Ankle-to-Brachial Index and Dementia

Atherosclerotic burden and cerebral small vessel disease: exploring the link through microvascular aging and cerebral microhemorrhages

Cerebral microhemorrhages (CMHs, also known as cerebral microbleeds) are a critical but frequently underestimated aspect of cerebral small vessel disease (CSVD), bearing substantial clinical consequences. Detectable through sensitive neuroimaging techniques, CMHs reveal an extensive pathological landscape. They are prevalent in the aging population, with multiple CMHs often being observed in a given individual. CMHs are closely associated with accelerated cognitive decline and are increasingly recognized as key contributors to the pathogenesis of vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD). This review paper delves into the hypothesis that atherosclerosis, a prevalent age-related large vessel disease, extends its pathological influence into the cerebral microcirculation, thereby contributing to the development and progression of CSVD, with a specific focus on CMHs. We explore the concept of vascular aging as a continuum, bridging macrovascular pathologies like atherosclerosis with microvascular abnormalities characteristic of CSVD. We posit that the same risk factors precipitating accelerated aging in large vessels (i.e., atherogenesis), primarily through oxidative stress and inflammatory pathways, similarly instigate accelerated microvascular aging. Accelerated microvascular aging leads to increased microvascular fragility, which in turn predisposes to the formation of CMHs. The presence of hypertension and amyloid pathology further intensifies this process. We comprehensively overview the current body of evidence supporting this interconnected vascular hypothesis. Our review includes an examination of epidemiological data, which provides insights into the prevalence and impact of CMHs in the context of atherosclerosis and CSVD. Furthermore, we explore the shared mechanisms between large vessel aging, atherogenesis, microvascular aging, and CSVD, particularly focusing on how these intertwined processes contribute to the genesis of CMHs. By highlighting the role of vascular aging in the pathophysiology of CMHs, this review seeks to enhance the understanding of CSVD and its links to systemic vascular disorders. Our aim is to provide insights that could inform future therapeutic approaches and research directions in the realm of neurovascular health.

Association between vascular aging and cognitive function in Chinese adults

BACKGROUND

Vascular health has been associated with cognition but related evidence is limited in Chinese. The objective of this study was to examine the association of vascular aging assessed by arterial stiffness and blood pressure with cognitive function in an unselected Chinese population.

METHODS

In the Tianning Cohort (N = 5158), indicators of arterial stiffness and blood pressure including carotid-femoral pulse wave velocity (cfPWV), ankle-brachial index (ABI), pulse pressure (PP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured. Cognitive function was assessed using the Mini Mental State Examination (MMSE) questionnaire. We applied Poisson regression and logistic regression to examine the associations of vascular aging and blood pressure with cognitive function.

RESULTS

76 (1.47%) participants had impaired cognitive function diagnosed by a MMSE score of less than 24 points. Participants with a higher level of PP were more likely to have a decreased score of MMSE (β=-0.0121, P < 0.001 for log-transformed pulse pressure) and a higher risk of having impaired cognitive function (OR = 5.95, 95%CI: 2.02-17.79, P < 0.001 for log-transformed PP). Per standard deviation increment in SBP was significantly associated with lower MMSE score (β=-0.0020, P < 0.001) and impaired cognitive function (OR = 1.69, 95%CI: 1.38-2.06, P < 0.001). No significant associations were found regarding other parameters.

CONCLUSIONS

Blood pressure and hypertension were associated with cognitive function in Chinese adults. PP may be a potential predictor for impaired cognitive function.

The link between impaired oxygen supply and cognitive decline in peripheral artery disease

Although peripheral artery disease (PAD) primarily affects large arteries outside the brain, PAD is also associated with elevated cerebral vulnerabilities, including greater risks for brain injury (such as stroke), cognitive decline and dementia. In the present review, we aim to evaluate recent literature and extract information on potential mechanisms linking PAD and consequences on the brain. Furthermore, we suggest novel therapeutic avenues to mitigate cognitive decline and reduce risk of brain injury in patients with PAD. Various interventions, notably exercise, directly or indirectly improve systemic blood flow and oxygen supply and are effective strategies in patients with PAD or cognitive decline. Moreover, triggering protective cellular and systemic mechanisms by modulating inspired oxygen concentrations are emerging as potential novel treatment strategies. While several genetic and pharmacological approaches to modulate adaptations to hypoxia showed promising results in preclinical models of PAD, no clear benefits have yet been clinically demonstrated. We argue that genetic/pharmacological regulation of the involved adaptive systems remains challenging but that therapeutic variation of inspired oxygen levels (e.g., hypoxia conditioning) are promising future interventions to mitigate associated cognitive decline in patients with PAD.

A systematic review/meta-analysis of prevalence and incidence rates illustrates systemic underrepresentation of individuals racialized as Asian and/or Asian-American in ADRD research

We investigate Alzheimer's disease and related dementia (ADRD) prevalence, incidence rate, and risk factors in individuals racialized as Asian and/or Asian-American and assess sample representation. Prevalence, incidence rate, risk factors, and heterogeneity of samples were assessed. Random-effects meta-analysis was conducted, generating pooled estimates. Of 920 records across 14 databases, 45 studies were included. Individuals racialized as Asian and/or Asian-American were mainly from Eastern and Southern Asia, had higher education, and constituted a smaller sample relative to non-Hispanic white cohorts. The average prevalence was 10.9%, ranging from 0.4% to 46%. The average incidence rate was 20.03 (12.01-33.8) per 1000 person-years with a range of 75.19-13.59 (12.89-14.33). Risk factors included physiological, genetic, psychological, behavioral, and social factors. This review underscores the systemic underrepresentation of individuals racialized as Asian and/or Asian-American in ADRD research and the need for inclusive approaches accounting for culture, language, and immigration status. HIGHLIGHTS: There is considerable heterogeneity in the prevalence of ADRD among studies of Asian-Americans. There is limited data on group-specific risk factors for ADRD among Asian-Americans. The average prevalence of (ADRD) among Asian-Americans was found to be 7.4%, with a wide range from 0.5% to 46%.

Diverticular disease and risk of dementia: a Danish population-based cohort study

BACKGROUND AND AIM

Patients with diverticular disease (DD) have ongoing chronic inflammation associated with changes in the gut microbiome, which might contribute to the development of dementia.

METHODS

Using Danish medical and administrative registries from 1980 to 2013, we conducted a nationwide population-based cohort study including all DD patients and a matched (5:1) general population comparison cohort without DD. A nested case-control analysis was then conducted using a risk set sampling, matching four DD controls without dementia to each DD patient with dementia. Clinical severity was categorized as uncomplicated DD (outpatient), conservatively treated DD (inpatient), and surgically treated DD.

