute for Health and Clinical Excellence guidelines recommend calcium-channel blockers or thiazide-type diuretics for the treatment of hypertension in patients over 55 years. These guidelines take no account of the potential cognitive effects of the antihypertensive therapies, consideration of which might lead to a review. There may be benefit in stressing that adherence to antihypertensive medication not only decreases the risk of cardiovascular disease and death, but may also decrease the risk or severity of mild cognitive impairment, dementia and Alzheimer's disease.

A summary risk score for the prediction of Alzheimer disease in elderly persons

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.

Risk factors for incident mild cognitive impairment--results from the German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe)

OBJECTIVES

To provide age- and gender-specific incidence rates of MCI among elderly general practitioner (GP) patients (75+ years) and to identify risk factors for incident MCI.

METHOD

Data were derived from the longitudinal German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe). Incidence was calculated according to the 'person-years-at-risk' method. Risk factors were analysed using multivariate logistic regression models.

RESULTS

During the 3-year follow-up period, 350 (15.0%) of the 2331 patients whose data were included in the calculation of incidence developed MCI [person-years (PY) = 6198.20]. The overall incidence of MCI was 56.5 (95% confidence interval = 50.7-62.7) per 1000 PY. Older age, vascular diseases, the apoE epsilon4 allele and subjective memory complaints were identified as significant risk factors for future MCI.

CONCLUSION

Mild cognitive impairment is frequent in older GP patients. Subjective memory complaints predict incident MCI. Especially vascular risk factors provide the opportunity of preventive approaches.

Hypertension and cognitive function in the elderly

Alzheimer's disease is the most prevalent and common form of cognitive impairment, ie, dementia, in the elderly followed in second place by vascular dementia due to the microangiopathy associated with poorly-controlled hypertension. Besides blood pressure elevation, advancing age is the strongest risk factor for dementia. Deterioration of intellectual function and cognitive skills that leads to the elderly patient becoming more and more dependent in his, her, activities of daily living, ie, bathing, dressing, feeding self, locomotion, and personal hygiene. It has been known and demonstrated for many years that lowering of blood pressure from a previous hypertensive point can result in stroke prevention yet lowering of blood pressure does not prevent the microangiopathy that leads to white matter demyelinization which when combined with the clinical cognitive deterioration is compatible with a diagnosis of vascular dementia. It is known from many large studies, ie, SHEP, SCOPE, and HOPE, that lowering of blood pressure gradually will not and should not worsen the cognitive impairment. However, if the pressure is uncontrolled a stroke which might consequently occur would further worsen their cognitive derangement. So an attempt at slow reduction of blood pressure since cerebral autoregulation is slower as age increases is in the patient's best interest. It is also important to stress that control of blood glucose can also be seen as an attempt to prevent vascular dementia from uncontrolled hyperglycemia. Vascular dementia is not considered one of the reversible causes of dementia. Reversible causes of cognitive impairment are over medication with centrally acting drugs such as sedatives, hypnotics, antidepressants, and antipsychotics, electrolyte imbalance such as hyponatremia, azotemia, chronic liver disease, and poor controlled chronic congestive heart failure. Criteria for the clinical diagnosis of vascular dementia include cognitive decline in regards to preceding functionally higher level characterized by alterations in memory and in two or more superior cortical functions that include orientation, attention, verbal linguistic capacities, visual spacial skills, calculation, executive functioning, motor control, abstraction and judgment. Patients with disturbances of consciousness, delirium (acute confusional states), psychosis, serious aphasia, or sensory-motor alterations that preclude proper execution of neuro-psychological testing are also considered to have probably vascular dementia. Furthermore, these are ten of the other essential cerebral or systematic pathologies present that would be able to produce a dementia syndrome.

Effect of acute and chronic hypertension on short- and long-term spatial and avoidance memory in male rats

It has been demonstrated that hypertension can lead to coronary heart disease, heart failure, stroke, and memory loss. In this study we investigated the effect of acute and chronic hypertension on the avoidance and spatial learning and memory in rats. The forty male rats were divided into acute hypertensive, chronic hypertensive and control for each group rats. Hypertension was induced by Deoxy Corticosterone Acetate (DOCA)-salt method. DOCA was injected 30mg/kg of body weight subcutaneously, twice a week. These rats received NaCl 1% instead of tap water for drinking throughout the experiment. The control group received normal saline injection with usual drinking water. Spatial learning and memory was investigated by Morris water maze test and passive avoidance learning by Shuttle box test in the rats after hypertension induction. Results showed that acute hypertension impaired short-term memory in passive avoidance learning. However, acute and chronic hypertension did not affect spatial learning and memory. These data suggest that simple uncomplicated hypertension does not remarkably alter cognition.

