Vascular factors and prevention of dementia

Optimal cardiovascular health is associated with slower cognitive decline

BACKGROUND

Life's Simple 7, a lifestyle and cardiovascular index associated with cognition, has been updated to Life's Essential 8 (LE8) to include sleep. LE8 has been related to cardiovascular outcomes but its association with cognition is unclear.

METHODS

In this longitudinal analysis of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), LE8 score was based on health behaviors (diet, physical activity, nicotine exposure, and sleep health) as well as health-related factors (body mass index, blood lipids, blood glucose, and blood pressure). Cognition was assessed in three waves, 4 years apart, using the Consortium to Establish a Registry for Alzheimer's Disease - Word List, semantic and phonemic verbal fluency, the Trail-Making Test B (TMT-B), and a global composite score. We used linear mixed-model analysis, inverse probability weighting, and interaction analysis.

RESULTS

At baseline, the mean age of the study cohort was 51.4 ± 8.9 years, 56% were women, and 53% were White. Higher baseline LE8 scores were associated with slower decline in global cognition (β = 0.001, 95% confidence interval [CI] 0.001, 0.002; p < 0.001), memory (β = 0.001, 95% CI 0.000, 0.002; p = 0.013), verbal fluency (β = 0.001, 95% CI 0.000, 0.002; p = 0.003), and TMT-B (β = 0.004, 95% CI 0.003, 0.005; p < 0.001). This association was mainly driven by LE8 health factors, particularly blood glucose and blood pressure. Age, sex, and race were modifiers of the association between LE8 and global cognitive decline (p < 0.001), suggesting it was more pronounced in older, male, and Black participants.

CONCLUSIONS

Higher baseline LE8 scores were associated with slower global and domain-specific cognitive decline during 8 years of follow-up, mainly due to health factors such as blood glucose and blood pressure. Sociodemographic factors were modifiers of this association.

Poor pulmonary function is associated with mild cognitive impairment, its progression to dementia, and brain pathologies: A community-based cohort study

INTRODUCTION

The relationship between pulmonary function (PF) and mild cognitive impairment (MCI), dementia, and brain pathologies remains unclear.

METHODS

A total of 1312 dementia-free participants, including a cognitively intact group (n = 985) and an MCI group (n = 327), were followed for up to 21 years to detect incident MCI and dementia. PF was assessed at baseline with a composite score and tertiled. Over follow-up, 540 participants underwent autopsies for neuropathological assessment.

RESULTS

Compared to the highest PF, the hazard ratios (95% confidence intervals [CIs]) of the lowest PF were 1.95 (1.43-2.66) for MCI in the cognitively intact group and 1.55 (1.03-2.33) for dementia in the MCI group. Low PF was further related to Alzheimer's disease pathology (odds ratio [OR] 1.32, 95% CI 1.19-1.47) and vascular pathology (OR 3.05, 95% CI 1.49-6.25).

DISCUSSION

Low PF increases MCI risk and accelerates MCI progression to dementia. Both neurodegenerative and vascular mechanisms may underlie the PF-dementia association.

Respiratory Disease and Lower Pulmonary Function as Risk Factors for Dementia: A Systematic Review With Meta-analysis

BACKGROUND

In addition to affecting the oxygen supply to the brain, pulmonary function is a marker of multiple insults throughout life (including smoking, illness, and socioeconomic deprivation). In this meta-analysis of existing longitudinal studies, the hypothesis that lower pulmonary function and respiratory illness are linked to an elevated risk of dementia was tested.

METHODS

A systematic review was conducted of longitudinal studies using PubMed until April 1, 2019, and, where possible, results were pooled in random effects meta-analyses.