RESULTS

149 527 DD patients and 747 635 general population comparators were identified. The 30-year cumulative incidence of dementia among DD patients and general population comparators were 12.4 (95% confidence interval [CI] 12.1-12.7) and 13.73% (95% CI 13.6-13.9), respectively. This corresponded to a 30-year hazard ratio (HR) of 1.10 (95% CI 1.1-1.1). The highest HRs were found in the conservatively treated DD group (1.15 95% CI 1.1-1.2) and the group with young onset of DD (1.52 95% CI 1.2-2.0). In the nested case-control analysis, we identified 8875 dementia cases and 35 491 matched controls. The adjusted odds ratio (OR) for conservatively treated DD was increased (1.08, 95% CI; 1.0-1.2) compared to the reference of uncomplicated DD.

CONCLUSIONS

We observed a slight increased risk of dementia in patients with young onset DD and conservatively treated DD. Findings suggest an association between disease duration, perhaps reflecting the duration of gut inflammation, and the risk of developing dementia.

Cardiovascular Disease and Alzheimer's Disease: The Heart-Brain Axis

Cardiovascular disease (CVD) remains one of the leading causes of morbidity and mortality in aging adults across the United States. Prior studies indicate that the presence of atherosclerosis, the pathogenic basis of CVD, is linked with dementias. Alzheimer's disease (AD) and AD-related dementias are a major public health challenge in the United States. Recent studies indicate that ≈3.7 million Americans ≥65 years of age had clinical AD in 2017, with projected increases to 9.3 million by 2060. Treatment options for AD remain limited. Development of disease-modifying therapies are challenging due, in part, to the long preclinical window of AD. The preclinical incubation period of AD starts in midlife, providing a critical window for identification and optimization of AD risk factors. Studies link AD with CVD risk factors such as hypertension, inflammation, and dyslipidemia. Both AD and CVD are progressive diseases with decades-long development periods. CVD can clinically manifest several years earlier than AD, making CVD and its risk factors a potential predictor of future AD. The current review focuses on the state of literature on molecular and metabolic pathways modulating the heart-brain axis underlying the potential association of midlife CVD risk factors and their effect on AD and related dementias. Further, we explore potential CVD/dementia preventive strategies during the window of opportunity in midlife and the future of research in the field in the multiomics and novel biomarker use era.

Vascular contributions to Alzheimer's disease

Alzheimer's disease (AD) is the most common cause of dementia and is characterized by progressive neurodegeneration and cognitive decline. Understanding the pathophysiology underlying AD is paramount for the management of individuals at risk of and suffering from AD. The vascular hypothesis stipulates a relationship between cardiovascular disease and AD-related changes although the nature of this relationship remains unknown. In this review, we discuss several potential pathological pathways of vascular involvement in AD that have been described including dysregulation of neurovascular coupling, disruption of the blood brain barrier, and reduced clearance of metabolite waste such as beta-amyloid, a toxic peptide considered the hallmark of AD. We will also discuss the two-hit hypothesis which proposes a 2-step positive feedback loop in which microvascular insults precede the accumulation of Aß and are thought to be at the origin of the disease development. At neuroimaging, signs of vascular dysfunction such as chronic cerebral hypoperfusion have been demonstrated, appearing early in AD, even before cognitive decline and alteration of traditional biomarkers. Cerebral small vessel disease such as cerebral amyloid angiopathy, characterized by the aggregation of Aß in the vessel wall, is highly prevalent in vascular dementia and AD patients. Current data is unclear whether cardiovascular disease causes, precipitates, amplifies, precedes, or simply coincides with AD. Targeted imaging tools to quantitatively evaluate the intracranial vasculature and longitudinal studies in individuals at risk for or in the early stages of the AD continuum could be critical in disentangling this complex relationship between vascular disease and AD.

Low Ankle-Brachial Index Relates to Alzheimer-Signature Cerebral Glucose Metabolism in Cognitively Impaired Older Adults

BACKGROUND

Ankle-brachial index (ABI), an indicator of atherosclerosis or arterial stiffness, has been associated with Alzheimer's disease (AD) dementia and related cognitive impairment. Nevertheless, only limited information is available regarding its contribution to brain alterations leading to cognitive decline in late-life.

OBJECTIVE

We aimed to investigate the relationship of ABI with in vivo AD pathologies and cerebrovascular injury in cognitively impaired older adults.

METHODS

Total 127 cognitively impaired (70 mild cognitive impairment and 57 AD dementia) individuals, who participated in an ongoing prospective cohort study, were included. All participants underwent comprehensive clinical and neuropsychological assessment, ABI measurement, apolipoprotein E (APOE) ɛ4 genotyping, and multi-modal brain imaging including [11C] Pittsburgh Compound B (PiB)-positron emission tomography (PET) and [18F] fludeoxyglucose (FDG)-PET, and MRI.

RESULTS

General linear model analysis showed significant relationship between ABI strata (low ABI: <1.00, normal ABI: 1.00-1.29, and high ABI: ≥1.30) and AD-signature region cerebral glucose metabolism (AD-CM), even after controlling age, sex, clinical dementia rating-sum of box, and APOE ɛ4 positivity (p = 0.029). Post hoc comparison revealed that low ABI had significantly lower AD-CM than middle and high ABI, while no difference of AD-CM was found between middle and high ABI. There was no significant difference of global Aβ deposition, AD-signature region cortical thickness, and white matter hyperintensity volume between the three ABI strata.

CONCLUSION

Our findings suggest that lower ABI, likely related to atherosclerosis, may contribute to the aggravation of AD-related regional neurodegeneration in cognitively impaired older adults.

Ankle-Brachial Index and Cardio-Ankle Vascular Index as Predictors of Cognitive Decline Over Time After Carotid Endarterectomy

Objective: Patients with carotid stenosis risk cognitive impairment even after carotid endarterectomy (CEA) because of the long-term presence of vascular risk factors. Early prediction of cognitive decline is useful because early appropriate training for impaired cognitive domains can improve their functions. Ankle-brachial index (ABI) and cardio-ankle vascular index (CAVI) are frequently used as general indicators of systemic atherosclerosis and are associated with cognitive function in the general population. This study aimed to evaluate the utility of those vascular biomarkers for predicting cognitive decline in patients after CEA.

Methods: Patients who had undergone both CEA at our institute and cognitive evaluations between March 2016 and January 2022 were invited to participate in this study. Associations between ABI or CAVI three years before baseline and cognitive function at baseline were assessed retrospectively in 94 patients, and associations between ABI or CAVI at baseline and three-year changes in cognitive functions were assessed prospectively in 24 patients. Cognitive functions were assessed using the Frontal Assessment Battery (FAB) and Neurobehavioral Cognitive Status Examination (Cognistat).