Angiotensin-converting enzyme inhibitors and cognitive decline in older adults with hypertension: results from the Cardiovascular Health Study

BACKGROUND

Hypertension (HTN) is a risk factor for dementia, and animal studies suggest that centrally active angiotensin-converting enzyme (ACE) inhibitors (those that cross the blood-brain barrier) may protect against dementia beyond HTN control.

METHODS

Participants in the Cardiovascular Health Study Cognition Substudy with treated HTN and no diagnosis of congestive heart failure (n = 1054; mean age, 75 years) were followed up for a median of 6 years to determine whether cumulative exposure to ACE inhibitors (as a class and by central activity), compared with other anti-HTN agents, was associated with a lower risk of incident dementia, cognitive decline (by Modified Mini-Mental State Examination [3MSE]), or incident disability in instrumental activities of daily living (IADLs).

RESULTS

Among 414 participants who were exposed to ACE inhibitors and 640 who were not, there were 158 cases of incident dementia. Compared with other anti-HTN drugs, there was no association between exposure to all ACE inhibitors and risk of dementia (hazard ratio [HR], 1.01; 95% confidence interval [CI], 0.88-1.15), difference in 3MSE scores (-0.32 points per year; P = .15), or odds of disability in IADLs (odds ratio [OR], 1.06; 95% CI, 0.99-1.14). Adjusted results were similar. However, centrally active ACE inhibitors were associated with 65% less decline in 3MSE scores per year of exposure (P = .01), and noncentrally active ACE inhibitors were associated with a greater risk of incident dementia (adjusted HR, 1.20; 95% CI, 1.00-1.43 per year of exposure) and greater odds of disability in IADLs (adjusted OR, 1.16; 95% CI, 1.03-1.30 per year of exposure) compared with other anti-HTN drugs.

CONCLUSIONS

While ACE inhibitors as a class do not appear to be independently associated with dementia risk or cognitive decline in older hypertensive adults, there may be within-class differences in regard to these outcomes. These results should be confirmed with a randomized clinical trial of a centrally active ACE inhibitor in the prevention of cognitive decline and dementia.

Risk Factors for Alzheimer's Disease: An Overview for Clinical Practitioners

OBJECTIVE

To review current information on various risk factors of Alzheimer's disease (AD) for clinicians so that they may educate patients or their families in a clinical setting.

DATA SOURCES

Published medical literature and research articles from MEDLINE.

STUDY SELECTION

Reviews and articles from 1985 to 2003 concerning risk factors associated with AD.

DATA EXTRACTION

Data on risk factors ranging from possible or controversial to well established.

DATA SYNTHESIS

AD is an irreversible, progressive neurodegenerative disorder. AD is currently known to be the most common cause of dementia in the United States. Over the last several decades, different levels of risk factors associated with AD have been identified. With more information available to the public via various resources, there is greater need for clinical practitioners to provide up-to-date information on risk factors in a meaningful way. This article discusses advanced age, family history, gender, low education, apolipoprotein E e4, head injury, cardiovascular conditions, and aluminum.

CONCLUSION

Since there currently is no cure or preventive measure for AD, it is important to educate patients and their families about risk factors of AD in clinical practice.

Vascular compliance is reduced in vascular dementia and not in Alzheimer's disease

OBJECTIVE

to determine whether functional changes in the vasculature differ between Alzheimer's disease (AD) and vascular dementia (VAD).

DESIGN

we determined vascular stiffness in patients with a clinical and radiological diagnosis of either AD or VAD and compared them to normal age- and sex-matched controls.

METHODS

In all, 16 patients with late onset AD, 13 subjects with VAD and 16 age- and sex-matched controls were recruited to this study. Central arterial compliance (CAC), augmentation index (AI) and pulse wave velocity (PWV) (measures of arterial stiffness) were measured.

RESULTS

the mean age was 77.7 +/- 8.3 years (mean +/- SD) in the AD group, 79.7 +/- 8.9 years in the VAD group and 76.4 +/- 6.9 in the controls (P = 0.44). CAC was significantly lower in subjects with VAD compared to both the AD and the control groups (0.57 +/- 0.46 ml/mm Hg versus 1.12 +/- 0.57 and 1.1 +/- 0.47 ml/mm Hg respectively, P = 0.01). AI was significantly higher in the subjects with VAD compared to both the AD and the control groups (13.3 +/- 9.0 versus 3.5 +/- 11.4 and 4.2 +/- 9.7% respectively, P = 0.03). PWV in the muscular and elastic arteries were not statistically different between the three groups but tended to be highest in the VAD group for carotid-radial measurements.