RESULTS

Ten studies relating pulmonary function to later dementia risk and 11 studies of respiratory illness and dementia (including one that assessed both factors) were identified. The lowest quartile of FEV₁ compared with the highest was associated with a 1.4-fold (hazard ratio [HR], 1.46; 95% CI, 0.77-2.75) increased dementia risk (N_total = 62,209; two studies). A decrease of 1 SD in FEV₁ was associated with a 28% increase in dementia risk (HR, 1.28; 95% CI, 1.03-1.60; N_total = 67,505; six studies). Respiratory illness was also associated with increased dementia risk to a similar degree (pooled HR, 1.54; 95% CI, 1.30-1.81; N_total = 288,641; 11 studies).

CONCLUSIONS

Individuals with poor pulmonary function experience an increased risk of dementia. The extent to which the association between poor pulmonary function and dementia is causal remains unclear and requires examination.

Cerebral vascular structure in the motor cortex of adult mice is stable and is not altered by voluntary exercise

The cerebral vasculature provides blood flow throughout the brain, and local changes in blood flow are regulated to match the metabolic demands of the active brain regions. This neurovascular coupling is mediated by real-time changes in vessel diameter and depends on the underlying vascular network structure. Neurovascular structure is configured during development by genetic and activity-dependent factors. In adulthood, it can be altered by experiences such as prolonged hypoxia, sensory deprivation and seizure. Here, we have sought to determine whether exercise could alter cerebral vascular structure in the adult mouse. We performed repeated in vivo two-photon imaging in the motor cortex of adult transgenic mice expressing membrane-anchored green fluorescent protein in endothelial cells (tyrosine endothelial kinase 2 receptor (Tie2)-Cre:mTmG). This strategy allows for high-resolution imaging of the vessel walls throughout the lifespan. Vascular structure, as measured by capillary branch point number and position, segment diameter and length remained stable over a time scale of months as did pericyte number and position. Furthermore, we compared the vascular structure before, during, and after periods of voluntary wheel running and found no alterations in these same parameters. In both running and control mice, we observed a low rate of capillary segment subtraction. Interestingly, these rare subtraction events preferentially remove short vascular loops.

The mediational role of physical activity, social contact and stroke on the association between age, education, employment and dementia in an Asian older adult population

BACKGROUND

Our study aimed to investigate the pathways by which socio-demographic factors, modifiable health and lifestyle risk factors influence each other, and subsequently, lead to dementia.

METHODS

We used data from the Well-being of the Singapore Elderly study, a nationally representative survey of the older adult population aged 60 years and above in Singapore. Dementia diagnosis was established using 10/66 dementia criteria. Structural equation modelling (SEM) without latent variable was applied to confirm the hypothesized model.

RESULTS

The results of SEM supported the hypothesized model (χ ² = 14.999, df = 10, p = 0.132). The final model showed that those aged 75-84 years and 85 years and over (vs. 60-74 years), having no formal education, who had completed primary or secondary education (vs. completed tertiary), who were homemakers and retired (vs. paid work), and with a history of stroke were directly associated with higher odds of having dementia, while those who had more frequent contact with friends and neighbors as well as being physically active were directly associated with lower odds of having dementia diagnosis. The study also found that physical activity, more frequent contact with friends and stroke played a significant role as mediators in these relationships. The overall pathways model explained 57.7% of the variance in dementia.

CONCLUSION

Our results suggest that physical activity, social contact and stroke were potential mediators in the relationship between age, education, employment and dementia. Intervention programmes focusing on physical activity such as exercise and social contact may be useful in reducing the risk of dementia among older adults.

Cognitive Impairment Among the Aging Population in a Community in Southwest Nigeria

Background. Vascular risk models can be quite informative in assisting the clinician to make a prediction of an individual’s risk of cognitive impairment. Thus, a simple marker is a priority for low-capacity settings. This study examines the association of selected simple to deploy vascular markers with cognitive impairment in an elderly population. Method. This cross-sectional study assessed the cognitive functions of older persons 65 years and older in southwest Nigeria. Vascular parameters and risk factors were also measured. Analysis was done using SPSS, and logistic regression was used to explore the association between cognitive impairment and certain vascular risk factors such as elevated blood pressure, diabetes, and pulse pressure. Results. The study population comprised 623 participants (29.1% men) with mean age 73 ± 8.9 years. Having mean arterial pressure (MAP) and pulse pressure in the fourth quartiles (27% and 29.9%, respectively) was significantly associated with cognitive impairment ( p = .001, p < .001). Predicted cardiovascular risks of 10% or more was significantly associated with cognitive impairment ( p < .001). After adjusting for age, gender, educational level, and years of smoking, those with MAP in the fourth quartile were up to 3 times more likely to have cognitive impairment compared to those within the first quartile. Conclusion. Our study demonstrated that among elderly Nigerians, MAPs of 114 mmHg and more was an independent predictor of cognitive impairment. This is a simple measure that is available in low-capacity areas.

