Prevention of dementia in randomised double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) trial

Hypertension and cerebral white matter lesions in a prospective cohort study

White matter lesions are frequently found on cerebral MRI scans of elderly people and are thought to be important in the pathogenesis of dementia. Hyper tension has been associated with the presence of white matter lesions but this has been investigated almost exclusively in cross-sectional studies. We studied prospectively the association of these lesions with the duration and treatment of hypertension. We randomly sampled 1077 subjects aged between 60 and 90 years from two prospective population-based studies. One-half of the study subjects had their blood pressure measured between 1975 and 1978 and the other half between 1990 and 1993. All subjects underwent 1.5 T MRI scanning; white matter lesions in the subcortical and periventricular regions were rated separately. Subjects with hypertension had increased rates of both types of white matter lesion. Duration of hypertension was associated with both periventricular and subcortical white matter lesions. This relationship was influenced strongly by age. For participants with >20 years of hypertension and aged between 60 and 70 years at the time of follow-up, the relative risks for subcortical and periventricular white matter lesions were 24.3 [95% confidence interval (CI) 5.1-114.8] and 15.8 (95% CI 3.4-73.5), respectively, compared with normotensive subjects. Subjects with successfully treated hypertension had only moderately increased rates of subcortical white matter lesions and periventricular white matter lesions (relative risk 3.3, 95% CI 1.3-8.4 and 2.6, 95% CI 1.0-6.8, respectively) compared with normotensive subjects. For poorly controlled hypertensives, these relative risks were 8.4 (95% CI 3.1-22.6) and 5.8 (95% CI 2.1-16.0), respectively. In conclusion, we found a relationship between long-standing hypertension and the presence of white matter lesions. Our findings are consistent with the view that effective treatment may reduce the rates of both types of white matter lesion. Adequate treatment of hypertension may therefore prevent white matter lesions and the associated cognitive decline.

Isolated systolic hypertension: a new challenge in medicine

In the elderly, isolated systolic hypertension (ISH) is a particularly good predictor of subsequent cardiovascular events. The purpose of this article is to review the evidence provided by the Systolic Hypertension Elderly Program (SHEP) and the Systolic Hypertension in Europe Study (Syst-Eur) on the benefits of lowering systolic blood pressure (SBP) and to report on the preliminary findings of the Maracaibo Aging Study (MAS) on ISH. These two trials, the SHEP using chlorthalidone and atenolol as step 2 and the Syst-Eur using nitrendipine and hydrochlorothyazide as step 2, demonstrated a decrease of more than 30% for all cardiovascular complications, including stroke and coronary events. MAS is a population-based study that included all the subjects older than 55 years of age that resided in a defined area of the city of Maracaibo. There was a high prevalence of ISH (45.7%) being higher among women than in men, and significantly increased with advancing age. SBP was associated with dementia when it was measured by an ambulatory blood pressure monitor (ABPM), while there was no association when it was assessed by the casual method. Diastolic blood pressure (DBP) as casual or measured by ABPM was not related to dementia. In conclusion, ISH is a serious public health problem and benefits from lowering elevated SBP to reduce the risk of cardiovascular events. It was shown there was a strong correlation between high SBP and cognitive dysfunction and this was best demonstrated by using ABPM. Research should address the impact of using modern diagnostic tools and to compare the efficacy of the different types of antihypertensive drugs.

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.

Vascular dementia: a diagnosis running out of time

BACKGROUND

The concept of vascular dementia has a long history but its usefulness as a diagnostic category has been called into question.

AIMS

To evaluate vascular disease as a risk factor for dementia and the interface between cerebrovascular pathology and Alzheimer's disease.

METHOD

The literature on this topic was selectively reviewed and synthesised.

RESULTS

Risk factors for cerebrovascular disease are also risk factors for dementia. However, the course of dementia, once it has developed, appears to be frequently determined by Alzheimer's disease.

CONCLUSIONS

As a public health measure, modification of vascular risk represents a potentially powerful means to prevent dementia through delaying its onset. However, an effect on progression of dementia, once it has developed, has yet to be established. The traditional view of vascular dementia and Alzheimer's disease as distinguishable conditions is becoming steadily less tenable.

Prevalence of dementia in the older Japanese-Brazilian population

The prevalence of dementing disorders in Campo Grande of a community of Japanese-Brazilians who immigrated from Okinawa was studied. Previous reports showed that the dietary pattern in Japanese immigrants in Brazil, which characterized by a low fish and large meat intake, is possibly responsible for increased risk of cardiovascular diseases compared with Japanese in Okinawa. A total of 157 persons over 70-year-old were examined, and 19 cases were diagnosed as having dementia. The prevalence (cases/100 aged 70-year-older) was 12.1 for all types of dementia, 5.7 for Alzheimer's disease (AD), 0.6 for vascular dementia (VD), 4.5 for mixed dementia (AD/VD) and 1.3 for other types of dementia. There was no case of dementia with Lewy bodies or frontotemporal lobar degeneration. These results are similar to many previous studies in Western countries and some recent surveys in Japan, and clearly show that more AD than VD appears even in the Japanese-Brazilian population. The higher prevalence rate of dementia in Japanese-Brazilians compared with several studies in Japan may indicate the importance of dietary factors rather than genetic factors.