Results: Low ABI three years before baseline was associated with poor performances on Cognistat and FAB at baseline. ABI, as a continuous measure, three years before baseline, showed positive linear associations with total Cognistat score and subscores for naming, construction, and judgment at baseline. The Wilcoxon signed-rank test showed that the total Cognistat score, total FAB score, and subscores for attention and inhibitory control declined after three years. CAVI at baseline was negatively associated with three-year changes in total Cognistat score and subscores for naming, construction, and memory.

Conclusion: Cognitive function can decline over time in patients with carotid stenosis even after CEA. ABI and CAVI might be useful to predict cognitive function and its decline among patients who have undergone CEA.

Association of Vascular Risk Scores and Cognitive Performance in a Diverse Cohort: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Vascular risk scores are associated with incident dementia. Information regarding their association with cognitive performance and decline in racially/ethnically diverse cohorts is lacking.

METHOD

In 4 392 Multi-Ethnic Study of Atherosclerosis participants (aged 60.1 ± 9.4 years; 53% women; 41% White, 11% Chinese American, 26% African American, 21% Hispanic), we compared associations of Exam 1 (2000-2002) Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE), Framingham Stroke Risk Profile (FSRP), and atherosclerotic cardiovascular disease pooled cohort equation (ASCVD-PCE) risk scores with Exam 5 (2010-2012) Cognitive Abilities Screening Instrument (CASI), Digit Symbol Coding (DSC), and Digit Span (DS) cognitive test performance using multivariable linear regression, and examined racial/ethnic interactions. In 1 838 participants with repeat CASI data at Exam 6 (2016-2018), we related risk scores to odds of a 1-SD decline in CASI performance using multivariable logistic regression.

RESULTS

SD increments in each risk score were associated with worse cognitive performance. CAIDE had stronger associations with CASI performance than the FSRP and ASCVD-PCE, but associations of ASCVD-PCE with the DSC and DS were similar to CAIDE (difference in β [95% CI] = -0.57 [-1.48, 0.34] and -0.21 [-0.43, 0.01], respectively). Race/ethnicity modified associations. For example, associations between CAIDE and CASI were greater in African Americans and Hispanics than in Whites (difference in β = 0.69 [0.02, 1.36] and 1.67 [0.95, 2.39], respectively). Risk scores were comparably associated with decline in CASI performance.

CONCLUSIONS

Antecedent vascular risk scores are associated with cognitive performance and decline in the 4 most common U.S. racial/ethnic groups, but associations differ among risk scores and by race/ethnicity.

Association of ankle-brachial index with cognitive decline in patients with lacunar infarction

Atherosclerosis is an important risk factor for cognitive decline. This study aimed to investigate the relationship of ankle-brachial pressure index (ABI) and brachial-ankle pulse wave velocity (baPWV) with cognitive function in patients with lacunar infarction. We included records of consecutive patients with their first-ever acute stroke and a diagnosis of lacunar infarction through magnetic resonance imaging (MRI) from July 1, 2011 to December 31, 2018. We excluded patients diagnosed with dementia, including strategic single-infarct dementia, before or after stroke onset. Moreover, we excluded patients with one or more microbleeds, severe white matter lesions, or severe medial temporal atrophy on MRI. For ABI, we used the lower ankle side and divided the results into ABI < 1.0 and ABI ≥ 1.0. For baPWV, we used the higher ankle side and divided the results into two groups based on the median value of the participants. We analyzed 176 patients with stroke (age 72.5 ± 11.4 years, 67 females). The median score on the Mini-Mental State Examination (MMSE) was 27. The number of patients with ABI < 1.0 was 19 (10.8%). Univariate analysis revealed that the MMSE score was associated with age, body mass index, education, chronic kidney disease, periventricular hyperintensity, and ABI < 1.0 (p < 0.10), but not baPWV. Multivariate analysis revealed that body mass index (p = 0.039) and ABI < 1.0 (p = 0.015) were independently associated with the MMSE score. For patients with lacunar infarction, a lower ABI, but not a higher PWV, was associated with cognitive decline.

Lower Extremity Peripheral Artery Disease: Contemporary Epidemiology, Management Gaps, and Future Directions: A Scientific Statement From the American Heart Association

Lower extremity peripheral artery disease (PAD) affects >230 million adults worldwide and is associated with increased risk of various adverse clinical outcomes (other cardiovascular diseases such as coronary heart disease and stroke and leg outcomes such as amputation). Despite its prevalence and clinical importance, PAD has been historically underappreciated by health care professionals and patients. This underappreciation seems multifactorial (eg, limited availability of the first-line diagnostic test, the ankle-brachial index, in clinics; incorrect perceptions that a leg vascular disease is not fatal and that the diagnosis of PAD would not necessarily change clinical practice). In the past several years, a body of evidence has indicated that these perceptions are incorrect. Several studies have consistently demonstrated that many patients with PAD are not receiving evidence-based therapies. Thus, this scientific statement provides an update for health care professionals regarding contemporary epidemiology (eg, prevalence, temporal trends, risk factors, and complications) of PAD, the present status of diagnosis (physiological tests and imaging modalities), and the major gaps in the management of PAD (eg, medications, exercise therapy, and revascularization). The statement also lists key gaps in research, clinical practice, and implementation related to PAD. Orchestrated efforts among different parties (eg, health care providers, researchers, expert organizations, and health care organizations) will be needed to increase the awareness and understanding of PAD and improve the diagnostic approaches, management, and prognosis of PAD.

Potentially undiagnosed cognitive impairment in patients with peripheral arterial disease: A systematic review of the literature

INTRODUCTION

It is purported that patients with peripheral arterial disease (PAD) may have impaired cognitive function due to concomitant cerebrovascular disease. Such disease may be clinically unrecognized but can impact on a patient's recovery and prognosis. The purpose of this systematic review was to interrogate the body of published evidence on undiagnosed cognitive impairment in PAD patients.

METHODS

A search strategy encompassing MEDLINE, Scopus, and the Cochrane database was developed to identify peer-reviewed articles examining rates of undiagnosed cognitive impairment in patients with PAD. The following search terms were used: 'PAD'; 'PVD'; 'dementia'; 'peripheral arterial disease'; 'peripheral vascular disease'; 'cognitive impairment'; 'alzheimer's disease' and 'cogniti∗'. Our primary outcome was the incidence of previously undiagnosed cognitive impairment in patients with PAD.

RESULTS

The initial search yielded 1492 titles. After removal of duplicates, 961 abstracts were screened to ascertain if they were eligible for inclusion. Abstract review yielded 62 full texts for further evaluation. Eight case-control studies consisting of 1161 patients were included. Analysis of these studies revealed that PAD patients performed significantly worse than controls on a variety of neuropsychological measures.

