Treating vascular risk factors and maintaining vascular health: is this the way towards successful cognitive ageing and preventing cognitive decline?

Cerebral Blood Flow in Alzheimer's Disease: A Meta-Analysis on Transcranial Doppler Investigations

BACKGROUND

Cerebrovascular hemodynamic impairment has been reported in Alzheimer's disease (AD). We performed a systematic review and meta-analysis to investigate changes in cerebral blood flow (CBF) in AD patients.

METHODS

Data were obtained by searching MEDLINE and Scopus for all investigations published between 1 January 2011 and 1 November 2021, comparing the cerebrovascular hemodynamic between AD patients and cognately healthy age-matched controls, using transcranial Doppler (TCD) ultrasound.

RESULTS

Twelve studies, based on 685 patients [395 with AD and 290 age-matched cognitively healthy controls, with a mean age of 71.5 and 72.1 years, respectively] were included in the analysis. A random effect model revealed that AD patients, in the proximal segments of the middle cerebral artery (MCA), have a significantly lower CBF velocity, compared to controls (MD: -7.80 cm/s, 95%CI: -10.78 to -5.13, p < 0.0001, I2 = 71.0%). Due to a significant Egger's test (t = 3.12, p = 0.008), a trim-and-fill analysis was performed, confirming the difference (MD: -11.05 cm/s, 95%CI: -12.28 to -9.82, p < 0.0001). Meta-regression analysis demonstrated that the mean CBF at the proximal MCA was directly correlated with arterial hypertension (p = 0.03) and MMSE score (p < 0.001), but inversely correlated with age (p = 0.01). In AD patients, the pulsatility index was significantly higher compared to controls (MD: 0.16, 95%CI: 0.07 to 0.25, p < 0.0001, I2: 84.5%), while the breath-holding index test results were significant lower (MD: -1.72, 95%CI: -2.53 to -0.91, p < 0.001, I2: 85.4%).

CONCLUSIONS

AD patients have a significant impairment in relation to their cerebrovascular perfusion, suggesting that cerebrovascular hemodynamic deterioration, evaluated using TCD, may be a useful diagnostic tool.

Elevated Soluble TNF-Receptor 1 in the Serum of Predementia Subjects with Cerebral Small Vessel Disease

Tumor necrosis factor-receptor 1 (TNF-R1)-mediated signaling is critical to the regulation of inflammatory responses. TNF-R1 can be proteolytically released into systemic blood circulation in a soluble form (sTNF-R1), where it binds to circulating TNF and functions to attenuate TNF-mediated inflammation. Increases of peripheral sTNF-R1 have been reported in both Alzheimer’s disease (AD) dementia and vascular dementia (VaD). However, the status of sTNF-R1 in predementia subjects (cognitive impairment, no dementia, CIND) is unknown, and putative associations with cerebral small vessel disease (CSVD), as well as with longitudinal changes in cognitive functions are unclear. We measured baseline serum sTNF-R1 in a longitudinally assessed cohort of 93 controls and 103 CIND, along with neuropsychological evaluations and neuroimaging assessments. Serum sTNF-R1 levels were increased in CIND compared with controls (p < 0.001). Higher baseline sTNF-R1 levels were specifically associated with lacunar infarcts (rate ratio = 6.91, 95% CI 3.19–14.96, p < 0.001), as well as lower rates of cognitive decline in the CIND subgroup. Our data suggest that sTNF-R1 interacts with vascular cognitive impairment in a complex manner at predementia stages, with elevated levels associated with more severe CSVD at baseline, but which may subsequently be protective against cognitive decline.

Effects of traditional Chinese exercise on vascular function in patients with Alzheimer's disease: A protocol for systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with an insidious onset, usually characterized by memory impairment, visual-spatial skill impairment, executive dysfunction and personality behavioral changes. Studies have confirmed that vascular dysfunction may precede AD pathological changes and can present as vascular malformations, atherosclerosis, and impaired self-regulation, and can affect oxidative stress and amyloidosis. Therefore, it is important to improve or prevent vascular dysfunction in AD patients. Regular exercise can effectively inhibit the production of reactive oxygen species during the occurrence of AD and can improve the reduction of cerebral blood flow due to AD. Previous studies have shown that exercise can achieve superior clinical results in improving vascular function in AD patients. Therefore, we hypothesize that traditional Chinese exercises (TCEs) may have a good clinical effect in improving vascular function in patients with AD.

