The association of antihypertensive agents with MRI white matter findings and with Modified Mini-Mental State Examination in older adults

Cross-sectional associations between short and mid-term blood pressure variability, cognition, and vascular stiffness in older adults

Background

High blood pressure variability (BPV), particularly in older age, appears to be an independent risk factor for incident dementia. The current study aimed to investigate the association between different BPV measures (short- and mid-term BPV including circadian patterns) and cognitive functioning as well as vascular stiffness measures to better understand the role that BPV plays in cognitive impairment.

Methods

70 older adults (60-80-year-olds) without dementia completed a cognitive test battery and had their blood pressure (BP) assessed via a 24-hour ambulatory BP monitor (divided into sleep and wake for short-term BPV) and 4-day morning and evening home-based BP monitor (for day-to-day BPV). Arterial stiffness was evaluated via pulse wave analysis and pulse wave velocity (PWV) and cerebrovascular pulsatility was assessed via transcranial doppler sonography of the middle cerebral arteries.

Results

High systolic as well as diastolic short- and mid-term BPV were associated with poorer cognitive functioning, independent of the mean BP. Higher short-term BPV was associated with poorer attention and psychomotor speed, whilst day-to-day BPV was negatively linked with executive functioning. Circadian BP patterns (dipping and morning BP surge) showed no significant relationships with cognition after adjusting for covariates. Higher systolic short-term BPV was associated with higher arterial stiffness (PWV) and higher diastolic day-to-day BPV was linked with lower arterial stiffness. No significant associations between BPV measures and cerebrovascular pulsatility were present.

Conclusion

High BPV, independently of the mean BP, is associated with lower cognitive performance and increased arterial stiffness in older adults without clinically-relevant cognitive impairment. This highlights the role of systolic and diastolic BPV as a potential early clinical marker for cognitive impairment.

Beta-amyloid pore linked to controlled calcium influx into the cell: A new paradigm for Alzheimer's Disease

Despite tremendous worldwide efforts, clinical trials assessing Alzheimer's disease (AD)‐related therapeutics have been relentlessly unsuccessful. Hence, there is an urgent need to challenge old hypotheses with novel paradigms. An emerging concept is that the amyloid‐beta (Aβ) peptide, which was until recently deemed a major player in the cause of AD, may instead modulate synaptic plasticity and protect against excitotoxicity. The link between Aβ‐mediated synaptic plasticity and Aβ trafficking is central for understanding AD pathogenesis and remains a perplexing relationship. The crossover between Aβ pathological and physiological roles is subtle and remains controversial. Based on existing literature, as a signaling molecule, Aβ is proposed to modulate its own turnover and synaptic plasticity through what is currently believed to be the cause of AD: the transient formation of pore‐like oligomers. A change of perspective regarding how Aβ pores exert a protective function will unavoidably revolutionize the entire field of anti‐amyloid drug development.

Neuroimaging in the Oldest-Old: A Review of the Literature

The oldest-old, those 85 years and older, are the fastest growing segment of the population and present with the highest prevalence of dementia. Given the importance of neuroimaging measures to understand aging and dementia, the objective of this study was to review neuroimaging studies performed in oldest-old participants. We used PubMed, Google Scholar, and Web of Science search engines to identify in vivo CT, MRI, and PET neuroimaging studies either performed in the oldest-old or that addressed the oldest-old as a distinct group in analyses. We identified 60 studies and summarized the main group characteristics and findings. Generally, oldest-old participants presented with greater atrophy compared to younger old participants, with most studies reporting a relatively stable constant decline in brain volumes over time. Oldest-old participants with greater global atrophy and atrophy in key brain structures such as the medial temporal lobe were more likely to have dementia or cognitive impairment. The oldest-old presented with a high burden of white matter lesions, which were associated with various lifestyle factors and some cognitive measures. Amyloid burden as assessed by PET, while high in the oldest-old compared to younger age groups, was still predictive of transition from normal to impaired cognition, especially when other adverse neuroimaging measures (atrophy and white matter lesions) were also present. While this review highlights past neuroimaging research in the oldest-old, it also highlights the dearth of studies in this important population. It is imperative to perform more neuroimaging studies in the oldest-old to better understand aging and dementia.

Chronic Use of Aspirin and Total White Matter Lesion Volume: Results from the Women's Health Initiative Memory Study of Magnetic Resonance Imaging Study

OBJECTIVE

To investigate the relationship between aspirin and subclinical cerebrovascular heath, we evaluated the effect of chronic aspirin use on white matter lesions (WML) volume among women.

METHODS

Chronic aspirin use was assessed in 1365 women who participated in the Women's Health Initiative Memory Study of Magnetic Resonance Imaging. Differences in WML volumes between aspirin users and nonusers were assessed with linear mixed models. A number of secondary analyses were performed, including lobe-specific analyses, subgroup analyses based on participants' overall risk of cerebrovascular disease, and a dose-response relationship analysis.

RESULTS

The mean age of the women at magnetic resonance imaging examination was 77.6 years. Sixty-one percent of participants were chronic aspirin users. After adjusting for demographic variables and comorbidities, chronic aspirin use was nonsignificantly associated with 4.8% (95% CI: -6.8%, 17.9%) larger WML volumes. These null findings were confirmed in secondary and sensitivity analyses, including an active comparator evaluation where aspirin users were compared to users of nonaspirin nonsteroidal anti-inflammatory drugs or acetaminophen.

CONCLUSIONS

There was a nonsignificant difference in WML volumes between aspirin users and nonusers. Further, our results suggest that chronic aspirin use may not have a clinically significant effect on WML volumes in women.