CONCLUSION

Our review indicated that PAD patients are more likely to suffer with undiagnosed cognitive impairment than healthy controls.

Risk factors for delayed-onset dementia after stroke or transient ischemic attack-A five-year longitudinal cohort study

BACKGROUND

Stroke not only substantially increases the risk of incident dementia early after stroke but also the risk remains elevated years after.

AIM

We aimed to determine the risk factors of dementia onset more than three to six months after stroke or transient ischemic attack.

METHODS

This is a single-center prospective cohort study. We recruited consecutive subjects with stroke/transient ischemic attack without early-onset dementia. We conducted an annual neuropsychological assessment for five years. We investigated the association between baseline demographic, clinical, genetic (APOEɛ4 allele), and radiological factors as well as incident recurrent stroke with delayed-onset dementia using Cox proportional hazards models.

RESULTS

In total, 1007 patients were recruited, of which 88 with early-onset dementia and 162 who lost to follow-ups were excluded. Forty-nine (6.5%) out of 757 patients have incident delayed-onset dementia. The presence of ≥3 lacunes, history of ischemic heart disease, history of ischemic stroke, and a lower baseline Hong Kong version of the Montreal Cognitive Assessment (MoCA) score were significantly associated with delayed-onset dementia. APOEɛ4 allele, medial temporal lobe atrophy, and recurrent stroke were not predictive.

CONCLUSION

The presence of ≥3 lacunes, history of ischemic heart disease, history of ischemic stroke, and a lower baseline MoCA score are associated with delayed-onset dementia after stroke/transient ischemic attack.

Cognitive Function Changes in Older People. Results of Second Wave of Cognition of Older People, Education, Recreational Activities, NutritIon, Comorbidities, fUnctional Capacity Studies (COPERNICUS)

Background

Cognitive reserve explains why subjects with more years of education, professional achievement, or participation in recreational activities show less cognitive decline with aging. We hypothesize that levels of recreational travel, education, occupation, systemic health, physical performance, and current cognitive activity levels affect the trajectory of cognitive function in older, healthy people in Poland.

Materials and Methods

Healthy, older people (N = 205) were examined and followed-up at 2 years. Participants completed physical and cognitive function assessments: including the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA) and its two subtests Delayed Recall (DR) and Verbal Fluency (VF), and Trail Making Test Part B (TMT B). Factors associated with cognitive functioning were also examined.

Results

The MMSE result significantly decreased over 2 years. No significant decrease in other cognitive tests was noted. However, the trajectory of cognitive tests results varied between individual participants. Percentage of variance of change was explained by the following predictors: 21 in MMSE, 24 in MoCA, 8 in DR, 25 in VF, and 24 in TMT B. Age and the presence of varicose veins were significantly linked to negative changes in MMSE and MoCA scores, while working in a professional occupational status associated with a higher score. The subgroup with varicose veins did worse on the Delayed Recall subtest of MoCA.

Conclusion

Cognitive reserve could be extended by proxies of reserve that are related to systemic health and travel activity. The latter is a combination of social, physical, and cognitive activity and potentially might serve as an intervention to improve cognitive function in older people. However, due to the limitations of this study, results should be interpreted with caution and needs to be replicated in the further studies.

Cardiovascular Disease, Diabetes Mellitus, and Hypertension in Lewy Body Disease: A Comparison with Other Dementia Disorders

Background:

Research concerning the potential roles of cardiovascular disease (CaVD) and diabetes mellitus (DM) as risk factors for Lewy body disease (LBD) is limited. These disorders are, however, established risk factors for vascular dementia (VaD) and have been proposed as risk factors for Alzheimer’s disease (AD).

Objective:

The aim of this study was to investigate the prevalence of CaVD and DM in LBD and compare the results with previous findings in cases with AD, VaD, and mixed AD-VaD (MD).

Methods:

Autopsy reports at the Clinical Department of Pathology in Lund from 2001–2018 were analyzed. All cases with a complete neuropathological diagnosis of LBD were selected, not distinguishing between subjects with clinical Parkinson disease dementia and dementia with Lewy bodies, on the condition of a clinical diagnosis of dementia. Clinical data were retrieved through the patients’ medical records and the Swedish National Diabetes Register (NDR) and compared with those of the AD, VaD, and MD cases.

Results:

In LBD, there was less CaVD, significantly less DM (p = 0.002) and likewise significantly less hypertension (p < 0.001) than in VaD. The results of the LBD group were consistent with the results of the AD group.

Conclusion:

Our findings of a low prevalence of CaVD and CaVD risk factors in LBD and in AD argue against the association between these risk factors and their contribution to the development of neurodegenerative diseases.

The Ankle-Brachial Index Is Associated with Cerebral β-Amyloid Deposition in Cognitively Normal Older Adults

BACKGROUND

Although ankle-brachial index (ABI), an indicator of atherosclerosis or arterial stiffness, has been associated with dementia and Alzheimer's disease (AD), no information is yet available for its contribution to AD pathologies. We investigated the relationship between the ABI and in vivo β-amyloid (Aβ) deposition and AD-specific neurodegeneration in cognitively normal (CN) elderly individuals.

METHODS

A total of 256 CN elderly subjects who participated in the Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's Disease (KBASE), an ongoing prospective cohort study, were included. All subjects underwent comprehensive clinical and neuropsychological assessments, ABI measurement, apolipoprotein E (APOE) genotyping, [11C]Pittsburgh Compound B (PiB)-positron emission tomography (PET), [18F]-fludeoxyglucose PET, and magnetic resonance imaging.

RESULTS

A significant positive association was found between the ABI and global cerebral Aβ retention measured by PiB-PET, even after controlling for age, sex, and APOE ε4. When three stratified ABI subgroups (ABI < 1.00, 1.00-1.29, and ≥ 1.30) were compared, the highest ABI subgroup (ie, ABI ≥ 1.30) showed significantly higher Aβ deposition than that of the other subgroups. This relationship between Aβ deposition and the ABI was significant only in APOE ε4 carriers, but not in noncarriers. No significant association was observed between the ABI and neurodegeneration in the AD-signature regions.

CONCLUSION

Our findings suggest that a high ABI, possibly related to arterial stiffness, is associated with elevated brain Aβ burden in cognitively healthy elderly individuals, particularly in APOE ε4 carriers.

Cerebrovascular amyloid Angiopathy in bioengineered vessels is reduced by high-density lipoprotein particles enriched in Apolipoprotein E

Background

Several lines of evidence suggest that high-density lipoprotein (HDL) reduces Alzheimer’s disease (AD) risk by decreasing vascular beta-amyloid (Aβ) deposition and inflammation, however, the mechanisms by which HDL improve cerebrovascular functions relevant to AD remain poorly understood.

