Vascular risk factors and dementia in the general population aged >85 years: prospective population-based study

Ultra-Early Screening of Cognitive Decline Due to Alzheimer's Pathology

Alzheimer's pathology can be assessed and defined via Aβ and tau biomarkers. The preclinical period of Alzheimer's disease is long and lasts several decades. Although effective therapies to block pathological processes of Alzheimer's disease are still lacking, downward trends in the incidence and prevalence of dementia have occurred in developed countries. Accumulating findings support that education, cognitive training, physical exercise/activities, and a healthy lifestyle can protect cognitive function and promote healthy aging. Many studies focus on detecting mild cognitive impairment (MCI) and take a variety of interventions in this stage to protect cognitive function. However, when Alzheimer's pathology advances to the stage of MCI, interventions may not be successful in blocking the development of the pathological process. MCI individuals reverting to normal cognitive function exhibited a high probability to progress to dementia. Therefore, it is necessary to take effective measures before the MCI stage. Compared with MCI, an earlier stage, transitional cognitive decline, may be a better time window in which effective interventions are adopted for at-risk individuals. Detecting this stage in large populations relies on rapid screening of cognitive function; given that many cognitive tests focus on MCI detection, new tools need to be developed.

Dementia and Related Comorbidities in the Population Aged 90 and Over in the Vitality 90+ Study, Finland: Patterns and Trends From 2001 to 2018

OBJECTIVES

To examine trends in the prevalence of dementia and related comorbidities among the oldest old.

METHODS

Six repeated cross-sectional surveys were conducted between 2001 and 2018, each including all inhabitants aged over 90 in Tampere, Finland (n = 5386). Co-occurring conditions and their time trends among participants with dementia were examined using logistic regression and generalized estimating equations.

RESULTS

The prevalence of dementia decreased from 47% in 2007 to 41% in 2018. Throughout the study period, depression was more common among people with dementia compared to those without. The prevalence of hypertension, diabetes, and osteoarthritis increased and the prevalence of depression decreased among people with dementia. The mean number of comorbidities increased from 2.0 in 2001 to 2.3 in 2018.

DISCUSSION

Dementia remains highly prevalent among the oldest old and it is accompanied by an increasing burden of comorbidities, posing a challenge to people with dementia, their caregivers, and care systems.

Neurodegenerative diseases and blood pressure variability: A comprehensive review from HOPE Asia

Asia has an enormous number of older people and is the primary contributor to the rise in neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The therapy of many neurodegenerative diseases has not yet progressed to the point where it is possible to alter the course of the disease. Mid-life hypertension is an important predictor of later-life cognitive impairment and brain neurodegenerative conditions. These findings highlight the pivotal role of preventing and managing hypertension as a risk factor for neurodegenerative disease. Autonomic dysfunction, neuropsychiatric and sleep disturbances can arise in neurodegenerative diseases, resulting in blood pressure variability (BPV). The BPV itself can worsen the progression of the disease. In older people with neurodegenerative disease and hypertension, it is critical to consider 24-h blood pressure monitoring and personalized blood pressure therapy.

Dendritic Spines: Mediators of Cognitive Resilience in Aging and Alzheimer's Disease

Cognitive resilience is often defined as the ability to remain cognitively normal in the face of insults to the brain. These insults can include disease pathology, such as plaques and tangles associated with Alzheimer's disease, stroke, traumatic brain injury, or other lesions. Factors such as physical or mental activity and genetics may contribute to cognitive resilience, but the neurobiological underpinnings remain ill-defined. Emerging evidence suggests that dendritic spine structural plasticity is one plausible mechanism. In this review, we highlight the basic structure and function of dendritic spines and discuss how spine density and morphology change in aging and Alzheimer's disease. We note evidence that spine plasticity mediates resilience to stress, and we tackle dendritic spines in the context of cognitive resilience to Alzheimer's disease. Finally, we examine how lifestyle and genetic factors may influence dendritic spine plasticity to promote cognitive resilience before discussing evidence for actin regulatory kinases as therapeutic targets for Alzheimer's disease.

Modifiable Risk Factors and Change in Cognition of Māori and Non-Māori in Advanced Age: LiLACS NZ

OBJECTIVE

This study investigated whether previously identified modifiable risk factors for dementia were associated with cognitive change in Māori (indigenous people of New Zealand) and non-Māori octogenarians of LiLACS NZ (Life and Living in Advanced Age; a Cohort Study in New Zealand), a longitudinal study.

METHOD

Multivariable repeated-measure mixed effect regression models were used to assess the association between modifiable risk factors and sociodemographic variables at baseline, and cognitive change over 6 years, with p values of <.05 regarded as statistically significant.

RESULTS

Modifiable factors associated with cognitive change differed between ethnic groups. Depression was a negative factor in Māori only, secondary education in non-Māori was protective, and obesity predicted better cognition over time for Māori. Diabetes was associated with decreased cognition for both Māori and non-Māori.

CONCLUSION

Our results begin to address gaps in the literature and increase understanding of disparities in dementia risk by ethnicity. These findings have implications for evaluating the type and application of culturally appropriate methods to improve cognition.

The Effects of Cardiovascular Risk Factors on Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Performance in Cognitively Healthy Older Adults

OBJECTIVE

The current study investigated the differential impact cardiovascular risk factors (CVRFs) on Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) performance in a large, cognitively healthy, older adult sample across 4 years.

METHOD

Participants were 486 individuals recruited through a longitudinal aging research study in the southeastern United States. Participants were 69.3% female, an average of 69.96 years old (SD = 6.58), 16.32 years of education (SD = 2.27), and Mini-Mental Status Exam score of 29.12 (SD = 1.16). Participants completed the RBANS at baseline and yearly thereafter, as well as the Uniform Data Set demographic and health questionnaires and the Geriatric Depression Scale.

RESULTS

Multilevel modeling was conducted using standardized RBANS index scores. Overall, across indices, performance generally improved across time consistent with practice effects from repeated testing. Some CVRFs were associated with worse performance over time. For example, individuals with hypertension performed more poorly on immediate memory over time (t = -2.06, p < .05). Other CVRFs (e.g., BMI) were not associated with baseline performance or performance over time. (p > .05).

CONCLUSIONS

CVRFs differentially affect RBANS performance over time. These results extend previous cross-sectional findings regarding the impact of different cardiovascular health risks to a large, cognitively healthy, longitudinal sample.

Television Viewing and Cognitive Dysfunction of Korean Older Adults

This study examined the association between television (TV) viewing and cognitive dysfunction in elderly Koreans. Among participants of the 2014 National Survey of Older Koreans, 9644 were considered in this study. To better identify the association between two factors, propensity score (PS) matching with exact method was used. Finally, 168 viewers and non-viewers each were selected based on estimated PS on key variables and eliminating double matches. Multivariate logistic regression analysis was performed when controlling for possible covariates. Viewers were more likely to have cognitive dysfunction than non-viewers, with significant differences in most covariates. After correcting confounding effects of these covariates with PS matching, TV viewing was found to be a significant risk factor of cognitive dysfunction, along with absence of diagnosed hypertension and non-participation in physical leisure activities. TV viewing might be associated with increased risk of cognitive dysfunction in later life. Appropriate education and strategies to minimize TV viewing among older adults should be established to contribute to attenuating cognitive aging. More interventional studies can help older adults, caregivers, and healthcare professionals explore the cognitively beneficial alternatives to TV use considering the impact of socioeconomic factors of selecting TV viewing as a preferred leisure activity.