Intracellular Calcium Dysregulation: Implications for Alzheimer's Disease

Alzheimer's Disease (AD) is a neurodegenerative disorder characterized by progressive neuronal loss. AD is associated with aberrant processing of the amyloid precursor protein, which leads to the deposition of amyloid-β plaques within the brain. Together with plaques deposition, the hyperphosphorylation of the microtubules associated protein tau and the formation of intraneuronal neurofibrillary tangles are a typical neuropathological feature in AD brains. Cellular dysfunctions involving specific subcellular compartments, such as mitochondria and endoplasmic reticulum (ER), are emerging as crucial players in the pathogenesis of AD, as well as increased oxidative stress and dysregulation of calcium homeostasis. Specifically, dysregulation of intracellular calcium homeostasis has been suggested as a common proximal cause of neural dysfunction in AD. Aberrant calcium signaling has been considered a phenomenon mainly related to the dysfunction of intracellular calcium stores, which can occur in both neuronal and nonneuronal cells. This review reports the most recent findings on cellular mechanisms involved in the pathogenesis of AD, with main focus on the control of calcium homeostasis at both cytosolic and mitochondrial level.

Our "energy-Ca(2+) signaling deficits" hypothesis and its explanatory potential for key features of Alzheimer's disease

Sporadic Alzheimer's disease (sAD) has not been explained by any current theories, so new hypotheses are urgently needed. We proposed that "energy and Ca(2+) signaling deficits" are perhaps the earliest modifiable defects in brain aging underlying memory decline and tau deposits (by means of inactivating Ca(2+)-dependent protease calpain). Consistent with this hypothesis, we now notice that at least eight other known calpain substrates have also been reported to accumulate in aging and AD. Thus, protein accumulation or aggregation is not a "pathogenic" event, but occurs naturally and selectively to a peculiar family of proteins, and is best explained by calpain inactivation. Why are only calpain substrates accumulated and how can they stay for decades in the brain without being attacked by many other non-specific proteases there? We believe that these long-lasting puzzles can be explained by calpain's unique properties, especially its unusual specificity and exclusivity in substrate recognition, which can protect the substrates from other proteases' attacks after calpain inactivation. Interestingly, our model, in essence, may also explain tau phosphorylation and the formation of amyloid plaques. Our studies suggest that α-secretase is an energy-/Ca(2+)-dual dependent protease and is also the primary determinant for Aβ levels. Therefore, β- and γ-secretases can only play secondary roles and, by biological laws, they are unlikely to be "positively identified". This study thus raises serious questions for policymakers and researchers and these questions may help explain why sAD can remain an enigma today.

Use of calcium channel blockers is associated with better cognitive performance in older hypertensive patients with subjective memory complaints

BACKGROUND

Hypertension is strongly associated with cognitive decline and a promising target for dementia prevention. Our aim was to investigate the association between different antihypertensive treatments and cognitive performance in elderly hypertensive patients presenting with subjective memory complaints.

PATIENTS AND METHODS

Three hundred and seventy-eight elderly hypertensive patients more than 60 years (mean age 70.4 ± 6.3 years) treated with at least one antihypertensive agent and presenting with subjective memory complaints but without dementia were prospectively recruited and underwent a combination of neuropsychological tests, brain magnetic resonance imaging with semiquantification of white matter hyperintensities, carotid echotracking, brachial endothelial function, and ambulatory blood pressure assessments.

RESULTS

None of the three composite scores (memory score, verbal fluency, and visual memory capacity) was found associated with blood pressure levels. On the other hand, age-adjusted and sex-adjusted analyses showed a significant and positive association between memory score and use of calcium channel blockers (CCBs) (users: +0.14 ± 0.09 versus nonusers: -0.12 ± 0.06; P = 0.016). Multivariate analyses also revealed that CCB use was significantly associated with a better memory score, independently of age, male sex, white matter hyperintensities, and carotid wall cross-sectional area, all of which were associated with worse memory scores.

CONCLUSION

In elderly hypertensive treated patients with subjective memory complaints, CCB use was associated with better memory performance independently of blood pressure level and macrovascular and microvascular alterations, suggesting a specific neuroprotective effect of this pharmacological class. Interventional controlled trials are required to confirm the specific protective effect of CCBs on cognitive decline.

Hypertension and cognitive function

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.

Current Concepts in Vascular Cognitive Impairment and Pharmacotherapeutic Implications

Objective:

To review evolution of the vascular cognitive impairment (VCI) construct, including diagnosis, pharmacotherapeutic implications, and address challenges that will shape future developments.

Data Sources:

Literature retrieval was accessed through PubMed, from 1966 to December 2008, using the terms vascular cognitive impairment, vascular dementia, post-stroke dementia, vascular cognitive disorder, mild cognitive impairment, criteria, disease progression, outcomes, treatment, prevention, biomarkers, and neuroimaging.

Study Selection and Data Extraction:

All articles in published English identified from the data sources were evaluated for inclusion. Regarding pharmacotherapy, prospective double-blind, placebo-controlled studies were included as well as extensions or relevant post hoc analyses.

Data Synthesis:

In the 1970s, “senile dementia due to hardening of the arteries” was used to describe dementia due to vascular causes. This was a narrow view of what is now known to be a common form of cognitive impairment in older people. Multiple infarct dementia (MID) was first proposed to describe dementia attributable to multiple cerebral infarcts, followed by the vascular dementia (VaD) construct, itself meant to be an improvement over MID. The VaD construct had limitations, not the least of which was that, by the time a patient was diagnosed with VaD, the opportunity for prevention was lost. Thus arose the concept of VCI, representing a group of heterogeneous disorders that share presumed vascular causes. The importance of VCI is centered on the fact that vascular risk factors are treatable, and thus should lead to a reduction in the incidence of cognitive impairment due to vascular causes. There is evidence that treatment of hypertension can lead to a reduction in the incidence of cognitive impairment and dementia, and that treatment of VaD with acetylcholinesterase inhibitors may be beneficial.

Conclusions:

Careful attention needs to be given to controlling vascular risk factors in at-risk patients. Pharmacists should play an active role in this important area of geriatric pharmacotherapy.

