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

Pathophysiologic relationship between Alzheimer's disease, cerebrovascular disease, and cardiovascular risk: A review and synthesis

As the population ages due to demographic trends and gains in life expectancy, the incidence and prevalence of dementia increases, and the need to understand the etiology and pathogenesis of dementia becomes ever more urgent. Alzheimer's disease (AD), the most common form of dementia, is a complex disease, the mechanisms of which are poorly understood. The more we learn about AD, the more questions are raised about our current conceptual models of disease. In the absence of a cure or the means by which to slow disease progress, it may be prudent to apply our current knowledge of the intersection between AD, cardiovascular disease, and cerebrovascular disease to foster efforts to delay or slow the onset of AD. This review discusses our current understanding of the epidemiology, genetics, and pathophysiology of AD, the intersection between AD and vascular causes of dementia, and proposes future directions for research and prevention.

Predicting Risk of Cognitive Decline in Very Old Adults Using Three Models: The Framingham Stroke Risk Profile; the Cardiovascular Risk Factors, Aging, and Dementia Model; and Oxi-Inflammatory Biomarkers

OBJECTIVES

To examine the Framingham Stroke Risk Profile (FSRP); the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) risk score, and oxi-inflammatory load (cumulative risk score of three blood biomarkers-homocysteine, interleukin-6, C-reactive protein) for associations with cognitive decline using three cohort studies of very old adults and to examine whether incorporating these biomarkers with the risk scores can affect the association with cognitive decline.

DESIGN

Three longitudinal, population-based cohort studies.

SETTING

Newcastle-upon-Tyne, United Kingdom; Leiden, the Netherlands; and Lakes and Bay of Plenty District Health Board areas, New Zealand.

PARTICIPANTS

Newcastle 85+ Study participants (n = 616), Leiden 85-plus Study participants (n = 444), and Life and Living in Advanced Age, a Cohort Study in New Zealand (LiLACS NZ Study) participants (n = 396).

MEASUREMENTS

FSRP, CAIDE risk score, oxi-inflammatory load, FSRP incorporating oxi-inflammatory load, and CAIDE risk score incorporating oxi-inflammatory load. Oxi-inflammatory load could be calculated only in the Newcastle 85+ and the Leiden 85-plus studies. Measures of global cognitive function were available for all three data sets. Domain-specific measures were available for the Newcastle 85+ and the Leiden 85-plus studies.

RESULTS

Meta-analysis of pooled results showed greater risk of incident global cognitive impairment with higher FSRP (hazard ratio (HR) = 1.46, 95% confidence interval (CI) = 1.08-1.98), CAIDE (HR = 1.53, 95% CI = 1.09-2.14), and oxi-inflammatory load (HR = 1.73, 95% CI = 1.04-2.88) scores. Adding oxi-inflammatory load to the risk scores increased the risk of cognitive impairment for the FSRP (HR = 1.65, 95% CI = 1.17-2.33) and the CAIDE model (HR = 1.93, 95% CI = 1.39-2.67).

CONCLUSION

Adding oxi-inflammatory load to cardiovascular risk scores may be useful for determining risk of cognitive impairment in very old adults.

Short-term hypertension management in community is associated with long-term risk of stroke and total death in China: A community controlled trial

BACKGROUND

It is not fully clear whether the effect of short-term management in community can reduce the long-term risk of stroke OBJECTIVES:: To evaluate whether short-term hypertension management is associated with long-term incidence of stroke and total death in community health centers in China.

DESIGN

Community controlled trail.

PARTICIPANTS

Six community health centers (4 active, 2 control) in China, patients with hypertension.

CONTROL ARM

Patients were treated with normally therapy method.

ACTIVE ARM

Patients were treated oriented by the Guideline for hypertension management.

RANDOMIZATION

Two centers (Hebei and Zhejiang) from the Hypertension Control in Community (HCC) Project, which was conducted from 2005 to 2008, were randomly selected for this study. Four thousand hypertensive patients from these centers, who were under management for one year in the baseline, were followed up in 2013. The electronic health record system (2005-2008) was used to identify 2000 hypertensive patients, who were not included in HCC but lived in comparable community health center in the same province, as the control group. All baseline and follow-up data were collected using standardized questionnaires for stroke outcomes.

MAIN OUTCOME MEASURES

Stroke.

