Carotid atherosclerosis and 10-year changes in cognitive function

Arterial Health Markers in Relation to Behavior and Cognitive Outcomes at School Age

BACKGROUND

Impaired arterial health is associated with a decline in cognitive function and psychopathology in adults. We hypothesized that these associations originate in early life. We examined the associations of blood pressure, common carotid artery intima media thickness, and carotid distensibility with behavior and cognitive outcomes during adolescence.

METHODS AND RESULTS

This study was embedded in the Dutch Generation R Study, a population-based prospective cohort study from early fetal life onwards. Blood pressure, carotid intima media thickness, and carotid distensibility were measured at the age of 10 years. At the age of 13 years, total, internalizing and externalizing problems and attention-deficit hyperactivity disorder symptoms were measured using the parent-reported Child Behavior Checklist (CBCL/6-18), autistic traits were assessed by the Social Responsiveness Scale, and IQ was assessed using the Wechsler Intelligence Scale for Children-Fifth Edition. A 1-SD score higher mean arterial pressure was associated with lower odds of internalizing problems (odds ratio [OR], 0.92 [95% CI, 0.85-0.99]). However, this association was nonsignificant after correction for multiple testing. Carotid intima media thickness and carotid distensibility were not associated with behavior and cognitive outcomes at 13 years old.

CONCLUSIONS

From our results, we cannot conclude that the associations of blood pressure, carotid intima media thickness, and carotid distensibility at age 10 years with behavior and cognitive outcomes are present in early adolescence. Further follow-up studies are needed to identify the critical ages for arterial health in relation to behavior and cognitive outcomes at older ages.

Lifestyle and factors of vascular and metabolic health and inflammation are associated with sensorineural-neurocognitive aging in older adults

This study's aim was to identify risk factors associated with sensorineural and neurocognitive function (brain aging) in older adults. In N = 1,478 Epidemiology of Hearing Loss Study participants (aged 64-100 years, 59% women), we conducted sensorineural and cognitive tests, which were combined into a summary measure using Principal Component Analysis (PCA). Participants with a PCA score <-1 standard deviation (SD) were considered to have brain aging. Incident brain aging was defined as PCA score <-1 SD at 5-year follow-up among participants who had a PCA score ≥-1 SD at baseline. Logistic regression and Poisson models were used to estimate associations between baseline risk factors of lifestyle, vascular and metabolic health, and inflammation and prevalent or incident brain aging, respectively. In an age-sex adjusted multivariable model, not consuming alcohol (odds ratio(OR) = 1.77, 95% confidence Interval (CI) = 1.18,2.66), higher interleukin-6 levels (OR = 1.30, 95% CI = 1.03,1.64), and depressive symptoms (OR = 2.44, 95% CI = 1.63,3.67) were associated with a higher odds of having brain aging, while higher education had protective effects (OR = 0.55, 95% CI = 0.33,0.94). A history of stroke, arterial stiffness, and obesity were associated with an increased risk of developing brain aging during the five years of follow-up. Lifestyle, vascular, metabolic and inflammatory factors were associated with brain aging in older adults, which adds to the evidence of shared pathways for sensorineural and neurocognitive declines in aging. Targeting these shared central processing etiological factors with interventions may lead to retention of better neurological function, benefiting multiple systems, i.e., hearing, smell, and cognition, ultimately helping older adults retain independence and higher quality of life longer.

