The evidence for treating hypertension in older people with dementia: a systematic review

Hypertension & dementia: Pathophysiology & potential utility of antihypertensives in reducing disease burden

Dementia is a common cause of disability and dependency among the elderly due to its progressive neurodegenerative nature. As there is currently no curative therapy, it is of major importance to identify new ways to reduce its prevalence. Hypertension is recognised as a modifiable risk factor for dementia, particularly for the two most common subtypes; vascular dementia (VaD) and Alzheimer's disease (AD). From the current literature, identified through a comprehensive literature search of PubMed and Cochrane Library, this review aims to establish the stage in adulthood when hypertension becomes a risk for cognitive decline and dementia, and whether antihypertensive treatment is effective as a preventative therapy. Observational studies generally found hypertension in mid-life (age 45-64) to be correlated with an increased risk of cognitive decline and dementia incidence, including both VaD and AD. Hypertension manifesting in late life (age ≥ 65) was demonstrated to be less of a risk, to the extent that incidences of high blood pressure (BP) in the very elderly (age ≥ 75) may even be related to reduced incidence of dementias. Despite the evidence linking hypertension to dementia, there were conflicting findings as to whether the use of antihypertensives was beneficial for its prevention and this conflicting evidence and inconsistent results could be due to the methodological differences between the reviewed observational and randomised controlled trials. Furthermore, dihydropyridine calcium channel blockers and potassium-sparing diuretics were proposed to have neuroprotective properties in addition to BP lowering. Overall, if antihypertensives are confirmed to be beneficial by larger-scale homogenous trials with longer follow-up durations, treatment of hypertension, particularly in mid-life, could be an effective strategy to considerably lower the prevalence of dementia. Furthermore, greater clarification of the neuroprotective properties that some antihypertensives possess will allow for better clinical practice guidance on the choice of antihypertensive class for both BP lowering and dementia prevention.

Differential restoration of functional hyperemia by antihypertensive drug classes in hypertension-related cerebral small vessel disease

Dementia resulting from small vessel diseases (SVDs) of the brain is an emerging epidemic for which there is no treatment. Hypertension is the major risk factor for SVDs, but how hypertension damages the brain microcirculation is unclear. Here, we show that chronic hypertension in a mouse model progressively disrupts on-demand delivery of blood to metabolically active areas of the brain (functional hyperemia) through diminished activity of the capillary endothelial cell inward-rectifier potassium channel, Kir2.1. Despite similar efficacy in reducing blood pressure, amlodipine, a voltage-dependent calcium-channel blocker, prevented hypertension-related damage to functional hyperemia whereas losartan, an angiotensin II type 1 receptor blocker, did not. We attribute this drug class effect to losartan-induced aldosterone breakthrough, a phenomenon triggered by pharmacological interruption of the renin-angiotensin pathway leading to elevated plasma aldosterone levels. This hypothesis is supported by the finding that combining losartan with the aldosterone receptor antagonist eplerenone prevented the hypertension-related decline in functional hyperemia. Collectively, these data suggest Kir2.1 as a possible therapeutic target in vascular dementia and indicate that concurrent mineralocorticoid aldosterone receptor blockade may aid in protecting against late-life cognitive decline in hypertensive patients treated with angiotensin II type 1 receptor blockers.

Blood Pressure Targets for Older Patients-Do Advanced Age and Frailty Really Not Matter?

In 2017, Hypertension Canada removed advanced age and frailty as considerations for caution when deciding on intensive therapy in their guidelines for the diagnosis, risk assessment, prevention, and treatment of hypertension in adults. Dementia is not mentioned. In this commentary, we review why advanced age and frailty were removed, and examine what is currently known about the relationship between hypertension and both incident and prevalent dementia. We make the case that the presence of frailty (especially when severe) and dementia should be considered when deciding on intensive therapy in future iterations of Hypertension Canada guidelines.