RESULTS

Of the 6000 participants, 3787 (63.1%) were eligible for analysis. At the time of follow-up, the average BP was kept in the lower level than that in baseline, and the control rate was 59.3%. After propensity-score matching, 110 strokes (2.0% vs 4.6%) and 141 deaths (1.4% vs 3.8%) were noted in the matched intervention and control groups (1078 pairs), respectively. Patients in the intervention group were less likely to experience a stroke or die than those in the control group (hazard ratio [HR] = 0.40, 95% confidence interval [CI]: 0.26-0.62, P < 0.01; HR = 0.50, 95% CI: 0.35-0.72, P < 0.01). The sensitivity analysis showed similar results.

CONCLUSIONS

Short-term management of hypertension had a positive effect on the long-term risk reduction of death and stroke in hypertensive patients.

Impact of Hypertension on Cognitive Function: A Scientific Statement From the American Heart Association

BACKGROUND

Age-related dementia, most commonly caused by Alzheimer disease or cerebrovascular factors (vascular dementia), is a major public health threat. Chronic arterial hypertension is a well-established risk factor for both types of dementia, but the link between hypertension and its treatment and cognition remains poorly understood. In this scientific statement, a multidisciplinary team of experts examines the impact of hypertension on cognition to assess the state of the knowledge, to identify gaps, and to provide future directions.

METHODS

Authors with relevant expertise were selected to contribute to this statement in accordance with the American Heart Association conflict-of-interest management policy. Panel members were assigned topics relevant to their areas of expertise, reviewed the literature, and summarized the available data.

RESULTS

Hypertension disrupts the structure and function of cerebral blood vessels, leads to ischemic damage of white matter regions critical for cognitive function, and may promote Alzheimer pathology. There is strong evidence of a deleterious influence of midlife hypertension on late-life cognitive function, but the cognitive impact of late-life hypertension is less clear. Observational studies demonstrated a cumulative effect of hypertension on cerebrovascular damage, but evidence from clinical trials that antihypertensive treatment improves cognition is not conclusive.

CONCLUSIONS

After carefully reviewing the literature, the group concluded that there were insufficient data to make evidence-based recommendations. However, judicious treatment of hypertension, taking into account goals of care and individual characteristics (eg, age and comorbidities), seems justified to safeguard vascular health and, as a consequence, brain health.

The association among smoking, HSV-1 exposure, and cognitive functioning in schizophrenia, bipolar disorder, and non-psychiatric controls

Previous investigations have found that smokers with schizophrenia demonstrate reduced performance on cognitive tasks compared to non-smokers. However previous studies have not taken into account other environmental factors associated with cognitive functioning such as exposure to Herpes Simplex Virus type 1 (HSV-1). We examined these factors in a sample consisting of individuals with schizophrenia (n=773), bipolar disorder (n=493), or controls without a psychiatric disorders (n=548). Participants were assessed on a cognitive battery, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and had a blood sample drawn to measure seropositivity to HSV-1. Within each group linear regression models were constructed to determine whether cigarette smoking and HSV-1 seropositivity were jointly associated with cognitive functioning after adjusting for relevant covariates. Within the schizophrenia group, the effect size of lower total cognitive score was -0.279 (p<0.0001) for individuals who were both smokers and HSV-1 seropositive and a significant effect was found in all cognitive domains. The odds of being in the highest quartile of RBANS Total score were significantly lower for smokers (OR=0.58, 95% CI 0.41, 0.82, p=0.002). Smoking was not as consistently associated with levels of cognitive functioning in the bipolar disorder or the non-psychiatric control group. While experimental studies show that nicotine transiently improves functioning on sensory gating and attention tasks known to be deficient in schizophrenia, long-term nicotine exposure via smoking appears to have an adverse effect on cognitive functioning.

Age-Related Sensory Impairments and Risk of Cognitive Impairment

OBJECTIVES

To evaluate the associations between sensory impairments and 10-year risk of cognitive impairment.

DESIGN

The Epidemiology of Hearing Loss Study (EHLS), a longitudinal, population-based study of aging in the Beaver Dam, Wisconsin community. Baseline examinations were conducted in 1993 and follow-up examinations have been conducted every 5 years.

SETTING

General community.

PARTICIPANTS

EHLS members without cognitive impairment at EHLS-2 (1998-2000). There were 1,884 participants (mean age 66.7) with complete EHLS-2 sensory data and follow-up information.