Vascular risk factors, cognitive decline, and dementia

Dementia is one of the most important neurological disorders in the elderly. Aging is associated with a large increase in the prevalence and incidence of degenerative (Alzheimer's disease) and vascular dementia, leading to a devastating loss of autonomy. In view of the increasing longevity of populations worldwide, prevention of dementia has turned into a major public health challenge. In the past decade, several vascular risk factors have been found to be associated with vascular dementia but also Alzheimer's disease. Some longitudinal studies, have found significant associations between hypertension, diabetus mellitus, and metabolic syndrome, assessed at middle age, and dementia. Studies assessing the link between hypercholesterolemia, atrial fibrillation, smoking, and dementia have given more conflicting results. Furthermore, some studies have highlighted the possible protective effect of antihypertensive therapy on cognition and some trials are evaluating the effects of statins and treatments for insulin resistance. Vascular risk factors and their treatments are a promising avenue of research for prevention of dementia, and further long-term, placebo-controlled, randomized studies, need to be performed.

Relation of neurocardiovascular instability to cognitive, emotional and functional domains

There is bulk of evidence suggesting that blood pressure dysregulation, as low blood pressure (LBP) or hypotension, orthostatic hypotension (OH) and high blood pressure (HPB) or hypertension are associated with alterations in cognitive and emotional domains. Some studies suggest that LBP, neurocardiovascular instability, like the OH, and atherosclerosis resulting from long standing HBP, reduces cerebral blood flow, increasing the risk of cognitive impairment, morbidity and mortality. This study aims to evaluate whether patients with cognitive impairment and cardiovascular disease would show any differences in some anamnestic indicators and/or psychometric measures of cognitive performance and affective symptoms. We recruited 36 patients over 65 years of age admitted to both psycho- and cardio-geriatric ambulatories of our hospital during the last year. The population (mean age of 80.5 years, 72.2% females, 27.8% males) was divided in 2 groups, with OH (25%), and without OH (75%). The first group was subdivided in subgroups: patients with HBP, normal BP and LBP, respectively. Cognitive and depressive domains were assessed with the mini mental state examination (MMSE) and the Italian "scala di valutazione del benessere emotivo nell' anziano" (SVEBA). Information about the present status, comorbidities (cumulative illness rating scale=CIRS), functional ability (activities of daily living=ADL, instrumental ADL=IADL) and drugs were collected during clinical examination. BP was measured 4 times, at the beginning of examination, then with the patient in clinostatic and orthostatic position (1st and 3rd minute). Data were analyzed by MANCOVA, considering age and gender as covariates, MMSE, SVEBA, CIRS, ADL, IADL and drugs as dependent variables, and presence/absence of OH as factor. Covariates were not significant sources of variance, as well as overall factor. Due to the heuristic aim of the study, we considered of interest the results of subsequent ANOVAs showing significant differences in SVEBA and ADL with respect to the factor. These data give us the basis to develop a longitudinal study to confirm the detrimental effect of OH on a wide range of health domains.

The apolipoprotein E epsilon4-allele and antihypertensive treatment are associated with increased risk of cerebral MRI white matter hyperintensities

OBJECTIVE

Apolipoprotein E-epsilon4 (APOE-epsilon4) is a potential risk factor for cerebral vascular disease. The aim of the present study was to examine the relative importance of APOE-epsilon4 and other relevant risk factors for the extent of cerebral white matter hyperintensity (WMH) in a community-based sample of elderly subjects.

MATERIALS AND METHODS

From a cohort of 976 subjects born in 1914, APOE genotype was determined and MRI examinations were carried out in 75 subjects. WMH were rated using a standard semi-quantitative method. ANOVA and regression analyses were conducted to explore the relative importance of the potential risk factors.

RESULTS

APOE genotype and antihypertensive treatment were significantly associated with severity of total WMH load (P < 0.05).

CONCLUSIONS

The study confirmed the association between APOE-epsilon4 and WMH. Pharmaceutical treatment for arterial hypertension was also associated with the total burden of WMH in this study.

Dementia epidemiology research: it is time to modify the focus of research

The incidence and prevalence of dementia are increasing. There is an urgent need to develop a preventive strategy. The identification of modifiable risk factors must therefore be a high priority. Newer imaging techniques provide an opportunity to identify subclinical manifestations of "dementias" that can be limited to the risk factors and subsequent clinical disease. The contribution of vascular disease to dementia and Alzheimer's disease (AD) should be a high priority as it offers a potential preventive strategy. Study designs need to be modified, including a greater emphasis on geographic variations in AD and dementia based on imaging studies, longitudinal studies of successful aging without cardiovascular disease (CVD) or AD, gene-environment interactions, and studies of unique populations that may be at lower risk because of specific lifestyles. Primary prevention trials for vascular disease should include a dementia component. Most, if not all, studies should include newer imaging studies.

Cardiac risk factors and potential treatments in Alzheimer's disease

Dementia is one of the commonest neurological disorders in the elderly population. In regards to the increasing longevity of populations worldwide, prevention of dementia has become a major public health challenge. There has been an intense research in the identification of modifiable risk factors for dementia. These risk factors could then be used as targets for intervention, pharmacologic or non-pharmacologic. Numerous reports of the relation between cardiovascular risk factors and cognitive decline and dementia have been published over the past years. This review focuses on the cardiovascular risk factors hypertension, hyperlipidemia and diabetes mellitus as targets for prevention of cognitive decline, overall dementia and Alzheimer's disease. Observational studies and clinical trials regarding the association between antihypertensive, lipid lowering and antidiabetic medications and the risk of impaired cognition, dementia or Alzheimer's disease are reviewed. Based on these data, we propose that early interventions at reducing these cardiovascular risk factors may have an impact on future incidence and prevalence of cognitive deficits of many etiologies including Alzheimer's disease.