Association of Angiotensin II-Stimulating Antihypertensive Use and Dementia Risk: Post Hoc Analysis of the PreDIVA Trial

OBJECTIVE

To assess whether angiotensin II-stimulating antihypertensives (thiazides, dihydropyridine calcium channel blockers, and angiotensin I receptor blockers) convey a lower risk of incident dementia compared to angiotensin II-inhibiting antihypertensives (angiotensin-converting enzyme inhibitors, β-blockers, and nondihydropyridine calcium channel blockers), in accordance with the "angiotensin hypothesis."

METHODS

We performed Cox regression analyses of incident dementia (or mortality as competing risk) during 6-8 years of follow-up in a population sample of 1,909 community-dwelling individuals (54% women) without dementia, aged 70-78 (mean 74.5 ± 2.5) years.

RESULTS

After a median of 6.7 years of follow-up, dementia status was available for 1,870 (98%) and mortality for 1,904 (>99%) participants. Dementia incidence was 5.6% (27/480) in angiotensin II-stimulating, 8.2% (59/721) in angiotensin II-inhibiting, and 6.9% (46/669) in both antihypertensive type users. Adjusted for dementia risk factors including blood pressure and medical history, angiotensin II-stimulating antihypertensive users had a 45% lower incident dementia rate (hazard ratio [HR], 0.55; 95% CI, 0.34-0.89) without excess mortality (HR, 0.86; 95% CI, 0.64-1.16), and individuals using both types had a nonsignificant 20% lower dementia rate (HR, 0.80; 95% CI,0.53-1.20) without excess mortality (HR, 0.97; 95% CI, 0.76-1.24), compared to angiotensin II-inhibiting antihypertensive users. Results were consistent for subgroups based on diabetes and stroke history, but may be specific for individuals without a history of cardiovascular disease.

CONCLUSIONS

Users of angiotensin II-stimulating antihypertensives had lower dementia rates compared to angiotensin II-inhibiting antihypertensive users, supporting the angiotensin hypothesis. Confounding by indication must be examined further, although subanalyses suggest this did not influence results. If replicated, dementia prevention could become a compelling indication for older individuals receiving antihypertensive treatment.

Serum homocysteine and risk of dementia in Japan

OBJECTIVE

To examine the association between serum total homocysteine levels (tHcy) and dementia risk.

METHODS

A total of 1588 Japanese adults aged ≥60 years without dementia were prospectively followed from 2002 to 2012. Cox proportional hazards models and restricted cubic splines were used to estimate the HRs of tHcy levels on the risk of dementia.

RESULTS

During the follow-up, 372 subjects developed all-cause dementia; 247 had Alzheimer's disease (AD) and 98 had vascular dementia (VaD). Compared with the lowest tHcy quintile (≤6.4 µmol/L), the multivariable-adjusted HRs (95% CI) of the highest quintile (≥11.5 µmol/L) were 2.28 (1.51-3.43) for all-cause dementia, 1.96 (1.19-3.24) for AD and 2.51 (1.14-5.51) for VaD. In restricted cubic splines, the risk of all-cause dementia steadily increased between approximately 8-15 µmol/L and plateaued thereafter, with a similar non-linear shape observed for AD and VaD (all p for non-linearity ≤0.02). In stratified analyses by the most recognised genetic polymorphism affecting tHcy concentrations (methylenetetrahydrofolate reductase C677T), the positive association of tHcy with all-cause dementia persisted in both non-carriers and carriers of the risk allele, and even tended to be stronger in the former (p for heterogeneity=0.07).

CONCLUSION

High serum tHcy levels are associated with an elevated risk of dementia, AD and VaD in a non-linear manner, such that an exposure-response association is present only within a relatively high range of tHcy levels. Non-genetic factors affecting serum tHcy concentrations may play important roles in tHcy-dementia associations irrespective of the genetic susceptibility for raised tHcy.

High blood pressure in dementia: How low can we go?

Hypertension is an important public health concern. The prevalence keeps increasing, and it is a risk factor for several adverse health outcomes including a decline in cognitive function. Recent data also show that the prevalence of hypertension and age-related dementia is rising in Asian countries, including in the oldest old group. This study aims to discuss possible treatments for high blood pressure in the elderly and propose an optimal target for BP relative to cognitive outcomes. This review discusses several studies on related blood pressure treatments that remain controversial and the consequences if the treatment target is too low or aggressive. Longitudinal, cross-sectional, and RCT studies were included in this review. An optimum systolic blood pressure of 120-130 mm Hg is recommended, especially in nondiabetic hypertensive patients with significant risk factors. In the oldest old group of patients, hypertension might have a protective effect. The use of calcium channel blockers (CCB) and angiotensin receptor blocker (ARB) is independently associated with a decreased risk of dementia in older people. However, personalized care for patients with hypertension, especially for patients who are frail or very old, is encouraged.

Sweet Mitochondria: A Shortcut to Alzheimer's Disease

A growing body of evidence supports a clear association between Alzheimer's disease and diabetes and several mechanistic links have been revealed. This paper is mainly devoted to the discussion of the role of diabetes-associated mitochondrial defects in the pathogenesis of Alzheimer's disease. The research experience and views of the author on this subject will be highlighted.

Is There a Link Between Cognitive Reserve and Cognitive Function in the Oldest-Old?

Background

The oldest-old (aged ≥85 years) are the fastest growing age group, with the highest risk of cognitive impairment and dementia. This study investigated whether cognitive reserve applies to the oldest-old. This has implications for cognitive interventions in this age group.

Methods

Baseline and 5-year follow-up data from the Newcastle 85+ Study were used (N = 845, mean age = 85.5, 38% male). A Cognitive Reserve Index (CRI) was created, including: education, social class, marital status, engagement in mental activities, social participation, and physical activity. Global (Mini-Mental State Examination) and domain specific (Cognitive Drug Research Battery subtests assessing memory, attention, and speed) cognitive functions were assessed. Dementia diagnosis was determined by health records. Logistic regression analysis examined the association between CRI scores and incident dementia. Mixed effects models investigated baseline and longitudinal associations between the CRI scores and cognitive function. Analyses controlled for sex, age, depression, and cardiovascular disease history.

Results

Higher reserve associated with better cognitive performance on all baseline measures, but not 5-year rate of change. The CRI associated with prevalent, but not incident dementia.

Conclusions

In the oldest-old, higher reserve associated with better baseline global and domain-specific cognitive function and reduced risk of prevalent dementia; but not cognitive decline or incident dementia. Increasing reserve could promote cognitive function in the oldest-old. The results suggest there would be little impact on trajectories, but replication is needed. Development of preventative strategies would benefit from identifying the role of each factor in building reserve and why rate of change is not affected.