The effect of the living situation on the severity of dementia at diagnosis

INTRODUCTION

Previous studies have shown that social determinants not directly involved in the disease process may be implicated in the timing of dementia diagnosis. This study explores the relationship between a patient's living situation and the severity of dementia at diagnosis.

METHODS

Data were collected from the baseline interviews of 1,325 patients with cognitive decline enrolled in the Consortium for the Investigation of Vascular Impairment of Cognition study. Data collected included: age, sex, living situation and scores on the Mini-Mental State Examination (MMSE), Global Deterioration Scale (GDS), the Functional Rating Scale (FRS), the Disability Assessment for Dementia (DAD) scale and the Cumulative Illness Rating Scale (CIRS). Living situation was grouped as: (1) lives alone, (2) lives with spouse, (3) lives with child, relative or other and (4) lives in a nursing home. A general linear model univariate analysis was used to compare patients by their respective living situations for differences in mean scores on each of the 4 measures of dementia severity.

RESULTS

Statistical analysis of both unadjusted data and data adjusted for age, sex and CIRS scores showed significant differences among the groups. Those who lived alone were diagnosed at an earlier stage (mean scores: MMSE 21.4, GDS 3.6, FRS 20.0, DAD 29.8) followed by those who lived with a spouse (mean scores: MMSE 20.5, GDS 3.7, FRS 20.4, DAD 28.0), those who lived with a child or other (mean scores: MMSE 19.3, GDS 3.9, FRS 22.5, DAD 24.9) and finally those who lived in a nursing home (mean scores: MMSE 15.2, GDS 4.8, FRS 27.5, DAD 16.9).

CONCLUSION

Living situation is related to the severity of dementia at diagnosis. Primary care providers should have a low threshold for case-finding in older adults who live with family or friends.

Calcium channel antagonists in the treatment of hypertension

Calcium channel antagonists are widely used antihypertensive agents. Their popularity among primary care physicians is not only due to their blood pressure-lowering effects, but also because they appear to be effective regardless of the age or ethnic background of the patients. The first available calcium channel antagonists utilized immediate-release formulations which, although effective in patients with angina pectoris, were not approved by the US FDA for use in hypertension. When long-acting once-daily formulations were approved in this indication, the short-acting preparations--which had by then become generic and inexpensive--retained some residual unapproved use for hypertension. An observational case-controlled trial, based on such usage, noted that these agents were associated with a greater risk of myocardial infarctions than conventional agents such as diuretics and beta-adrenoceptor antagonists. Further case-controlled trials showed, in fact, that the dangers of calcium channel antagonists were confined to the short-acting agents and that approved long-acting agents were at least as well tolerated and effective as other antihypertensive drugs. Cardiovascular outcomes during treatment with calcium channel antagonists have been examined in randomized, controlled trials. Compared with placebo, the calcium channel antagonists clearly prevented strokes and other cardiovascular events and reduced mortality. The effects of these agents on survival and clinical outcomes were similar to those with other antihypertensive drugs. There is a slight tendency for the calcium channel antagonists to be more effective than other drug types in preventing stroke, but slightly less effective in preventing coronary events. These observations extend to high-risk patients with hypertension including those with diabetes mellitus. Even so, patients with evidence of nephropathy should not receive monotherapy with calcium channel antagonists. Such patients are optimally treated with angiotensin receptor antagonists or ACE inhibitors, although addition of other drugs, including calcium channel antagonists, is often required to achieve the tight blood pressure control necessary to provide adequate renal protection. Calcium channel antagonists have a highly acceptable tolerability profile and careful reviews of available data have shown that their use is not associated with increased bleeding or promotion of tumor formation. It is now recognized that reduction of blood pressure in patients with hypertension to levels often <130/85 mm Hg should be undertaken in presence of other cardiovascular risk factors or evidence of end organ damage. Because of this important concept, calcium channel antagonists, like the other antihypertensive drug classes, are progressively being prescribed less often as monotherapy, but more typically as part of combination regimens.

Effect of the treatment of Type II diabetes mellitus on the development of cognitive impairment and dementia

BACKGROUND

There is increasing interest in preventing cognitive impairment and dementia in later life. Epidemiological evidence shows a relationship between cognitive impairment and Type II diabetes. This association is stronger in patients who have been diagnosed for longer periods of time and in those who are on insulin therapy. There is little information on the short- and long-term influence of type of treatment and level of metabolic control on cognitive function of people with diabetes.

OBJECTIVES

To assess the effects of different types and intensities of treatments for Type II diabetes on cognitive function.

SEARCH STRATEGY

The Cochrane Control Trials Register, MEDLINE, EMBASE, PsycINFO, SIGLE LILACS and CINAHL as well as a number of ongoing trials databases were searched on 11 June 2002 using appropriate strategies.

SELECTION CRITERIA

Randomized controlled trials in which different treatments for Type II diabetes have been compared and in which measures of cognitive function were made at entry and after the treatment.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality. Five trials were identified for possible inclusion but none of them could be included. In one, cognitive function was assessed before and after intensive or conventional diabetic treatment, but the comparison was not double-blind. The three other studies explored the effect of different treatments on QOL but did not include appropriate evaluation of cognitive function. The fifth did not report baseline data on cognitive function in the trial groups.

MAIN RESULTS

No studies were found to be appropriate for inclusion in meta-analysis.

REVIEWER'S CONCLUSIONS

There is no convincing evidence relating type or intensity of diabetic treatment to the prevention or management of cognitive impairment in Type II diabetes. Future research on treatments for diabetes should include standardized assessments of cognitive function as outcome measures.