Progress in cardiovascular diseases: cognitive function in essential hypertension

Essential hypertension has rather recently become recognized as a major factor in the development of the 2 main types of dementia, that is, no longer merely vascular dementia but Alzheimer disease as well. The relationship between high blood pressure (BP) and the dementias is quite a complicated one, given a wide variability in temporal courses. The interval between the respective manifestations of hypertension and cognitive deterioration may vary from a few years to several decades. Moreover, temporal relationships may be obscured because of the observation that BP tends to fall in the face of imminent Alzheimer disease. Although the cause-and-effect sequence of this relationship has not been established, it may suggest that a low BP in this phase of life could be equally harmful as hypertension in the preceding period. Individual monitoring of BP and drug titration in the hypertensive elderly may well become mandatory in the highest age group. The question whether some antihypertensive drug categories might act more effectively in preventing cognitive deterioration than others, irrespective of their antihypertensive potential, remains. A modest meta-analysis on our part seems to suggest that suppression of the renin-angiotensin-aldosterone system (RAAS) would fail to offer such protection, in contrast to certain dihydropyridine (DHP) calcium-channel blockers. Unfortunately, recently published comparative prospective megatrials (Anti-hypertensive and Lipid-lowering Treatment to Prevent Heart Attack Trial and Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure Lowering Arm) failed to carry any record on the mental status of the study populations, thereby missing a golden opportunity to resolve the above issue. Consequently, there remains an urgent need for further blinded long-term comparative hypertension trials, including follow-up evaluation of cognitive functions in relation to the course of BP.

White matter grade and ventricular volume on brain MRI as markers of longevity in the cardiovascular health study

High white matter grade (WMG) on magnetic resonance imaging (MRI) is a risk factor for dementia, stroke and disability. Higher ventricular size is a marker of brain "atrophy." In the Cardiovascular Health Study (CHS) (n=3245) mean age 75 years, 50% black and 40% men, we evaluated WM and ventricular grade (VG), total, cardiovascular and noncardiovascular mortality and longevity before and after adjusting for numerous determinants of longevity over an approximate 10-12 years of follow-up. A low WMG and VG was a marker for low total, cardiovascular and noncardiovascular mortality and for increased longevity over 10+ years of follow-up. We estimated that a 75-year-old with WMG below median would have about a 5-6 years greater longevity and for VG about 3 years, than above the median even after adjustment for numerous risk factors. Low WMG and VG on MRI is a powerful determinant of long-term survival among older individuals.

Blood pressure variability and white matter hyperintensities in older adults with cardiovascular disease

The present study examined the relationship between multiple blood pressure (BP) indices and white matter hyperintensities (WMH) in a sample of 39 older adults with cardiovascular disease (CVD). Resting BP was measured using an automated monitor every 10 min for 2 h. WMH were quantified on FLAIR images and separate indices were generated for neocortical, periventricular and subcortical brain regions. Correlation analyses revealed systolic BP variability was related to neocortical and total WMH. A function of systolic BP variability and average diastolic pressure showed the strongest relationships, including significant correlation to neocortical, subcortical and total WMH. No BP index was related to WMH in periventricular regions. Exploratory analyses showed only the function of systolic BP variability and average diastolic pressure predicted total WMH, whereas as age, CVD conditions and psychosocial factors did not. These findings demonstrate BP variability is an important contributor to WMH in older adults with CVD and suggests it may have differential relationships to WMH in different brain regions. Additional studies are needed to examine the role of autoregulatory systems in the development of WMH, particularly those using beat-to-beat measures of BP.

[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.

The age-dependent relation of blood pressure to cognitive function and dementia

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.

Blutdruck und Gehirn

During acute cerebral infarction, autoregulation is abolished. Brain perfusion therefore directly depends on perfusion pressure and cardiac output. For this reason, in the early state of stroke, elevated blood pressure improves cerebral blood flow and only values of 210 mmHg systolic or above should be lowered. With the development of a vasogenic brain edema or a dysfunctional blood-brain barrier (usually on day 2 to 4 after infarction), blood pressure must be normalized in order to avoid hemorrhage and to minimize edema. In the presence of space occupying edema or intracranial hemorrhage, only those antihypertensive substances may be used which do not cause a dilatation of brain vessels. Direct vasodilators and calcium antagonists are not suitable in this situation. Furthermore, antihypertensive medication which causes bradycardia (e.g. beta blockers) should be avoided, because in acute stroke, brain perfusion also depends on the cardiac output. For primary and secondary stroke prevention normalization of blood pressure is essential. Efficacy is basically independent of the kind of antihypertensive medication used. Effective normalization of blood pressure probably helps to prevent vascular dementias of all kinds. Convincing studies however are still lacking for most sorts of antihypertensive medication.

Effects of immediate versus delayed antihypertensive therapy on outcome in the Systolic Hypertension in Europe Trial

BACKGROUND

To assess the impact of immediate versus delayed antihypertensive treatment on the outcome of older patients with isolated systolic hypertension, we extended the double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) trial by an open-label follow-up study lasting 4 years.

METHODS

The Syst-Eur trial included 4695 randomized patients with minimum age of 60 years and an untreated blood pressure of 160-219 mmHg systolic and below 95 mmHg diastolic. The double-blind trial ended after a median follow-up of 2.0 years (range 1-97 months). Of 4409 patients still alive, 3517 received open-label treatment consisting of nitrendipine (10-40 mg daily) with the possible addition of enalapril (5-20 mg daily), hydrochlorothiazide (12.5-25 mg daily), or both add-on drugs. Non-participants (n = 892) were also followed up.

RESULTS

Median follow-up increased to 6.1 years. Systolic pressure decreased to below 150 mmHg (target level) in 2628 participants (75.0%). During the 4-year open-label follow-up, stroke and cardiovascular complications occurred at similar frequencies in patients formerly randomized to placebo and those continuing active treatment. These rates were similar to those previously observed in the active-treatment group during the double-blind trial. Considering the total follow-up of 4695 randomized patients, immediate compared with delayed antihypertensive treatment reduced the occurrence of stroke and cardiovascular complications by 28% (P = 0.01) and 15% (P = 0.03), respectively, with a similar tendency for total mortality (13%, P = 0.09). In 492 diabetic patients, the corresponding estimates of long-term benefit (P < 0.02) were 60, 51 and 38%, respectively.

CONCLUSIONS

Antihypertensive treatment can achieve blood pressure control in most older patients with isolated systolic hypertension. Immediate compared with delayed treatment prevented 17 strokes or 25 major cardiovascular events per 1000 patients followed up for 6 years. These findings underscore the necessity of early treatment of isolated systolic hypertension.