Prediction models for dementia and neuropathology in the oldest old: the Vantaa 85+ cohort study

Background

We developed multifactorial models for predicting incident dementia and brain pathology in the oldest old using the Vantaa 85+ cohort.

Methods

We included participants without dementia at baseline and at least 2 years of follow-up (N = 245) for dementia prediction or with autopsy data (N = 163) for pathology. A supervised machine learning method was used for model development, considering sociodemographic, cognitive, clinical, vascular, and lifestyle factors, as well as APOE genotype. Neuropathological assessments included β-amyloid, neurofibrillary tangles and neuritic plaques, cerebral amyloid angiopathy (CAA), macro- and microscopic infarcts, α-synuclein pathology, hippocampal sclerosis, and TDP-43.

Results

Prediction model performance was evaluated using AUC for 10 × 10-fold cross-validation. Overall AUCs were 0.73 for dementia, 0.64–0.68 for Alzheimer’s disease (AD)- or amyloid-related pathologies, 0.72 for macroinfarcts, and 0.61 for microinfarcts. Predictors for dementia were different from those in previous reports of younger populations; for example, age, sex, and vascular and lifestyle factors were not predictive. Predictors for dementia versus pathology were also different, because cognition and education predicted dementia but not AD- or amyloid-related pathologies. APOE genotype was most consistently present across all models. APOE alleles had a different impact: ε4 did not predict dementia, but it did predict all AD- or amyloid-related pathologies; ε2 predicted dementia, but it was protective against amyloid and neuropathological AD; and ε3ε3 was protective against dementia, neurofibrillary tangles, and CAA. Very few other factors were predictive of pathology.

Conclusions

Differences between predictors for dementia in younger old versus oldest old populations, as well as for dementia versus pathology, should be considered more carefully in future studies.

Electronic supplementary material

The online version of this article (10.1186/s13195-018-0450-3) contains supplementary material, which is available to authorized users.

Resilience to cognitive impairment in the oldest-old: design of the EMIF-AD 90+ study

BACKGROUND

The oldest-old (subjects aged 90 years and older) population represents the fastest growing segment of society and shows a high dementia prevalence rate of up to 40%. Only a few studies have investigated protective factors for cognitive impairment in the oldest-old. The EMIF-AD 90+ Study aims to identify factors associated with resilience to cognitive impairment in the oldest-old. In this paper we reviewed previous studies on cognitive resilience in the oldest-old and described the design of the EMIF-AD 90+ Study.

METHODS

The EMIF-AD 90+ Study aimed to enroll 80 cognitively normal subjects and 40 subjects with cognitive impairment aged 90 years or older. Cognitive impairment was operationalized as amnestic mild cognitive impairment (aMCI), or possible or probable Alzheimer's Disease (AD). The study was part of the European Medical Information Framework for AD (EMIF-AD) and was conducted at the Amsterdam University Medical Centers (UMC) and at the University of Manchester. We will test whether cognitive resilience is associated with cognitive reserve, vascular comorbidities, mood, sleep, sensory system capacity, physical performance and capacity, genetic risk factors, hallmarks of ageing, and markers of neurodegeneration. Markers of neurodegeneration included an amyloid positron emission tomography, amyloid β and tau in cerebrospinal fluid/blood and neurophysiological measures.

DISCUSSION

The EMIF-AD 90+ Study will extend our knowledge on resilience to cognitive impairment in the oldest-old by extensive phenotyping of the subjects and the measurement of a wide range of potential protective factors, hallmarks of aging and markers of neurodegeneration.

TRIAL REGISTRATION

Nederlands Trial Register NTR5867 . Registered 20 May 2016.

Antihypertension drugs in prevention of cognition disorder and dementia: focus on calcium channel blockers and diuretics

Arterial hypertension is associated with elevated risk of cognition decline and vascular dementia development, as the Alzheimer disease development. Therefore, antihypertension therapy might be of preventive value. The review is focused on literary data that witness on, despite controversial, evidence of cerebroprotective action of the range of antihypertension medications. Especially, dihydropyridine calcium antagonists, diuretics and some blockers of renin-angiotensin-aldosterone system. These act not only via blood pressure decrease, but due to additional specific neuroprotective mechanisms. This makes it to consider calcium antagonists and diuretics as a major component of systemic hypertension management, incl. elderly and senile patients, aiming to prevent cognition decline and dementia of various types development.

Nitrendipine, among the calcium channels antagonists, and indapamide among diuretics have acquired the broadest evidence that points on their cerebroprotective properties.

Stroke and dementia risk: A systematic review and meta-analysis

INTRODUCTION

Stroke is an established risk factor for all-cause dementia, though meta-analyses are needed to quantify this risk.

METHODS

We searched Medline, PsycINFO, and Embase for studies assessing prevalent or incident stroke versus a no-stroke comparison group and the risk of all-cause dementia. Random effects meta-analysis was used to pool adjusted estimates across studies, and meta-regression was used to investigate potential effect modifiers.

RESULTS

We identified 36 studies of prevalent stroke (1.9 million participants) and 12 studies of incident stroke (1.3 million participants). For prevalent stroke, the pooled hazard ratio for all-cause dementia was 1.69 (95% confidence interval: 1.49-1.92; P < .00001; I2 = 87%). For incident stroke, the pooled risk ratio was 2.18 (95% confidence interval: 1.90-2.50; P < .00001; I2 = 88%). Study characteristics did not modify these associations, with the exception of sex which explained 50.2% of between-study heterogeneity for prevalent stroke.

DISCUSSION

Stroke is a strong, independent, and potentially modifiable risk factor for all-cause dementia.

Population-based analysis of pathological correlates of dementia in the oldest old

Objective

The aim of this study was to analyze brain pathologies which cause dementia in the oldest old population.

Methods

All 601 persons aged ≥85 years living in the city of Vantaa (Finland), on April 1st, 1991 formed the study population of the Vantaa85 +  study, 300 of whom were autopsied during follow‐up (79.5% females, mean age‐at‐death 92 ± 3.7 years). Alzheimer's disease (AD) pathology (tau and beta‐amyloid [Aβ]), cerebral amyloid angiopathy (CAA) and Lewy‐related pathologies were analyzed. Brain infarcts were categorized by size (<2 mm, 2–15 mm, >15 mm) and by location. Brain hemorrhages were classified as microscopic (<2 mm) and macroscopic.

Results

195/300 (65%) were demented. 194/195 (99%) of the demented had at least one neuropathology. Three independent contributors to dementia were identified: AD‐type tau‐pathology (Braak stage V‐VI), neocortical Lewy‐related pathology, and cortical anterior 2–15 mm infarcts. These were found in 34%, 21%, and 21% of the demented, respectively, with the multivariate odds ratios (OR) for dementia 5.5, 4.5, and 3.4. Factor analysis investigating the relationships between different pathologies identified three separate factors: (1) AD‐spectrum, which included neurofibrillary tau, Aβ plaque, and neocortical Lewy‐related pathologies and CAA (2) >2 mm cortical and subcortical infarcts, and (3) <2 mm cortical microinfarcts and microhemorrhages. Multipathology was common and increased the risk of dementia significantly.