Cardiovascular drug use among people with cognitive impairment living in nursing homes in northern Sweden

PURPOSE

The aim of this study was to describe changes in the pattern of cardiovascular agents used in elderly people living in nursing homes between 2007 and 2013. Further, the aim was to analyse the use of cardiovascular drugs in relation to cognitive impairment and associated factors within the same population, where prescription of loop diuretics was used as a proxy for heart failure.

METHODS

Two questionnaire surveys were performed including 2494 people in 2007 and 1654 people in 2013 living in nursing homes in northern Sweden. Data were collected concerning drug use, functioning in activities of daily living (ADL) and cognition, using the Multi-Dimensional Dementia Assessment Scale (MDDAS). The use of different drugs and drug classes among people at four different levels of cognitive function in 2007 and 2013 were compared.

RESULTS

The proportion of people prescribed ASA and diuretics was significantly lower at all four levels of cognitive function in 2013 compared to 2007. Among people prescribed loop diuretics, the use of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (ACEI/ARBs) increased from 37.8 to 45.6%, β-blockers from 36.0 to 41.8% and warfarin from 4.4 to 11.4%. The use of warfarin, ACEI/ARBs, β-blockers and mineralocorticoid receptor antagonists (MRAs) were less common among individuals with more severe cognitive impairment.

CONCLUSION

The results indicate that cardiovascular drug treatment has improved between 2007 and 2013, but there is room for further improvement, especially regarding adherence to guidelines for heart failure. Increasing cognitive impairment had an effect on treatment patterns for heart failure and atrial fibrillation.

Increased mortality and hospital readmission risk in patients with dementia and a history of cardiovascular disease: Results from a nationwide registry linkage study

OBJECTIVE

To evaluate the impact of cardiovascular disease (CVD) on mortality and readmission risk in patients with dementia.

METHODS

Prospective hospital-based cohort of 59 194 patients with dementia admitted to hospital or visiting a day-clinic between 2000 and 2010. Patients were divided in those with and without a history of CVD (ie, previous admission for CVD; coronary heart disease, heart failure, stroke, atrial fibrillation, or other CVD). Absolute mortality risks (ARs), median survival times, and hazard ratios (adjusted for age, sex, and comorbidity) were calculated.

RESULTS

Three-year ARs and HRs were higher, and survival times were shorter among patients visiting a day-clinic with a history of CVD than in those without. The differences were less pronounced for inpatients. Readmission risk was further increased in the presence of CVD in both day clinic and inpatients.

CONCLUSION

Clinicians need to be more aware of worse prognosis of the population with CVD and dementia.

Decline in mortality in patients with dementia: Results from a nationwide cohort of 44 258 patients in the Netherlands during 2000 to 2008

OBJECTIVE

To investigate whether mortality and readmission risk have changed over the last decade.

METHODS

Prospective hospital-based cohort of 44 258 patients with dementia admitted to hospital or visiting a day clinic between 2000 and 2008. Absolute risks (ARs) of 1- and 3-year mortality and 1-year hospital readmission were quantified and stratified by type of care (day clinic or inpatient care). Cox models were used to compare hazard ratios (HRs), adjusted for age, sex, comorbidity, of death, and readmission across the years using 2000 as the reference group.

RESULTS

One-year mortality declined among men visiting a day clinic (AR in 2008 versus 2000: 13.0%, 29.9%; HR 0.41, 95% CI, 0.30-0.55). Among inpatients, these ARs were 48.7%, 53.0% (HR 0.85, 95% CI, 0.77-0.94). Three-year mortality also declined (AR for men visiting a day clinic: 37.5%, 58.4%, HR 0.53, 95% CI, 0.43-0.64; for inpatients: 74.4%, 78.9%, HR 0.80, 95% CI, 0.73-0.88). Whereas 1-year readmission risk decreased among men visiting a day clinic (AR 44.1%, 65.9%, HR 0.52, 95% CI, 0.43-0.63), the risk increased among inpatients (AR 36.9%, 27.6%, HR 1.48, 95% CI, 1.28-1.72).