Methods

Here we use a human bioengineered model of cerebral amyloid angiopathy (CAA) to define several mechanisms by which HDL reduces Aβ deposition within the vasculature and attenuates endothelial inflammation as measured by monocyte binding.

Results

We demonstrate that HDL reduces vascular Aβ accumulation independently of its principal binding protein, scavenger receptor (SR)-BI, in contrast to the SR-BI-dependent mechanism by which HDL prevents Aβ-induced vascular inflammation. We describe multiple novel mechanisms by which HDL acts to reduce CAA, namely: i) altering Aβ binding to collagen-I, ii) forming a complex with Aβ that maintains its solubility, iii) lowering collagen-I protein levels produced by smooth-muscle cells (SMC), and iv) attenuating Aβ uptake into SMC that associates with reduced low density lipoprotein related protein 1 (LRP1) levels. Furthermore, we show that HDL particles enriched in apolipoprotein (apo)E appear to be the major drivers of these effects, providing new insights into the peripheral role of apoE in AD, in particular, the fraction of HDL that contains apoE.

Conclusion

The findings in this study identify new mechanisms by which circulating HDL, particularly HDL particles enriched in apoE, may provide vascular resilience to Aβ and shed new light on a potential role of peripherally-acting apoE in AD.

A Low Ankle-Brachial Index and High Brachial-Ankle Pulse Wave Velocity Are Associated with Poor Cognitive Function in Patients Undergoing Hemodialysis

Patients with end-stage renal disease (ESRD) have an increased risk of both impaired cognitive function and peripheral artery disease (PAD) than the general population. The association between PAD and dementia is recognized, but there are limited studies in patients with ESRD. The aim of this study was to evaluate the relationship between ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) and cognitive impairment in patients receiving hemodialysis (HD). We enrolled 136 prevalent HD patients (mean age 59.3 ± 10.5 years, 55.9% male). Cognitive performance was measured using the Montreal Cognitive Assessment (MoCA) and Cognitive Abilities Screening Instrument (CASI) by trained psychiatrists. Associations between the cognitive function and ABI and baPWV were assessed using multiple linear regression analysis. Compared with HD patients with ABI ≥ 0.9, patients with ABI < 0.9 had lower MoCA score (p = 0.027) and lower CASI score but did not achieve significant level (p = 0.056). In the multivariate stepwise linear regression analysis, ABI (per 0.1) was independently positively associated with the MoCA score (β coefficient = 0.62, p = 0.011) and the CASI score (β coefficient = 1.43, p = 0.026). There is a negative association between baPWV (per 100 cm/s) and CASI (β coefficient = −0.70, p = 0.009). In conclusion, a low ABI or high baPWV was associated with a lower cognitive function in HD patients.

Cognitive Functioning in Older People. Results of the First Wave of Cognition of Older People, Education, Recreational Activities, Nutrition, Comorbidities, Functional Capacity Studies (COPERNICUS)

Background: Cognitive reserve is a way of explaining why some individuals with a high degree of brain pathology are without clinical manifestations. In this study, factors related to systemic diseases, body composition, aerobic capacity, past and current behavior were examined and included as predictors of cognitive function.

Materials and Methods: 407 subjects (60–88 years old) underwent physical examination and cognitive function assessment [Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Trail Making Test Part B (TMT B)]. Predictors of cognitive functioning were evaluated: occupational status (OS), diet, mental and touristic activities were assessed using an ad hoc questionnaire. Aerobic capacity was measured using a six-minute walk test (6MWT).

Results: With each year of age there is a decrease in MMSE score by 0.18 points. Varicose veins on lower extremities and low OS were also significantly associated with MMSE result. For every year of having hypertension, low OS and not being abroad in the last 3 years, there was 0.17, 0.30, and 0.16 less points, respectively, and 0.15 more point per one additional meter walked in 6MWT in the MoCA score. With each year of age and for low OS there was there were 0.31 and 0.21 s more to complete TMT B, respectively.

Conclusion: Education, OS, presence of systemic diseases and social and tourist activities, aerobic capacity and body composition could be considered as factors contributing to cognitive functioning in older people. However, the relationship of above mentioned factors with education level and cognitive function may be not fully orthogonal.

Lack of genetic support for shared aetiology of Coronary Artery Disease and Late-onset Alzheimer's disease

Epidemiological studies suggest a positive association between coronary artery disease (CAD) and late-onset Alzheimer's disease (LOAD). This large-scale genetic study brings together 'big data' resources to examine the causal impact of genetic determinants of CAD on risk of LOAD. A two-sample Mendelian randomization approach was adopted to estimate the causal effect of CAD on risk of LOAD using summary data from 60,801 CAD cases from CARDIoGRAMplusC4D and 17,008 LOAD cases from the IGAP Consortium. Additional analyses assessed the independent relevance of genetic associations at the APOE locus for both CAD and LOAD. Higher genetically determined risk of CAD was associated with a slightly higher risk of LOAD (Odds Ratio (OR) per log-odds unit of CAD [95% CI]: 1.07 [1.01-1.15]; p = 0.027). However, after exclusion of the APOE locus, the estimate of the causal effect of CAD for LOAD was attenuated and no longer significant (OR 0.94 [0.88-1.01]; p = 0.072). This Mendelian randomization study indicates that the APOE locus is the chief determinant of shared genetic architecture between CAD and LOAD, and suggests a lack of causal relevance of CAD for risk of LOAD after exclusion of APOE.

Impact of Nitric Oxide Bioavailability on the Progressive Cerebral and Peripheral Circulatory Impairments During Aging and Alzheimer's Disease

Advanced aging, vascular dysfunction, and nitric oxide (NO) bioavailability are recognized risk factors for Alzheimer's disease (AD). However, the contribution of AD, per se, to this putative pathophysiological mechanism is still unclear. To better answer this point, we quantified cortical perfusion with arterial spin labeling (PVC-CBF), measured ultrasound internal carotid (ICA), and femoral (FA) artery blood flow in a group of patients with similar age (~78 years) but different cognitive impairment (i.e., mild cognitive impairment MCI, mild AD-AD1, moderate AD-AD2, and severe AD-AD3) and compared them to young and healthy old (aged-matched) controls. NO-metabolites and passive leg-movement (PLM) induced hyperemia were used to assess systemic vascular function. Ninety-eight individuals were recruited for this study. PVC-CBF, ICA, and FA blood flow were markedly (range of 9–17%) and significantly (all p < 0.05) reduced across the spectrum from YG to OLD, MCI, AD1, AD2, AD3 subjects. Similarly, plasma level of nitrates and the values of PLM were significantly reduced (range of 8–26%; p < 0.05) among the six groups. Significant correlations were retrieved between plasma nitrates, PLM and PVC-CBF, CA, and FA blood flow. This integrative and comprehensive approach to vascular changes in aging and AD showed progressive changes in NO bioavailability and cortical, extracranial, and peripheral circulation in patients with AD and suggested that they are directly associated with AD and not to aging. Moreover, these results suggest that AD-related impairments of circulation are progressive and not confined to the brain. The link between cardiovascular and the central nervous systems degenerative processes in patients at different severity of AD is likely related to the depletion of NO.