Brain, Learning, and Memory: Role of H2S in Neurodegenerative Diseases

For more than 300 years, the toxicity of hydrogen sulfide (H2S) has been known to mankind. However, this point of view is changing as an increased interest was observed in H2S biology in the last two decades. The scientific community has succeeded to unravel many important physiological and pathological effects of H2S on mammalian body systems. Thus, H2S is now referred to as a third endogenous gaseous mediator along with nitric oxide and carbon monoxide. Acting as a neuromodulator, H2S facilitates long-term potentiation and regulates intracellular calcium levels, which are important processes in learning and memory. Aberrant endogenous production and metabolism of H2S are implicated in pathogenesis of neurodegenerative diseases including Alzheimer's disease (AD) and Parkinson's disease (PD). Various H2S donors have shown beneficial therapeutic effects in neurodegenerative disease models by targeting hallmark pathological events (e.g., amyloid-β production in AD and neuroinflammation in PD). The results obtained from many in vivo studies clearly show that H2S not only prevents neuronal and synaptic deterioration but also improves deficits in memory, cognition, and learning. The anti-inflammatory, antioxidant, and anti-apoptotic effects of H2S underlie its neuroprotective properties. In this chapter, we will overview the current understanding of H2S in context of neurodegenerative diseases, with special emphasis on its corrective effects on impaired learning, memory, and cognition.

Arterial Stiffness Predicts Cognitive Decline in Japanese Community-dwelling Elderly Subjects: A One-year Follow-up Study

AIM

The purpose of this study was to determine whether arterial stiffness can be used to predict one-year changes in the cognitive function in Japanese community-dwelling elderly subjects.

METHODS

A total of 103 Japanese community-dwelling elderly patients joined this study. Information regarding the age, height, weight, gender and past medical history of each participant was obtained. Additionally, arterial stiffness was determined according to the cardio-ankle vascular index (CAVI), and the cognitive function was assessed with the Mini-Mental State Examination (MMSE). One year later, we performed the MMSE in the same subjects. After dividing the cohort according to the 80th percentile of the CAVI (normal and arterial stiffness [AS] groups), we examined whether the degree of cognitive decline, as determined using the pre- and post-MMSE, was significantly different based on the severity of arterial stiffness, adjusted for age, BMI, gender and the pre-MMSE scores.

RESULTS

Of the 103 subjects who participated in the pre-data collection, 74 (38 men and 36 women, 73.4±4.0 years) joined the post-data collection. We found a significant difference in the change in the post-MMSE scores between the normal and AS groups (pre-MMSE: normal group [27.4±2.1] and AS group [26.9±2.4] and post-MMSE: normal group [27.2±2.1] and AS group [25.5±2.3], F=5.95, p=0.02). For each domain of the MMSE, the changes in MMSE-attention-and-calculation (F=5.11, p=0.03) and MMSE-language (F=4.32, p=0.04) were significantly different according to an ANCOVA.

CONCLUSIONS

We found that arterial stiffness predicts cognitive decline in Japanese community-dwelling elderly subjects regardless of the initial level of the global cognitive function. This finding indicates the potential use of the degree of arterial stiffness as an indicator for preventing or delaying the onset of dementia in the elderly.