Treatment of hypertension in the elderly

Hypertension is a common condition among older people in most developed countries, and is a very important, if not the most important, risk factor for all subtypes of vascular disease and death. Many clinical trials in older people have demonstrated significant reductions in myocardial infarctions and strokes when antihypertensive drugs are provided. Lifestyle modifications are still recommended because they can lower a surrogate end point--blood pressure--but there are no data showing they reduce event rates. It is not appropriate to limit the choice of initial drug for hypertensive older individuals to a single class of agents, since so many older people have other medical problems that affect this decision. Monotherapy with an alpha blocker, however, is no longer recommended, even for men with hypertension and benign prostatic hypertrophy, as doxazosin was associated with a higher rate of cardiovascular events in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial. The classic strategy of an initial diuretic (for at least 1 month) will likely be verified by the final results of ongoing randomized trials, expected in 2003. Until then, this strategy is effective, inexpensive, and unlikely to cause many adverse effects. Probably the most important exhortation, however, should be to achieve the blood pressure goal appropriate for the patient's risk status. Numerous clinical trials in older hypertensive patients have shown that more benefits accrue when the goal blood pressure is achieved than if a specific antihypertensive agent is chosen as initial therapy. Future cardiovascular risk may be related directly to the blood pressure attained, rather than to how it was attained.

Cerebrovascular structure and dementia: new drug targets

Effective pharmacological treatment of cognitive disorders in dementia is lacking despite extensive efforts to produce active therapy aimed at neuronal and vascular targets. In this review, the evidence for the involvement of vascular mechanisms in the pathology and evolution of dementia will be examined and the potential importance of age-related changes in cerebrovascular structure and cerebral blood flow (CBF) autoregulation will be discussed. With a description of recent clinical results (on statins, angiotensin-converting enzyme inhibitors and Ca(2+) channel blockers) and experimental results (on beta-amyloid), the impact of drugs on cerebrovascular targets is examined. The working hypothesis that targeting vascular mechanisms in dementia is an option for future therapy is proposed.

Multifactorial cardiovascular disease prevention in patients aged 75 years and older: A randomized controlled trial: Drugs and Evidence Based Medicine in the Elderly (DEBATE) Study

BACKGROUND

The number of patients aged 75+ years with cardiovascular diseases (CVD) is increasing, but few studies of secondary prevention in this age group exist. The aim of the Drug and Evidence Based Medicine in the Elderly (DEBATE) study is to test the applicability and effectiveness of established CVD treatments in elderly patients.

METHODS

From 1998 to 2000, population-based postal surveys were performed in Helsinki, Finland, including the age groups 75, 80, 85, 90, and 95 years (n = 4821). Of the 812 individuals reporting any atherosclerotic disease, 400 patients (66% of those eligible) were included in a randomized trial. In the intervention group, CVD treatments will be individualized according to current guidelines. A control group will receive the usual care. The trial period will last 2 years with a 3-year extension. The primary end point will be a composite of major CVD. In addition, a number of secondary end points will be recorded, including permanent institutionalization, decline in cognitive and physical function, and quality of life.

RESULTS

During 2000, 400 home-dwelling patients were randomized to the intervention (n = 199) and control (n = 201) groups. The mean age is 80.2 years and 65.3% are women. Of the participants, 82% have coronary heart disease (41% with history of myocardial infarction), 37% history of stroke, 19% non-insulin-dependent diabetes mellitus, and 45% hypertension, and 6% are current smokers. Before randomization, 67% used aspirin, 40% b-blockers, 14% angiotensin-converting enzyme inhibitors, 36% nitrates, and 20% lipid-lowering drugs. The groups were well balanced at baseline.

CONCLUSION

We have successfully randomized elderly patients with a high degree of comorbidity into a multifactorial CVD prevention trial.

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.

Joint effect of the APOE gene and midlife systolic blood pressure on late-life cognitive impairment: the Honolulu-Asia aging study

BACKGROUND AND PURPOSE

The aim of this study was to explore the joint effect of the APOE epsilon4 allele and midlife systolic blood pressure (SBP) on the risk for poor cognitive function in late life.

METHODS

The study includes 3605 surviving members of the cohort of the Japanese-American men followed prospectively over 26 years (1965-1991) as a part of the Honolulu Heart Program. In 1965 men were aged 45 to 68 years and were living in the island of Oahu, Hawaii. For this study the sample was divided into 4 categories: normal SBP (<160 mm Hg)/No epsilon4, as the reference category; normal SBP/epsilon4; high SBP/no epsilon4; high SBP/epsilon4. The relative risk (RR) of late-life intermediate and poor cognitive function relative to good function was measured by the Cognitive Abilities Screening Instrument (CASI) test.

RESULTS

After adjusting for age, education, smoking, alcohol use, and body mass index, the RR for poor cognitive function (CASI <74) compared with good cognitive function (CASI >/=82) in never-treated subjects was 1.3 (95% CI 0.9 to 1.9) for the normal SBP/epsilon4 category, 2.6 (0.7 to 10.0) for the high SBP/no epsilon4, and 13.0 (1.9 to 83.8) for the high SBP/epsilon4. Adjustment for diabetes, prevalent stroke, coronary disease, and ankle-brachial index reduced the RR of poor cognition by 25.5% (RR 13.0 to 10.8) in those with both risk factors. In the treated group, the RR was 1.9 (0.7 to 4.5) for those with both risk factors.