MEASUREMENTS

Cognitive impairment was defined as a Mini-Mental State Examination score of <24 or history of dementia or Alzheimer's disease. Hearing impairment was a pure-tone average of hearing thresholds (0.5, 1, 2, 4 kHz) of >25 dB hearing level in either ear, visual impairment was a Pelli-Robson contrast sensitivity of <1.55 log units in the better eye, and olfactory impairment was a San Diego Odor Identification Test score of <6.

RESULTS

Hearing, visual, and olfactory impairment were independently associated with cognitive impairment risk (hearing: hazard ratio (HR) = 1.90, 95% confidence interval (CI) = 1.11-3.26; vision: HR = 2.05, 95% CI = 1.24-3.38; olfaction: HR = 3.92, 95% CI = 2.45-6.26)). Nevertheless, 85% of participants with hearing impairment, 81% with visual impairment, and 76% with olfactory impairment did not develop cognitive impairment during follow-up.

CONCLUSION

The relationship between sensory impairment and cognitive impairment was not unique to one sensory system, suggesting that sensorineural health may be a marker of brain aging. The development of a combined sensorineurocognitive measure may be useful in uncovering mechanisms of healthy brain aging.

Longitudinal Trends in Hypertension Management and Mortality Among Octogenarians: Prospective Cohort Study

The role of hypertension management among octogenarians is controversial. In this long-term follow-up (>10 years) study, we estimated trends in hypertension prevalence, awareness, treatment, and control among octogenarians, and evaluated the relationship of systolic blood pressure (SBP) ranges with mortality. Data were based on the English Longitudinal Study of Ageing (ELSA). Outcome measures were hypertension prevalence, awareness, treatment and control, and cardiovascular disease, and all-cause mortality events. Participants were separated into 8 categories of SBP values (<110, 110-119, 120-129, 130-139, 140-149, 150-159, 160-169, and >169 mm Hg). Among 2692 octogenarians, mean SBP levels declined from 147 mm Hg in 1998/2000 to 134 mm Hg in 2012/2013. The decline was of lower magnitude in the 50 to 79 years old subgroup (n=22007). Hypertension prevalence and awareness were 40% and 13%, respectively, higher among octogenarians than the 50 to 79 years of age subgroup, but hypertension treatment rates were similar (≈90%). Around 47% of the treated octogenarians achieved conventional BP targets (<140/90 mm Hg), increasing to 59% when assessed against revised targets (<150/90 mm Hg). All-cause mortality rates were higher (hazard ratio, 1.55; 95% confidence interval, 0.89-2.72) at lower extremes of SBP values (<110 mm Hg). The lowest cardiovascular disease and all-cause mortality risk among treated octogenarians was observed for an SBP range of 140 to 149 mm Hg (1.04, 0.60-1.78) and 160 to 169 mm Hg (0.78, 0.51-1.21). An increasing trend in hypertension awareness and treatment was observed in a large sample of community-dwelling octogenarians. The results do not support the view that more stringent BP targets may be associated with lower mortality.

Endocrine Risk Factors for Cognitive Impairment

Cognitive impairment, including Alzheimer's disease and other kinds of dementia, is a major health problem in older adults worldwide. Although numerous investigators have attempted to develop effective treatment modalities or drugs, there is no reasonably efficacious strategy for preventing or recovering from cognitive impairment. Therefore, modifiable risk factors for cognitive impairment have received attention, and the growing literature of metabolic risk factors for cognitive impairment has expanded from epidemiology to molecular pathogenesis and therapeutic management. This review focuses on the epidemiological evidence for the association between cognitive impairment and several endocrine risk factors, including insulin resistance, dyslipidemia, thyroid dysfunction, vitamin D deficiency, and subclinical atherosclerosis. Researches suggesting possible mechanisms for this association are reviewed. The research investigating modifiable endocrine risk factors for cognitive impairment provides clues for understanding the pathogenesis of cognitive impairment and developing novel treatment modalities. However, so far, interventional studies investigating the beneficial effect of the "modification" of these "modifiable risk factors" on cognitive impairment have reported variable results. Therefore, well-designed, randomized prospective interventional studies are needed.

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.

Mid-life Cardiovascular Risk Impacts Memory Function: The Framingham Offspring Study

INTRODUCTION

This study incorporates unique error response analyses with traditional measures of memory to examine the association between mid-life cardiovascular risk factors and later-life memory function.