CONCLUSION

One- and 3-year mortality remarkably declined. One-year hospital readmission risk increased among inpatients and decreased among patients visiting a day clinic. The results should raise awareness for the increased survival with dementia, as this has direct consequences for patients and (in)formal caregivers, and probably also for health care costs.

Management of hypertension in older people

INTRODUCTION

As the population ages, the prevalence of hypertension is increasing. Treatment of hypertension is associated with a reduction in cardiovascular risk. However, the optimal blood pressure targets in older people are not clearly defined due to paucity of randomised clinical trials specific to this age group.

AREAS COVERED

We performed a Medline and Embase search from 1998 to present for articles on the management of hypertension in older people published in English language.

EXPERT COMMENTARY

The recent guidelines have suggested a lower blood pressure target of less than 130/80 mmHg. Due to the heterogeneity of older people, this universal low target may not be applicable to all of them. Targets based on functional level rather than chronological age are more appropriate. Special considerations in older people such as increased prevalence of frailty, falls, dementia, polypharmacy and the predominance of isolated systolic hypertension should also be taken into account. Tighter control, if well tolerated, is suitable for the fit person but relaxed targets are more reasonable in individuals with physical or cognitive decline. Therefore, in older people, targets should be individualised putting quality, rather than quantity, of life at the heart of their care plans.

Cerebral Hemodynamics in Mild Cognitive Impairment: A Systematic Review

BACKGROUND

The incidence of dementia is projected to rise over the coming decades, but with no sensitive diagnostic tests available. Vascular pathology precedes the deposition of amyloid and is an attractive early target.

OBJECTIVE

The aim of this review was to investigate the use of cerebral hemodynamics and oxygenation as a novel biomarker for mild cognitive impairment (MCI), focusing on transcranial Doppler ultrasonography (TCD) and near-infrared spectroscopy (NIRS).

METHODS

2,698 articles were identified from Medline, Embase, PsychINFO, and Web of Science databases. 306 articles were screened and quality assessed independently by two reviewers; 26 met the inclusion criteria. Meta-analyses were performed for each marker with two or more studies and limited heterogeneity.

RESULTS

Eleven studies were TCD, 8 NIRS, 5 magnetic resonance imaging, and 2 positron/single photon emission tomography. Meta-analyses showed reduced tissue oxygenation index, cerebral blood flow and velocity, with higher pulsatility index, phase and cerebrovascular resistance in MCI compared to controls. The majority of studies found reduced CO2 reactivity in MCI, with mixed findings in neuroactivation studies.

CONCLUSION

Despite small sample sizes and heterogeneity, meta-analyses demonstrate clear abnormalities in cerebral hemodynamic and oxygenation parameters, even at an early stage of cognitive decline. Further work is required to investigate the use of cerebral hemodynamic and oxygenation parameters as a sensitive biomarker for dementia.

Withdrawal of antihypertensive medication: a systematic review

: Although antihypertensive medication is usually continued indefinitely, observations during wash-out phases in hypertension trials have shown that withdrawal of antihypertensive medication might be well tolerated to do in a considerable proportion of people. A systematic review was completed to determine the proportion of people remaining normotensive for 6 months or longer after cessation of antihypertensive therapy and to investigate the safety of withdrawal. The mean proportion adjusted for sample size of people remaining below each study's threshold for hypertension treatment was 0.38 at 6 months [95% confidence interval (CI) 0.37-0.49; 912 participants], 0.40 at 1 year (95% CI 0.40-0.40; 2640 participants) and 0.26 at 2 years or longer (95% CI 0.26-0.27; 1262 participants). Monotherapy, lower blood pressure before withdrawal and body weight were reported as predictors for successful withdrawal. Adverse events were more common in those who withdrew but were minor and included headache, joint pain, palpitations, oedema and a general feeling of being unwell. Prescribers should consider offering patients with well controlled hypertension a trial of withdrawal of antihypertensive treatment with subsequent regular blood pressure monitoring.