CONCLUSIONS

The results suggest that midlife high SBP has a stronger adverse effect on cognitive function in persons with higher genetic susceptibility, but this effect may be modified by antihypertensive treatment.

Dementia due to subcortical ischemic vascular disease

Ischemic vascular disease (IVD) is the second most common cause of dementia in the Western world. This article focuses on dementia resulting from subcortical ischemic vascular disease (SIVD), a subtype of IVD, which in many cases may be prevented. Hypertension and diabetes are the leading causes of small-artery disease, subcortical brain ischemia, and stepwise or slowing progressive decline in cognitive function. The pattern of cognitive impairment in SIVD, as compared with Alzheimer's disease, is characterized by greater impairment of executive function but better preservation of recognition memory. Structural neuroimaging studies, such as computed tomography and especially magnetic resonance imaging, are more sensitive than the clinical examination and can enable detection of subcortical lacunes and deep white matter changes that are clinically silent. Often the brain can be protected against SIVD by early diagnosis and management of risk factors. Once end-organ damage has occurred, however, treatment outcome is less satisfactory. The most common risk factors for SIVD--hypertension and diabetes mellitus--are best detected and managed in primary care settings.

Improved outcomes with antihypertensive medication in the elderly with isolated systolic hypertension

Isolated systolic hypertension affects over 15% of all individuals aged >60 years. In the elderly, systolic hypertension is a major modifiable cardiovascular risk factor. Systolic blood pressure (SBP) is associated with higher risk of an adverse outcome, whereas diastolic blood pressure (DBP) is inversely correlated with total mortality, independent of SBP, highlighting the role of pulse pressure as a risk factor. Three placebo-controlled outcome trials on antihypertensive drug treatment in older patients with isolated systolic hypertension have been published: the Systolic Hypertension in the Elderly Program (SHEP), the Systolic Hypertension in Europe (Syst-Eur) Trial and the Systolic Hypertension in China (Syst-China) Trial. These 3 trials demonstrated the benefit of antihypertensive drug treatment. A meta-analysis was performed by pooling the patients from these 3 trials with a subset of patients with isolated systolic hypertension from 5 other trials in the elderly. The pooled results of 15,693 older patients with isolated systolic hypertension prove that antihypertensive drug treatment isjustified if on repeated clinic measurements SBP is 160 mm Hg or higher.

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.

Treating hypertension in the elderly

Hypertension is highly prevalent in elderly individuals, the most rapidly growing segment of the US population. Epidemiologic studies have established that increased risk of cardiovascular disease is associated with elevated blood pressure. Treatment of hypertension in elderly patients significantly reduces their cardiovascular morbidity and mortality. However, antihypertensive therapy is often challenging in this patient population because of potential metabolic and physiologic alterations, multiple comorbidities, polypharmacy, and biologic variability. Drugs with a convenient dosing schedule, minimal side effects, and the ability to impact comorbid conditions are important considerations in the treatment of hypertension in the elderly.

Hypertensive brain damage: comparative evaluation of protective effect of treatment with dihydropyridine derivatives in spontaneously hypertensive rats

Hypertension is the main risk factor for cerebrovascular disease including vascular dementia and control of blood pressure might protect from lesions causing cognitive impairment. The influence of anti-hypertensive treatment on hypertensive brain damage was assessed in spontaneously hypertensive rats (SHR). SHR and age-matched normotensive Wistar Kyoto (WKY) rats were treated from the 14-26th week of age with the dihydropyridine-type Ca2+ channel blockers lercanidipine, manidipine and nimodipine and as a reference with the non-dihydropyridine-type vasodilator hydralazine. Volume of brain areas, number of nerve cells and glial fibrillary-acidic protein (GFAP)-immunoreactive astrocytes and neurofilament 200 kDa immunoreactivity were investigated in frontal and occipital cortex and in hippocampus. In control SHR, systolic blood pressure (SBP) was significantly higher in comparison with WKY rats. Compounds tested decreased to a similar extent SBP values in SHR, with the exception of nimodipine that caused a smaller reduction of SBP compared with other compounds. Decreased volume and number of nerve cells and loss of neurofilament protein immunoreactivity were observed in SHR. GFAP-immunoreactive astrocytes increased in number (hyperplasia) and in size (hypertrophy) in the frontal and occipital cortex of control SHR, and only in number in the hippocampus. Anti-hypertensive treatment countered in part microanatomical changes occurring in SHR. Drugs investigated with the exception of nimodipine exerted an equi-hypotensive effect. In spite of this the best protection was exerted by lercanidipine and, to a lesser extent, by nimodipine. Compared with nimodipine, lercanidipine induced a more effective decrease of SBP. This may represent an advantage in the treatment of hypertension with risk of brain damage.