Associations of Hearing Loss and Hearing Aid Use With Cognition, Health-Related Quality of Life, and Depressive Symptoms

ObjectivesDetermine associations of hearing loss (HL) and hearing aid (HA) use with cognition, health-related quality of life (HRQoL), and depressive symptoms. Methods: Participants were from the Epidemiology of Hearing Loss Study or Beaver Dam Offspring Study. HL was defined as pure-tone average (.5-4.0 kHz) > 25 dB. A principal component analysis of 5 cognitive tasks measured cognition. The SF-12 measured mental and physical HRQoL. The Centers for Epidemiological Studies Depression Scale measured depressive symptoms (score ≥ 16). Regression models returned beta (B) coefficients or odds ratios (OR) with 95% confidence intervals. Results: This study included 3574 participants. HL (vs. none) was associated with poorer cognition (B-.12 [-.18, -.06]), mental (B-.99 [-1.65, -.33]) and physical (B-.76 [-1.50, -.03]) HRQoL, and increased odds of depressive symptoms (OR 1.49 [1.16, 1.91]). HA users had better cognition than non-users. Discussion: HL likely impacts cognition and well-being. HA use may have cognitive benefits.

Carotid dysfunction in senescent female mice is mediated by increased α1A-adrenoceptor activity and COX-derived vasoconstrictor prostanoids

α-Adrenergic receptors are crucial regulators of vascular hemodynamics and essential pharmacological targets for cardiovascular diseases. With aging, there is an increase in sympathetic activation, which could contribute to the progression of aging-associated cardiovascular dysfunction, including stroke. Nevertheless, there is little information directly associating adrenergic receptor dysfunction in the blood vessels of aged females. This study determined the role of a-adrenergic receptors in carotid dysfunction of senescent female mice (accelerated-senescence prone, SAMP8), compared with a nonsenescent (accelerated-senescence prone, SAMR1). Vasoconstriction to phenylephrine (Phe) was markedly increased in common carotid artery of SAMP8 [area under the curve (AUC), 527 ± 53] compared with SAMR1 (AUC, 334 ± 30, P = 0.006). There were no changes in vascular responses to the vasoconstrictor agent U46619 or the vasodilators acetylcholine (ACh) and sodium nitroprusside (NPS). Hyperactivity to Phe in female SAMP8 was reduced by cyclooxygenase-1 and cyclooxygenase-2 inhibition and associated with augmented ratio of TXA2/PGI2 release (SAMR1, 1.1 ± 0.1 vs. SAMP8, 2.1 ± 0.3, P = 0.007). However, no changes in cyclooxygenase expression were seen in SAMP8 carotids. Selective α_1A-receptor antagonism markedly reduced maximal contraction, whereas α_1D antagonism induced a minor shift in Phe contraction in SAMP8 carotids. Ligand binding analysis revealed a threefold increase of α-adrenergic receptor density in smooth muscle cells (VSMCs) of SAMP8 vs. SAMR1. Phe rapidly increased intracellular calcium (Ca_i²⁺) in VSMCs via the α_1A-receptor, with a higher peak in VSMCs from SAMP8. In conclusion, senescence intensifies vasoconstriction mediated by α_1A-adrenergic signaling in the carotid of female mice by mechanisms involving increased Ca_i²⁺ and release of cyclooxygenase-derived prostanoids.NEW & NOTEWORTHY The present study provides evidence that senescence induces hyperreactivity of α₁-adrenoceptor-mediated contraction of the common carotid. Impairment of α₁-adrenoceptor responses is linked to increased Ca²⁺ influx and release of COX-derived vasoconstrictor prostanoids, contributing to carotid dysfunction in the murine model of female senescence (SAMP8). Increased reactivity of the common carotid artery during senescence may lead to morphological and functional changes in arteries of the cerebral microcirculation and contribute to cognitive decline in females. Because the elderly population is growing, elucidating the mechanisms of aging- and sex-associated vascular dysfunction is critical to better direct pharmacological and lifestyle interventions to prevent cardiovascular risk in both sexes.

Carotid Intima-Media Thickness (cIMT) and Cognitive Performance: A Population-Based Cross-Sectional Study From North India

INTRODUCTION

Atherosclerosis has been shown to impact cognitive impairment, with most of the evidence originating from European, African, or East Asian populations that have employed carotid intima-media thickness (cIMT) as a biomarker for atherosclerosis. Vascular disease is related to dementia/cognitive decline. There is no community-based study from India that has looked at the association of cIMT with cognitive performance.