METHODS

We will search "PubMed," "the Cochrane Library," "Embase," "Web of Science," "CINAHL," "ProQuest Dissertations and Theses," and "ProQuest-Health & Medical Collection," "CNKI," "SinoMed," "VIP," and "Wanfang Data" to find randomized controlled trials of the effects of TCEs on AD vascular function from the creation of the database to the present, including at least 1 indicator in carotid intima-media thickness (cIMT), middle cerebral artery mean flow velocity (MFV), blood indicators [Heme Oxidase-1 (HO-1), angiopoietin I (Ang I), vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor, matrix metalloproteinase-9 (MMP-9)], and arterial stiffness [(Ankle Brachial Index (ABI), pulse wave velocity (PWV)]. For the included literature, Excel 2019 will be used for data extraction and collection. For the indicators that can be netted for network meta-analysis, Surface Under the Cumulative Ranking for each exercise modality will be calculated with the help of Stata 16.0 and rank, where the higher the SUCRA score, the higher the ranking. For the indicators that cannot be netted, Review Manager 5.4 will be used for meta-analysis will be performed to evaluate the improvement effect of TCEs on AD patients.

RESULTS

This meta-analysis will further determine the efficacy and safety of TCEs on vascular function in AD patients.

CONCLUSION

In this study, randomized controlled trials of the effects of TCEs on vascular function in AD patients will be selected to provide evidence-based medical evidence for promoting the application of TCEs by observing the order of advantages and disadvantages of various exercise modalities through network meta-analysis.

Psychiatric disorders and risk of subsequent dementia: Systematic review and meta-analysis of longitudinal studies

OBJECTIVES

Although psychiatric disorders have been found to be associated with increased risk of dementia, previous findings are mixed, and the nature of these relationships remains poorly understood. We examined longitudinal associations between depression, anxiety, post-traumatic stress disorders (PTSD), bipolar disorder (BPD), psychotic disorders and subsequent dementia.

METHODS

We searched three databases for longitudinal, population-based studies investigating associations between psychiatric disorders and dementia (PROSPERO registration: CRD42020209638). We conducted narrative synthesis, and random-effects meta-analyses to obtain pooled estimates. We used meta-regression and stratified analyses to examine variation by sex, age-at-onset and follow-up time.

RESULTS

Fifty-seven citations met eligibility criteria. Most studies focussed on depression (n = 33), which was associated with subsequent all-cause dementia (pooled relative risk [RR]: 1.96, 95% confidence interval [CI]: 1.59-2.43; I2  = 96.5%), Alzheimer's Disease (pooled RR: 1.9, 95% CI: 1.52-2.38; I2  = 85.5%), and Vascular Dementia (pooled RR: 2.71, 95% CI: 2.48-2.97; I2  = 0). Associations were stronger in studies with shorter follow-up periods and for severe and late-onset depression. Findings regarding anxiety were mixed, and we did not find evidence of an overall association (pooled RR: 1.18, 95% CI: 0.96-1.45; I2  = 52.2%, n = 5). Despite sparse evidence, psychotic disorders (pooled RR: 2.19, 95% CI: 1.44-3.31; I2  = 99%), PTSD and BPD were associated with subsequent dementia.

CONCLUSIONS

People with psychiatric disorders represent high-risk groups for dementia, highlighting the importance of ongoing symptom monitoring in these groups. Findings regarding temporality and age-at-onset indicate that depression symptoms could reflect prodromal dementia for some individuals. Further longitudinal research is required to determine whether psychiatric disorders represent causal risk factors or early markers of dementia neuropathology.

Exercise training improves vascular function in patients with Alzheimer's disease

PURPOSE

Vascular dysfunction has been demonstrated in patients with Alzheimer's disease (AD). Exercise is known to positively affect vascular function. Thus, the aim of our study was to investigate exercise-induced effects on vascular function in AD.

METHODS

Thirty-nine patients with AD (79 ± 8 years) were recruited and randomly assigned to exercise training (EX, n = 20) or control group (CTRL, n = 19). All subjects performed 72 treatment sessions (90 min, 3 t/w). EX included moderate-high-intensity aerobic and strength training. CTRL included cognitive stimuli (visual, verbal, auditive). Before and after the 6-month treatment, the vascular function was measured by passive-leg movement test (PLM, calculating the variation in blood flow: ∆peak; and area under the curve: AUC) tests, and flow-mediated dilation (FMD, %). A blood sample was analyzed for vascular endothelial growth factor (VEGF). Arterial blood flow (BF) and shear rate (SR) were measured during EX and CTRL during a typical treatment session.