Undetected Peripheral Arterial Disease Among Older Adults With Alzheimer's Disease and Other Dementias

BACKGROUND

Peripheral arterial disease (PAD) was reported to increase the risk of dementia(s) even more than stroke. We assessed the prevalence of PAD in a group with definite diagnosis of dementia.

METHODS

Patients aged 65 years or older with Alzheimer's disease (AD), vascular dementia (VaD), or AD-VaD were enrolled (n = 162, mean age: 78.87 [6.05] years). An age- and gender-matched control group was also included (n = 190). Peripheral arterial disease was diagnosed by the ankle-brachial index.

RESULTS

Frequency of PAD among patients with and without dementia was 35.2% and 16.3%, respectively ( P < .001), being similar among different types of dementia. After adjustment for covariates, dementia (odds ratio: 2.41, 95% confidence interval: 1.34-4.32; P = .003) was among the predictors of PAD diagnosis along with older age, female gender, and diabetes.

CONCLUSIONS

The prevalence of PAD was more than double in patients with dementia, with no difference among AD, VaD, and AD-VaD types.

Ankle-Brachial Index: An Ubiquitous Marker of Cognitive Impairment-The EPIDEMCA Study

Epidemiological research on the implication of atherosclerosis in the development of cognitive impairment is lacking in low- and middle-income countries, where two-thirds of the individuals affected by dementia live. Individuals aged ≥65 years living in urban and rural areas of 2 countries in Central Africa were invited. Demographic, clinical, and biological data were collected, and the ankle-brachial index (ABI) was measured. Cognitive impairment was defined according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) criteria. Among 1662 participants (age 72.9 years, 59.3% females), the prevalence of cognitive impairment was 13.6%, which is higher in individuals with ABI ≤ 0.90 and ABI ≥ 1.40 than those with 0.90 < ABI < 1.40 (20.1% and 17% vs 12%, P = .0024). Cognitive impairment was significantly associated with the factors such as age (odds ratio [OR]: 1.09; 95% confidence interval [CI]: 1.07-1.12, P < .0001), female gender (OR: 2.36, 95% CI: 1.59-3.49, P < .0001), smoking (OR: 1.54, 95% CI: 1.06-2.23, P = .0026), and low ABI (≤0.90; OR: 1.52, 95% CI: 1.03-2.25, P = .0359). The ABI, a ubiquitous marker of atherosclerosis, provides independent and incremental information on susceptibility to present with cognitive disorders.

Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's Disease: Methodology and Baseline Sample Characteristics

OBJECTIVE

The Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's disease (KBASE) aimed to recruit 650 individuals, aged from 20 to 90 years, to search for new biomarkers of Alzheimer's disease (AD) and to investigate how multi-faceted lifetime experiences and bodily changes contribute to the brain changes or brain pathologies related to the AD process.

METHODS

All participants received comprehensive clinical and neuropsychological evaluations, multi-modal brain imaging, including magnetic resonance imaging, magnetic resonance angiography, [11C]Pittsburgh compound B-positron emission tomography (PET), and [18F]fluorodeoxyglucose-PET, blood and genetic marker analyses at baseline, and a subset of participants underwent actigraph monitoring and completed a sleep diary. Participants are to be followed annually with clinical and neuropsychological assessments, and biannually with the full KBASE assessment, including neuroimaging and laboratory tests.

RESULTS

As of March 2017, in total, 758 individuals had volunteered for this study. Among them, in total, 591 participants-291 cognitively normal (CN) old-aged individuals, 74 CN young- and middle-aged individuals, 139 individuals with mild cognitive impairment (MCI), and 87 individuals with AD dementia (ADD)-were enrolled at baseline, after excluding 162 individuals. A subset of participants (n=275) underwent actigraph monitoring.

CONCLUSION

The KBASE cohort is a prospective, longitudinal cohort study that recruited participants with a wide age range and a wide distribution of cognitive status (CN, MCI, and ADD) and it has several strengths in its design and methodologies. Details of the recruitment, study methodology, and baseline sample characteristics are described in this paper.

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Interarm differences in systolic blood pressure and the risk of dementia and subclinical brain injury

INTRODUCTION

This study examined whether interarm differences in systolic blood pressure (IDSBP) ≥10 mm Hg were associated with the risk of incident dementia and subclinical brain injury.

METHODS

Between 1992 and 1998, 2063 participants of the Framingham Heart Study underwent assessment of IDSBP with results related to the 10-year risk of incident dementia including clinically characterized Alzheimer's disease. Secondary outcomes included markers of subclinical brain injury on magnetic resonance imaging.

RESULTS

High IDSBP were associated with a greater risk of incident dementia (hazard ratio [HR] 1.92; 95% confidence interval [CI], 1.09-3.40) and Alzheimer's disease (HR, 2.32; 95% CI, 1.29-4.18), but only in those who carried an apolipoprotein E (APOE) ε4 allele. IDSBP also predicted lower total brain volumes and more prevalent silent brain infarcts in those who were APOE ε4 positive.

DISCUSSION

High IDSBP were associated with an increased risk of dementia, including clinical Alzheimer's disease, and subclinical brain injury in those who were APOE ε4 positive.

Associations Between Ankle-Brachial Index and Cognitive Function: Results From the Lifestyle Interventions and Independence for Elders Trial

OBJECTIVE

The objective of this study was to evaluate cross-sectional and longitudinal associations between ankle-brachial index (ABI) and indicators of cognitive function.

DESIGN

Randomized clinical trial (Lifestyle Interventions and Independence for Elders Trial).

SETTING

Eight US academic centers.

PARTICIPANTS

A total of 1601 adults ages 70-89 years, sedentary, without dementia, and with functional limitations.

MEASUREMENTS

Baseline ABI and interviewer- and computer-administered cognitive function assessments were obtained. These assessments were used to compare a physical activity intervention with a health education control. Cognitive function was reassessed 24 months later (interviewer-administered) and 18 or 30 months later (computer-administered) and central adjudication was used to classify individuals as having mild cognitive impairment, probable dementia, or neither.

RESULTS

Lower ABI had a modest independent association with poorer cognitive functioning at baseline (partial r = 0.09; P < .001). Although lower baseline ABI was not associated with overall changes in cognitive function test scores, it was associated with higher odds for 2-year progression to a composite of either mild cognitive impairment or probable dementia (odds ratio 2.60 per unit lower ABI; 95% confidence interval 1.06-6.37). Across 2 years, changes in ABI were not associated with changes in cognitive function.