METHODS

The Framingham Stroke Risk Profile (FSRP), a composite score of cardiovascular risk, was assessed in 1755 Framingham Offspring participants (54% women, mean age=54±9 y) from 1991 to 1995. Memory tests including Logical Memory and Visual Reproductions were administered from 2005 to 2008. Linear and logistic regression examined the association between FSRP and memory measures. Interaction between the presence of the ApoE4 allele and each FSRP component on the memory measures was also assessed.

RESULTS

FSRP and the individual components of age, sex, and smoking were related to lower standard scores of memory. The new error response analyses reinforced the standard analyses and also identified new relationships. Participants with diabetes were found to make more errors on Logical Memory, and those with a history of smoking were found to make more errors on Visual Reproductions. Lastly, ApoE4 smokers experienced significant verbal memory loss, whereas ApoE4 smokers did not.

CONCLUSIONS

Middle-aged healthy adults with cardiovascular risk factors including diabetes, history of smoking, and ApoE4 positivity were found to have greater later-life memory impairments.

Is Metabolic Syndrome On the Radar? Improving Real-Time Detection of Metabolic Syndrome and Physician Response by Computerized Scan of the Electronic Medical Record

OBJECTIVE

Metabolic syndrome is a common underdiagnosed condition among psychiatric patients exacerbated by second-generation antipsychotics, with the exception of aripiprazole and ziprasidone. This study evaluated the prescribing and treating behavior with regard to antipsychotics and metabolic syndrome of psychiatrists before and after implementation of a mandatory admission order set and electronic notification of results.

METHOD

Baseline data from 9,100 consecutive psychiatric admissions to a mental health hospital (July 2013-July 2014) were compared to postintervention data (July 2014-January 2015), which included 1,499 consecutive patient records. The intervention initiated standardized admission testing with electronic notification to psychiatrists when patients met metabolic syndrome criteria (according to Axis III of the DSM-IV). Charts were examined for inclusion of this diagnosis at discharge and for treatment changes.

RESULTS

At baseline, only 2.4% of patients (n = 214) were evaluated for metabolic syndrome. Of these, 34.5% (0.8% of the total sample) met metabolic syndrome criteria. Only 15 patients (0.16%) were comprehensively treated. No chart listed metabolic syndrome under Axis III of the DSM-IV. After the intervention, the diagnosis of patients meeting the criteria for metabolic syndrome increased from 0% to 29.3%. Less than 3% of patients were switched to drugs with a more benign metabolic profile. All patients who continued on second-generation antipsychotics had metabolic retesting. Thirty-eight experienced a significant and rapid increase in triglyceride levels after only 3 to 17 days.

CONCLUSIONS

Mandatory intake testing increases the number of patients evaluated for metabolic syndrome. Electronic alerts increase the inclusion of metabolic syndrome among discharge diagnoses but rarely affect prescribing practices.

Visual Impairment, Hearing Loss and Cognitive Function in an Older Population: Longitudinal Findings from the Blue Mountains Eye Study

The presence of visual impairment (VI) and hearing loss (HL) with may be a marker for subsequent cognitive decline over time in older people. A prospective, longitudinal population-based study of the 3654 participants of the Blue Mountains Eye Study were assessed for the associations between VI and HL and a decline in mini-mental state examination (MMSE) scores over a duration of 10 years from the 5-year (baseline of this report) to the 15-year follow-up visits. MMSE was assessed at the 5-, 10- and 15-year follow-up visits. A decline ≥3 scores from 5-year to 10- or 15-year visits indicated possible cognitive decline. VI was defined as best-corrected visual acuity <6/12 in the worse-eye, HL was defined as pure-tone average >40 decibels in the worse-ear and dual sensory impairment (DSI) was defined by the co-presence of VI and HL, detected at 5-year follow-up (baseline of this report). Participants with no VI and HL over the same 5- or 10-year corresponding period were controls. Associations of VI, HL and DSI with possible cognitive decline were assessed using logistic regression models adjusting for age and sex after excluding subjects with a stroke history. The presence of VI, HL or DSI was not associated with possible cognitive decline over 5 years (odds ratio (OR) 0.84, 95% confidence-intervals (CI) 0.40-1.79, OR 1.02, 95% CI 0.61-1.70 and 1.41, 95% CI 0.54-3.72, respectively) or 10 years (OR 1.09, 95% CI 0.52-2.30, OR 1.09, 95% CI 0.65-1.82 and 1.15, 95% CI 0.28-4.73, respectively). There were no changes to these findings after adjustment for other potential confounders. Age was significantly associated with possible cognitive decline (OR 1.07, 95% CI 1.04-1.10 for both periods). Neither visual impairment, hearing loss nor dual sensory impairment was independently associated with subsequent decline in cognition.