RESULTS

EX group has increased FMD% (+ 3.725%, p < 0.001), PLM ∆peak (+ 99.056 ml/min, p = 0.004), AUC (+ 37.359AU, p = 0.037) and VEGF (+ 8.825 pg/ml, p = 0.004). In the CTRL group, no difference between pre- and post-treatment was found for any variable. Increase in BF and SR was demonstrated during EX (BF + 123%, p < 0.05; SR + 134%, p < 0.05), but not during CTRL treatment.

CONCLUSION

Exercise training improves peripheral vascular function in AD. These ameliorations may be due to the repetitive increase in SR during exercise which triggers NO and VEGF upregulation. This approach might be included in standard AD clinical practice as an effective strategy to treat vascular dysfunction in this population.

Effect of physical exercise and medication on enhancing cognitive function in older adults with vascular risk

AIM

To examine the association of physical exercise (PE) and medication on cognitive function in older adults with vascular risk.

METHODS

This was a cross-sectional study of 478 non-demented participants aged ≥60 years with vascular risk. Management strategy included PE (mind-body exercise and/or strenuous exercise), medication, PE combined with medication and no management at all. Participation of PE was determined by self-reporting exercise engagement in the past year. Cognitive preservation was defined as a global composite z-score that was equal to or above the age and educational adjusted mean of cognitively normal older adults. Binary logistic regression was carried out to examine the association between management strategy and cognitive preservation in each exercise modality adjusted by sociodemographic, physical, mental and genetic factors.

RESULTS

An association was found in preserved cognitive function for those who managed their vascular risk through PE (OR 2.5, 95% CI 1.2-5.3, P = 0.015) and in combination with medication (OR 2.1, 95% CI 1.0-4.6, P = 0.05). A similar pattern was also found in each exercise subtype. A significant short-term (OR 3.6, 95% CI 1.0-12.4, P = 0.042) to lifelong (OR 3.5, 95% CI 1.4-8.5, P = 0.006) cognitive benefit was found in MB exercise.

CONCLUSION

Medication alone may be insufficient to preserve cognitive function in older adults with vascular risk. In our sample, medication in combined with PE is found to have significant impact on cognitive improvement. Mind-body exercise might be better than strenuous exercise, as a more sustainable cognitive effect is observed. Geriatr Gerontol Int 2020; 20: 1067-1071..

HDAC inhibitor protects chronic cerebral hypoperfusion and oxygen-glucose deprivation injuries via H3K14 and H4K5 acetylation-mediated BDNF expression

Vascular dementia (VaD) is the second most common cause of dementia, but the treatment is still lacking. Although many studies have reported that histone deacetylase inhibitors (HDACis) confer protective effects against ischemic and hypoxic injuries, their role in VaD is still uncertain. Previous studies shown, one HDACi protected against cognitive decline in animals with chronic cerebral hypoperfusion (CCH). However, the underlying mechanisms remain elusive. In this study, we tested several 10,11‐dihydro‐5H‐dibenzo[b,f]azepine hydroxamates, which act as HDACis in the CCH model (in vivo), and SH‐SY5Y (neuroblastoma cells) with oxygen‐glucose deprivation (OGD, in vitro). We identified a compound 13, which exhibited the best cell viability under OGD. The compound 13 could increase, in part, the protein levels of brain‐derived neurotrophic factor (BDNF). It increased acetylation status on lysine 14 residue of histone 3 (H3K14) and lysine 5 of histone 4 (H4K5). We further clarified which promoters (I, II, III, IV or IX) could be affected by histone acetylation altered by compound 13. The results of chromatin immunoprecipitation and Q‐PCR analysis indicate that an increase in H3K14 acetylation leads to an increase in the expression of BDNF promoter II, while an increase in H4K5 acetylation results in an increase in the activity of BDNF promoter II and III. Afterwards, these cause an increase in the expression of BDNF exon II, III and coding exon IX. In summary, the HDACi compound 13 may increase BDNF specific isoforms expression to rescue the ischemic and hypoxic injuries through changes of acetylation on histones.