Cardiovascular disease risk models and longitudinal changes in cognition: a systematic review

Background

Cardiovascular disease and its risk factors have consistently been associated with poor cognitive function and incident dementia. Whether cardiovascular disease prediction models, developed to predict an individual's risk of future cardiovascular disease or stroke, are also informative for predicting risk of cognitive decline and dementia is not known.

Objective

The objective of this systematic review was to compare cohort studies examining the association between cardiovascular disease risk models and longitudinal changes in cognitive function or risk of incident cognitive impairment or dementia.

Materials and Methods

Medline, PsychINFO, and Embase were searched from inception to March 28, 2014. From 3,413 records initially screened, 21 were included.

Results

The association between numerous different cardiovascular disease risk models and cognitive outcomes has been tested, including Framingham and non-Framingham risk models. Five studies examined dementia as an outcome; fourteen studies examined cognitive decline or incident cognitive impairment as an outcome; and two studies examined both dementia and cognitive changes as outcomes. In all studies, higher cardiovascular disease risk scores were associated with cognitive changes or risk of dementia. Only four studies reported model prognostic performance indices, such as Area Under the Curve (AUC), for predicting incident dementia or cognitive impairment and these studies all examined non-Framingham Risk models (AUC range: 0.74 to 0.78).

Conclusions

Cardiovascular risk prediction models are associated with cognitive changes over time and risk of dementia. Such models are easily obtainable in clinical and research settings and may be useful for identifying individuals at high risk of future cognitive decline and dementia.

Relating education, brain structure, and cognition: the role of cardiovascular disease risk factors

The protective effect of education on cognitive and brain health is well established. While the direct effects of individual cardiovascular disease (CVD) risk factors (i.e., hypertension, smoking, diabetes, and obesity) on cerebral structure have been investigated, little is understood about the possible interaction between the protective effect of education and the deleterious effects of CVD risk factors in predicting brain ageing and cognition. Using data from the PATH Through Life study (N = 266), we investigated the protective effect of education on cerebral structure and function and tested a possible mediating role of CVD risk factors. Higher education was associated with larger regional grey/white matter volumes in the prefrontal cortex in men only. The association between education and cognition was mediated by brain volumes but only for grey matter and only in relation to information processing speed. CVD risk factors did not mediate the association between regional volumes and cognition. This study provides additional evidence in support for a protective effect of education on cerebral structures and cognition. However, it does not provide support for a mediating role of CVD risk factors in these associations.

The relationship between abuse, psychosocial factors, and pain complaints among older persons in Europe

BACKGROUND AND OBJECTIVE

Abuse and pain complaints are common among older persons. However, little is known about relationships between abuse (e.g. psychological) and pain complaints (e.g. backache) among older persons while considering other factors (e.g. depression). Therefore, the aim of this study was to determine these relationships.

MATERIALS AND METHODS

The design was cross-sectional. A total of 4467 women and men aged 60-84 years from Germany, Greece, Italy, Lithuania, Portugal, Spain, and Sweden answered questionnaires regarding various areas such as abuse, mental health (e.g. anxiety) and pain complaints (e.g. backache). The data were examined with bivariate (analyses of variance) and multivariate methods (linear regressions).

RESULTS

The bivariate analyses showed that psychological abuse was connected with all pain complaints; physical with headache and head pressure; sexual with neck or shoulder pain and headache; injury with all complaints (except pain in joints or limbs); financial with pain in joints or limbs and head pressure; and overall abuse (one or more types) with all complaints (except headache). The regressions showed that psychological abuse increased the likelihood of being affected by head pressure and heaviness or tiredness in the legs; physical abuse of being affected by headache and head pressure; financial abuse of being affected by head pressure; and overall abuse of being affected by headache and head pressure. In general, respondents from Sweden and younger (60-64 years) were less affected by the complaints than those from other countries (e.g. Germany) and older (e.g. 70-74 years), respectively. Respondents on medication (e.g. pain killers) were less affected by all pain complaints and those with high social support by pain in joints or limbs. High scores on anxiety and depression and having many diseases increased the likelihood of being affect by all pain complaints.