Hypertension and cerebrovascular diseases: a specific role of vascular protection for the prevention of dementia

Despite the use of antihypertensive drugs, mortality (but not morbidity) from cerebrovascular diseases has been reduced significantly. As a consequence, an increasing number of patients suffer from recurring strokes and from the debilitating consequences of cerebrovascular diseases and develop progressive cognitive impairment. Its pathological substrates are regional alteration of cerebral perfusion, lacunae, white matter lesions, progressive cortical atrophy, even in the asymptomatic patient and in the absence of extracranial carotid artery stenosis. Lacunar infarction and white matter lesions are particularly frequent in the hypertensive diabetic patient. Lacunae and white matter lesions sometimes coexist and may favour the development of dementia in the hypertensive patient, through focal ischaemia, perivascular oedema, disruption of the blood-brain barrier, cerebral diaschisis and cortical deafferentation. Treatment with calcium channel blockers, angiotensin converting enzyme inhibitors and diuretics smooth the patchy hypoperfusion despite the fall in pressure. However, the time course and the extent of this effect vary according to the drug administered. In particular, only a calcium channel blocker increased perfusion of both cortical and subcortical areas, while diuretic treatment increased perfusion only after prolonged treatment, and this effect was limited to the cortical areas. Such differences may explain the discrepant results on risk reduction for dementia observed in large intervention trials.

[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).

Pharmacotheraphy for Alzheimer's disease

In the past 2 years, substantive advances in therapy for Alzheimer's disease (AD) have occurred. The nature of the effects of cholinesterase inhibitors has been refined with the publication of several studies that have examined different aspects of the symptomatology of AD. Breakthroughs in the basic science of Alzheimer's disease have led to new insights into potential therapeutic strategies targeted at the secretases involved in the metabolism of the Alzheimer precursor protein. An immunization approach, in which the beta-amyloid protein itself was used as the immunizing agent, has also been presented and independently validated. Other areas of investigation with disappointing results, such as estrogen replacement therapy, anti-inflammatory approaches, and several other therapeutic agents, are also reviewed.

The benefit of treating isolated systolic hypertension

Isolated systolic hypertension affects over 15% of all people older than 60 years of age. In the elderly, systolic hypertension is a major modifiable cardiovascular risk factor. Systolic blood pressure is associated with higher risk of an adverse outcome. Diastolic blood pressure is inversely correlated with total mortality, independent of systolic blood pressure, highlighting the role of pulse pressure as risk factor. Three placebo-controlled outcome trials on antihypertensive drug treatment in older patients with isolated systolic hypertension have been published: the Systolic Hypertension in the Elderly Program (SHEP), the Systolic Hypertension in Europe (Syst-Eur) Trial, and the Systolic Hypertension in China (Syst-China) Trial. These three trials showed the benefit of antihypertensive drug treatment. A meta-analysis was done by pooling the patients from these three trials with a subset of patients with isolated systolic hypertension from five other trials in the elderly. The pooled results of 15,693 older patients with isolated systolic hypertension prove that antihypertensive drug treatment is justified if systolic blood pressure on repeated clinic measurements is 160 mm Hg or higher.

Methodological issues and therapeutic perspectives in vascular dementia: a review

Vascular dementia (VaD) is the most common form of dementia after Alzheimer's disease (AD). However, it is now increasingly recognized that not only is VaD a heterogeneous syndrome but also that VaD and AD are not mutually exclusive. Thus, the currently used criteria may no longer be sufficient for an accurate diagnosis of VaD. In addition, although it is widely assumed that risk factors for vascular disease are also risk factors for VaD, the evidence, in most cases, is circumstantial. For the effective prevention of VaD, therefore, large-scale and long-term clinical trials are required to investigate the validity of these putative risk factors. These trials should also include the VaD subtypes in their outcome measurements and to this end a simplified classification system should be adopted. Additional large-scale trials are required to facilitate the secondary prevention and symptomatic treatment of VaD, in particular to investigate the potential application of several nootropic and neuroprotective drugs. In both cases, these clinical trials should aim to move the field of VaD from opinion-based medicine to evidence-based medicine.

Antihypertensive drugs and incidence of dementia: the Rotterdam Study

There is increasing evidence that hypertension may contribute to the development of dementia. We investigated the relation of antihypertensive drug use and the risk of dementia in the cohort of the population based Rotterdam Study. The study cohort included 7046 elderly, free of dementia at baseline. Dementia was diagnosed in a stepwise procedure. Participants were first screened. Screen positives were further tested. Those suspected of dementia underwent a diagnostic work-up. Dementia and its subtypes were diagnosed according to prevailing criteria. A Cox proportional hazards model was used to estimate relative risks. After a mean follow-up of 2.2 years, subjects taking antihypertensive medication at baseline (n = 2015) had a reduced incidence of dementia (adjusted relative risk, 0.76; 95% confidence interval 0.52-1.12). This risk reduction was most pronounced for vascular dementia, (adjusted relative risk, 0.30; 95% confidence interval 0.11-0.99). For Alzheimer's disease the relative risk was 0.87, not significant. Dementia may be prevented by antihypertensive treatment. In order to confirm any relation in Alzheimer's disease larger observational studies with longer follow-up are needed.

Functional status and clinical correlates in cognitively impaired community-living older people

We describe the prevalence of cognitive impairment in a population of community-living older people, its association with functional decline, and degree of comorbidity. In addition, we examined the relationship between different levels of cognitive impairment and mortality. We conducted an observational study of 1787 patients aged 65 years and above with any degree of cognitive impairment. Patient data were collected with the Minimum Data Set for Home Care. More than 50% of patients had some level of cognitive impairment, which correlates with the degree of physical frailty. On the contrary, patients with cognitive impairment appear to have fewer comorbid conditions and are less likely to receive medications than patients with normal cognitive status. In particular, hypertension, congestive heart failure, chronic obstructive pulmonary disease, cancer, diabetes mellitus, and osteoporosis are found more frequently among patients with normal mental status compared with those showing some level of cognitive defects. Yet, more severe cognitive impairment is associated with a higher mortality rate. Demented patients are characterized by a high prevalence of functional disability and by increased mortality. This increased morbidity and mortality rate is associated with a lower prevalence of comorbid clinical conditions and drug use, relative to patients with normal cognitive performance. The present findings support the possibility that severe cognitive impairment has an independent effect on survival.