Adverse vascular risk is related to cognitive decline in older adults

BACKGROUND

Cardiovascular disease (CVD) and related risk factors are associated with Alzheimer's disease (AD). This association is less well-defined in normal cognition (NC) or prodromal AD (mild cognitive impairment, MCI).

OBJECTIVE

Cross-sectionally and longitudinally relate a vascular risk index to cognitive outcomes among elders free of clinical dementia.

METHODS

3,117 MCI (74 ± 8 years, 56% female) and 6,603 NC participants (72 ± 8 years, 68% female) were drawn from the National Alzheimer's Coordinating Center. A composite measure of vascular risk was defined using the Framingham Stroke Risk Profile (FSRP) score (i.e., age, systolic blood pressure, anti-hypertensive medication, diabetes, cigarette smoking, CVD history, atrial fibrillation). Ordinary linear regressions and generalized linear mixed models related baseline FSRP to cross-sectional and longitudinal cognitive outcomes, separately for NC and MCI, adjusting for age, gender, race, education, and follow-up time (in longitudinal models).

RESULTS

In NC participants, increasing FSRP was related to worse baseline global cognition, information processing speed, and sequencing abilities (p-values <0.0001) and a worse longitudinal trajectory on all cognitive measures (p-values <0.0001). In MCI, increasing FSRP correlated with worse longitudinal delayed memory (p = 0.004). In secondary models using an age-excluded FSRP score, associations persisted in NC participants for global cognition, naming, information processing speed, and sequencing abilities.

CONCLUSIONS

An adverse vascular risk profile is associated with worse cognitive trajectory, especially global cognition, naming, and information processing speed, among NC elders. Future studies are needed to understand how effective management of CVD and related risk factors can modify cognitive decline to identify the ideal timeframe for primary prevention implementation.

Are different vascular risk scores calculated at midlife uniformly associated with subsequent poor cognitive performance?

BACKGROUND

Research concerning the link between individual vascular risk factors and cognition is plentiful but few studies have investigated the role of global vascular risk. We examined the cross-time associations of several vascular risk scores with cognitive performance during aging.

METHODS

Using data from the French SU.VI.MAX cohort, we studied a sample of 3061 participants. Framingham coronary heart disease, cardiovascular and stroke risk profiles were computed using baseline data (1994-1996). Cognitive performance was assessed after a mean of 13 years via a battery of six validated instruments. Principal component analysis identified scores for verbal memory and working memory. Associations between risk profiles (as continuous variables and in quartiles (Q)) and subsequent poor performance (defined as cognitive score ≤10th percentile) were examined via logistic regression (odds ratios, 95% CI) and analysis of covariance.

RESULTS

All continuous-scale Framingham risk scores assessed at midlife were inversely and uniformly associated with subsequent poor global cognitive performance, and especially in terms of verbal memory. Considering risk score Q, higher Q were associated with poorer performance in verbal memory: The fully-adjusted odds ratios (95% CI), comparing Q4 versus Q1, were 2.84 (1.70, 4.75), 2.31 (1.43, 3.73) and 1.77 (1.13, 2.76) for Framingham coronary heart disease, cardiovascular and stroke risk profiles, respectively. Similar findings were observed when modeling cognitive outcomes as continuous variables using covariance analyses.

CONCLUSION

This study supports the existence of an inverse cross-time association between midlife vascular risk profiles and subsequent poor cognitive performance, especially in the verbal memory domain. Beyond their importance as regards vascular risk, such risk scores may help primary prevention efforts in identifying and targeting middle-aged individuals at high risk of cognitive aging.

Is Cardiac Rehabilitation Exercise Feasible for People with Mild Cognitive Impairment?

Background

Exercise is a promising strategy to prevent dementia, but no clinically supervised exercise program is widely available to people with mild cognitive impairment (MCI). The objective was to survey health professionals to assess the feasibility of using cardiac rehabilitation exercise programs for MCI populations.