CONCLUSIONS

the reduced CAC and increased AI in VAD subjects indicate that the disease process is associated with less vascular compliance of the large elastic arteries in these patients, but not in patients with AD.

Hypertension and cognitive function in the elderly

Alzheimer's disease is the most prevalent and common form of cognitive impairment, ie, dementia, in the elderly followed in second place by vascular dementia due to the microangiopathy associated with poorly-controlled hypertension. Besides blood pressure elevation, advancing age is the strongest risk factor for dementia. Deterioration of intellectual function and cognitive skills that leads to the elderly patient becoming more and more dependent in his, her, activities of daily living, ie, bathing, dressing, feeding self, locomotion, and personal hygiene. It has been known and demonstrated for many years that lowering of blood pressure from a previous hypertensive point can result in stroke prevention yet lowering of blood pressure does not prevent the microangiopathy that leads to white matter demyelinization which when combined with the clinical cognitive deterioration is compatible with a diagnosis of vascular dementia. It is known from many large studies, ie, SHEP, SCOPE, and HOPE, that lowering of blood pressure gradually will not and should not worsen the cognitive impairment. However, if the pressure is uncontrolled a stroke which might consequently occur would further worsen their cognitive derangement. So an attempt at slow reduction of blood pressure since cerebral autoregulation is slower as age increases is in the patient's best interest. It is also important to stress that control of blood glucose can also be seen as an attempt to prevent vascular dementia from uncontrolled hyperglycemia. Vascular dementia is not considered one of the reversible causes of dementia. Reversible causes of cognitive impairment are over medication with centrally acting drugs such as sedatives, hypnotics, antidepressants, and antipsychotics, electrolyte imbalance such as hyponatremia, azotemia, chronic liver disease, and poor controlled chronic congestive heart failure. Criteria for the clinical diagnosis of vascular dementia include cognitive decline in regards to preceding functionally higher level characterized by alterations in memory and in two or more superior cortical functions that include orientation, attention, verbal linguistic capacities, visual spacial skills, calculation, executive functioning, motor control, abstraction and judgment. Patients with disturbances of consciousness, delirium (acute confusional states), psychosis, serious aphasia, or sensory-motor alterations that preclude proper execution of neuro-psychological testing are also considered to have probably vascular dementia. Furthermore, these are ten of the other essential cerebral or systematic pathologies present that would be able to produce a dementia syndrome.

Hypertension and the risk of mild cognitive impairment

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.

Comparative analysis of the persistence of a conditioned passive avoidance reflex in rats with different forms of inherited hypertension

The characteristics of anxiety behavior and reproduction of a conditioned passive avoidance reflex acquired in response to a single combination with an unconditioned aversive stimulus were studied in NISAG rats with inherited stress-sensitive arterial hypertension and spontaneously hypertensive SHR rats. SHR rats were characterized by hyperactive behavior, very low levels of anxiety, and poor reproduction of the conditioned reflex as compared with NISAG and control Wistar and WAG rats. Intermediate-anxiety NISAG rats showed no difficulties in acquiring and subsequently retaining the conditioned reflex. These differences in the ability to undergo single-combination learning in rats with different forms of hypertension suggest that memory processes are independent of elevated arterial blood pressure. The effects of the genetic characteristics of behavior and emotional status of these animals on memory are discussed.

Relation of Blood Pressure to Cognitive Impairment and Dementia

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.

Blood Pressure Treatment and Cognition in the Elderly

While the health and longevity benefits of antihypertensive treatment have been established in past research, the cognitive consequences of blood pressure control in the elderly are still under debate. In this paper, the authors review the current evidence and the different ways in which cognition is measured. Since research on the cognitive consequences of blood pressure control in the elderly population is characterized by a variety of research questions, designs, and cognitive measurements, the authors conclude that a large-scale study that compares the cognitive benefits of different methods of blood pressure reduction is urgently needed.

Peculiarities of active avoidance conditioning in rats with various forms of inherited arterial hypertension

Peculiarities of active avoidance conditioning were studied in NISAG rats (hereditary stress-induced arterial hypertension) and spontaneously hypertensive SHR rats. Conditioning was successful in 90% normotensive Wistar rats and in only 9.1% NISAG rats. Hypertensive SHR rats were intermediate between Wistar and NISAG rats by their learning capacity (66.7%). Our results suggest that differences in learning capacity of hypertensive rats are determined by genetic characteristics of animal behavior and emotional state, rather than blood pressure elevation.