Midlife vascular risk factors and Alzheimer's disease in later life: longitudinal, population based study

OBJECTIVE

To examine the relation of midlife raised blood pressure and serum cholesterol concentrations to Alzheimer's disease in later life.

DESIGN

Prospective, population based study.

SETTING

Populations of Kuopio and Joensuu, eastern Finland.

PARTICIPANTS

Participants were derived from random, population based samples previously studied in a survey carried out in 1972, 1977, 1982, or 1987. After an average of 21 years' follow up, a total of 1449 (73%) participants aged 65-79 took part in the re-examination in 1998.

MAIN OUTCOME MEASURES

Midlife blood pressure and cholesterol concentrations and development of Alzheimer's disease in later life.

RESULTS

People with raised systolic blood pressure (>/=160 mm Hg) or high serum cholesterol concentration (>/=6.5 mmol/l) in midlife had a significantly higher risk of Alzheimer's disease in later life, even after adjustment for age, body mass index, education, vascular events, smoking status, and alcohol consumption, than those with normal systolic blood pressure (odds ratio 2.3, 95% confidence interval 1.0 to 5.5) or serum cholesterol (odds ratio 2.1, 1.0 to 4.4). Participants with both of these risk factors in midlife had a significantly higher risk of developing Alzheimer's disease than those with either of the risk factors alone (odds ratio 3.5, 1.6 to 7.9). Diastolic blood pressure in midlife had no significant effect on the risk of Alzheimer's disease.

CONCLUSION

Raised systolic blood pressure and high serum cholesterol concentration, and in particular the combination of these risks, in midlife increase the risk of Alzheimer's disease in later life.

Heart disease and vascular risk factors in the cognitively impaired elderly: implications for Alzheimer's dementia

The term "cardiogenic dementia" was introduced a few decades ago to indicate an alteration of consciousness and cognition due to heart disease. Although this term is now disused, the relationship between cardiovascular disease and cognitive impairment is currently of great interest, not only for its potential therapeutic implications. but also for the recently recognized important role that vascular factors appear to play in Alzheimer's disease. The aims of this review are therefore 1) to show data supporting the role of cardiac disease--namely congestive heart failure, myocardial infarction and atrial fibrillation--and other vascular risk factors--i.e., hypertension and diabetes--in the development or worsening of cognitive impairment; 2) to highlight recent observations on the relationship between presence and severity of congestive heart failure/ myocardial infarction/atrial fibrillation and Alzheimer's disease: and 3) to uncover the type of studies needed in this field in order to facilitate a more precise algorithm of dementia prevention as well as intervention in demented patients with cardiovascular disease.

Mild cognitive impairment: clinical features and review of screening instruments

Clinical criteria to recognize subjects with cognitive impairment in the pre-dementia stage are becoming available. These are frail subjects, at risk of adverse outcomes, such as death, institutionalization, and functional and cognitive deterioration. Early identification of these subjects has a great importance in order to start rehabilitative or pharmacological interventions that could slow the progression of cognitive impairment, and the onset of disability. In this regard, cognitive screening tests might be helpful in different clinical settings (general practice, acute care, rehabilitation, and nursing home). We describe the most frequent clinical presentations of cognitive impairment in the pre-dementia stage, and review eleven screening tests to provide recommendations on which should be preferred in each setting.

Hypertension in older adults

The high prevalence of hypertension in older persons (nearly one of two subjects aged 60 years and older) suggests that the recognition and treatment should be a priority for physicians. Although diastolic blood pressure is regarded as an important risk factor, it is now clear that isolated systolic hypertension and elevated pulse pressure also play an important role in the development of cerebrovascular disease, congestive heart failure, and coronary heart disease, which are the major causes of cardiovascular morbidity and mortality in the population aged older than 65 years. Controlled, randomized trials have shown that treatment of systolic as well as systolodiastolic hypertension decreases the incidence of cardiovascular and cerebrovascular complications in older adults. The question of whether treatment of hypertension should be maintained in very old persons, those older than 80 years, is still undecided.

How can cerebral infarcts and hemorrhages lead to dementia?

The incidence of new onset dementias is increased after stroke. The objective of this review is to investigate how cerebral infarcts and hemorrhages can lead to dementia. Stroke subtypes, total volume of cerebral lesion and functional tissue loss, and location of the lesions are the major determinant of dementia in stroke patients. The causal relationship between stroke and dementia is clear: (1) in young patients who are unlikely to have associated Alzheimer pathology; (2) when the cognitive functioning was normal before stroke, impaired immediately after, and does not worsen over time; (3) when the lesions are located in strategic areas; and (4) when a well-defined vasculopathy known to be associated with dementia is proven. However, white matter changes and associated Alzheimer pathology may also contribute to the dementia syndrome in stroke patients.