Methods

We distributed surveys to: 1) health professionals working in cardiac rehabilitation exercise programs (36/72 responded); and 2) physicians who treat MCI (22/32 responded). Questions addressed clinician and clinic characteristics and feasibility of referring and accommodating people with MCI.

Results

Most cardiac rehabilitation exercise programs currently treat people with MCI (61.1%). Nearly all were willing and able to accept people with MCI and comorbid vascular risk (91.7%), though only a minority could accept MCI without vascular risk (16.7%). Although most physicians recommend exercise to people with MCI (63.6%), few referred patients with MCI to programs or people to guide exercise (27.3%). However, all physicians (100%) would refer patients with MCI to a cardiac rehabilitation exercise program.

Conclusions

Our study supports cardiac rehabilitation exercise programs as a feasible model of exercise for patients with MCI with vascular risk. Patients with and without vascular risk could likely be accommodated if program mandates were expanded.

Voluntary cognitive screening: characteristics of participants in an Asian setting

BACKGROUND

Mild cognitive impairment (MCI) and dementia are reaching epidemic proportions in Asia. Lack of awareness and late presentation are major obstacles to early diagnosis and timely intervention. Cognitive screening may be an effective method for early detection of dementia in Asia. The purpose of this work was to study the characteristics of subjects volunteering for cognitive screening in an Asian setting and to determine the prevalence of MCI.

METHODS

Retrospective and cross-sectional data from community subjects attending a screening program from 2008 to 2013 were analyzed. Information on demographics, vascular risk factors, subjective symptoms, and cognitive measures were analyzed over the 6-year period.

RESULTS

Over the 6 years from 2008 to 2013, 1,243 community subjects voluntarily turned up for cognitive screening (91.2% were Chinese, 5.23% were Indian, 1.37% were Malay, and 2.25% were Eurasian). The mean age of the participants was 61.3 years and the mean number of years of education was 11.0 years. A total of 71.1% of participants were living in public housing, 59.8% had at least one cardiovascular risk factor, and 56.2% reported subjective cognitive symptoms. Over a period of 6 years, no significant change in demographic or clinical variables was noted. High cholesterol and hypertension were consistently the top two risk factors found in the population screened. In total, 17.2% of the total cohort had MCI. Across the 6 years, the proportion with MCI and depression was relatively constant.

CONCLUSION

A significant proportion of participants attending voluntary cognitive screening have MCI. Low level of education and presence of vascular risk factors are general predisposing characteristics for MCI, and there are more specific factors pertaining to sex and employment status.

Carotid intima-media thickness is associated with the progression of cognitive impairment in older adults

BACKGROUND AND PURPOSE

We investigated the association between cardiovascular risk factors, including carotid intima-media thickness (CIMT), and future risk of mild cognitive impairment (MCI) and dementia in elderly subjects.

METHODS

We conducted a population-based prospective study as a part of the Korean Longitudinal Study on Health and Aging. Our study included 348 participants who were nondemented at the baseline (mean age, 71.7±6.3 years) and underwent cognitive evaluation at the 5-year follow-up. Baseline cardiovascular risk factors were compared according to the development of MCI or dementia during the study period.

RESULTS

At the baseline evaluation, 278 subjects were cognitively normal and 70 subjects had MCI. Diagnoses of cognitive function either remained unchanged or improved during the study period in 292 subjects (nonprogression group), whereas 56 subjects showed progression of cognitive impairment to MCI or dementia (progression group). The progression group exhibited a higher prevalence of hypertension and greater CIMT compared with the nonprogression group. Other baseline cardiovascular risk factors, including sex, body mass index, diabetes mellitus, insulin resistance, total cholesterol, waist-to-hip ratio, visceral fat, pulse wave velocity, and ankle-brachial index, were not significantly different between 2 groups. The association between greater baseline CIMT and the progression of cognitive impairment was maintained after adjustment for conventional baseline risk factors of cognitive impairment. Greater baseline CIMT was also independently associated with the development of MCI in the subjects whose baseline cognitive function was normal.

CONCLUSIONS

Greater baseline CIMT was independently associated with the risk of cognitive impairment, such as MCI and dementia in elderly subjects.

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.