Clinical manifestations in neuropathologically defined subgroups of vascular dementia

AIMS

To study cardio-cerebrovascular disease and clinical features, such as falls, dizziness/unsteadiness, urinary incontinence, hallucinations/delusions and delirium in neuropathologically defined subgroups of vascular Dementia (VaD): pure Small Vessel Dementia (SVD), combined SVD and Alzheimer's disease (SVD-AD), pure Large Vessel Dementia (LVD) and pure Hypoxic Hypoperfusive Dementia (HHD), and to analyse the clinical differences between these groups.

MATERIALS AND METHODS

From 175 consecutive cases with neuropathologically verified VaD cases with pure SVD (n = 36) and SVD-AD (n = 38) with varying severity of AD pathology were selected and studied with respect to cardio-cerebrovascular and other clinical features. Furthermore, a comparison between pure SVD, pure LVD (n = 7) and pure HHD (n = 6) was made.

RESULTS

Neither cardiovascular symptoms, hypertension, Transitoric Ischemic Attacks (TIA) nor complete cerebrovascular lesions (CVL) differed significantly between the pure SVD and SVD-AD groups. However, a wide variation of clinical features were reported. The prevalence of cardiovascular features varied markedly in the pure groups, with the highest prevalence consistently found in the LVD group. Hypertension was common in the pure LVD and SVD-groups, while it was a rare finding in the HHD-group. TIA and/or CVL were, as expected, most common in the LVD-group.

CONCLUSION

In conclusion, this longitudinal and retrospective study of VaD shows important clinical similarities as well as differences between pathologically defined subgroups. Hopefully these findings will contribute to a better understanding of etiopathogenetic and diagnostic issues and form a solid basis for possible treatment strategies in VaD.

Neuropsychological characteristics of adolescent boys differing in risk for high blood pressure

BACKGROUND

Individuals with established hypertension have been found to display deficits in a number of neuropsychological abilities. In general, these are probably due to structural changes in the brain produced by sustained high blood pressure. However, a potentially important line of research suggests that some of these deficits may extend to younger individuals with less severe elevations of blood pressure, perhaps even children, and thus be related more to risk for hypertension than hypertension per se.

PURPOSE

The objective was to examine the relationships between neuropsychological function and risk for hypertension in children.

METHODS

Measurements of blood pressure and parental history of hypertension were obtained in 88 French-Canadian 14-year-old boys and used to predict performance on a neuropsychological battery.

RESULTS

Boys at greater risk of hypertension by virtue of having a parental history of high blood pressure and normatively elevated systolic blood pressure had significantly lower scores on a verbal learning factor score compared to boys at lower risk. Boys with normatively elevated systolic blood pressure also had significantly lower scores on a spatial learning and memory factor score compared to boys with lower blood pressure. The results could not be attributed to differences in family socioeconomic status.

CONCLUSIONS

Using a younger sample than typically employed in the area, the results support previous suggestions that some of the neuropsychological characteristics displayed by hypertensive individuals may predate the development of clinically elevated blood pressure and could be associated with risk for the disorder.

Aggregation of vascular risk factors and risk of incident Alzheimer disease

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.

Lipid metabolism in cognitive decline and dementia

This review will focus on the current knowledge on circulating serum and plasma risk factors of cognitive decline of degenerative (Alzheimer's disease, AD) or vascular origin (vascular dementia, VaD) linked to cholesterol homeostasis and lipoprotein disturbances, i.e. total cholesterol (TC), 24S-hydroxy-cholesterol, lipoprotein(a) (Lp(a)), or apolipoprotein E (APOE). These measures linked to lipoprotein metabolism appear to be altered in AD, VaD, or predementia syndrome relative to controls, but with contrasting results. At present, several studies have demonstrated the dependence of APOE serum levels upon the APOE genotype, nonetheless serum APOE levels seems not to be a credible risk factor or a biochemical marker for AD instead of APOE genotyping. In fact, there was no consistent association of serum or plasma apoE protein levels with the disease when controlled for APOE genotype. In addition, there are some evidence that higher Lp(a) levels could be linked with AD, although there are studies suggesting an increased presence of low molecular weight apo(a) in AD, VaD, and frontotemporal dementia, that are associated with elevated Lp(a) levels. In fact, the apo(a) gene is highly polymorphic in length due to variation in the numbers of a sequence encoding the apo(a) kringle 4 domain, and plasma levels of Lp(a) are inversely correlated with apo(a) size. Furthermore, although serum/plasma levels of TC and 24S-hydroxycholesterol are not credible diagnostic markers for AD and cognitive decline, the current evidence suggests that they may be modifiable risk/protective factors. The prevailing wisdom is that high TC is a risk factor for dementia. However, the relationship between TC and dementia may vary considerably depending on when cholesterol is measured over the life course or, alternatively, in relation to the underlying course of the disease. Several observational studies have suggested that statins, which are effective in lowering cholesterol, may reduce the risk of dementia, but the results of these reports are inconclusive. Thus, more studies with long-term follow-up and serial assessments of TC are needed to further clarify the causal relationship between cholesterol and dementia.