Reliable assessment of the effects of treatment on mortality and major morbidity, I: clinical trials

This two-part review is intended principally for practising clinicians who want to know why some types of evidence about the effects of treatment on survival, and on other major aspects of chronic disease outcome, are much more reliable than others. Although there are a few striking examples of treatments for serious disease which really do work extremely well, most claims for big improvements turn out to be evanescent. Unrealistic expectations about the chances of discovering large treatment effects could misleadingly suggest that evidence from small randomised trials or from non-randomised studies will suffice. By contrast, the reliable assessment of any more moderate effects of treatment on major outcomes--which are usually all that can realistically be expected from most treatments for most common serious conditions--requires studies that guarantee both strict control of bias (which, in general, requires proper randomisation and appropriate analysis, with no unduly data-dependent emphasis on specific parts of the overall evidence) and strict control of random error (which, in general, requires large numbers of deaths or of some other relevant outcome). Past failures to produce such evidence, and to interpret it appropriately, have already led to many premature deaths and much unnecessary suffering.

Apolipoprotein E genotypes and the incidence of Alzheimer's disease among persons aged 75 years and older: variation by use of antihypertensive medication?

The authors examined the impact of the apolipoprotein E (APOE)(*)epsilon4 allele on Alzheimer's disease incidence in relation to use of antihypertensive medication. A population-based (Kungsholmen Project) cohort of 985 nondemented Swedish subjects aged >/=75 years was followed for an average of 3 years (1990-1992); 164 dementia (122 Alzheimer's disease) cases were identified. Compared with (*)epsilon3/(*)epsilon3, the APOE(*)epsilon4 allele increased the risk of developing dementia (relative risk (RR) = 1.5, 95% confidence interval (CI): 1.1, 2.1) and Alzheimer's disease (RR = 1.7, 95% CI: 1.2, 2.5). Subjects using antihypertensive medication at baseline (n = 432, 80% used diuretics) had a decreased risk of dementia (RR = 0.6, 95% CI: 0.5, 0.9) and Alzheimer's disease (RR = 0.5, 95% CI: 0.3, 0.8) after adjustment for several variables, including APOE. The effect of antihypertensive medication use was more pronounced among (*)epsilon4 carriers. For those not using antihypertensive medication, the relative risks of dementia and Alzheimer's disease for carriers were 2.2 (95% CI: 1.4, 3.4) and 2.3 (95% CI: 1.4, 3.7), respectively. The corresponding relative risks for those using antihypertensive medication were 0.9 (95% CI: 0.5, 1.6) and 1.1 (95% CI: 0.6, 2.2). The APOE(*)epsilon4 allele is an important predictor of dementia and Alzheimer's disease incidence. Further studies are needed to clarify whether use of antihypertensive medication, especially diuretics, modifies the effect of the allele.

Rational pharmacotherapy of hypertension in the elderly: analysis of the choice and dosage of drugs

OBJECTIVES

To determine in older people with uncomplicated hypertension: (a) the pattern of prescribing of antihypertensives; (b) the extent of physicians' adherence to recommendations on dosage for antihypertensive combinations; (c) whether prescribing practice conforms with recommended therapeutic guidelines; and (d) the frequency of prescribing of other drugs which have the potential to alter the efficacy of antihypertensive agents.

METHODS

A survey of prescribing in older patients with uncomplicated hypertension in primary care setting of Bahrain was conducted.

RESULTS

Of the 432 (56.5%) patients on monotherapy, 192 (44.4%) were treated with beta-blockers, 87 (20.1%) with calcium channel blockers (CCBs), 53 (12.3%) with alpha-methyldopa, 47 (10.9%) with diuretics, 46 (10.6%) with angiotensin converting enzyme (ACE) inhibitors, and 7 (1.6%) with hydralazine. Of the 1146 patients on mono- or combination therapies, 434 (56.8%) were treated with beta-blockers, 244 (31.9%) with diuretics, 211 (27.6%) with CCBs, 139 (18.2%) with ACE inhibitors, 103 (13.5%) with alpha-methyldopa 8 (1.0%) with brinerdine and 7 (0.9%) with hydralazine. In the 332 (43.5%) patients on combination therapy, 15 different two- and three-antihypertensive drug combinations were prescribed: a diuretic with a beta-blocker (37.2%) and a beta-blocker with either a CCB (20.9%) or an ACE inhibitor (12.4%) were the most popular two-drug regimens. The most commonly prescribed triple drug regimens were a diuretic and a beta-blocker plus either a CCB (26.1%) or an ACE inhibitor (17.4%) and diuretic plus an ACE inhibitor and a CCB (15.2%). Daily dosage of beta-blockers, ACE inhibitors and alpha-methyldopa were somewhat high in a considerable proportion of patients on both mono- and combined therapies. A substantial proportion (9.7%) of patients on monotherapy were treated with immediate release nifedipine.

CONCLUSION

The pharmacotherapy of hypertension in elderly patients was found in some instances not to conform to recommended guidelines. For certain classes of antihypertensive agent such as beta-blockers, ACE inhibitors and alpha-methyldopa, neither the principles of geriatric pharmacology nor of antihypertensive combination therapy, and in particular, the need to reduce daily dosage, were followed. The use of immediate release nifedipine in the elderly is irrational, and instead, the use of long-acting dihydropyridine CCBs should be considered. The results of long-term randomized clinical trials published during the last decade have had a minimal impact on clinical practice of primary care physicians in Bahrain.