Cognition in the First Year After a Minor Stroke, Transient Ischemic Attack, or Mimic Event and the Role of Vascular Risk Factors

Background: Cognitive impairment following a minor stroke or transient ischemic attack (TIA) is common; however, due to diagnostic difficulties, the prevalence and underlying cause of impairment remain poorly defined. We compared cognition in patients after a minor stroke, TIA, or mimic event at three time points in the first year following the event. We examine whether cognitive impairment occurs following these events and whether this impairment differs based on the event type. Further, we measure whether these findings persist after controlling for age, education, and the presence of vascular risk factors and whether the presence of vascular risk factors, independent of event etiology, is associated with cognitive impairment. Lastly, we investigate whether increased stroke risk, as assessed by the ABCD2, is associated with reduced cognition.

Methods: Medical information, a cognitive screening test, and a measure of executive functioning were collected from 613 patients (123 minor stroke, 175 TIA, and 315 mimics) using phone interviews at three time points in the first year following the event. Linear mixed models were used to determine the effect of event type, vascular risk factors, and predicted stroke risk on cognitive performance while controlling for confounders.

Results: There was no relationship between event type and performance on either cognitive measure. When all confounders are controlled for, performance on the cognitive screening test was uniquely accounted for by the presence of heart failure, myocardial infarction, angina, and hypertension (all p < 0.047), whereas the measure of executive functioning was uniquely accounted for by the presence of hypertension and angina (all p < 0.032). Increased stroke risk also predicted performance on the cognitive screening test and the measure of executive functioning (all p < 0.002).

Conclusions: Our findings indicate that cognitive impairment following a minor stroke or TIA may be attributed to the high prevalence of chronic vascular risk factors in these patients. This highlights the importance of long-term management of vascular risk factors beyond event recovery to reduce the risk of cognitive impairment. Increased stroke risk (i.e., ABCD2 score) was also associated with reduced cognition, suggesting that it may be helpful in signaling the need for further cognitive evaluation and intervention post-event.

The association between platelet indices, cognitive screening tests and functional dependence screening questionnaires in hospitalized older people

PURPOSE

Activated platelets have been suggested to play an important role in the pathogenesis of dementia. Recent studies have shown contradictory results concerning the relationship between blood platelet indices and cognitive performance.

METHODS

This cross-sectional study evaluates the relationship between basic platelet indices and cognitive and functional performance of 754 men and women, aged 60-105 years old, admitted to the geriatric hospital unit. Assessment of global cognitive function and functional ability were performed using Mini-Mental State Examination, the seven-point Clock Drawing Test, the Katz Activities of Daily Living, the Lawton Instrumental Activities of Daily Living Scale and the Vulnerable Elders Survey Questionnaire. As platelet indices, platelet count, mean platelet volume, plateletcrit and platelet distribution width were measured.

RESULTS

There was no significant correlation between cognitive performance and platelet indices. Out of the functional dependence questionnaires, only the Katz Activities of Daily Living and the Vulnerable Elders Survey Questionnaire were weakly correlated with platelet count (r = - 0.080 and r = 0.096) and plateletcrit (r = - 0.075 and 0.082, respectively), but these associations diminished in sex-specific analyses.

CONCLUSIONS

Cognitive and functional status are not systematically related to platelet indices in multimorbid hospitalized older adults.

Aging of the frontal lobe

Healthy aging is associated with numerous deficits in cognitive function, which have been attributed to changes within the prefrontal cortex (PFC). This chapter summarizes some of the most prominent cognitive changes associated with age-related alterations in the anatomy and physiology of the PFC. Specifically, aging of the PFC results in deficient aspects of cognitive control, including sustained attention, selective attention, inhibitory control, working memory, and multitasking abilities. Yet, not all cognitive functions associated with the PFC exhibit age-related declines, such as arithmetic, comprehension, emotion perception, and emotional control. Moreover, not all older adults exhibit declines in cognition. Multiple life-course and lifestyle factors, as well as genetics, play a role in the trajectory of cognitive performance across the life span. Thus many adults retain cognitive function well into advanced age. Moreover, the brain remains plastic throughout life and there is increasing evidence that most age-related declines in cognition can be remediated by various methods such as physical exercise, cognitive training, or noninvasive brain stimulation. Overall, because cognitive aging is associated with numerous life-course and lifestyle factors, successful aging likely begins in early life, while maintaining cognition or remediating declines is a life-long process.