A Module Map Showing Interaction between Apolipoprotein E and Phospholipase A2 Polymorphism in Lipid Profiles

OBJECTIVE

Establish a possible conceptual relationship among Apo E and PLA2 polymorphism and lipid profiles.

METHODS

Five hundred subjects aged 65 to 74 years were randomly selected from a community in southern Taiwan to assess the relationship between Apo E and PLA2 polymorphisms and lipid profiles. Two hundred fifty-six participants agreed to have venous blood drawn for DNA studies.

RESULTS

By multiple linear regression, the PLA2 A2 allele showed a statistically significant influence on LDL-C (p = 0.0097), and the Apo epsilon2 allele showed a statistically significant influence on HDL-C (p = 0.0004), however, the interaction between the PLA2 A2 allele and the Apo epsilon2 allele was found to be significant in the blood fraction of HDL-C (p = 0.0388) and LDL-C (p = 0.0002). Decreasing HDL-C and increasing LDL-C were found when the PLA2 A2 and Apo epsilon2 allele co-existed.

CONCLUSION

The presence of a physiologic balance contributes significantly to homeostatic and compensatory responses regulating blood HDL-C and LDL-C profiles. A module map of the generation-control cycle and conditional activity among Apo E, PLA2, and lipid levels is presented, and both behaviours and biological perspectives under the consilience model may suggest a new approach to many kinds of complex disorders.

[Arterial hypertension and dementia]

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.

A randomized, double-blind, study of rofecoxib in patients with mild cognitive impairment

Inflammatory mechanisms have been implicated in Alzheimer's disease (AD) and might be mediated via the COX-2 enzyme. Previous studies with the selective COX-2 inhibitors, rofecoxib and celecoxib, have shown that they do not alter the progression of AD. We conducted a double-blind study to investigate whether rofecoxib could delay a diagnosis of AD in patients with mild cognitive impairment (MCI), a group with an expected annual AD diagnosis rate of 10-15%. MCI patients > or =65 years were randomized to rofecoxib 25 mg (N=725) or placebo (N=732) daily for up to 4 years. The primary end point was the percentage of patients with a clinical diagnosis of AD. The estimated annual AD diagnosis rate was lower than the anticipated 10-15%: 6.4% in the rofecoxib group vs 4.5% in the placebo group (rofecoxib : placebo hazard ratio=1.46 (95% CI: 1.09, 1.94), p=0.011). Analyses of secondary end points, including measures of cognition (eg the cognitive subscale of the AD Assessment Scale (ADAS-Cog)) and global function (eg the Clinical Dementia Rating (CDR)), did not demonstrate differences between treatment groups. There was also no consistent evidence that rofecoxib differed from placebo in post hoc analyses comparing ADAS-Cog and CDR-sum of boxes scores in overlapping subgroups of patients who had Mini Mental State Exam scores of 24-26 in the present MCI study and in a previous AD treatment study with a similar design. The results from this MCI study did not support the hypothesis that rofecoxib would delay a diagnosis of AD. In conjunction with the lack of effects observed in previous AD studies, the findings suggest that inhibition of COX-2 is not a useful therapeutic approach in AD.

Cholinesterase inhibitors and vascular dementia: another string to their bow?