Effect of Antihypertensive Agents on Quality of Life in the Elderly

Management of hypertension in the elderly should take into account, in particular, the possible negative impact of antihypertensive drugs on the patient's quality of life, the deterioration of which may result in a loss of independence and reduced treatment compliance. Quality of life is recognised as a multifactorial variable and can be subdivided into different domains (symptomatic well-being, emotional, physical, work-social, cognitive and life satisfaction), which are generally explored by means of specific questionnaires or scales. When evaluating elderly patients with hypertension, it is necessary to pay particular attention to specific domains such as symptomatic well-being, cognitive function, activity and sexual function, which have already been diminished by the age itself and the disease. The results of some large trials that specifically evaluated the quality of life effects of long-term therapy of hypertension in older people (Medical Research Council's [MRC] Trial of Hypertension in Older Adults, Systolic Hypertension in the Elderly Program [SHEP], Systolic Hypertension in Europe [Syst-Eur], Study on COgnition and Prognosis in the Elderly [SCOPE]) have shown that antihypertensive treatment as a whole either had no negative impact on quality of life, or even produced some improvement. The question whether some classes of antihypertensive agents are more beneficial or harmful than others in terms of quality-of-life effects remains largely unanswered. Results from long-term trials suggest that treatment with diuretics is not associated with adverse effects on quality of life. Nevertheless, chlortalidone and other diuretics have been more often associated with sexual dysfunction in men, including decreased libido, erectile dysfunction and difficult ejaculation, than other drug classes. Nonselective lipophilic beta-adrenoceptor antagonists, such as propranolol, have been reported to exert some negative effect on quality of life and have been associated with depression, impairment of memory function and adverse effects such as erectile problems. A less unfavourable impact has been described with beta(1)-adrenoceptor antagonists and those with vasodilating properties. Calcium channel antagonists have generally been associated with a positive effect on quality of life, although some trials have shown high rates of adverse effects and withdrawals, particularly with first-generation dihydropyridines. Concern has also been raised about the potential for adverse cognitive effects associated with the use of calcium channel antagonists, but studies on this topic are not univocal. ACE inhibitors have usually been reported to exert favourable effects on quality of life. These drugs seem to be effective in maintaining, or even improving, cognitive function through mechanisms other than blood pressure control. In addition, a number of studies reported favourable impact of ACE inhibitors on sexual function. Angiotensin II receptor antagonists have been associated with good tolerability and low withdrawal rate. They have been demonstrated not to interfere with or even improve cognitive function as well as sexual performance. Although no class of antihypertensive agents presents a clearly superior effect over the others in terms of quality of life, the current impression is that ACE inhibitors and angiotensin II receptor antagonists may offer some advantage, at least in regard to effects on cognitive function and sexual activity.

Serial MR imaging of volumes of hyperintense white matter lesions in elderly patients: correlation with vascular risk factors

OBJECTIVE

The purpose of the study was to examine change in volume of hyperintense white matter lesions in a cohort of community-dwelling elderly subjects without neuropsychiatric disease. SUBJECTS AND METHODS. One hundred seventeen volunteers underwent brain MR imaging on a 1.5-T scanner. Demographic data and the presence of specific medical illnesses were recorded at the time of the initial scanning. Hyperintense white matter lesion volume was measured using a supervised semiautomated technique that seeded lesions and then created a segmented lesion image. Subjects underwent repeated MR imaging at a mean of 25 months. Mean change in lesion volume and mean percentage of change were determined between the two time points. Logistic regression models were used to examine the differential effects of age, sex, race, and self-reported medical morbidity.

RESULTS

Mean baseline volume of cerebral hyperintense lesions was 4.91 cc, and at 2-year follow-up, it was 6.42 cm(2) (p < 0.0001), for a mean increase of 26.7%. Comparable results were seen in separate analyses of hemispheric hyperintense lesion volumes. Neither sex, race, nor baseline hyperintense lesion volume was significantly associated with an interval increase in lesion volume. Age (p = 0.0117) and presence of diabetes (p = 0.0215) were associated with greater change.

CONCLUSION

Elderly subjects exhibited approximately a 27% increase in hyperintense lesion volume over a 2-year period, a finding influenced by both age and medical comorbidity rates. Because hyperintense lesions can be associated with several neuropsychiatric conditions, further research is needed to determine if interventions designed to slow hyperintense lesion disease progression may improve neuropsychiatric outcomes.

Does the angiotensin II receptor antagonist losartan improve cognitive function?

Newer classes of antihypertensive agents, such as angiotensin II receptor antagonists, may offer benefits to patients in addition to their ability to lower blood pressure. It is accepted that chronic hypertension contributes to the development of cerebrovascular and cardiovascular disease, and several studies have demonstrated a link between hypertension and reduced cognitive function, especially in patients not receiving antihypertensive medication. In an initial clinical trial, the angiotensin II receptor antagonist losartan was shown to improve cognitive function in patients with hypertension, including in those who were elderly (up to 73 years of age). This effect cannot be explained by a reduction in blood pressure alone and is likely to involve interactions with the diverse biological actions of the renin-angiotensin system. Improving or maintaining cognitive function in patients with hypertension may translate into economic benefits beyond those expected due to blood pressure control, and would result in considerable quality-of-life benefits for the aging population.

The role of cerebrovascular disease in dementia

BACKGROUND

Improvements in health care over the last 50 years have lengthened average life expectancy significantly, resulting in considerable growth of the population over 65 years of age. With increased age, however, comes an increased risk for Alzheimer's disease (AD), and the prevalence of AD is predicted to reach epidemic proportions by the later half of the 21st century. The prevalence of cerebrovascular disease also increases with age, and recent evidence suggests that cerebrovascular risk factors such as hypertension and hypercholesterolemia also increase an individual's risk for AD, suggesting a potential interaction between these two very common disorders. The potential impact of cerebrovascular disease on general cognitive health is not yet well understood, but is now being actively explored and clarified.