Interpretation

These results indicate that AD‐type neurodegenerative processes play the most prominent role in twilight cognitive decline. The high prevalence of both neurodegenerative and vascular pathologies indicates that multiple preventive and therapeutic approaches are needed to protect the brains of the oldest old.

Long-Term Risk of Dementia Among Survivors of Ischemic or Hemorrhagic Stroke

BACKGROUND AND PURPOSE

Stroke is a risk factor for dementia, but the risk of dementia after different stroke types is poorly understood. We examined the long-term risk of dementia among survivors of any first-time stroke and of first-time ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage.

METHODS

We conducted a 30-year nationwide population-based cohort study using data from Danish medical databases (1982-2013) covering all Danish hospitals. We identified 84 220 ischemic stroke survivors, 16 723 intracerebral hemorrhage survivors, 9872 subarachnoid hemorrhage survivors, and 104 303 survivors of unspecified stroke types. Patients were aged ≥18 years and survived for at least 3 months after diagnosis. We formed a comparison cohort from the general population (1 075 588 patients without stroke, matched to stroke patients by age and sex). We computed absolute risks and hazard ratios of dementia up to 30 years after stroke.

RESULTS

The 30-year absolute risk of dementia among stroke survivors was 11.5% (95% confidence interval, 11.2%-11.7%). Compared with the general population, the hazard ratio (95% confidence interval) for dementia among stroke survivors was 1.80 (1.77-1.84) after any stroke, 1.72 (1.66-1.77) after ischemic stroke, 2.70 (2.53-2.89) after intracerebral hemorrhage, and 2.74 (2.45-3.06) after subarachnoid hemorrhage. Younger patients regardless of stroke type faced higher risks of poststroke dementia than older patients. The pattern of hazard ratios by stroke type did not change during follow-up and was not altered appreciably by age, sex, or preexisting diagnoses of vascular conditions.

CONCLUSIONS

Stroke increases dementia risk. Survivors of intracerebral hemorrhage and subarachnoid hemorrhage are at particularly high long-term risk of poststroke dementia.

Independent and interactive impacts of hypertension and diabetes mellitus on verbal memory: A coordinated analysis of longitudinal data from England, Sweden, and the United States

The importance of preventing and controlling hypertension (HTN) and diabetes mellitus (DM) to mitigate risks to physical health has long been understood by health care professionals. More recently, a growing body of evidence implicates HTN and DM in age-related cognitive decline and risk for dementia, though consensus has yet to be reached on whether older adults living with comorbid HTN and DM are at heightened risk for cognitive impairment. The present study sought to contribute to this topic through a coordinated analysis of 3 longitudinal studies of aging from England, Sweden, and the United States (total N = 12,513). Identical multilevel linear growth models were fit to each to estimate the impact of baseline disease status on initial level and change in verbal declarative memory performance. Overall, few associations between HTN, DM, and cognition were observed. Rate of decline was steeper for Swedish participants with independent HTN but attenuated for their American counterparts. Americans with comorbid HTN and DM showed attenuated decline. Treatment with medication was substantially less prevalent in the earlier-born and lower-educated Swedish sample, which may help to explain our pattern of results. In addition, those living with multiple conditions may be more likely to receive treatment, mitigating cognitive decline. Our results present a nuanced view of the interactions between HTN, DM, and cognition, and lead us to recommend consideration of treatment status or proxies such as birth cohort and education, in combination with age at assessment and specific measure used to interpret research in this area. (PsycINFO Database Record

Diabetes is associated with cerebrovascular but not Alzheimer's disease neuropathology

INTRODUCTION

The relationship of diabetes to specific neuropathologic causes of dementia is incompletely understood.

METHODS

We used logistic regression to evaluate the association between diabetes and infarcts, Braak neurofibrillary tangle stage, and neuritic plaque score in 2365 autopsied persons. In a subset of >1300 persons with available cognitive data, we examined the association between diabetes and cognition using Poisson regression.

RESULTS

Diabetes increased odds of brain infarcts (odds ratio [OR] = 1.57, P < .0001), specifically lacunes (OR = 1.71, P < .0001), but not Alzheimer's disease neuropathology. Diabetes plus infarcts was associated with lower cognitive scores at end of life than infarcts or diabetes alone, and diabetes plus high level of Alzheimer's neuropathologic changes was associated with lower mini-mental state examination scores than the pathology alone.

DISCUSSION

This study supports the conclusions that diabetes increases the risk of cerebrovascular but not Alzheimer's disease pathology, and at least some of diabetes' relationship to cognitive impairment may be modified by neuropathology.

Risk Factors and Hospitalization Costs of Dementia Patients: Examining Race and Gender Variations

AIMS

To examine the variation in risk factors and hospitalization costs among four elderly dementia cohorts by race and gender.

MATERIALS AND METHODS

The 2008 Tennessee Hospital Discharged database was examined. The prevalence, risk factors and cost of inpatient care of dementia were examined for individuals aged 65 years and above, across the four race gender cohorts - white males (WM), black males (BM), white females (WF), and black females (BF).

RESULTS

3.6% of patients hospitalized in 2008 had dementia. Dementia was higher among females than males, and higher among blacks than whites. Further, BF had higher prevalence of dementia than WF; similarly, BM had a higher prevalence of dementia than WM. Overall, six risk factors were associated with dementia for the entire sample including HTN, DM, CKD, CHF, COPD, and stroke. These risk factors varied slightly in predicting dementia by race and gender. Hospital costs were 14% higher among dementia patients compared to non-dementia patients.

CONCLUSIONS

There exist significant race and gender disparities in prevalence of dementia. A greater degree of co-morbidity, increased duration of hospital stay, and more frequent hospitalizations, may result in a higher cost of inpatient dementia care. Aggressive management of risk factors may subsequently reduce stroke and cost of dementia care, especially in the black population. Race and gender dependent milestones for management of these risk factors should be considered.

White matter hyperintensities are associated with the severity of late-life somatoform disorders and executive functions

BACKGROUND

Medically unexplained symptoms are often seen in the elderly. Recently, correlations between medically unexplained symptoms and somatoform disorders (SDs) have been reported. The existence of many interactive psychiatric aetiologies is known among SDs. Late-life SDs might be influenced by some aetiological factors caused by ageing processes, such as structural changes in the brain and cognitive dysfunctions.

AIMS

Under such circumstances, we investigated the presence of subcortical white matter hyperintensities (WMHs), which increase with ageing, and hypothesized that subcortical WMHs are related to the disease severity of late-life SDs. Furthermore, we confirmed whether cognitive dysfunction influences this process.

METHODS

To evaluate these hypotheses, we examined patients with medically unexplained symptoms who met the criteria for undifferentiated somatoform disorder and divided the patients into three groups according to the degree of subcortical WMHs: grade 0, grade 1, and grade 2. The subcortical WMHs were rated using Fazekas grading. Differences in symptom severity and cognitive functions were compared among the three groups.

RESULTS

The grade 2 group had the severest symptoms. Furthermore, the grade 2 group had lower cognitive function scores than the other groups.

CONCLUSIONS

The present study showed that the presence of subcortical WMHs in patients with late-life SDs was a predictor of disease severity. Moreover, cognitive dysfunction appeared to play a role in the advancement of disease severity.