New horizons: the management of hypertension in people with dementia

The optimal management of hypertension in people with dementia is uncertain. This review explores if people with dementia experience greater adverse effects from antihypertensive medications, if cognitive function is protected or worsened by controlling blood pressure (BP) and if there are subgroups of people with dementia for whom antihypertensive therapy is more likely to be harmful. Robust evidence is scant, trials of antihypertensive medications have generally excluded those with dementia. Observational data show changes in risk association over the life course, with high BP being a risk factor for cognitive decline in mid-life, while low BP is predictive in later life. It is therefore possible that excessive BP lowering in older people with dementia might harm cognition. From the existing literature, there is no direct evidence of benefit or harm from treating hypertension in people with dementia. So what practical steps can the clinician take? Assess capacity, establish patient preferences when making treatment decisions, use ambulatory monitoring to thoroughly assess BP, individualise and consider deprescribing where side effects (e.g. hypotension) outweigh the benefits. Future research might include pragmatic randomised trials of targeted deprescribing, which include patient-centred outcome measures to help support decision-making and studies to address mechanistic uncertainties.

Antihypertensive withdrawal for the prevention of cognitive decline

BACKGROUND

Clinical trials and observational data have variously shown a protective, harmful or neutral effect of antihypertensives on cognitive function. In theory, withdrawal of antihypertensives could improve cerebral perfusion and reduce or delay cognitive decline. However, it is also plausible that withdrawal of antihypertensives may have a detrimental effect on cognition through increased incidence of stroke or other vascular events.

OBJECTIVES

To assess the effects of complete withdrawal of at least one antihypertensive medication on incidence of dementia, cognitive function, blood pressure and other safety outcomes in cognitively intact and cognitive impaired adults.

SEARCH METHODS

We searched ALOIS, the specialised register of the Cochrane Dementia and Cognitive Improvement Group, with additional searches conducted in MEDLINE, Embase, PsycINFO, CINAHL, LILACS, Web of Science Core Collection, ClinicalTrials.gov and the World Health Organization Portal/ICTRP on 12 December 2015. There were no language or date restrictions applied to the electronic searches, and no methodological filters were used to restrict the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and controlled clinical trials (CCTs) provided they compared withdrawal of antihypertensive medications with continuation of the medications and included an outcome measure assessing cognitive function or a clinical diagnosis of dementia. We included studies with healthy participants, but we also included studies with participants with all grades of severity of existing dementia or cognitive impairment.

DATA COLLECTION AND ANALYSIS

Two review authors examined titles and abstracts of citations identified by the search for eligibility, retrieving full texts where needed to identify studies for inclusion, with any disagreement resolved by involvement of a third author. Data were extracted independently on primary and secondary outcomes. We used standard methodological procedures expected by Cochrane.The primary outcome measures of interest were changes in global and specific cognitive function and incidence of dementia; secondary outcomes included change in systolic and diastolic blood pressure, mortality, adverse events (including cardiovascular events, hospitalisation and falls) and adherence to withdrawal. The quality of the evidence was evaluated using the GRADE approach.