Cardiac rehabilitation and its effects on cognition in patients with coronary artery disease and heart failure

INTRODUCTION

Cardiac rehabilitation program is an evidence-based intervention and established model of exercise delivery following myocardial infarction and heart failure. Although it forms an important part of recovery and helps to prevent future events and complications, there has been little focus on its potential cognitive benefits. Areas covered: Coronary artery disease and heart failure are common heart problems associated with significant morbidity and mortality, and cognitive decline is commonly seen in affected individuals. Cognitive impairment may influence patient self-management by reducing medication adherence, rendering patients unable to make lifestyle modifications and causing missed healthcare visits. Cognitive assessment in cardiac rehabilitation as an outcome measure has the potential to improve clinical, functional and behavioral domains as well as help to reduce gaps in the quality of care in these patients. Expert commentary: Limited evidence at present has shown that cardiac rehabilitation and exercise has potential in preventing cognitive decline. Cardiac prehabilitation, a rehabilitation-like program delivered before cardiac surgery, may also play a role in preventing postoperative cognitive dysfunction, but needs future research studies to support it.

Imaging small vessel-associated white matter changes in aging

Alterations in cerebrovascular structure and function may underlie the most common age-associated cognitive, psychiatric, and neurological conditions presented by older adults. Although much remains to understand, existing research suggests several age-associated detrimental conditions may be mediated through sometimes subtle small vessel-induced damage to the cerebral white matter. Here we review a selected portion of the vast work that demonstrates links between changes in vascular and neural health as a function of advancing age, and how even changes in low-to-moderate risk individuals, potentially beginning early in the adult age-span, may have an important impact on functional status in late life.

[Genetic aspects of Alzheimer's disease (Review)]

Alzheimer's disease is a degenerative brain disorder, which concerns memory, cognition and behavior pattern. Its etiology is unknown, it is characterized by typical histological lesions: senile plaques and neuro-fibrillary tangles. Alzheimer's disease is a multifactorial pathology, characterized by interactions between genetic and environmental factors. Genetic factors concern first of all the exceptional monogenic forms, characterized by early onset (<60 years), autosomal dominant forms. Mutations of the genes coding for amyloid-ß precursor protein or preselinins 1 and 2 are involved. The much more frequent sporadic forms also have genetic factors, the best studied being the apolipoprotein E4 coding allele and some more recent genotypes which will be mentioned. No causal, only symptomatic treatments are available.

Plasma homocysteine, brain imaging and cognition in older patients with mental illness

BACKGROUND

Total plasma homocysteine (tHcy) concentration is elevated in older patients with mental illness, and patients with vascular disease have higher plasma tHcy concentration than patients without vascular disease. Plasma tHcy has been reported to be associated with cognitive functions. The mechanism by which plasma tHcy may influence cognitive functions is not clear.

METHOD

We have investigated the relation between plasma tHcy, brain imaging findings (computer tomography scan [CT]) and cognition, measured as Mini mental state examination (MMSE), in 395 consecutively enrolled older patients with mental illness.

RESULTS

Age and plasma tHcy were significant predictors of MMSE score, whereas pathological CT findings, indicating cerebrovascular disease, showed no prediction of MMSE score.

CONCLUSION

The relation between plasma tHcy and cognition is not mediated by cerebrovascular disease as evaluated by pathological CT findings.

The use of N-terminal pro-brain natriuretic Peptide to evaluate vascular disease in elderly patients with mental illness

Background

Serum N-terminal pro-brain natriuretic peptide (NT-proBNP) is regarded as a sensitive marker of cardiovascular disease. Vascular disease plays an important role in cognitive impairment.

Method

In 447 elderly patients with mental illness, serum NT-proBNP level and the presence or absence of vascular disease according to the medical record were used to categorize patients in different subgroups of vascular disease.

Results and Conclusion

Patients with vascular disease and elevated serum NT-proBNP level had a lower cognition level, shorter survival time, lower renal function and a higher percentage of pathological brain imaging than patients with vascular disease and normal NT-proBNP level. Thus, elevated serum NT-proBNP level might be helpful to detect patients who have a more severe cardiovascular disease.