METHODS

In this cross-sectional study between December 2014 and 2019, we recruited 7505 persons [(mean age 64.6 (9.2) y) and 50.9% women] from a community-dwelling population in New Delhi. These persons underwent carotid ultrasound to quantify cIMT and a cognitive test battery that tapped into memory, processing speed, and executive function. We also computed the general cognitive factor (g-factor), which was identified as the first unrotated component of the principal component analysis and explained 37.4% of all variances in the cognitive tests. We constructed multivariate linear regression models adjusted for age, sex, education, and cardiovascular risk factors. Additional adjustment was made for depression, anxiety, and psychosocial support in the final model.

RESULTS

We found a significant association of higher cIMT with worse performance in general cognition (β=-0. 01(95% CI: -0.01; -0.01); P<0.001), processing speed (β=-0.20; 95% CI: -0.34; -0.07); P=0.003), memory (β=-0.29; 95% CI: -0.53; -0.05); P=0.016), and executive function (β=-0.54; 95% CI: -0.75; -0.33); P=<0.001). There was no statistically significant association of cIMT with Mini-Mental Status Examination score (β=0.02; 95% CI: -0.34; 0.40; 0.89).

CONCLUSION

The cross-sectional study found significant associations of increased cIMT with worse performance in global cognition, information processing, memory, and executive function.

Associations of Midlife Lifestyle and Health Factors with Long-Term Changes in Blood-Based Biomarkers of Alzheimer's Disease and Neurodegeneration

BACKGROUND

Pathological biomarkers of Alzheimer's disease (AD) and other dementias can change decades before clinical symptoms. Lifestyle and health factors might be relevant modifiable risk factors for dementia. Many previous studies have been focusing on associations of lifestyle and health-related factors with clinical outcomes later in life.

OBJECTIVE

We aimed to determine to what extent midlife factors of lifestyle, inflammation, vascular, and metabolic health were associated with long-term changes in blood-based biomarkers of AD (amyloid beta (Aβ)) and neurodegeneration (neurofilament light chain (NfL); total tau(TTau)).

METHODS

In 1,529 Beaver Dam Offspring Study (BOSS) participants (mean age 49 years, standard deviation (SD) = 9; 54% were women), we applied mixed-effects models with baseline risk factors as determinants and 10-year serum biomarker change as outcomes.

RESULTS

We found that education and inflammatory markers were associated with levels and/or change over time across all three markers of AD and neurodegeneration in the blood. There were baseline associations of measures of cardiovascular health with lower Aβ42/Aβ40. TTau changed little over time and was higher in individuals with diabetes. Individuals with lower risk in a number of cardiovascular and metabolic risk factors, including diabetes, hypertension, and atherosclerosis had slower accumulation of neurodegeneration over time, as determined by NfL levels.

CONCLUSION

Various lifestyle and health factors, including education and inflammation, were associated with longitudinal changes of neurodegenerative and AD biomarker levels in midlife. If confirmed, these findings could have important implications for developing early lifestyle and health interventions that could potentially slow processes of neurodegeneration and AD.

Better cognitive function in younger generations - Insights from two cohort studies of middle-aged to older adults in Wisconsin

BACKGROUND

Understanding generational trends in dementia and cognitive decline is essential to quantify future healthcare needs and may help identify interventions and preventions. We aimed to determine whether individuals from more recent generations showed better neurocognitive function.

METHODS

This cross-sectional study combined data from 4439 participants (mean age 64 years (SD = 13); 57% were women) from the Epidemiology of Hearing Loss Study and Beaver Dam Offspring Study. We assessed participants' birth cohort (1901-1924, Greatest Generation; 1925-1945, Silent Generation; 1946-1964, Baby Boom Generation; 1965-1984, Generation X) and neurocognition (Trail-Making Tests A and B, Digit Symbol Substitution Test, Auditory Verbal Learning Test, Verbal Fluency Test). Multivariable linear regression models were utilized.