Assessment of suspected dementia

At the Second Canadian Consensus Conference on Dementia (CCCD) (February, 1998), a group of neurologists, geriatricians, and psychiatrists met to consider guidelines for evaluation of dementia in Canada. This review paper formed a background paper for their discussion of dementia diagnosis. These experts from across the country concluded that diagnosis of suspected dementia cases continued to rest on skilled clinical assessment. Mental status exam, preferably in some quantifiable form, has become an essential part of the assessment. Selected laboratory tests are advisable in all cases (CBC, TSH, electrolytes, calcium, and glucose), but the CCCD continued to advise that CT scanning was mandatory only in selected cases where clinical findings pointed to another possibility besides Alzheimer's disease. The growing list of other diagnostic measures with potential usefulness in diagnosis of Alzheimer's disease or dementia in general was reviewed, but the evidence was judged as insufficient to support routine use of these tests by physicians. As new treatments for Alzheimer's disease become available, neurologists face new diagnostic challenges--differentiating Mild Cognitive Impairment, Frontotemporal dementias and Mixed dementias, and Lewy Body Dementia. Guidelines to aid in differential diagnosis are presented.

The recognition, assessment and management of dementing disorders: conclusions from the Canadian Consensus Conference on Dementia

OBJECTIVE

i) To develop evidence based consensus statements on which to build clinical practice guidelines for primary care physicians towards the recognition, assessment and management of dementing disorders; ii) to disseminate and evaluate the impact of these statements and guidelines built on these statements.

OPTIONS

Structured approach to assessment, including recommended laboratory tests, choices for neuroimaging and referral; management of complications (especially behaviour problems and depression) and use of cognitive enhancing agents. POTENTIAL OUTCOMES: Consistent and improved clinical care of persons with dementia; cost containment by more selective use of laboratory investigations, neuroimaging and referrals; appropriate use of cognitive enhancing agents.

EVIDENCE

Authors of each background paper were entrusted to: perform a literature search, discover additional relevant material including references cited in retrieved articles; consult with other experts in the field and then synthesize information. Standard rules of evidence were applied. Based upon this evidence, consensus statements were developed by a group of experts, guided by a steering committee of eight individuals from the areas of Neurology, Geriatric Medicine, Psychiatry, Family Medicine, Preventive Health Care and Health Care Systems.

VALUES

Recommendations have been developed with particular attention to the context of primary care and are intended to support family physicians in their ongoing assessment and care of patients with dementia.

BENEFITS, HARMS AND COSTS

Potential for improved clinical care of individuals with dementia. A dissemination and evaluation strategy will attempt to measure the impact of the recommendations.

RECOMMENDATIONS

See text.

VALIDATION

Four other sets of consensus statements and/or guidelines have been published recently. These recommendations are generally congruent with our own consensus statements. The consensus statements have been endorsed by relevant bodies in Canada.

Preventing dementia

Primary prevention will become increasingly important as dementia prevalence increases and effective retardive therapies are developed. To date, only one randomized controlled trial (involving treatment of systolic hypertension) has demonstrated that the incidence of dementia can be reduced. Physicians should remain alert to possible secondary causes of dementia and correct these whenever possible. Primary and secondary prevention of stroke should reduce dementia related to cerebrovascular disease either directly or as a comorbid factor in Alzheimer's disease (AD). Epidemiological studies have revealed a number of risk factors for AD including genetic mutation, susceptibility genes, positive family history, Down's syndrome, age, sex, years of education, head trauma and neurotoxins. In case-control studies non-steroidal anti-inflammatory medication and estrogen replacement therapy appear to decrease the relative risk of developing AD. Further research to develop and test preventative therapies in AD and other dementias should be strongly encouraged.

Dementia and disability outcomes in large hypertension trials: lessons learned from the systolic hypertension in the elderly program (SHEP) trial

In the Systolic Hypertension in the Elderly Program (SHEP) trial (1985-1990), active treatment reduced the incidence of cardiovascular events, but not that of dementia and disability, as compared with placebo. This study aims to evaluate if assessment of cognitive and functional outcomes was biased by differential dropout. Characteristics of subjects who did or did not participate in follow-up cognitive and functional evaluations were compared. The relative risks of incident cognitive impairment and disability were assessed in the two treatment groups, with the use of the reported findings and under the assumption that the proportions of cognitive and functional impairment among dropouts increased. Assignment to the placebo group and the occurrence of cardiovascular events independently predicted missed assessments. From the reported findings, the risk of cognitive and functional impairment was similar between the two treatment groups. However, when 20-30% and 40-80% of the subjects who missed the assessment were assumed to be cognitively and, respectively, functionally impaired, assignment to active treatment reduced the risk of these outcomes. In the SHEP, the cognitive and functional evaluations were biased toward the null effect by differential dropout. This might have obscured the appraisal of a protective effect of treatment on the cognitive and functional decline of older hypertensive adults.

Alzheimer's disease: current and future therapeutic perspectives

1. A better understanding of the pathophysiology of AD has been made possible through population-based epidemiological studies, human genetic and post-mortem studies, leading to a number of testable hypothesis towards delaying progression. 2. A number of disease milestones have been identified as therapeutic targets, such as conversion from MCI to diagnosable dementia. 3. Clinicians caring for patients with AD have currently available a number of symptomatic drugs, and will have in the future the ability to predict the risk for asymptomatic individuals to develop AD, and provide advice towards prevention.