MAIN RESULTS

We included two RCTs investigating withdrawal of antihypertensives in 2490 participants. There was substantial clinical heterogeneity between the included studies, therefore we did not combine data for our primary outcome. Overall, the quality of included studies was high and the risk of bias was low. Neither study investigated incident dementia.One study assessed withholding previously prescribed antihypertensive drugs for seven days following acute stroke. Cognition was assessed using telephone Mini-Mental State Examination (t-MMSE) and Telephone Interview for Cognitive Status (TICS-M) at 90 days as a secondary outcome. The t-MMSE score was a mean of 1.0 point higher in participants who withdrew antihypertensive medications compared to participants who continued them (95% confidence interval (CI) 0.35 to 1.65; 1784 participants) and the TICS-M was a mean of 2.10 points higher (95% CI 0.69 to 3.51; 1784 participants). However, in both cases the evidence was of very low quality downgraded due to risk of bias, indirectness and evidence from a single study. The other study was community based and included participants with mild cognitive impairment. Drug withdrawal was for 16 weeks. Cognitive performance was assessed using a composite of at least five out of six cognitive tests. There was no evidence of a difference comparing participants who withdrew antihypertensive medications and participants who continued (mean difference 0.02 points, 95% CI -0.19 to 0.21; 351 participants). This evidence was of low quality and was downgraded due to risk of bias and evidence from single study.In one study, the systolic blood pressure after seven days of withdrawal was 9.5 mmHg higher in the intervention compared to the control group (95% CI 7.43 to 11.57; 2095 participants) and diastolic blood pressure was 5.1 mmHg higher (95% CI 3.86 to 6.34; 2095 participants). This evidence was low quality, downgraded due to indirectness, because the data must be interpreted in the context of the wider study looking at glyceryl trinitrate administration or not, and evidence from a single study. In the other study, systolic blood pressure increased by 7.4 mmHg in the withdrawal group compared to the control group (95% CI 7.08 to 7.72; 356 participants) and diastolic blood pressure increased by 2.6 mmHg (95% CI 2.42 to 2.78; 356 participants). This was moderate quality evidence, downgraded as evidence was from a single study. We combined data for mortality and cardiovascular events. There was no clear evidence that antihypertensive medication withdrawal affected adverse events, although there was a possible trend to increased cardiovascular events in the large post-stroke study (pooled mortality risk ratio 0.88, 95% CI 0.72 to 1.08; 2485 participants; and cardiovascular events risk ratio 1.29, 95% CI 0.96 to 1.72). Certain prespecified outcomes of interest (falls, hospitalisation) were not reported.

AUTHORS' CONCLUSIONS

The effects of withdrawing antihypertensive medications on cognition or prevention of dementia are uncertain. There was a signal of a positive effect in one study looking at withdrawal after acute stroke but these results are unlikely to be generalisable to non-stroke settings and were not a primary outcome of the study. Withdrawing antihypertensive drugs was associated with increased blood pressure. It is unlikely to increase mortality at three to four months' follow-up, although there was a signal from one large study looking at withdrawal after stroke that withdrawal was associated an increase in cardiovascular events.

The association between SBP and mortality risk differs with level of cognitive function in very old individuals

Objective:

Cognitive impairment and dementia are highly prevalent in very old populations. Cardiovascular disease is a common cause of death in people with dementia.

This study investigated whether the association of blood pressure (BP) with mortality differed with respect to mini-mental state examination (MMSE) score in a representative sample of very old individuals.

Methods:

The sample consisted of 1115 participants aged 85, 90, and at least 95 years from the Umeå85+/GErontological Regional DAtabase cohort study. The main outcome was all-cause mortality within 2 years according to BP and MMSE score, using Cox proportional-hazard regression models adjusted for sociodemographic and clinical characteristics associated with death.

Results:

Mean age, MMSE score, and SBP and DBP were 89.4 ± 4.6 years, 21.1 ± 7.6, 146.1 ± 23.4 mmHg, and 74.1 ± 11.7 mmHg, respectively. Within 2 years, 293 (26%) participants died. BP was not associated independently with mortality risk, except among participants with MMSE scores of 0–10 among whom mortality risk was increased in association with SBP at least 165 mmHg and 125 mmHg or less, compared with 126–139 mmHg (adjusted hazard ratio 4.54, 95% confidence interval = 1.52–13.60 and hazard ratio 2.23, 95% confidence interval = 1.12–4.45, respectively). In age and sex-adjusted analyses, SBP 125 mmHg or less was associated with increased mortality risk in participants with MMSE scores at least 18.