RESULTS

Adjusted for age, sex, education, and known risk factors for cognitive decline, more recent generations showed better processing speed, executive function, attention, and verbal fluency than the Greatest Generation. Largest benefits were found in the Baby Boom Generation. Compared with the Greatest Generation, individuals from the Baby Boom Generation performed better on Trail-Making Tests A (-0.21 ln(time in s); 95% confidence interval (CI) -0.29, -0.13) and B (-0.31 ln(time in s); 95% CI -0.40, -0.22), Digit Symbol Substitution Test (6.07 numbers correct; 95% CI 3.61, 8.52) and Verbal Fluency Test (8.75 numbers correct; 95% CI 5.07, 12.42 in women; 5.28 numbers correct; 95% CI 0.79, 9.78 in men), with effect sizes similar to effects of 11-15 years of less aging.

CONCLUSIONS

This indicates that some benefits of younger generations might be related to yet unknown and potentially modifiable environmental, health-related or lifestyle factors and motivates research of such underlying factors to promote healthy cognitive aging.

Is carotid artery atherosclerosis associated with poor cognitive function assessed using the Mini-Mental State Examination? A systematic review and meta-analysis

OBJECTIVES

To determine associations between carotid atherosclerosis assessed by ultrasound and the Mini-Mental State Examination (MMSE), a measure of global cognitive function.

DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE and EMBASE databases were searched up to 1 May 2020 to identify studies assessed the associations between asymptomatic carotid atherosclerosis and the MMSE. Studies reporting OR for associations between carotid plaque or intima-media thickness (cIMT) and dichotomised MMSE were meta-analysed. Publication bias of included studies was assessed.

RESULTS

A total of 31 of 378 reviewed articles met the inclusion criteria; together they included 27 738 participants (age 35-95 years). Fifteen studies reported some evidence of a positive association between measures of atherosclerosis and poorer cognitive performance in either cross-sectional or longitudinal studies. The remaining 16 studies found no evidence of an association. Seven cross-sectional studies provided data suitable for meta-analysis. Meta-analysis of three studies that assessed carotid plaque (n=3549) showed an association between the presence of plaque and impaired MMSE with pooled estimate for the OR (95% CI) being 2.72 (0.85 to 4.59). An association between cIMT and impaired MMSE was reported in six studies (n=4443) with a pooled estimate for the OR (95% CI) being 1.13 (1.04 to 1.22). Heterogeneity across studies was moderate to small (carotid plaque with MMSE, I2=40.9%; cIMT with MMSE, I2=4.9%). There was evidence of publication bias for carotid plaque studies (p=0.02), but not cIMT studies (p=0.2).

CONCLUSIONS

There is some, limited cross-sectional evidence indicating an association between cIMT and poorer global cognitive function assessed with MMSE. Estimates of the association between plaques and poor cognition are too imprecise to draw firm conclusions and evidence from studies of longitudinal associations between carotid atherosclerosis and MMSE is limited.

PROSPERO REGISTRATION NUMBER

CRD42021240077.

Intima Media Thickness and Cognitive Function Among Adults: Meta-Analysis of Observational and Longitudinal Studies

Background

Carotid structural changes measured by intima media thickness (IMT) have been related to cognitive complaints during aging. Therefore, the aims of this meta‐analysis were (1) to elucidate the relationship between vascular status, measured as IMT, and cognitive domains distinguishing between global cognition, executive functions, memory and attention; and (2) to explore whether demographic (ie, age and sex), clinical (ie, body mass index and IMT baseline values), and procedure characteristics influence this association.