REVIEW SUMMARY

Cerebrovascular disease may manifest itself in many ways, and this review begins by discussing the possible spectrum of brain injury associated with common cerebrovascular risk factors. The prominent role of brain imaging to detect clinically silent cerebrovascular disease is recognized and reviewed. The neuropsychological consequences of cerebrovascular disease across the cognitive spectrum is also reviewed, including potential mechanisms by which cerebrovascular disease may interact with AD to increase the expression or hasten the progression of dementia.

CONCLUSIONS

Cerebrovascular risk factors, common to the elderly, lead to pernicious brain injury and subtle cognitive impairment that most probably places the individual at greater lifetime risk for dementia. The cause of dementia among individuals with cerebrovascular disease, however, remains AD. Recognition of the potential role of cerebrovascular disease as an independent risk factor for AD offers the possibility of primary prevention through treatment of well-recognized risk factors and deserves further study. In the meantime, clinicians presented with an individual suffering from a slowly progressive dementia and findings of clinically silent cerebrovascular brain injury should recognize the potential role of cerebrovascular disease in the dementia process but not ignore the likely overwhelming effects of AD and treat appropriately.

Prevention of brain aging and dementia

The brain is subjected to multiple factors that result in damage to its cellular constituents, the neuron and supporting cells, and the neural networks that form the bases of cognitive ability. Like other systems, the brain has remarkable capacity to repair that damage and to adapt or compensate for the loss of neurons and the disruption of the neural architecture. Brain aging and dementia can be conceptualized as a balance between neuronal injury and repair. This balance can be affected not only by genetic and age-related factors but also by multiple environmental factors. The latter includes many factors, including education, nutrition, exercise, socialization, and stress. As individuals, we have the potential to modify these factors through lifestyle choices. Advances in neuroscience have led to the development of pharmacologic agents that can ameliorate the effects of even genetic (e.g., statins and antihypertensive agents) and age-related (e.g., antioxidants and estrogen replacement) factors. By altering the balance between neuronal injury and repair, we can delay the expression and progression of the neurodegenerative processes of brain aging, AD, and related dementias.

Effects of six anti-hypertensive medications on cognitive performance

OBJECTIVE

To describe and compare the effects of six different antihypertensive medications on cognitive performance.

DESIGN

Prospective, randomized, and double-blind with treatment cross-over.

SETTING

University hypertension clinic and neuropsychology laboratory.

PARTICIPANTS

Ninety-eight Caucasian men between 25 and 55 years of age with mild-to-moderate essential hypertension (88 of whom completed the study), and 32 normotensive men with similar socio-demographic characteristics.

INTERVENTIONS

Six-week treatment periods with atenolol, metoprolol, hydrochlorothiazide, methyldopa, enalapril and verapamil, and 2-week placebo baseline and wash-out periods.

MAIN OUTCOME MEASURES

In-depth neuropsychological assessments and several mood questionnaires were completed during placebo (baseline) periods and active treatment periods. Practice effects due to repeated neuropsychological testing were estimated from data collected concurrently in the normotensive participants.

RESULTS

The antihypertensive treatments lowered blood pressure comparably and did not affect mood or anxiety. Small treatment effects were noted in four of seven domains of cognitive performance. Irrespective of medication type, treatment reduced the simple motor speed (P < 0.001), and slowed completion of two tests measuring perceptuo-motor speed and mental flexibility (P </= 0.05). Manual dexterity declined somewhat with metoprolol and methyldopa (P = 0.01). In contrast, all antihypertensive agents favorably affected performance on several tests that require working memory (P < 0.01). Performance on other tests assessing grip strength, learning and memory, attention and executive function was not affected.

CONCLUSION

Short-term treatment with standard antihypertensive medications was associated with some small decrements in psychomotor performance and small improvements in working memory, without notable drug-class differences. Long-term effects await further study.

White matter lesions, quantitative magnetic resonance imaging, and dementia

The authors performed quantitative and qualitative image analysis on a sample of the elderly population of Cache County, Utah, relating neuroimaging findings to Mini-Mental Status Examination (MMSE) scores and the presence of the apolipoprotein E epsilon4 allele. Neuroimaging measures included white, gray, and hippocampal volumes; a ventricle-to-brain ratio (VBR); and qualitative ratings of white matter lesions (WMLs) in the periventricular (PV) and centrum semiovale (CS) regions. Subjects included 85 persons with possible and probable Alzheimer disease (AD), 21 with vascular dementia (VaD), 30 with cognitive symptoms classified as mild/ambiguous (M/A), a heterogenous group of 39 non-AD or VaD subjects but diagnosed with some form of neuropsychiatric disorder ("Mixed Neuropsychiatric" group), and 20 normal control subjects aged 65 years or older. Controlling for age, sex, and length of disease, the authors found that AD and VaD subjects differed significantly from control subjects on WMLs, but only the VaD subjects significantly differed from M/A subjects. The two dementia groups also displayed, as expected, significant cerebral atrophy. The WMLs generally increased with age and severity of dementia. PV WMLs were significantly but only modestly associated with white matter volume loss and greater impairment on the MMSE. Modest correlations were also present between the quantitative measures of cerebral structure and MMSE performance. However, when degree of cerebral atrophy was controlled by using the VBR measure, WML effects on MMSE performance became nonsignificant, with the only significant relationship remaining being that between hippocampal volume and MMSE performance. There were no significant qualitative or quantitative findings related to presence of the epsilon4 allele and MMSE performance. The role of WMLs in aging and dementia is discussed.

Antihypertensive drugs and cognitive function

The increase in life expectancy is associated with a sharp rise in cognitive disorders, particularly after the age of 80 years. The identification and management of risk factors for these invalidating and distressing conditions must be considered a priority. Hypertension has been shown to carry an increased risk not only for cerebrovascular morbidity and mortality, but also for cognitive impairment and dementia. The fact that antihypertensive treatment has been demonstrated to decrease those risks offers a new opportunity to reduce the prevalence of such related disorders and to promote healthy aging.

Relationship of race/ethnicity and blood pressure to change in cognitive function

OBJECTIVES

To determine whether there are racial/ethnic differences regarding the relationship of level of blood pressure to change in cognitive function in older people.