Heart failure and Alzheimer's disease

It has recently been proposed that heart failure is a risk factor for Alzheimer's disease. Decreased cerebral blood flow and neurohormonal activation due to heart failure may contribute to the dysfunction of the neurovascular unit and cause an energy crisis in neurons. This leads to the impaired clearance of amyloid beta and hyperphosphorylation of tau protein, resulting in the formation of amyloid beta plaques and neurofibrillary tangles. In this article, we will summarize the current understanding of the relationship between heart failure and Alzheimer's disease based on epidemiological studies, brain imaging research, pathological findings and the use of animal models. The importance of atherosclerosis, myocardial infarction, atrial fibrillation, blood pressure and valve disease as well as the effect of relevant medications will be discussed.

Target risk factors for dementia prevention: a systematic review and Delphi consensus study on the evidence from observational studies

OBJECTIVE

Dementia has a multifactorial etiology, but the importance of individual health and lifestyle related risk factors is often uncertain or based on few studies. The goal of this paper is to identify the major modifiable risk factors for dementia as a first step in developing an effective preventive strategy and promoting healthy late life cognitive functioning.

METHODS

A mixed-method approach combined findings from a systematic literature review and a Delphi consensus study. The literature search was conducted in PubMed and updated an earlier review by the United States National Institutes of Health from 2010. We reviewed the available evidence from observational epidemiological studies. The online Delphi study asked eight international experts to rank and weigh each risk factor for its importance for dementia prevention.

RESULTS

Out of 3127 abstracts, 291 were included in the review. There was good agreement between modifiable risk factors identified in the literature review and risk factors named spontaneously by experts. After triangulation of both methods and re-weighting by experts, strongest support was found for depression, (midlife) hypertension, physical inactivity, diabetes, (midlife) obesity, hyperlipidemia, and smoking, while more research is needed for coronary heart disease, renal dysfunction, diet, and cognitive activity.

CONCLUSIONS

Findings provide good support for several somatic and lifestyle factors and will be used to inform the design of a new multicenter trial into dementia prevention.

Variation in risk factors of dementia among four elderly patient cohorts

AIM: To examine variation in risk factors that contributed to dementia among four elderly cohorts by race and gender.

METHODS: We examined 2008 Tennessee Hospital Discharged database for vascular factors that play a role in both stroke and dementia. Risk factors for dementia were examined for black and white patients aged 65+. Four race-gender groups of patients-white males (WM), black males (BM), white females (WF), and black females (BF) were compared for prevalence of dementia and stroke. A logistic model predicting dementia in each group separately used several vascular factors affecting dementia directly or indirectly through stroke.

RESULTS: Three point six percent of patients hospitalized in 2008 had dementia and dementia was higher among females than males (3.9% vs 3.2%, P < 0.001), and higher among blacks than whites (4.2% vs 3.5%, P < 0.000). Further, BF had higher prevalence of dementia than WF (4.2% vs 3.8%, P < 0.001); similarly BM had more dementia than WM (4.1% vs 3.1%, P < 0.001). In logistic regression models, however, different patterns of risk factors were associated with dementia in four groups: among WF and WM, hypertension, diabetes, congestive heart failure, and stroke predicted dementia. Among BF and BM, only stroke and diabetes were related to dementia.

CONCLUSION: Aggressive management of risk factors (hypertension and diabetes) may subsequently reduce stroke and dementia hospitalization.

Synergistic neuroprotective effects of combined treatment with olmesartan plus azelnidipine in stroke-prone spontaneously hypertensive rats

An angiotensin 2 type 1 receptor blocker, olmesartan, and a calcium channel blocker, azelnidipine, possess not only an antihypertensive effect but also an antioxidative effect and other beneficial effects. In the present study, we examined the efficacy of olmesartan and azelnidipine monotherapy (2 mg/kg or 10 mg/kg each) and their combination therapy (1 mg/kg each) on stroke-prone spontaneously hypertensive rats (SHR-SP) in relation to oxidative stress, inflammation, and the neurovascular unit. In comparison with the vehicle group, body weight, regional cerebral blood flow, and motor function were preserved, whereas systolic blood pressure and diastolic blood pressure decreased in the five drug-treatment groups. Spontaneous infarct volume decreased with the low-dose combination of olmesartan plus azelnidipine and with the high-dose olmesartan, with a further decrease in the high-dose azelnidipine group. In addition, these drugs dose-dependently reduced oxidative stresses, proinflammatory molecules, and well-preserved components of the neurovascular unit. The low-dose combination of olmesartan plus azelnidipine showed a better effect than the low-dose olmesartan or azelnidipine monotherapy. The present study shows that the low-dose combination of olmesartan plus azelnidipine demonstrates a greater synergistic benefit than monotherapy with a low-dose of olmesartan or azelnidipine in SHR-SP for preventing spontaneous infarct volume, reducing oxidative stresses and proinflammatory molecules, and imparting neurovascular protection. In addition, a high-dose of olmesartan showed a greater benefit without the lowering of blood pressure, probably because of the antioxidative and anti-inflammatory effects. A high dose of azelnidipine showed the best benefit, probably because of the two effects mentioned above related to the lowering of blood pressure.

Plasma homocysteine, Alzheimer and cerebrovascular pathology: a population-based autopsy study

Elevated plasma total homocysteine is associated with increased risk of dementia/Alzheimer's disease, but underlying pathophysiological mechanisms are not fully understood. This study investigated possible links between baseline homocysteine, and post-mortem neuropathological and magnetic resonance imaging findings up to 10 years later in the Vantaa 85+ population including people aged ≥85 years. Two hundred and sixty-five individuals had homocysteine and autopsy data, of which 103 had post-mortem brain magnetic resonance imaging scans. Methenamine silver staining was used for amyloid-β and modified Bielschowsky method for neurofibrillary tangles and neuritic plaques. Macroscopic infarcts were identified from cerebral hemispheres, brainstem and cerebellum slices. Standardized methods were used to determine microscopic infarcts, cerebral amyoloid angiopathy, and α-synuclein pathology. Magnetic resonance imaging was used for visual ratings of the degree of medial temporal lobe atrophy, and periventricular and deep white matter hyperintensities. Elevated baseline homocysteine was associated with increased neurofibrillary tangles count at the time of death: for the highest homocysteine quartile, odds ratio (95% confidence interval) was 2.60 (1.28-5.28). The association was observed particularly in people with dementia, in the presence of cerebral infarcts, and with longer time between the baseline homocysteine assessment and death. Also, elevated homocysteine tended to relate to amyloid-β accumulation, but this was seen only with longer baseline-death interval: odds ratio (95% confidence interval) was 2.52 (0.88-7.19) for the highest homocysteine quartile. On post-mortem magnetic resonance imaging, for the highest homocysteine quartile odds ratio (95% confidence interval) was 3.78 (1.12-12.79) for more severe medial temporal atrophy and 4.69 (1.14-19.33) for more severe periventricular white matter hyperintensities. All associations were independent of several potential confounders, including common vascular risk factors. No relationships between homocysteine and cerebral macro- or microinfarcts, cerebral amyoloid angiopathy or α-synuclein pathology were detected. These results suggest that elevated homocysteine in adults aged ≥85 years may contribute to increased Alzheimer-type pathology, particularly neurofibrillary tangles burden. This effect seems to be more pronounced in the presence of cerebrovascular pathology. Randomized controlled trials are needed to determine the impact of homocysteine-lowering treatments on dementia-related pathology.