The clinical use of N-terminal-pro brain natriuretic peptide in elderly patients with mental illness

BACKGROUND

Serum N-terminal-pro brain natriuretic peptide (NT-proBNP) is regarded as a marker of vascular disease and has previously been shown to exhibit an increased frequency of pathological values in elderly patients with mental illness with vascular disease compared to patients without vascular disease. Vascular disease plays an important role in cognitive impairment in elderly patients with mental illness.

METHOD

We have investigated the relation between NT-proBNP, vascular disease and cognition in consecutively enrolled elderly patients with mental illness.

RESULTS

NT-proBNP level is increased in patients with vascular disease compared to patients without vascular disease, and a logistic regression analysis showed that NT-proBNP was a significant predictor of vascular disease. However, NT-proBNP level did not predict cognition as assessed by MMSE score. NT-proBNP level also showed a highly significant relation to mortality in all patients.

CONCLUSION

Determinations of NT-proBNP could be used in elderly patients with mental illness to detect patients in need of control and treatment of vascular risk factors. The levels of NT-proBNP may also provide prognostic information.

Hypertension and cognitive function in the elderly

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

Plasma homocysteine, apolipoprotein E status and vascular disease in elderly patients with mental illness

BACKGROUND

Total plasma homocysteine (tHcy) concentration is increased in elderly patients with mental illness. Also, patients with vascular disease have significantly higher plasma tHcy concentration compared with patients without vascular disease. Apolipoprotein E (apoE) status is associated with cardiovascular disease and a major genetic risk factor is inheritance of the e4 allele. In the present study, we investigated the association between plasma tHcy and apoE status.

METHODS

The relation between apoE status, plasma tHcy and vascular disease was investigated in a cohort of consecutively enrolled elderly patients with mental illness (n=328).

RESULTS

Plasma tHcy concentrations were increased (p<0.01) in carriers of APOE4 (13.6 micromol/L; 9.2-21.7 micromol/L) compared to non-carriers (12.4 micromol/L; 8.3-19.9 micromol/L). The proportion of patients with vascular disease was significantly (p<0.001) increased among carriers (61%) compared to non-carriers (42%). An increased percentage (p<0.001) of APOE4 carriers was observed in patients with Alzheimer's disease (AD) with (71%) or without vascular disease (42%), and in patients with vascular dementia (VaD) (54%) compared to a reference group (34%).

CONCLUSIONS

Since carriers of APOE4 showed an increased likelihood of vascular disease, these patients need more intensive control of other modifiable vascular risk factors. Furthermore, the association between plasma tHcy and the presence of APOE4 might be attributed to an increased proportion of vascular disease in APOE4 carriers.

Classification models for early identification of persons at risk for dementia in primary care: an evaluation in a sample aged 80 years and older

AIM

To evaluate previously developed classification models to make implementation in primary care possible and aid early identification of persons at risk for dementia.

METHODS

Data were drawn from the OCTO-Twin study. At baseline, 521 persons >or= 80 years of age were nondemented, and for 387 a blood sample was available. Predictors of dementia were collected and analyzed in initially nondemented persons using generalized estimating equations and Cox survival analyses.

RESULTS

In the basic model using predictors already known or easily obtained (basic set), the mean 2-year predictive value increased from 6.9 to 28.8% in persons with memory complaints and an MMSE score <or= 25. In the extended model, using both the basic set and an extended set of predictors requiring further assessment, the 8-year predictive value increased from 15.0 to 45.8% in persons with low cholesterol and an MMSE score <or= 24.

CONCLUSION

Both models can contribute to an improved early identification of persons at risk for dementia in primary care.

Detection of cognitive impairment and dementia using the animal fluency test: the DECIDE study

OBJECTIVES

To evaluate the performance of a one-minute screening test measured against a validated 10-minute screening test for mild cognitive impairment (MCI) in detecting CI in patients aged > or = 65 years with two or more vascular risk factors (VRF).

METHODS

Patients (n=1523) aged 65 years or older without documented CI symptoms or dementia with two or more VRF participated in this study set in Canadian primary care practice. Baseline data was collected, followed by the 1-minute animal fluency (AF) test and the 10-minute Montreal Cognitive Assessment (MoCA). Physicians (n=122) completed case reports during patient interviews and reported their diagnostic impression. AF test sensitivity, specificity, and accuracy in predicting a positive MoCA was assessed.