Conclusion:

In people aged at least 85 years, the association of SBP with mortality appears to differ with respect to MMSE score. Very old individuals with very severe cognitive impairment and low or high BP may have increased mortality risk.

Blood Pressure and All-Cause Mortality by Level of Cognitive Function in the Elderly: Results From a Population-Based Study in Rural Greece

This study aimed to investigate whether the effect of blood pressure (BP) on mortality differs by levels of cognitive function. The associations of brachial systolic BP, diastolic BP, mean arterial pressure (MAP), and pulse pressure with all-cause mortality were prospectively explored (follow-up 7.0±2.2 years) in 660 community-dwelling individuals (≥60 years) using adjusted Cox models, stratified by cognitive impairment (Mini-Mental State Examination [MMSE] <24). No association between brachial BP variables and mortality was shown for the total sample in quartiles analysis; however, MAP in the highest quartile, compared with the second, was associated with mortality (hazard ratio, 1.85; 95% confidence intervals, 1.09-3.12) among cognitively impaired individuals. The fractional-polynomials approach for BP confirmed this finding and further showed, solely in the MMSE <24 subcohort, U-shaped trends of MAP and systolic BP, with increased mortality risk in extremely low or high values; no such pattern was evident for patients with MMSE ≥24. Elderly individuals with cognitive impairment might be more susceptible to the detrimental effects of low and elevated MAP and systolic BP.

p38 MAPK Inhibition Improves Synaptic Plasticity and Memory in Angiotensin II-dependent Hypertensive Mice

The pathogenesis of hypertension-related cognitive impairment has not been sufficiently clarified, new molecular targets are needed. p38 MAPK pathway plays an important role in hypertensive target organ damage. Activated p38 MAPK was seen in AD brain tissue. In this study, we found that long-term potentiation (LTP) of hippocampal CA1 was decreased, the density of the dendritic spines on the CA1 pyramidal cells was reduced, the p-p38 protein expression in hippocampus was elevated, and cognitive function was impaired in angiotensin II-dependent hypertensive C57BL/6 mice. In vivo, using a p38 heterozygous knockdown mice (p38(KI/+)) model, we showed that knockdown of p38 MAPK in hippocampus leads to the improvement of cognitive function and hippocampal synaptic plasticity in angiotensin II-dependent p38(KI/+) hypertensive mice. In vitro, LTP was improved in hippocampal slices from C57BL/6 hypertensive mice by treatment with p38MAPK inhibitor SKF86002. Our data demonstrated that p38 MAPK may be a potential therapeutic target for hypertension-related cognitive dysfunction.

Blood pressure strategies and goals in elderly patients with hypertension

The growing number of elderly subjects with hypertension in western countries represents a demanding problem to find accurate blood pressure goals with an evidence base for such patients. Previously we did not have enough evidence, but more recently new evidence has accumulated based on data from the HYVET and the SPRINT studies. For most elderly hypertensives a blood pressure goal below 150/90mmHg still seems reasonable, even if a lower goal could be defended based on the recent SPRINT study outcomes. However, the debate on the methodologies for blood pressure measurement in SPRINT is still ongoing and this is why we have to wait until a new recommendation is available. It should not be forgotten that many elderly patients are frail and will therefore not tolerate blood pressure lowering similar to other more fit elderly subjects. This is why an individualised treatment strategy has to be developed for this age group, not to deny the fit elderly the benefits of appropriate blood pressure control, but at the same time avoiding harm and adverse effects in the frail elderly patient.

Comorbidity and dementia: a mixed-method study on improving health care for people with dementia (CoDem)

Background

Among people living with dementia (PLWD) there is a high prevalence of comorbid medical conditions but little is known about the effects of comorbidity on processes and quality of care and patient needs or how services are adapting to address the particular needs of this population.