Antihypertensives, angiotensin, glucose and Alzheimer's disease

Evidence supporting a link between vascular disorders such as hypertension and Alzheimer's disease (AD) is increasing. Population studies have suggested an association between hypertension and an increased risk of developing AD. A potential role for antihypertensive medications in the management of cognitive disorders has also been suggested, although findings are mixed. However, it is of interest that evidence is now leaning towards the possibility that some of these antihypertensive medications may improve cognition independent of their blood pressure lowering effects. Many of these drugs cross the blood-brain barrier and may influence neurotransmitters involved in cognition. Increasing knowledge of the actions of antihypertensives in the brain and the vascular system could lead to better treatment and/or prevention options for AD.

Type 2 diabetes and 10-year risk of dementia and cognitive impairment among older Mexican Americans

OBJECTIVE

Type 2 diabetes has been linked with increased risk of dementia and cognitive impairment among older adults and with premature mortality in young and middle-aged adults. No studies have evaluated the association between diabetes and dementia among Mexican Americans, a population with a high burden of diabetes. We evaluated the association of diabetes with incidence of dementia and cognitive impairment without dementia (CIND) among older Mexican Americans while accounting for competing risk from death.

RESEARCH DESIGN AND METHODS

This study included 1,617 participants 60-98 years of age from the Sacramento Area Latino Study on Aging followed up to 10 years from 1998. We evaluated the association between diabetes and dementia/CIND with competing risk regression models.

RESULTS

Participants free of dementia/CIND at baseline (n = 1,617) were followed annually up to 10 years. There were 677 (41.9%) participants with diabetes, 159 (9.8%) incident dementia/CIND cases, and 361 (22.3%) deaths. Treated and untreated diabetes (hazard ratio 2.12 [95% CI 1.65-2.73] and 2.15 [1.58-2.95]) and dementia/CIND (2.48 [1.75-3.51]) were associated with an increased risk of death. In models adjusted for competing risk of death, those with treated and untreated diabetes had an increased risk of dementia/CIND (2.05 [1.41-2.97] and 1.55 [0.93-2.58]) compared with those without diabetes.

CONCLUSIONS

These findings provide evidence that the association between type 2 diabetes and dementia/CIND among Mexican Americans remains strong after accounting for competing risk of mortality. Treatments that modify risk of death among those with diabetes may change future dementia risk.

Risk factors for incident dementia in the very old

BACKGROUND

Several risk factors for dementia, Alzheimer's disease, and cognitive impairment have been established; however, knowledge about risk factors in the very old population (≥85 years) is limited. This study describes the association of several baseline factors with dementia in participants aged ≥85 years, and investigates factors associated with a higher risk of incident dementia over five years.

METHODS

The participants in this population-based cohort study were aged 85, 90, and ≥95 years at baseline (2000-2002). Data were collected during home visits for interviews and testing, from a review of medical records, and/or interviewing the caregiver or next of kin. After five years 212 participants could be followed up concerning incident dementia. Multivariate logistic regression was used.

RESULTS

At baseline, 100/353 (28%) of participants had a dementia diagnosis. Over five years, 71/212 (33.5%) participants developed dementia. Few participants with dementia at baseline remained alive after five years (12%). Depression at the baseline and follow-up time were associated with a higher risk of dementia, odds ratio (OR) (95% CI, p-value) 2.91 (1.37-6.16, 0.005) and 1.61 (1.26-2.05, <0.001) respectively. More social contact and a higher Mini-Mental State Examination score at baseline were associated with lower risk of incident dementia, OR (95% CI, p-value) 0.87 (0.78-0.97, 0.009) and 0.83 (0.74-0.93, 0.001) respectively.

CONCLUSIONS

Prevalence and incidence of dementia are high in very old people and dementia appears to be a fatal disorder. Depression is associated with higher risk of incident dementia over five years whereas more frequent social contacts and a higher MMSE score are associated with lower risk.

Dementia in the oldest old: a multi-factorial and growing public health issue

The population of oldest old, or people aged 85 and older, is growing rapidly. A better understanding of dementia in this population is thus of increasing national and global importance. In this review, we describe the major epidemiological studies, prevalence, clinical presentation, neuropathological and imaging features, risk factors, and treatment of dementia in the oldest old. Prevalence estimates for dementia among those aged 85+ ranges from 18 to 38%. The most common clinical syndromes are Alzheimer's dementia, vascular dementia, and mixed dementia from multiple etiologies. The rate of progression appears to be slower than in the younger old. Single neuropathological entities such as Alzheimer's dementia and Lewy body pathology appear to have declining relevance to cognitive decline, while mixed pathology with Alzheimer's disease, vascular disease (especially cortical microinfarcts), and hippocampal sclerosis appear to have increasing relevance. Neuroimaging data are sparse. Risk factors for dementia in the oldest old include a low level of education, poor mid-life general health, low level of physical activity, depression, and delirium, whereas apolipoprotein E genotype, late-life hypertension, hyperlipidemia, and elevated peripheral inflammatory markers appear to have less relevance. Treatment approaches require further study, but the oldest old may be more prone to negative side effects compared with younger patients and targeted therapies may be less efficacious since single pathologies are less frequent. We also highlight the limitations and challenges of research in this area, including the difficulty of defining functional decline, a necessary component for a dementia diagnosis, the lack of normative neuropsychological data, and other shortcomings inherent in existing diagnostic criteria. In summary, our understanding of dementia in the oldest old has advanced dramatically in recent years, but more research is needed, particularly among varied racial, ethnic, and socioeconomic groups, and with respect to biomarkers such as neuroimaging, modifiable risk factors, and therapy.

Development of vascular risk factors over 15 years in relation to cognition: the Hoorn Study

OBJECTIVES

To investigate the development of vascular risk factor levels at four points over 15 years in relation to late-life cognitive functioning.

DESIGN

Longitudinal population-based study.

SETTING

The Hoorn Study, a community-based cohort study of glucose metabolism and cardiovascular risk.

PARTICIPANTS

Three hundred eighty individuals without dementia (mean baseline age 57.7 ± 5.5).

MEASUREMENTS

Four extensive medical examinations were conducted over 15 years. Cognition was assessed in detail at the fourth examination. The time course of vascular risk factors across the examinations was compared between individuals in the highest tertile (good performance) and those in the lowest tertile (poor performance) of cognitive functioning on three cognitive domains (memory, information processing speed, and attention and executive functioning (A&EF)).

RESULTS

Individuals with poor information processing speed had higher levels of systolic blood pressure at baseline (mean difference (standard error) 11.6 (2.6) mmHg, P < .001) than those with good information processing speed. Individuals with poor A&EF had a higher waist:hip ratio (3.03 (1.15), P = .009), glycosylated hemoglobin (0.29% (0.10%), P = .005) and total cholesterol:high-density lipoprotein cholesterol ratio (0.38 (0.19), P = .04) at baseline than individuals with good A&EF, although the differences in vascular risk factor levels between the poor and good cognition group diminished with increasing age.