CONCLUSION

In an older cohort sedentary individuals with dementia and with functional limitations, lower baseline ABI was independently correlated with cognitive function and associated with greater 2-year risk for progression to mild cognitive impairment or probable dementia.

Smoking is associated with an increased risk of dementia: a meta-analysis of prospective cohort studies with investigation of potential effect modifiers

Background

Previous studies showed inconsistent results on the association of smoking with all-cause dementia and vascular dementia (VaD), and are limited by inclusion of a small number of studies and unexplained heterogeneity. Our review aimed to assess the risk of all-cause dementia, Alzheimer’s disease (AD) and VaD associated with smoking, and to identify potential effect modifiers.

Methods and Findings

The PubMed, Embase, Cochrane Library and Psychinfo databases were searched to identify studies that provided risk estimates on smoking and incidence of dementia. A random-effects model was used to yield pooled results. Thirty-seven studies were included. Compared with never smokers, current smokers showed an increased risk of all-cause dementia (risk ratio (RR) 1.30, 95% confidence interval (CI) 1.18–1.45), AD (RR 1.40, 95% CI 1.13–1.73) and VaD (RR 1.38, 95% CI 1.15–1.66). For all-cause dementia, the risk increased by 34% for every 20 cigarettes per day (RR 1.34, 95% CI 1.25–1.43). Former smokers did not show an increased risk of all-cause dementia (RR 1.01, 95% CI 0.96–1.06), AD (RR 1.04, 95% CI 0.96–1.13) and VaD (RR 0.97, 95% CI 0.83–1.13). Subgroup analyses indicated that (1) the significantly increased risk of AD from current smoking was seen only in apolipoprotein E ε4 noncarriers; (2) current smokers aged 65 to 75 years at baseline showed increased risk of all-cause dementia and AD compared to those aged over 75 or under 65 years; and (3) sex, race, study location and diagnostic criteria difference in risk of dementia was not found.

Conclusions

Smokers show an increased risk of dementia, and smoking cessation decreases the risk to that of never smokers. The increased risk of AD from smoking is more pronounced in apolipoprotein E ε4 noncarriers. Survival bias and competing risk reduce the risk of dementia from smoking at extreme age.

Spontaneous brain activity in type 2 diabetics revealed by amplitude of low-frequency fluctuations and its association with diabetic vascular disease: a resting-state FMRI study

Purpose

To investigate correlations between altered spontaneous brain activity, diabetic vascular disease, and cognitive function for patients with type 2 diabetes mellitus (T2DM) using resting-state functional magnetic resonance imaging (rs-fMRI).

Methods

Rs-fMRI was performed for T2DM patients (n = 26) and age-, gender-, and education-matched non-diabetic control subjects (n = 26). Amplitude of low frequency fluctuations (ALFF) were computed from fMRI signals to measure spontaneous neuronal activity. Differences in the ALFF patterns between patients and controls, as well as their correlations with clinical variables, were evaluated.

Results

Compared with healthy controls, T2DM patients exhibited significantly decreased ALFF values mainly in the frontal and parietal lobes, the bilateral thalumi, the posterior lobe of the cerebellum, and increased ALFF values mainly in the visual cortices. Furthermore, lower ALFF values in the left subcallosal gyrus correlated with lower ankle-brachial index values (r = 0.481, p = 0.020), while lower ALFF values in the bilateral medial prefrontal gyri correlated with higher urinary albumin-creatinine ratio (r = −0.418, p = 0.047). In addition, most of the regions with increased ALFF values in the visual cortices were found to negatively correlate with MoCA scores.

Conclusions

These results confirm that ALFF are altered in many brain regions in T2DM patients, and this is associated with the presence of diabetic vascular disease and poor cognitive performance. These findings may provide additional insight into the neurophysiological mechanisms that mediate T2DM-related cognitive dysfunction, and may also serve as a reference for future research.

High-density lipoproteins and cerebrovascular integrity in Alzheimer's disease

Cerebrovascular dysfunction significantly contributes to the clinical presentation and pathoetiology of Alzheimer's disease (AD). Deposition and aggregation of β-amyloid (Aβ) within vascular smooth muscle cells leads to inflammation, oxidative stress, impaired vasorelaxation, and disruption of blood-brain barrier integrity. Midlife vascular risk factors, such as hypertension, cardiovascular disease, diabetes, and dyslipidemia, increase the relative risk for AD. These comorbidities are all characterized by low and/or dysfunctional high-density lipoproteins (HDL), which itself is a risk factor for AD. HDL performs a wide variety of critical functions in the periphery and CNS. In addition to lipid transport, HDL regulates vascular health via mediating vasorelaxation, inflammation, and oxidative stress and promotes endothelial cell survival and integrity. Here, we summarize clinical and preclinical data examining the involvement of HDL, originating from the circulation and from within the CNS, on AD and hypothesize potential synergistic actions between the two lipoprotein pools.

Ankle-brachial index, cognitive impairment and cerebrovascular disease in a Chinese population

BACKGROUND

Previous studies have assessed the association between ankle-brachial index (ABI) and cognition, mainly using brief cognitive tests. We investigated whether ABI was associated with cognition independent of neuroimaging markers of cerebrovascular disease.

METHODS

Chinese subjects (n = 278, aged ≥60 years) were recruited from the ongoing Epidemiology of Dementia in Singapore (EDIS) Study. Ankle and brachial blood pressures were measured, and low ABI was defined as ≤0.9. A neuropsychological battery was utilized to determine cognition. Cognitive impairment no dementia (CIND) and dementia were diagnosed according to standard diagnostic criteria. Magnetic resonance imaging (MRI) was used to obtain semiquantitative and quantitative markers of cerebrovascular disease and atrophy.

RESULTS

A low ABI was related to the presence of intracranial stenosis (odds ratio, OR = 1.71; 95% confidence interval, CI: 1.13-2.59), but not with the presence of infarcts, microbleeds or grey matter, white matter and white matter lesion volumes. Furthermore, a low ABI was associated with poorer overall cognitive function and CIND-moderate/dementia (OR = 2.26; 95% CI: 1.11-4.59), independent of cardiovascular risk factors, and the MRI markers related to cerebrovascular disease and atrophy.

CONCLUSION

We found an association between a low ABI and cognitive impairment, independent of any MRI marker of cerebral small vessel disease or large artery atherosclerotic disease.