DESIGN

Longitudinal data 1986 to 1989 on representative, older, community-residing African Americans and whites. Blood pressure levels were assessed and a brief screen of cognitive functioning, the Short Portable Mental Status Questionnaire (SPMSQ), was performed at baseline and 3 years later.

SETTING

Five contiguous counties in the Piedmont area of North Carolina.

PARTICIPANTS

African-American (n = 2,260) and white(n = 1,876) participants in the Duke Established Populations for Epidemiologic Studies of the Elderly, aged 65 to 105 at baseline.

MEASUREMENTS

The outcome measure was change in SPMSQ score over 3 years. Covariates included age; education; gender; self-reported diabetes mellitus, stroke, heart attack, current smoking, and depressive symptomatology;and use of antihypertensive medication. The primary independent variable was measured blood pressure.

RESULTS

In unadjusted analyses, a statistically significant U-shaped relationship was found between systolic (but not diastolic) blood pressure levels and change in SPMSQ score over a 3-year period for older white men and women. No such relationships were found between these blood pressure measurements and change in SPMSQ score in older African Americans. These findings remained after adjustment for initial SPMSQ score, demographic characteristics, and use of antihypertensive medication. There were no significant interactions between race and blood pressure on change in cognitive function.

CONCLUSION

Decline in cognitive function was associated with extremes of systolic blood pressure in older white people. Although a similar but muted nonsignificant association was found in older African Americans, the curves for the two groups were not significantly different. Further studies in older African Americans are needed.

Variability in midlife systolic blood pressure is related to late-life brain white matter lesions: the Honolulu-Asia Aging study

BACKGROUND AND PURPOSE

Although white matter lesions (WMLs) on brain MRI in older persons are common, the mechanisms are unclear. Besides the associations with advanced age and high blood pressure (BP), variability in systolic BP (SBP) and the resulting changes in blood flow to the deep arteries of the brain may be contributing factors.

METHODS

Japanese-American men in Hawaii have participated in a long-term study of cardiovascular disease, including midlife BP measurements at 3 clinical examinations in the period from 1965 to 1974. In the period from 1991 to 1993, dementia status was added to the fourth examination, and a brain MRI was completed in a fifth examination, which was from 1994 to 1996, on a subset of 575 men, who averaged 82 years. WMLs and ventricular atrophy were determined as the upper fifth in a standardized semiquantitative measure. Excess SBP variability was defined as greater than average increases in BP measurements from up to 3 examinations over 6 years. Logistic regression was used for the association of this variability with WMLs and atrophy, controlling for age, apolipoprotein E4 status, dementia diagnosis, and history of stroke.

RESULTS

There were significant (2-fold) increased risks for WMLs among those with moderate and high SBP variability (third and fifth quintiles compared with the lowest quintile). Those in the highest SBP variability category (the fifth quintile) also had significantly more atrophy.

CONCLUSIONS

These SBP variability-MRI relationships suggest that variation in SBP in midlife may be a contributing factor to the development of WMLs and ventricular atrophy in late life.

Hypertension and dementia

The increase in life expectancy is associated with a sharp rise in cognitive disorders, particularly after the age of 80 years. The identification and management of risk factors for these invalidating and distressing conditions must be considered a priority. The fact that antihypertensive treatment has been demonstrated to decrease that risk offers a new opportunity to reduce the prevalence of such related disorders and promote healthy aging.

Risk and benefit of treatment of isolated systolic hypertension in the elderly: evidence from the Systolic Hypertension in Europe Trial

The Syst-Eur trial investigated whether active treatment starting with the dihydropyridine calcium channel blocker (CCB) nitrendipine, could reduce the cardiovascular complications of isolated systolic hypertension (ISH) in the elderly. The intention-to-treat analysis showed that active treatment improved outcome. The per-protocol analysis largely confirmed these results. The effect of treatment on total and cardiovascular mortality might be attenuated in very old patients. Further analysis also suggested benefit in those patients who remained on nitrendipine monotherapy. Active treatment was more beneficial in patients with diabetes as compared with those without diabetes at entry and reduced the incidence of dementia by 50%. Analyses of data from the Ambulatory Blood Pressure Monitoring (ABPM) Side Project suggested that most of the benefit of treatment was seen in patients with a daytime systolic BP > or = 160 mm Hg. Finally, a meta-analysis partly based on Syst-Eur data showed that in older hypertensive patients pulse pressure and not mean pressure is the major determinant of cardiovascular risk.

[Cerebral complications of hypertension in the elderly]

PURPOSE

This review focuses on cerebral complications of hypertension, which include stroke, impairment of cognitive function, dementia, and possibly depression and anxiety. These conditions are major causes of morbidity and mortality in the elderly.

CURRENT KNOWLEDGE AND KEY POINTS

Not only elevated diastolic blood pressure, but also isolated systolic hypertension and elevated pulse pressure play an important role in the development of brain complications. Randomised placebo-controlled trials have provided evidence that reduction of hypertension decreases safely and effectively morbidity and mortality rates in the elderly. The new classes of drugs, in particular calcium-channels blockers and angiotensin-converting enzyme inhibitors, have been shown to be as effective as the originally used diuretics and beta-blockers.

FUTURE PROSPECTS AND PROJECTS

Several trials are currently in progress and should provide more information on the benefit of antihypertensive treatment in very elderly persons (Hypertension in the Very Elderly Trial, HYVET) and secondary prevention of stroke (PROGRESS). The importance of assessing new dosages of the presently used antihypertensive drugs as well as the benefit of new classes of drugs is emphasised. Further trials specifically focusing on the prevention of dementia by antihypertensive drugs are needed to confirm the results of the Syst-Eur Vascular Dementia Project. The benefit of calcium antagonists in the prevention of dementia in elderly hypertensive patients should be assessed in the Dementia Prevention in Hypertension trial (DEPHY).