CONCLUSIONS

Abuse was related with certain pain complaints (e.g. headache), but other factors and in particular mental health and physical diseases impacted on all pain complaints. Medication and partly social support had a positive effect on the pain experience, i.e. the complaints interfered less with for instance the daily-life of the respondents.

Active music therapy improves cognition and behaviour in chronic vascular encephalopathy: a case report

OBJECTIVES

This study describes the effects of active music therapy (AMT) on cognition and behaviour in chronic vascular encephalopathy.

DESIGN

A single case study investigated different cognitive and psycho-behavioural changes after AMT.

SETTING

An adult patient with memory, attention, and verbal fluency deficits associated with Vascular Cognitive Impairment-No Dementia (VCI-ND) was treated.

INTERVENTION

A four-months AMT course was based on creative and interactive music playing. Sixteen sessions were conducted simultaneously to the pharmacological therapy.

MAIN OUTCOMES MEASURES

Cognitive performances, mood, interpersonal interactions, and perceived abilities were assessed using standardized neuropsychological and psycho-behavioural measurements.

RESULTS

At baseline, the patient reported a tendency to feel tense, nervous, and angry and difficulties in memory and visuospatial performances, frequently accompanied by attention drops. The social network was a habitual component of the patient's life, but not a source of sharing of personal experiences, safety or comfort. Neuropsychological tests showed deficits in object and figure naming, verbal fluency, short and long-term verbal memory, short-term spatial memory, selective attention, and visuomotor coordination. After AMT, the cognitive profile significantly improved in attention, visuomotor coordination, and verbal and spatial memory. Such positive changes were confirmed at the three-months follow-up. An increase of the interpersonal interactions and consistent reduction of anxiety were also observed.

CONCLUSIONS

In selected patients with VCI-ND, a well-structured AMT intervention added to standard therapy may contribute in determining a stable improvement of cognitive and psycho-behavioural aspects. Controlled studies are needed to confirm these promising results.

History of lifetime smoking, smoking cessation and cognitive function in the elderly population

To examine potential associations of the history of lifetime smoking and smoking cessation with cognitive function in the elderly. In a population-based cohort study of older adults in Saarland, Germany, a detailed lifetime history of smoking was obtained using standardised questionnaires. Cognitive function was assessed with a validated telephone-based instrument (COGTEL) at the five-year follow-up in a subsample of n = 1,697 participants with a baseline age >65 years. Multiple linear regression models were employed to predict cognitive performance, adjusting for potential confounding factors. Ever-smokers with a higher cumulative dose of smoking in pack-years scored lower in the cognitive assessment than never-smokers, with the association being more pronounced in current smokers than in former smokers. In fully adjusted models, current smokers with 21-40 pack-years scored 4.06 points lower (95 % CI -7.18 to -0.94) than never-smokers. In former smokers, a longer time since smoking cessation was associated with higher scores in the cognitive test with reference to current smokers, even after adjustment for pack-years. Former smokers who had quit for more than 30 years scored 4.23 points higher (95 % CI 1.75 to 6.71) than current smokers. Dose-response-relationships of cognitive function with cumulative dose of smoking as well as with time since smoking cessation were substantiated by restricted cubic splines regression. Our results support suggestions that smokers are at an increased risk for cognitive impairment in older age; that the risk increases with duration and intensity of smoking, and subsides with time after smoking cessation.

Cardiovascular risk factors and cognitive decline in adults aged 50 and over: a population-based cohort study

OBJECTIVES

the objective of the present study was to explore the association between cardiovascular risk and cognitive decline in adults aged 50 and over.

METHODS

participants were older adults who participated in the English Longitudinal Study of Ageing. Outcome measures included standardised z-scores for global cognition, memory and executive functioning. Associations between cardiovascular risk factors and 10-year Framingham risk scores with cognitive outcomes at 4-year and 8-year follow-ups were estimated.