RESULTS

Study sample mean age was 79.7 years, 55% were female, 97.6% were Caucasian and 75% had < or = 12 years of education. The AF test and MoCA detected CI in 52 and 56 percent of the study population, respectively. The AF test demonstrated sensitivity, specificity, and accuracy in predicting a positive MoCA of 67 percent each. Physicians diagnostic impression of MCI was reported for 37% of patients, and of dementia for 6%.

CONCLUSION

In an elderly population with at least two VRF, using AF can be useful in detecting previously unknown symptoms of CI or dementia. Screening for CI in this high risk population is warranted to assist physician recognition of early CI. The short AF administration time favours its incorporation into clinical practice.

Health behaviors from early to late midlife as predictors of cognitive function: The Whitehall II study

The authors examined associations of health behaviors over a 17-year period, separately and in combination, with cognition in late midlife in 5,123 men and women from the Whitehall II study (United Kingdom). Health behaviors were assessed in early midlife (mean age = 44 years; phase 1, 1985-1988), in midlife (mean age = 56 years; phase 5, 1997-1999), and in late midlife (mean age = 61 years; phase 7, 2002-2004). A score of the number of unhealthy behaviors (smoking, alcohol abstinence, low physical activity, and low fruit and vegetable consumption) was defined as ranging from 0 to 4. Poor (defined as scores in the worst sex-specific quintile) executive function and memory in late midlife (phase 7) were analyzed as outcomes. Compared with those with no unhealthy behaviors, those with 3-4 unhealthy behaviors at phase 1 (odds ratio (OR) = 1.84, 95% confidence interval (CI): 1.27, 2.65), phase 5 (OR = 2.38, 95% CI: 1.76, 3.22), and phase 7 (OR = 2.76, 95% CI: 2.04, 3.73) were more likely to have poor executive function. A similar association was observed for memory. The odds of poor executive function and memory were the greater the more times the participant reported unhealthy behaviors over the 3 phases. This study suggests that both the number of unhealthy behaviors and their duration are associated with subsequent cognitive function in later life.

Peripheral arterial disease and cognitive function

As a marker of generalized atherosclerosis, peripheral arterial disease (PAD) has implications not only for the affected lower extremity but also to overall cardiovascular health. It confers an increased risk of non-fatal and fatal vascular events which increases with the severity of the disease. Patient-based studies have shown that individuals with advanced PAD tend to perform poorly on cognitive tests compared to controls. In population studies, PAD is associated with an increased cognitive decline independently of previous cerebrovascular disease and cardiovascular risk factors. A low ankle-brachial index (ABI) may be an early predictor of cognitive decline and of potential value in identifying individuals at increased risk of cognitive impairment. In patients with PAD, secondary preventive measures directed at decreasing the long-term systemic vascular complications may also be important to the preservation of cognitive health. However, evidence suggests that PAD patients may be undertreated with regard to atherosclerotic risk factors, as demonstrated by an undue emphasis on symptom relief rather than essential risk factor reduction. More research needs to be carried out to determine the predictors of cognitive function in PAD patients, whether subtle cognitive disturbances are related to activities of daily living, including medical treatment compliance, and whether neuroprotective strategies and atherosclerotic risk factor control positively influence cognitive function in these high-risk patients.

Homocysteine, cystatin C and N-terminal-pro brain natriuretic Peptide. Vascular risk markers in elderly patients with mental illness

BACKGROUND

There is increasing evidence that vascular disease contributes to cognitive impairment and dementia. Clarification of the role of vascular risk factors in dementia is important because most are modifiable, in contrast to other risk factors such as age and genetics.

METHODS

In 451 patients with mental illness we have investigated three biochemical markers related to vascular disease, total plasma homocysteine (tHcy), cystatin C, and N-terminal-pro brain natriuretic peptide (NT-proBNP), and their association with vascular disease, diagnoses, and brain imaging findings (CT).

RESULTS

Plasma tHcy, serum cystatin C, and serum NT-proBNP showed significantly increased frequencies of elevated levels in patients with vascular disease, in patients with a pathological CT finding indicating cerebrovascular disease, and in patients above 75 years of age.