Update in pharmacologic treatment of hypertension

Initial pharmacologic therapy for hypertension is low-dose thiazide diuretics, beta-blockers, and ACE inhibitors. Increasing data have confirmed that ACE inhibitors have specific benefit in patients with diabetes, atherosclerosis, left ventricular dysfunction, and renal insufficiency. CCBs are alternative agents for ISH in the elderly and appear to decrease stroke with perhaps less protection against progression of renal insufficiency and proteinuria, CAD mortality and new onset heart failure versus other initial agents, especially ACE inhibitors. ARBs are well tolerated and effective blood pressure lowering agents but have not been confirmed as effective as ACE inhibitors for reducing renal progression, clinical events, or mortality from heart failure. Effective pharmacologic antihypertensive therapy may avoid disabling and undetected cerebrovascular disease, cognitive dysfunction, and disturbing symptoms of elevated blood pressure. Vasopeptidase inhibitor, such as omapatrilat, and endothelin-1 antagonist, such as bosentan, may become future agents approved for the reduction of morbidity and mortality with hypertension. The ALLHAT trial continues to examine the potential benefits and harms of amlodipine versus chlorthalidone and lisinopril in a diverse high-risk population. Based on ALLHAT data, however, doxazosin is no longer an acceptable initial pharmacological agent. Intensive pharmacologic treatment with blood pressure lowering to less than 130/85 mm Hg is recommended with diabetes, renal insufficiency, and heart failure with additional goal of less than 125/75 mm Hg with renal failure and proteinuria greater than 1 g/24 h, based on multiple outcome studies.

Longitudinal study of blood pressure and white matter hyperintensities: the EVA MRI Cohort

OBJECTIVE

To investigate the relationship between baseline hypertension and severity of white matter hyperintensities (WMH) at 4-year follow-up in a sample of subjects aged 59 to 71 years old at entry.

METHODS

Subjects were participants in the Epidemiology of Vascular Ageing study, a longitudinal study on vascular aging and cognitive decline. At 4-year follow-up, 845 subjects had a cerebral MRI. MRI examinations were read by a single rater to determine the severity of WMH, ranging from absent to severe. Hypertension at each wave of the study was defined as systolic blood pressure > or =160 mm Hg, diastolic blood pressure > or =95 mm Hg, or use of antihypertensive medication.

RESULTS

Hypertension at baseline was significantly associated with an increased risk of having severe WMH at 4-year follow-up. When taking into account both blood pressure levels and antihypertensive drug intake, analysis showed that the risk of having severe WMH was significantly reduced in subjects with normal blood pressure taking antihypertensive medication compared with those with high blood pressure taking antihypertensive agents. Cross-sectional relationships between hypertension and WMH at 4-year follow-up showed that the frequency of severe WMH was significantly higher in people who were hypertensive at both baseline and 4-year follow-up than those who were hypertensive only at 4-year follow-up.

CONCLUSIONS

Hypertension is a major risk factor for severe WMH. Subjects taking antihypertensive drugs and who have controlled blood pressure had a reduced risk of severe WMH. Longitudinal studies are needed to investigate whether reduction of the development of WMH, by treatment and prevention of hypertension, might reduce the subsequent risk of cognitive deterioration or stroke.

Diuretic therapy in elderly heart failure patients with and without left ventricular systolic dysfunction

Long term prescription of diuretics for heart failure is very prevalent among elderly patients, although the rationale for such a treatment strategy is often unclear, as diuretics are not indicated if volume overload is absent. The concept of diastolic heart failure in the elderly might particularly change the role of diuretic therapy, since diuretics may have additional adverse effects in these patients. This paper reviews the effects of diuretic therapy in elderly patients with heart failure, emphasising the differences between patients with normal and decreased left ventricular systolic function. Studies on diuretic withdrawal in elderly patients with heart failure are discussed, with emphasis on issues involved in decision making such as diuretic dose reduction and withdrawal in elderly patients and factors that have been established to predict successful withdrawal. Existing guidelines on the prescription of diuretics in elderly patients with heart failure with normal and decreased left ventricular systolic function and in those with diastolic heart failure are also discussed. By reducing intravascular volume, diuretics may further impair ventricular diastolic filling in patients with diastolic heart failure and thus reduce stroke volume. Indeed, preliminary studies demonstrate that diuretics may provoke or aggravate hypotension on standing and after meals in these patients. Therefore, it is suggested that elderly patients with heart failure with intact left ventricular systolic function should not receive long term diuretic therapy, unless proven necessary to treat or prevent congestive heart failure. This implies that physicians should carefully evaluate the opportunities for diuretic dose tapering or withdrawal in all of these patients, and that a cautiously guided intermittent diuretic treatment modality may be critical in the care for older patients with heart failure with intact left ventricular systolic function.

Ca2+ signaling down-regulation in ageing and Alzheimer's disease: why is Ca2+ so difficult to measure?

Ca2+ signaling is a central process in brain function, but the direction of its change in ageing and in the presymptomatic stages of Alzheimer's disease has been controversial. A great deal of studies have been interpreted as supportive to the current hypothesis that intracellular Ca2+ levels are steadily increased in ageing. We, however, believe that, although current studies have provided valuable knowledge for the mechanisms of the signal transduction process, they have not furnished relevant information regarding the global Ca2+ changes in the ageing brain, because the cognition-related Ca2+ pulses exist only in the intact brain.

Effects of hypertension and its treatment on mental function

This paper addresses the relationship between hypertension and cognitive status and the impact of antihypertensive treatment. Data from cross-sectional and longitudinal studies are reviewed. After adjustment for age and level of education, cognitive function of hypertensive patients is impaired compared with the cognitive status of their nonhypertensive counterparts. The mechanisms underlying hypertension associated cognitive impairment remain to be elucidated. The role of antihypertensive treatment also has to be determined. Some evidence suggests that antihypertensive treatment may prevent dementia in hypertensive patients.

Blood pressure and cognitive decline in the elderly

Elevated blood pressure is associated with cognitive decline in elderly people. Classically, hypertension was thought to lead to end-organ damage of the brain manifested by neuropsychological deficits. This review examines recent evidence for this hypothesis and also considers other possible causal mechanisms for the observed relationship between blood pressure and mental ability.