RESULTS

the mean age of participants (n = 8,780) at 2004-05 survey was 66.93 and 55% were females. Participants in the highest quartile of Framingham stroke risk score (FSR) had lower global cognition (b = -0.73,CI: -1.37, -0.10), memory (b = -0.56, CI: -0.99, -0.12) and executive (b = -0.37, CI: -0.74, -0.01) scores at 4-year follow-up compared with those in the lower quartile. Systolic blood pressure ≥160 mmHg at 1998-2001 survey was associated with lower global cognitive (b = -1.26, CI: -2.52, -0.01) and specific memory (b = -1.16, CI: -1.94, -0.37) scores at 8-year follow-up. Smoking was consistently associated with lower performance on all three cognitive outcomes.

CONCLUSION

elevated cardiovascular risk may be associated with accelerated decline in cognitive functioning in the elderly. Future intervention studies may be better focused on overall risk rather than individual risk factor levels.

The epidemiological neuropathology of dementia and the implications for drug development

SUMMARY Identification of the determinants and risk factors for dementia, in addition to the underlying brain changes associated with disease, is fundamental to the development of dementia therapeutics. The gold standard to achieving this is through population-based (epidemiological) studies of the biology of aging, cognitive decline and dementia. In this paper, the main findings from epidemiological cohorts on dementia pathology are compared to case–control and convenience samples, and findings on the different neuropathological features of dementia, its risk factors and clinical course are summarized. The strengths and weakness of different research designs, the keys aspects of disease these have identified and the targets that have been subsequently developed will be discussed. It is highlighted that dementia within epidemiological frameworks is found to be a heterogeneous disease. For treatment to be effective it will therefore need to reflect not only population variation in patterns of pathology, but also intra-individual reactions to these treatments.

Reduction of Long-Term Care Dependence After an 8-Year Primary Care Prevention Program for Stroke and Dementia: The INVADE Trial

BACKGROUND

Stroke and dementia are the major causes for long-term care (LTC) dependence in old age. This intervention trial compared a multidomain prevention program for stroke and dementia with usual medical care in reducing the need for LTC.

METHODS AND RESULTS

The Intervention Project on Cerebrovascular Disease and Dementia in the District of Ebersberg (INVADE) was a general practice-based 8-year trial in 2 defined catchment areas in Upper Bavaria, Germany. All 11 317 insurants of a statutory health insurance plan who were ≥55 years of age and lived in the intervention district were offered the opportunity to participate in a prevention program; 3908 enrolled. The 13 301 insurants in the reference district received usual medical care. The intervention consisted of the systematic identification and evidence-based treatment of vascular risk factors. The primary clinical end point was incidence of LTC dependence according to external assessment by a special medical service in the framework of the statutory German LTC insurance. Age- and sex-specific incidence rates from the reference district were used to calculate the expected number of cases of LTC dependence under usual medical care. The expected number was compared with the observed number of cases in the intervention district. Analysis was by intention to treat. During the 5 years after completion of the recruitment period, significantly fewer incident cases of LTC dependence arose in the intervention district than expected (χ(2)=13.25; P<0.001). In women, the incidence was reduced by 10% (P<0.01). In men, the incidence was reduced by 9.6% (P<0.05).

CONCLUSIONS

Our results support the feasibility and effectiveness of a primary care prevention program for stroke and dementia to reduce the risk of developing LTC dependence.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01107548. (J Am Heart Assoc. 2012;1:e000786 doi: 10.1161/JAHA.112.000786.).

Brain perfusion SPECT imaging and acetazolamide challenge in vascular cognitive impairment

Cerebrovascular disease is recognized as a common cause of cognitive impairment and dementia, alone or coexisting with other neurodegenerative diseases, mostly Alzheimer's disease. Vascular cognitive impairment (VCI) is a part of the heterogenous disorders group related to cerebral vessel disease. Although age is one of the most important risk factors for VCI, other common cardiovascular risk factors are also involved. By investigating these risk factors, a high proportion of these cognitive disorders can be prevented and/or delayed. Until now, only treatment of midlife arterial hypertension has been recognized as a preventing factor of vascular dementia. Brain MRI is becoming the method of choice to investigate cerebral vascular pathologies. However, this form of morphological imaging remains inadequate and does not provide useful functional information during VCI exploration, despite which functional imaging such as brain perfusion single-photon computed tomography, performed in baseline conditions and/or after an acetazolamide challenge, is underutilized in VCI exploration. The common strategies for VCI screening have not been standardized until now, and therefore further long-term imaging studies are needed to establish early diagnostic protocols. The present review summarizes the potential benefits of brain perfusion single-photon computed tomography imaging and possible scintigraphic quantification of cerebral hemodynamic reserves in investigation of VCI.