The Effects of Aerobic Exercise on Cognitive and Neural Decline in Aging and Cardiovascular Disease

Aging is characterized by a decline in cognitive functions, particularly in the domains of executive function, processing speed and episodic memory. These age-related declines are exacerbated by cardiovascular disease (CVD) and cardiovascular risk factors (hypertension, diabetes, obesity, elevated total cholesterol). Structural and functional alterations in brain regions, including the fronto-parietal and medial temporal lobes, have been linked to age- and CVD-related cognitive decline. Multiple recent studies indicate that aerobic exercise programs may slow the progression of age-related neural changes and reduce the risk for mild cognitive impairment as well as dementia. We review age- and CVD-related decline in cognition and the underlying changes in brain morphology and function, and then clarify the impact of aerobic exercise on moderating these patterns.

Abnormal levels of brain metabolites may mediate cognitive impairment in stroke-free patients with cerebrovascular risk factors

OBJECTIVE

conventional vascular risk factors (VRFs) are associated with cognitive impairment independent of stroke and detectable cerebral lesions. We used proton magnetic resonance spectroscopy ((1)H MRS) to examine the hypotheses that abnormal levels of brain metabolites may mediate the relationship between VRFs and cognitive impairment.

METHODS

a group of 54 stroke-free subjects with various VRFs underwent comprehensive cognitive assessments and (1)H MRS scan of the left hippocampus and prefrontal cortex. We indirectly measured the concentrations of N-acetylaspartate (NAA), choline, inositol, creatine (Cr) and total concentrations of glutamate plus glutamine (Glx). VRFs were quantified by Framingham stroke risk profile (FSRP) score. Subjects were divided into low- (<10%), medium- (10-20%) and high-risk (>20%) groups according to their FSRP scores. Pearson and partial correlation analysis were used to investigate the correlation between FSRP scores and cognitive performance along with the brain metabolism.

RESULTS

compared with subjects in low-risk group, high-risk group subjects had significantly poor performances on the tasks of working memory, delayed recall and executive function. In high-risk group, hippocampal Glx/Cr ratios and prefrontal NAA/Cr ratios were significantly lower than those in low-risk group. Lower prefrontal NAA/Cr ratios were associated with executive dysfunction, and lower hippocampal Glx/Cr ratios were associated with impaired delayed recall.

CONCLUSION

abnormal concentrations of brain metabolites and decreased glutamate plus glutamine concentration may play an important role in the pathophysiology of VRF-associated cognitive impairment. Brain metabolites detected by (1)H MRS may serve as important markers for monitoring VRFs burden.

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.

Cognitive performance in older adults is inversely associated with fish consumption but not erythrocyte membrane n-3 fatty acids

Higher n-3 (ω-3) polyunsaturated fatty acids (PUFAs) and fish intake may help maintain cognitive function in older age. However, evidence is inconsistent; few studies have examined the relation in cognitively healthy individuals across numerous cognitive domains, and none to our knowledge have considered lifetime fish intake. We examined associations between multiple domains of cognition and erythrocyte membrane n-3 PUFA proportions and historical and contemporary fish intake in 390 normal older adults, analyzing baseline data from the Older People, Omega-3, and Cognitive Health trial. We measured n-3 PUFA in erythrocyte membranes, and we assessed historical and contemporary fish intake by food-frequency questionnaires. We assessed cognitive performance on reasoning, working memory, short-term memory, retrieval fluency, perceptual speed, simple/choice reaction time, speed of memory-scanning, reasoning speed, inhibition, and psychomotor speed. Cognitive outcomes for each construct were factor scores from confirmatory factor analysis. Multiple linear regression models controlled for a number of potential confounding factors, including age, education, sex, apolipoprotein E-ε 4 allele, physical activity, smoking, alcohol intake, socioeconomic variables, and other health-related variables. Higher erythrocyte membrane eicosapaentonoic acid proportions predicted slower perceptual and reasoning speed in females, which was attenuated once current fish intake was controlled. No other associations were present between n-3 PUFA proportions and cognitive performance. Higher current fish consumption predicted worse performance on several cognitive speed constructs. Greater fish consumption in childhood predicted slower perceptual speed and simple/choice reaction time. We found no evidence to support the hypothesis that higher proportions of long-chain n-3 fatty acids or fish intake benefits cognitive performance in normal older adults.

Randomized Evaluation of Carotid Occlusion and Neurocognition (RECON) trial: main results

OBJECTIVE

To determine whether extracranial-intracranial (EC-IC) bypass can improve cognition over 2 years compared to best medical therapy alone in patients with symptomatic internal carotid artery (ICA) occlusion and increased oxygen extraction fraction (OEF) on PET.