Objectives

To explore the impact of dementia on access to non-dementia services and identify ways of improving the integration of services for this population.

Design

We undertook a scoping review, cross-sectional analysis of a population cohort database, interviews with PLWD and comorbidity and their family carers and focus groups or interviews with health-care professionals (HCPs). We focused specifically on three conditions: diabetes, stroke and vision impairment (VI). The analysis was informed by theories of continuity of care and access to care.

Participants

The study included 28 community-dwelling PLWD with one of our target comorbidities, 33 family carers and 56 HCPs specialising in diabetes, stroke, VI or primary care.

Results

The scoping review (n = 76 studies or reports) found a lack of continuity in health-care systems for PLWD and comorbidity, with little integration or communication between different teams and specialities. PLWD had poorer access to services than those without dementia. Analysis of a population cohort database found that 17% of PLWD had diabetes, 18% had had a stroke and 17% had some form of VI. There has been an increase in the use of unpaid care for PLWD and comorbidity over the last decade. Our qualitative data supported the findings of the scoping review: communication was often poor, with an absence of a standardised approach to sharing information about a person’s dementia and how it might affect the management of other conditions. Although HCPs acknowledged the vital role that family carers play in managing health-care conditions of PLWD and facilitating continuity and access to care, this recognition did not translate into their routine involvement in appointments or decision-making about their family member. Although we found examples of good practice, these tended to be about the behaviour of individual practitioners rather than system-based approaches; current systems may unintentionally block access to care for PLWD. Pathways and guidelines for our three target conditions do not address the possibility of a dementia diagnosis or provide decision-making support for practitioners trying to weigh up the risks and benefits of treatment for PLWD.

Conclusions

Significant numbers of PLWD have comorbid conditions such as stroke, diabetes and VI. The presence of dementia complicates the delivery of health and social care and magnifies the difficulties that people with long-term conditions experience. Key elements of good care for PLWD and comorbidity include having the PLWD and family carer at the centre, flexibility around processes and good communication which ensures that all services are aware when someone has a diagnosis of dementia. The impact of a diagnosis of dementia on pre-existing conditions should be incorporated into guidelines and care planning. Future work needs to focus on the development and evaluation of interventions to improve continuity of care and access to services for PLWD with comorbidity.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Effect of Vascular Risk Factors and Diseases on Mortality in Individuals with Dementia: A Systematic Review and Meta-Analysis

OBJECTIVES

To assess the effect of cardiovascular diseases and risk factors on mortality in individuals with dementia.

DESIGN

Systematic review and meta-analysis. English- and Dutch-language studies in PubMed, EMBASE, and PsycINFO databases were searched in April 2014 with hand-searching of in-text citations and no publication limitations. Inclusion criteria were original studies reporting on cardiovascular risk factors or diseases and their relationship with survival in individuals with dementia. The Quality In Prognosis Studies tool was used to appraise all included articles.

SETTING

Population-, hospital-, and nursing home-based.

PARTICIPANTS

Community-dwelling, hospitalized individuals and nursing home residents with dementia.

MEASUREMENTS

A random-effects meta-analysis was performed to investigate the effect of several cardiovascular diseases and risk factors on overall mortality.

RESULTS

Twelve studies with 235,865 participants were included. In pooled analyses, male sex (hazard ratio (HR)=1.67, 95% confidence interval (CI)=1.56-1.78), diabetes mellitus (DM) (HR=1.49, 95% CI=1.33-1.68), smoking (ever vs never) (HR=1.37, 95% CI=1.17-1.61), coronary heart disease (CHD) (HR=1.21, 95% CI=1.02-1.44) and congestive heart failure (CHF) (HR=1.37, 95% CI=1.18-1.59) were associated with mortality. Stroke, high blood pressure, being overweight, and hypercholesterolemia were not statistically significantly related to mortality.