Blood pressure, smoking and alcohol use, association with vascular dementia

The success of the ageing global population brings with it a growth in the number of dementia sufferers. Older adults are at highest risk of dementia and are likely to manifest both vascular and Alzheimer's pathology. Blood pressure also changes with ageing and there is evidence linking high blood pressure in midlife to an increased risk of later dementia. Data from later life is sparser. A number of intervention trials have been carried out with antihypertensives and have shown mixed results with regard to cognitive and dementia outcomes (both dementia overall and of vascular and Alzheimer's types). Meta-analyses have in general not found an association between blood pressure lowering and reduced dementia incidence, although the number of cases reported in the placebo controlled trials is invariably lower in the actively treated group. Systematic reviews and meta-analyses have also been published with regard to smoking and alcohol use and incident dementia. Despite mixed reports, overall smoking was associated with an increased risk of later dementia and alcohol with a 'U' or 'J' shaped relationship. Following the systematic reviews subsequent publications tend to report similar findings. The literature in this area suffers from differing populations, lengths of follow up and assessments of both risk factor and outcome. However, at present, maintenance of cognitive function would seem to be best served by treating cardiovascular risk factors in accordance with current guidelines, controlling blood pressure, reducing smoking and if consuming alcohol doing so in moderation. This review will concentrate on the prevention of dementia and attempt to provide an overview of the evidence relating to vascular related dementia and the potential risk factors of hypertension, alcohol use and smoking behaviour.

Is illicit drug use harmful to cognitive functioning in the midadult years? A cohort-based investigation

From March to July of 2011, the authors investigated the prospective association between illicit drug use and cognitive functioning during the midadult years. A total of 8,992 participants who were surveyed at 42 years of age in the National Child Development Study (1999-2000) were included. The authors analyzed data on 3 cognitive functioning measures (memory index, executive functioning index, and overall cognitive index) when the participants were 50 years of age (2008-2009). Illicit drug use at 42 years of age was based on self-reported current or past use of any of 12 illicit drugs. Multivariable regression analyses were performed to estimate the association between different illicit drug use measures at 42 years of age and cognitive functioning at 50 years of age. A positive association was observed between ever (past or current) illicit drug use and cognitive functioning (β = 0.62, P < 0.001), although the effect size was small. Even though there was no clear evidence against the null hypothesis, drug dependence (β = -0.27, P = 0.58) and long-term illicit drug use (β = -0.04, P = 0.87) tended to be negatively associated with cognitive functioning. At the population level, it does not appear that current illicit drug use is associated with impaired cognitive functioning in early middle age. However, the authors cannot exclude the possibility that some individuals and groups, such as those with heavier or more prolonged use, could be harmed.

Systematic review on the efficacy and safety of herbal medicines for vascular dementia

We present a systematic review of existing research that aims to assess the efficacy and safety of herbal medications (HM), as either monotherapy or adjunct to orthodox medications (OM), mainly comprised of cholinesterase inhibitors, for vascular dementia (VaD). We included 47 studies conducted in mainland China, each testing different HM. Of 43 HM monotherapy studies, 37 reported HM to be significantly better than OM or placebo; six reported similar efficacy between HM and OM. All four HM adjuvant studies reported significant efficacy. No major adverse events for HM were reported. Heterogeneity in diagnostic criteria, interventions and outcome measures hindered comprehensive data analysis. Studies suggested that HM can be a safe and effective treatment for VaD, either alone or in conjunction with OM. However, methodological flaws in the design of the studies limited the extent to which the results could be interpreted. Thirty most commonly used herbal constituents, including Rhizoma Chuanxiong (Chuanxiong in Chinese), Radix Polygoni Multiflori (Heshouwu in Chinese) and Radix Astragali (Huangqi in Chinese). were ranked. Further multi-center trials with large sample sizes, high methodological quality and standardized HM ingredients are necessary for clinical recommendations to be made.