METHODS

Patients underwent (15)O PET and were randomized if OEF ratio was >1.13 on the occluded side. Using blinded baseline and 2-year cognitive assessments, age-adjusted composite z scores were generated from subtests sensitive to right/left hemisphere plus global cognitive functioning. Multiple regression predicted 2-year cognitive change.

RESULTS

Eighty-nine patients were enrolled; 41 had increased OEF and were randomized. Two died, 2 were lost to follow-up, and 2 refused 2-year testing. Of the 35 remaining, 6 had ipsilateral stroke or death, leaving 13 surgical and 16 medical patients. Controlling for age, education, and depression, there was no difference in 2-year cognitive change between the medical and surgical arms (95% confidence interval -0.5 to 0.5, p = 0.9). In post hoc analysis of 26 patients with no stroke in the follow-up period, cognitive improvement was associated with less impaired PET OEF at baseline (p = 0.045).

CONCLUSION

Cognitive improvement following bypass surgery was not superior to medical therapy among patients with recently symptomatic carotid occlusion and increased OEF. Among those with no recurrent stroke, less hemodynamic impairment at baseline was associated with greater cognitive gain in both groups. Reversing cognitive impairment in hemodynamic failure remains an open challenge.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for patients with symptomatic ICA occlusion and increased OEF on PET, EC-IC bypass compared to no bypass does not improve cognitive function after 2 years.

Does the influence of stroke on dementia vary by different levels of prestroke cognitive functioning?: a cohort study

BACKGROUND AND PURPOSE

The association between stroke and subsequent dementia or Alzheimer disease is well established. What is less understood is the extent to which this association is dependent on prestroke cognitive functioning. The study estimated the occurrence in poststroke dementia as a function of prestroke cognitive status and incident stroke.

METHODS

Study data were derived from the English Longitudinal Study of Ageing, a 10-year long prospective cohort study of older adults living in England. Baseline data (2002/2003) were used to group participants into tertiles of cognitive, memory, and executive functioning before an incident stroke. Data from 4 follow-up surveys were used to identify new stroke and poststroke dementia events.

RESULTS

The analyses were based on 10 809 participants aged≥50 years at baseline. High prestroke executive functioning was associated with lower relative risk (RR) of dementia (RR, 0.24; 95% confidence interval, 0.13-0.45; P<0.001). Stroke was associated with increased RR of poststroke dementia (RR, 2.63; 95% confidence interval, 1.80-3.84; P<0.001). The association of stroke with poststroke dementia was greater for participants with higher prestroke executive functioning (interaction term RR, 4.4; 95% confidence interval, 1.35-14.63; P=0.014). For participants with higher executive functioning, the probability of dementia was 0.3% without stroke and 3.1% after stroke, compared with 1.9% and 5.2% for lower executive functioning.

CONCLUSIONS

Stroke and prestroke cognition were independently associated with increased probability of poststroke dementia. Stroke results in disproportionate increase in the risk of dementia when premorbid cognitive functioning is high.

The Use of Multiple Correspondence Analysis to Explore Associations between Categories of Qualitative Variables in Healthy Ageing

The main focus of this study was to illustrate the applicability of multiple correspondence analysis (MCA) in detecting and representing underlying structures in large datasets used to investigate cognitive ageing. Principal component analysis (PCA) was used to obtain main cognitive dimensions, and MCA was used to detect and explore relationships between cognitive, clinical, physical, and lifestyle variables. Two PCA dimensions were identified (general cognition/executive function and memory), and two MCA dimensions were retained. Poorer cognitive performance was associated with older age, less school years, unhealthier lifestyle indicators, and presence of pathology. The first MCA dimension indicated the clustering of general/executive function and lifestyle indicators and education, while the second association was between memory and clinical parameters and age. The clustering analysis with object scores method was used to identify groups sharing similar characteristics. The weaker cognitive clusters in terms of memory and executive function comprised individuals with characteristics contributing to a higher MCA dimensional mean score (age, less education, and presence of indicators of unhealthier lifestyle habits and/or clinical pathologies). MCA provided a powerful tool to explore complex ageing data, covering multiple and diverse variables, showing if a relationship exists and how variables are related, and offering statistical results that can be seen both analytically and visually.