Arterial stiffness and endothelial function are related to brain aging and episodic memory in community-dwelling middle-aged and older adults

Evaluation of: Tsao CW, Seshadri S, Beiser AS et al. Relations of arterial stiffness and endothelial function to brain aging in the community. Neurology 81, 1–8 (2013). This study reports the association between arterial stiffness and pressure pulsatility in middle-aged and older community-dwelling adults. As part of the Stroke- and Dementia-free Framingham Offspiring Study, 1587 participants were studied for tonometric arterial stiffness and endothelial function (years 1998–2001), and had MRI brain scans and cognitive assessments (1990–2002). The measures of the central aortic hemodynamics (e.g., carotid–femoral pulse wave velocity and mean arterial and central pulse pressure) were associated with greater white matter hyperintensity volumes and lower total cerebral brain volumes; this association was stronger for participants aged 65 years or older. The mean arterial and central pulse pressure were also associated with reduced verbal memory (p < 0.05) but not executive function. The brachial artery endothelial function was not associated with cerebral changes. These findings indicate that peripheral vascular changes are related not only to distal cerebral microvascular pathology, but may also be used as a surrogate marker for subclinical stages of cognitive dysfunction.

Subclinical atherosclerotic calcification and cognitive functioning in middle-aged adults: the CARDIA study

OBJECTIVE

Cardiovascular risk factors in middle-age are associated with cognitive impairment and dementia in older age. Less is known about the burden of calcified subclinical atherosclerosis and cognition, especially in midlife. We examined the association of coronary artery and abdominal aortic calcified plaque (CAC and AAC, respectively) with cognitive functioning in middle-aged adults.

METHODS

This cross-sectional study included 2510 black and white adults (age: 43-55 years) without heart disease or stroke who completed a year 25 follow-up exam (2010-11) as part of the Coronary Artery Risk Development in Young Adults Study. CAC and AAC were measured with non-contrast computed tomography. Cognition was assessed with the Digit Symbol Substitution Test (DSST) (psychomotor speed), Stroop Test (executive function), and Rey Auditory Verbal Learning Test (RAVLT) (verbal memory).

RESULTS

A greater amount of CAC and AAC was associated with worse performance on each test of cognitive function after adjustment for age, sex, race, education, and study center. Associations were attenuated, but remained significant for the DSST and RAVLT following additional adjustment for vascular risk factors, including adiposity, smoking, alcohol use, dyslipidemia, hypertension, and diabetes. Compared to participants without CAC or AAC, those with both CAC and AAC, but not CAC or AAC alone was associated with lower DSST scores (p < 0.05).

CONCLUSIONS

In this community-based sample, greater subclinical atherosclerotic calcification was associated with worse psychomotor speed and memory in midlife. These findings underscore the importance of a life course approach to the study of cognitive impairment with aging.

Chronic venous ulceration of leg associated with peripheral arterial disease: an underappreciated entity in developing country

Chronic venous ulcer can often be associated with asymptomatic peripheral arterial disease (PAD), which usually remains undiagnosed adding significantly to the morbidity of these patients. The Ankle-Brachial Pressure Index (ABPI) is suggested for PAD evaluation. Many PAD studies were conducted in western countries, but there is a scarcity of data on the prevalence of PAD in clinical venous ulcer patient in developing countries. We conducted a study in a tertiary care hospital of eastern part of India to find out the prevalence of PAD in venous ulcer patients, and also to find the sensitivity of ABPI as a diagnostic tool in these patients. We evaluated clinically diagnosed patients with venous ulcer using ABPI and Colour Doppler study for the presence of PAD. Possible associations such as age, sex, body mass index (BMI), smoking, hypertension and atherosclerosis were studied. All results were analysed using the software Statistica version 6. PAD was present in 23 (27·71%) patients. Older age, longer duration, smoking, high BMI and hypertension were found to be significantly associated with PAD. A very strong level of agreement was found between venous Doppler and ABPI. Assessment for the presence of PAD is important in all clinically diagnosed venous ulcer patients. ABPI being a simple, non-invasive outpatient department (OPD)-based procedure, can be routinely used in cases of venous ulcer to find out the hidden cases of PAD even in developing countries.

Risk factors related to low ankle-brachial index measured by traditional and modified definition in hypertensive elderly patients

Peripheral arterial disease (PAD) increases with age and ankle-brachial index (ABI) ≤ 0.9 is a noninvasive marker of PAD. The purpose of this study was to identify risk factors related to a low ABI in the elderly using two different methods of ABI calculation (traditional and modified definition using lower instead of higher ankle pressure). A cross-sectional study was carried out with 65 hypertensive patients aged 65 years or older. PAD was present in 18% of individuals by current ABI definition and in 32% by modified method. Diabetes, cardiovascular diseases, metabolic syndrome, higher levels of systolic blood pressure and pulse pressure, elevated risk by Framingham Risk Score (FRS), and a higher number of total and antihypertensive drugs in use were associated with low ABI by both definitions. Smoking and LDL-cholesterol were associated with low ABI only by the modified definition. Low ABI by the modified definition detected 9 new cases of PAD but cardiovascular risk had not been considered high in 3 patients when calculated by FRS. In conclusion, given that a simple modification of ABI calculation would be able to identify more patients at high risk, it should be considered for cardiovascular risk prediction in all elderly hypertensive outpatients.

Poorer clock draw test scores are associated with greater functional impairment in peripheral artery disease: the Walking and Leg Circulation Study II

We hypothesized that, in the absence of clinically recognized dementia, cognitive dysfunction measured by the clock draw test (CDT) is associated with greater functional impairment in men and women with peripheral artery disease (PAD). Participants were men and women aged 60 years and older with Mini-Mental Status Examination scores ≥ 24 with PAD (n = 335) and without PAD (n = 234). We evaluated the 6-minute walk test, 4-meter walking velocity at usual and fastest pace, the Short Physical Performance Battery (SPPB), and accelerometer-measured physical activity. CDTs were scored using the Shulman system as follows: Category 1 (worst): CDT score 0-2; Category 2: CDT score 3; Category 3 (best): CDT score 4-5. Results were adjusted for age, sex, race, education, ankle-brachial index (ABI), and comorbidities. In individuals with PAD, lower CDT scores were associated with slower 4-meter usual-paced walking velocity (Category 1: 0.78 meters/second; Category 2: 0.83 meters/second; Category 3: 0.86 meters/second; p-trend = 0.025) and lower physical activity (Category 1: 420 activity units; Category 2: 677 activity units; Category 3: 701 activity units; p-trend = 0.045). Poorer CDT scores were also associated with worse functional performance in individuals without PAD (usual and fast-paced walking velocity and SPPB, p-trend = 0.022, 0.043, and 0.031, respectively). In conclusion, cognitive impairment identified with CDT is independently associated with greater functional impairment in older, dementia-free individuals with and without PAD. Longitudinal studies are necessary to explore whether baseline CDT scores and changes in CDT scores over time can predict long-term decline in functional performance in individuals with and without PAD.