Two of the four licensed cholinesterase inhibitors, galantamine and donepezil, have recently featured in published work showing how they act in dementia associated with cerebrovascular disease (CVD). It is timely to review this new evidence and place it within the current consensus understanding of what makes up a clearly heterogeneous dementia population. To do this, the current review explores the relationship between Alzheimer's disease, for which this group of compounds originally received licensing approval, and vascular pathology within the brain, highlighting the significant overlap in risk factors and the frequent coexistence of the two conditions in the patients that are studied. Whether they are inter-related or separate entities is discussed, followed by a description of the current classifications of Alzheimer's disease with CVD, and the three subtypes of 'pure' vascular dementia - subcortical, cortical and strategic infarct. Understanding these entities allows more accurate diagnostic and prognostic information to be given to patients, and leads towards matching the published clinical evidence discussed with more predictable clinical syndromes. This distinction is particularly relevant in terms of the studies conducted thus far. Galantamine has been studied in a placebo-controlled study of patients with Alzheimer's disease and CVD as well as patients with vascular dementia, whereas donepezil was studied exclusively in patients with vascular dementia. Differences in the way the placebo groups acted in these studies confirmed the fact that these actually are two distinct groups. Galantamine showed efficacy across the combined groups studied, with placebo deterioration similar to previous Alzheimer's disease studies, while donepezil produced a positive effect in vascular dementia - with this placebo group relatively unchanged. The symptomatic improvements seen were not really surprising, as cholinergic deficits are a common factor across all of these syndromes. Wherever this is the predominant biological finding, it would be expected that cholinesterase inhibitors would have a similar effect, whatever the condition causing it.

Vers une prévention de la démence ?

Many studies have shown that high blood pressure and, to a lesser extent, other vascular risk factors could be the target of interventions aiming to reduce the incidence of dementia. Two large controlled trials have demonstrated that blood pressure lowering drugs have a significant effect on the risk of dementia including Alzheimer's disease. On another hand, large epidemiological studies have shown associations between different vascular factors and dementia. Overall, these data suggest that interventions aiming to reduce the level of vascular risk factors might prevent dementia. The expected benefit of these interventions could be estimated from data provided by epidemiological studies, but large population-based controlled studies are needed to demonstrate the efficacy of preventive interventions.

Medical comorbidity in black and white patients with Alzheimer's disease

BACKGROUND

Little is known about co-medical illnesses in black and white patients with probable Alzheimer's disease (AD).

METHODS

To address this question, we used two methods. In the first (Group I), black and white probable AD patients were matched on age at presentation to the clinic, age of onset of AD, duration of illness, and Mini-Mental State Examination scores; then, a variety of co-medical illnesses were compared between blacks and whites. In Group II, whites were randomly matched to blacks on the variables listed above.

RESULTS

In Group I, blacks were found to have a higher rate of hypertension than whites, whereas whites had a higher incidence of atrial fibrillation and cancer than blacks. In Group II, age at presentation to the clinic was found to be shorter for men than for women; duration of illness was shorter for black men than for white men, white women, and black women; and Mini-Mental State Examination scores were lower in blacks than whites. As in Group I, blacks were found to have a higher rate of hypertension, whereas whites had higher rates of atrial fibrillation, cancer, coronary artery disease, high cholesterol, and gastrointestinal disease.

CONCLUSION

In both groups, black patients with probable AD had a higher rate of hypertension than white patients with probable AD, and whites had higher rates of atrial fibrillation and cancer. This finding suggests that these comorbid illnesses in black and white patients with probable AD is not due to a statistical Type II error, but rather to differences in these groups.

Treatment Strategies in Alzheimer???s Disease with a Focus on Early Pharmacological Interventions

Complex interactive effects of genetic predisposition, neurochemical changes and disease comorbidity have been elucidated in the genesis of dementia syndromes. Alzheimer's disease is the most prevalent type of dementia in developed Western countries. In Alzheimer's disease, pharmacological treatment aims at symptomatic relief, disease modification or disease prevention. Cholinesterase inhibitors are established for the treatment of mild-to-moderate Alzheimer's disease. In Europe and the US, memantine is approved for the treatment of moderate-to-severe Alzheimer's disease. To date, there are no drugs with a disease modifying action that have proven efficacy in randomised, double-blind, placebo-controlled clinical trials. In patients not fulfilling the diagnostic criteria for early Alzheimer's disease, e.g. mild cognitive impairment, the efficacy of several drugs, mainly cholinesterase inhibitors, is currently tested in prospective studies by determining the conversion rate to Alzheimer's disease. However, prevention and disease-modifying strategies raise ethical questions because interventions are focused on non-diseased elderly at risk, which means that emphasis should be not only on efficacy but also on long-term safety. No disease-modifying strategy can presently be offered to patients; however, given the pace of recent research there is optimism that slowing progression of Alzheimer's disease will soon be possible.