CONCLUSION

High blood pressure, adiposity, hypercholesterolemia, and hyperglycemia at midlife are associated with late-life cognitive dysfunction, but for most risk factors, this relationship gradually attenuates with increasing age. These results suggest that timing of vascular treatment strategies to prevent cognitive impairment is critical.

Epidemiology of Alzheimer disease

The global prevalence of dementia has been estimated to be as high as 24 million, and is predicted to double every 20 years until at least 2040. As the population worldwide continues to age, the number of individuals at risk will also increase, particularly among the very old. Alzheimer disease is the leading cause of dementia beginning with impaired memory. The neuropathological hallmarks of Alzheimer disease include diffuse and neuritic extracellular amyloid plaques in brain that are frequently surrounded by dystrophic neurites and intraneuronal neurofibrillary tangles. The etiology of Alzheimer disease remains unclear, but it is likely to be the result of both genetic and environmental factors. In this review we discuss the prevalence and incidence rates, the established environmental risk factors, and the protective factors, and briefly review genetic variants predisposing to disease.

Clinical and pathological improvement in stroke-prone spontaneous hypertensive rats related to the pleiotropic effect of cilostazol

BACKGROUND AND PURPOSE

Cerebral infarction is a major cause of death or decreasing activities of daily living. This study aimed to investigate the efficacy of commonly used antiplatelet drugs on stroke and motor and cognitive functions in relation to oxidative stress markers and insulin-like growth factor 1 receptor (IGF-1R).

METHODS

Stroke-prone spontaneously hypertensive rats were treated with vehicle, aspirin, clopidogrel, and cilostazol from 8 to 10 weeks of age. Physiological parameters, regional cerebral blood flow, and serum lipids were examined. Motor and cognitive functions were evaluated weekly by the Rotorod and water maze task. Spontaneous infarct volume, oxidative stress markers for lipid, protein, and DNA at the ischemic boundary zone of spontaneous infarction, and the IGF-1R-positive cell ratio in the hippocampus were immunohistochemically examined in brain sections. IGF-1Rβ expression in the hippocampus was assessed by Western blotting.

RESULTS

The antiplatelet drugs, cilostazol and clopidogrel, reduced the spontaneous infarct volume more than aspirin. Only cilostazol improved motor and cognitive functions with a significant increase (P<0.05) in the memory-related IGF-1R-positive ratio and IGF-1Rβ expression in the hippocampus. Cilostazol reduced the 4 oxidative stress markers in affected neurons in stroke-prone spontaneously hypertensive rats regardless of blood pressure, regional cerebral blood flow, or serum lipid levels.

CONCLUSIONS

The present results suggest that a possible pleiotropic effect of cilostazol resulted in the reduction of spontaneous infarct volume and preservation of motor and spatial cognitive functions. The increase of IGF-1R-positive cells in the hippocampal CA1 region could partly explain the preservation of spatial cognitive function in stroke-prone spontaneously hypertensive rats.

Association between polypharmacy and dementia in older people: a population-based case-control study in Taiwan

AIM

The aim of the present study was to investigate whether polypharmacy correlates with the risk of dementia in older people.

METHODS

From representative claims data established from the National Health Insurance with a population coverage rate of 99% in Taiwan, we identified 7135 newly diagnosed patients with dementia in 2000-2008 and 2,8540 randomly selected controls without dementia, both aged ≥ 65 years. The daily use of prescribed drugs in the past 2 years was compared between cases and controls, controlling for demographic characters and comorbidities.

RESULTS

The incidence of dementia increased with the number of medications used and age. Cases were older than controls, predominant with women and more likely to use five or more drugs daily (44.0% vs 32.0%, P < 0.0001). Multivariate logistic regression analysis showed that, compared with participants using zero to one drug, the odds ratios (OR) of dementia were 1.28 (95% confidence interval [CI] 1.18-1.38) for those using two to four drugs, 1.34 (95% CI 1.23-1.46) for those using five to nine drugs and 1.56 (95% CI 1.38-1.76) for those using 10 or more drugs. Cerebrovascular disease (OR 3.19), diabetes mellitus (OR 1.23), chronic kidney disease (OR 1.21) and hypertension (OR 1.08) were significant comorbidities predicting the risk of dementia. There was significant interaction between cerebrovascular disease and the number of medications used in the dementia risk.

CONCLUSIONS

The risk of dementia increases steadily with the number of medications used and age in older people in Taiwan. Cerebrovascular disease, diabetes mellitus, chronic kidney disease and hypertension might also correlate with the risk of dementia.

Clinical predictors of cognitive decline in patients with mild cognitive impairment: the Chongqing aging study

Mild cognitive impairment (MCI) is considered as the early stage of dementia which currently has no effective treatments. Reducing progression of cognitive decline at the MCI stage could be an important strategy for preventing conversion to dementia. The goal of this work was to screen for clinical predictors indicating the prognosis of MCI comprehensively; therefore, we assumed vascular risk factors (VRFs), carotid stenosis, and white matter changes (WMC) to be independent predictors. A total of 257 patients with MCI underwent collection of VRF information, neuropsychological evaluation, computed tomography angiography (CTA) to investigate carotid stenosis, and magnetic resonance imaging (MRI) to identify severity of WMC. After a 3-year follow-up period, the neuropsychological evaluation, CTA, and MRI were repeated to assess the progression of cognitive decline, carotid stenosis, and WMC. The conversion rate from MCI to dementia was 11.65% per year, and the conversion rate from MCI to Alzheimer's disease was 7.05% per year in our cohort. Cognitive decline (in terms of changes in Mini Mental State Examination scores) was associated with diabetes mellitus (p = 0.004), baseline WMC severity (p < 0.001), baseline carotid stenosis (p < 0.001), and WMC severity change (p < 0.001). Besides, diabetes, baseline WMC severity, baseline moderate-to-severe carotid stenosis, and carotid stenosis change during follow-up were predictors of conversion from MCI to dementia. Given the potential clinical predictors, our findings could imply that controlling blood glucose, removing carotid stenosis, and improving cerebral perfusion could be effective measures to delay cognitive decline in patients with MCI and prevent conversion from MCI to dementia.

Morbidity in aged Finns: a systematic review

AIM

The aim was to carry out a systematic review of original studies about morbidity in the aged in Finland.

METHODS

Publications with data on morbidity in the aged (≥65 years) in peer-reviewed scientific journals in Finnish and English were systematically searched for in literature databases, websites of National Institute of Health and Welfare (NIHW), National Public Health Institute (NPHI), and Stakes and reference lists of retrieved articles. Publications from 1990 onwards were included.

RESULTS

The search produced 39 publications about morbidity in the aged in Finland fulfilling the inclusion criteria. The most common disease categories in the aged were cardiovascular diseases (CVDs), musculoskeletal disorders (MSDs), hypertension, orthostatic hypotension (OH), insomnia, diabetes, articular diseases, diseases causing cognitive decline, and depression. The prevalence of many of these diseases increased with age.