CONCLUSION

Individuals with dementia and DM, smoking, CHD, and CHF have a greater risk of death than individuals with dementia without these risk factors or diseases.

Excessive lowering of blood pressure is not beneficial for progression of brain white matter hyperintensive and cognitive impairment in elderly hypertensive patients: 4-year follow-up study

OBJECTIVES

This study was designed to explore the appropriate blood pressure (BP) target required to reduce cognitive decline and brain white matter lesions (WMLs) in elderly hypertensive patients.

METHODS

Elderly patients (n = 294, ≥80 years of age) being treated for hypertension were enrolled in a longitudinal study examining cognitive impairment after an initial assessment and a period of 4 years. All patients underwent neurological and cognitive assessment, laboratory examination, and magnetic resonance imaging of the brain.

RESULTS

The 4-year follow-up examination revealed that body mass index, alcohol consumption, systolic blood pressure (SBP), diastolic blood pressure, and Mini-Mental State Examination (MMSE) all showed a significant decline, whereas fasting plasma glucose, white matter hyperintensities (WMH) volume, and the WMH/total intracranial volume (TIV) ratio were significantly increased when compared with baseline observations. Interestingly, the decline in MMSE, as well as the increment of WMH and WMH/TIV ratio was smaller in patients with SBP ranging from 140 to 160 mm Hg than in those whose SBP was lower than 140 mm Hg or higher than 160 mm Hg (P < .05). Furthermore, we observed that a 15 to 35 mm Hg targeted lowering of SBP in the elderly patients was more beneficial to our cognitive analysis than treatments that achieved less than 15 mm Hg or greater than 35 mm Hg (P < .05).

CONCLUSIONS

In elderly hypertensive patients, there exists a beneficial target for SBP lowering beyond which treatment may not be beneficial for improving or delaying the progression of cognitive impairment and WMLs.

Systemic diseases and oral health

The US population is at the beginning of a significant demographic shift; the American geriatric population is burgeoning, and average longevity is projected to increase in the coming years. Elder adults are affected by numerous chronic conditions, such as diabetes, hypertension, osteoarthritis, osteoporosis, cardiovascular diseases, and cerebrovascular diseases. These older adults need special dental care and an improved understanding of the complex interactions of oral disease and systemic chronic diseases that can complicate their treatment. Oral diseases have strong associations with systemic diseases, and poor oral health can worsen the impact of systemic diseases.

Interactive effects of vascular risk burden and advanced age on cerebral blood flow

Vascular risk factors and cerebral blood flow (CBF) reduction have been linked to increased risk of cognitive impairment and Alzheimer's disease (AD); however the possible moderating effects of age and vascular risk burden on CBF in late life remain understudied. We examined the relationships among elevated vascular risk burden, age, CBF, and cognition. Seventy-one non-demented older adults completed an arterial spin labeling MR scan, neuropsychological assessment, and medical history interview. Relationships among vascular risk burden, age, and CBF were examined in a priori regions of interest (ROIs) previously implicated in aging and AD. Interaction effects indicated that, among older adults with elevated vascular risk burden (i.e., multiple vascular risk factors), advancing age was significantly associated with reduced cortical CBF whereas there was no such relationship for those with low vascular risk burden (i.e., no or one vascular risk factor). This pattern was observed in cortical ROIs including medial temporal (hippocampus, parahippocampal gyrus, uncus), inferior parietal (supramarginal gyrus, inferior parietal lobule, angular gyrus), and frontal (anterior cingulate, middle frontal gyrus, medial frontal gyrus) cortices. Furthermore, among those with elevated vascular risk, reduced CBF was associated with poorer cognitive performance. Such findings suggest that older adults with elevated vascular risk burden may be particularly vulnerable to cognitive change as a function of CBF reductions. Findings support the use of CBF as a potential biomarker in preclinical AD and suggest that vascular risk burden and regionally-specific CBF changes may contribute to differential age-related cognitive declines.