Tetrahydroxystilbene glucoside, a plant-derived cognitive enhancer, promotes hippocampal synaptic plasticity

Plant or food derived polyphenols have received a great deal of attention due to their biological properties including anti-oxidative effects, neuroprotection and memory enhancement. Here, we investigated the roles of 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside (TSG), an active component of the rhizome extracted from Polygonum multiflorum, in the regulation of hippocampal synaptic plasticity in normal mice as well as the underlying mechanisms. It was shown that TSG promoted the differentiation of PC12 cells and increased the intracellular calcium level in hippocampal neurons. TSG facilitated high-frequency stimulation (HFS)-induced hippocampal long-term potentiation (LTP) in a bell-shaped manner. The facilitation of LTP induction by TSG required calcium/calmodulin-dependent protein kinase II (CaMKII) and extracellular signal-regulated kinase (ERK) activation. Taken together, our data demonstrate that TSG promotes LTP induction and this effect may contribute to the enhancement of learning and memory seen in animal models.

The inclusion of cognition in vascular risk factor clinical practice guidelines

BACKGROUND

People with vascular risk factors are at increased risk for cognitive impairment as well as vascular disease. The objective of this study was to evaluate whether vascular risk factor clinical practice guidelines consider cognition as an outcome or in connection with treatment compliance.

METHODS

Articles from PubMed, EMBASE, and the Cochrane Library were assessed by at least two reviewers and were included if: (1) Either hypertension, high cholesterol, diabetes, or atrial fibrillation was targeted; (2) The guideline was directed at physicians; (3) Adult patients (aged 19 years or older) were targeted; and (4) The guideline was published in English. Of 91 guidelines, most were excluded because they were duplicates, older versions, or focused on single outcomes.

RESULTS

Of the 20 clinical practice guidelines that met inclusion criteria, five mentioned cognition. Of these five, four described potential treatment benefits but only two mentioned that cognition may affect compliance. No guidelines adequately described how to screen for cognitive impairment.

CONCLUSION

Despite evidence that links cognitive impairment to vascular risk factors, only a minority of clinical practice guidelines for the treatment of vascular risk factors consider cognition as either an adverse outcome or as a factor to consider in treatment.

Beyond mild cognitive impairment: vascular cognitive impairment, no dementia (VCIND)

Identifying the causes of dementia is important in the search for effective preventative and treatment strategies. The concept of mild cognitive impairment (MCI), as prodromal dementia, has been useful but remains controversial since in population-based studies it appears to be a limited predictor of progression to dementia. Recognising the relative contribution of neurodegenerative and vascular causes, as well as their interrelationship, may enhance predictive accuracy. The concept of vascular cognitive impairment (VCI) has been introduced to describe the spectrum of cognitive change related to vascular causes from early cognitive decline to dementia. A recent review of this concept highlighted the need for diagnostic criteria that encompass the full range of the VCI construct. However, very little is known regarding the mildest stage of VCI, generally termed 'vascular cognitive impairment, no dementia' (VCIND). Whether mild cognitive change in the context of neurodegenerative pathologies is distinct from that in the context of cerebrovascular diseases is not known. This is key to the definition of VCIND and whether it is possible to identify this state. Distinguishing between vascular (that is, VCIND) and non-vascular (that is, MCI) cognitive disorders and determining how well each might predict dementia may not be possible due to the overlap in pathologies observed in the older population. Here, we review the concept of VCIND in an effort to identify recent developments and areas of controversy in nosology and the application of VCIND for screening individuals at increased risk of dementia secondary to vascular disease and its risk factors.