CONCLUSION

It is possible that the control of conventional vascular risk factors and therapy could be guided by the level of plasma tHcy, serum cystatin C, and serum NT-proBNP. Patients with an elevation of any of these three parameters could be selected for a lower target level of risk factors such as blood pressure, hyperlipidemia etc. than conventional target levels.

Hypertension and cognitive function in the elderly

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

Cardiovascular diseases and decline in cognitive function in an elderly community population: the Edinburgh Artery Study

OBJECTIVE

To investigate cognitive performance and 4-year change in cognitive function in relation to different clinical manifestations of atherosclerotic disease in an elderly community population.

METHODS

The Edinburgh Artery Study is a population cohort study of men and women who were recruited to a baseline survey in 1987 and 1988. From the time of study entry, the participants have been invited to two follow-up clinical examinations and continuously monitored for major fatal and nonfatal vascular events. All alive and eligible subjects were invited for cognitive testing in two study years when the mean age of the sample was 73.1 (standard deviation = 5.0) years. A follow-up cognitive assessment was performed in 2002 and 2003 on 452 survivors.

RESULTS

In multivariate analyses controlling for demographic characteristics, depression, and major atherosclerotic risk factors, stroke was associated with a significantly worse performance on tests of verbal memory (p = .02) and letter fluency (p = .002). In addition, stroke was related to a significantly steeper 4-year decline in verbal memory performance (p = .04). Among the subjects who had not had an overt stroke, those with symptomatic peripheral arterial disease experienced a significantly greater 4-year decline in verbal memory functioning (p = .04).

CONCLUSIONS

In older people, stroke is associated with both worse performance on cognitive tests and progressive verbal memory decline. Elderly individuals with vascular diseases other than stroke may also be vulnerable to a greater decline in verbal memory function. A relationship between vascular diseases and verbal memory decline may exist independently of depressed mood and major atherosclerotic risk factors.

Blood Pressure Treatment and Cognition in the Elderly

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

Recommendations for best practices in the treatment of Alzheimer's disease in managed care

BACKGROUND

Alzheimer's disease and related dementias (ADRDs) are increasingly recognized as important causes of impaired cognition, function, and quality of life, as well as excess medical care utilization and costs in the elderly Medicare managed care population. Evidence-based clinical practice guidelines for ADRDs were published in 2001. More recent studies have resulted in the approval of new agents and demonstrated an expanded role for antidementia therapy in various types of dementia, settings of care, stages of disease, and the use of combination therapy. However, these clinical guidelines have not been updated in the past few years.

OBJECTIVE

The goal of this article was to provide practical recommendations developed by a panel of experts that address issues of early diagnosis, treatment, and care management of ADRDs. The panel also addressed the societal and managed care implications.

METHODS

A panel of leading experts was convened to develop consensus recommendations for the treatment and management of dementia based on currently available evidence and the panel's informed expert opinion. The panel comprised 12 leading experts, including clinical investigators and practitioners in geriatric medicine, neurology, psychiatry, and psychology; managed care medical and pharmacy directors; a health systems medical director; and a health policy expert. In addition, articles were collected based on PubMed searches (2000-2005) that were relevant to the key issues identified. Search terms included Alzheimer's disease, dementia, clinical practice guidelines, clinical trials, screening and assessment, and managed care.

RESULTS

ADRDs represent a significant clinical and economic burden to individuals and society, including Medicare managed care organizations (MCOs). Appropriate utilization of antidementia therapy and care management is vitally important to achieving quality of life and care for dementia patients and their caregivers, and for managing the excess costs of Alzheimer's disease. The recommendations address relevant, practical, and timely concerns that are faced on a daily basis by practitioners and by Medicare MCO medical management programs in the care of dementia patients. These consensus recommendations attempt to describe a reasonable current standard for the provision of quality care for patients with dementia. The panel recommendations support the use of screening for cognitive impairment and the use of antidementia therapy for ADRDs in different stages of disease and types of dementia in all clinical settings. The panel members evaluated the use of the 3 marketed cholinesterase inhibitors-donepezil, galantamine, and rivastigmine-as well as the N-methyl-D-aspartate antagonist memantine. Recommendations for using these medications are made with an appreciation of the difficulties in translating the results from investigational clinical trials into clinical practice.

CONCLUSIONS

The recommendations of the expert panel represent a clear consensus that nihilism in the diagnosis, treatment, and management of ADRDs is unwarranted, impairs quality of care, and is ultimately not costeffective.