CONCLUSIONS

The morbidity increases with aging, and even the oldest-old are not exceptionally healthy. Because of the increasing number of aged people, the absolute use of health and social services by this population sector will most probably increase in Finland and other developed countries.

Nutritional determinants of cognitive aging and dementia

The objective of this review is to provide an overview of nutritional factors involved in cognitive aging and dementia with a focus on nutrients that are also important in neurocognitive development. Several dietary components were targeted, including antioxidant nutrients, dietary fats and B-vitamins. A critical review of the literature on each nutrient group is presented, beginning with laboratory and animal studies of the underlying biological mechanisms, followed by prospective epidemiological studies and randomised clinical trials. The evidence to date is fairly strong for protective associations of vitamin E from food sources, the n-3 fatty acid, DHA, found in fish, a high ratio of polyunsaturated to saturated fats, and vitamin B12 and folate. Attention to the level of nutrient intake is crucial for interpreting the literature and the inconsistencies across studies. Most of the epidemiological studies that observe associations have sufficient numbers of individuals who have both low and adequate nutrient status. Few of the randomised clinical trials are designed to target participants who have low baseline status before randomising to vitamin supplement treatments, and this may have resulted in negative findings. Post-hoc analyses by some of the trials reveal vitamin effects in individuals with low baseline intakes. The field of diet and dementia is a relatively young area of study. Much further work needs to be done to understand dietary determinants of cognitive aging and diseases. Further, these studies must be particularly focused on the levels of nutrient intake or status that confer optimum or suboptimal brain functioning.

Consequences of stroke in community-dwelling elderly: the health and retirement study, 1998 to 2008

BACKGROUND AND PURPOSE

Stroke survivors are at risk of developing comorbidities that further reduce their quality of life. The purpose of this study was to determine the risk of developing a secondary health problem after stroke.

METHODS

We performed a case-control analysis using 6 biennial interview waves (1998 to 2008) of the Health and Retirement Study. We compared 631 noninstitutionalized individuals who had a single stroke with 631 control subjects matched for age, gender, and interview wave. We studied sleep problems, urinary incontinence, motor impairment, falls, and memory deficits among the 2 groups.

RESULTS

Stroke survivors frequently developed new or worsened motor impairment (33%), sleep problems (up to 33%), falls (30%), urinary incontinence (19%), and memory deficits (9%). As compared with control subjects, the risk of developing a secondary health problem was highest for memory deficits (OR, 2.45; 95% CI, 1.34 to 4.46) followed by urinary incontinence (OR, 1.86; 95% CI, 1.31 to 2.66), motor impairment (OR, 1.61; 95% CI, 1.16 to 2.24), falls (OR, 1.5; 95% CI, 1.12 to 2.0), and sleep disturbances (OR, 1.49; 95% CI, 1.09 to 2.03). In contrast, stroke survivors were not more likely to injure themselves during a fall (OR, 1.14; 95% CI, 0.72 to 1.79). After adjusting for cardiovascular risk factors, social status, psychiatric symptoms, and pain, the risks of falling or developing sleep problems were not different from the control subjects.

CONCLUSIONS

The risk of developing a secondary health problem that can impact daily life is markedly increased after stroke. A better understanding of frequencies and risks for secondary health problems after stroke is necessary for designing better preventive and rehabilitation strategies.

Operationalizing diagnostic criteria for Alzheimer's disease and other age-related cognitive impairment-Part 1

In this article, the challenges faced by several noted population studies for Alzheimer dementia in operationalizing current clinical diagnostic criteria for Alzheimer's disease (AD) have been reviewed. Differences in case ascertainment, methodological biases, cultural and educational influences on test performance, inclusion of special populations such as underrepresented minorities and the oldest old, and detection of the earliest symptomatic stages of underlying AD have been considered. Classification of Alzheimer dementia may be improved by the incorporation of biomarkers for AD if the sensitivity, specificity, and predictive value of the biomarkers are established and if they are appropriate for epidemiological studies, as may occur should a plasma biomarker be developed. Biomarkers for AD could also facilitate studies of the interactions of various forms of neurodegenerative disorders with cerebrovascular disease, resulting in "mixed dementia".

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

OBJECTIVE

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

METHODS

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

KEY FINDINGS

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

CONCLUSIONS

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

White matter changes and diabetes predict cognitive decline in the elderly: the LADIS study

OBJECTIVE

We aimed to study if age-related white matter changes (WMC) and vascular risk factors were predictors of cognitive decline in elderly subjects with WMC living independently.

METHODS

The Leukoaraiosis and Disability prospective multinational European study (LADIS) evaluates the impact of WMC on the transition of independent elderly subjects into disability. Independent elderly were enrolled due to the presence of WMC. Subjects were evaluated yearly during 3 years with a comprehensive clinical protocol and a neuropsychological battery. Additionally, dementia, subtypes of dementia, and cognitive decline without dementia were classified according to usual clinical criteria. MRI was performed at entry and at the end of the study.

RESULTS

A total of 639 subjects were included (74.1 +/- 5 years, 55% women, 9.6 +/- 3.8 years of schooling). At end of follow-up, 90 patients had dementia and 147 had cognitive impairment no dementia. Using Cox regression analysis, WMC severity independently predicted cognitive decline (dementia and not dementia), independently of age, education, and medial temporal atrophy (MTA). Diabetes at baseline was the only vascular risk factor that independently predicted cognitive decline during follow-up, controlling for age, education, WMC severity, and temporal atrophy. Considering subtypes of dementia, Alzheimer disease (AD) was predicted only by MTA, while vascular dementia was predicted by previous stroke, WMC severity, and MTA.

CONCLUSION

WMC severity and diabetes are independent predictors of cognitive decline in an initially nondisabled elderly population. Vascular dementia is predicted by previous stroke and WMC, while AD is predicted only by MTA.

Human cerebral neuropathology of Type 2 diabetes mellitus

The cerebral neuropathology of Type 2 diabetes (CNDM2) has not been positively defined. This review includes a description of CNDM2 research from before the 'Pubmed Era'. Recent neuroimaging studies have focused on cerebrovascular and white matter pathology. These and prior studies about cerebrovascular histopathology in diabetes are reviewed. Evidence is also described for and against the link between CNDM2 and Alzheimer's disease pathogenesis. To study this matter directly, we evaluated data from University of Kentucky Alzheimer's Disease Center (UK ADC) patients recruited while non-demented and followed longitudinally. Of patients who had come to autopsy (N = 234), 139 met inclusion criteria. These patients provided the basis for comparing the prevalence of pathological and clinical indices between well-characterized cases with (N = 50) or without (N = 89) the premortem diagnosis of diabetes. In diabetics, cerebrovascular pathology was more frequent and Alzheimer-type pathology was less frequent than in non-diabetics. Finally, a series of photomicrographs demonstrates histopathological features (including clinical-radiographical correlation) observed in brains of persons that died after a history of diabetes. These preliminary, correlative, and descriptive studies may help develop new hypotheses about CNDM2. We conclude that more work should be performed on human material in the context of CNDM2.