Methods and Results

We performed a systematic review of MEDLINE (via PubMed), Scopus, and Web of Science databases from their inception to June 2021. Studies meeting the following inclusion criteria were included: (1) the participants were adults; (2) the exposure was carotid IMT; (3) the outcome was cognitive function, including global cognition, executive function, memory, and attention measured using standardized tests; and (4) the study design was cross‐sectional or longitudinal including unadjusted and adjusted analyses. A total of 19 cross‐sectional and 15 longitudinal studies were included and demographic (age and sex), clinical (body mass index and baseline IMT values), and procedure characteristics were analyzed as potential mediator or moderators of the association.

Conclusions

Our data support negative associations between IMT and cognitive function in cross‐sectional studies. The association between IMT and cognition lost significance in longitudinal studies and when controlling for covariates in cross‐sectional studies. Finally, the strength of these associations seems not to be modified by age, sex, body mass index, and baseline IMT values. This systematic review and meta‐analysis adds to the evidence supporting the use of IMT as a measure for identifying patients at risk of cognitive decline.

Carotid intima-media thickness and risk of mild cognitive impairment: A systematic review and meta-analysis

Mild cognitive impairment (MCI) is an early phase of cognitive decline signalling the beginning of severe neurological diseases. Carotid intima-media thickness (cIMT) has shown some correlation with MCI development. This study was conducted to investigate the impact of elevated cIMT on the risk of MCI in adults. A literature search was conducted in PubMed, EMBASE, Cochrane Library, Scopus, Google Scholar and CINAHL databases till 30 July 2021, with keywords: ('Carotid Intima-Media Thickness' OR 'cIMT' OR 'IMT' AND 'Cognitive Impairment' OR 'Cognition' OR 'Cognitive Decline' AND 'Mild Cognitive Impairment' OR 'MCI'). Pooled standardized mean difference (SMD)/odds ratio (OR) and 95% confidence interval (CI) were determined for factor-disease association using either fixed (when I² <50%) or random effect (when I² >50%) models. Eight studies involving 1,585 MCI cases and 6,700 normal subjects were included in our meta-analysis which showed no significant association of increased cIMT with the risk of MCI [SMD 1.17, 95% CI -0.09 to 2.42]. However, sensitivity analysis revealed an outlier study significantly affecting the effect size. On omitting the outlier study, the re-evaluated meta-analysis revealed a significant association of cIMT with the risk of MCI [SMD 0.52, 95% CI 0.26 to 0.78]. This significant association was also observed during subgroup analysis in Caucasian population [SMD 0.65, 95% CI 0.13 to 1.18] but not in Asian population [SMD 0.39, 95% CI -0.01 to 0.79]. Elevated cIMT poses a potential risk for MCI. However, more population-based studies are required to corroborate these findings.

Associations Among Diffusion Tensor Image Along the Perivascular Space (DTI-ALPS), Enlarged Perivascular Space (ePVS), and Cognitive Functions in Asymptomatic Patients With Carotid Plaque

Background and Aim: Carotid atherosclerosis (CAS) is a common pathogenesis of cerebrovascular disease closely related to stroke and silent cerebrovascular disease (SCD), while the insufficient brain perfusion mechanism cannot quite explain the mechanism. The purpose of this study was to utilize diffusion tensor image analysis along the perivascular space (DTI-ALPS) to evaluate the glymphatic system activity and correlated DTI-ALPS with enlarged perivascular spaces (ePVS), carotid intima-media thickening (CIMT), mini-mental state examination (MMSE), and serological indicator in individuals with carotid plaque. Methods: Routine MRI and diffusion tensor images scan of the brain, carotid ultrasound, and blood examination were conducted on 74 individuals (52 carotid plaque subjects, 22 non-carotid plaque subjects), whose demographic and clinical characteristics were also recorded. DTI-ALPS index between patients with carotid plaque and normal controls were acquired and the correlations with other variables were analyzed. Results: The values of ALPS-index in the carotid plaque group was significantly lower compared to normal controls (2.12 ± 0.39, 1.95 ± 0.28, respectively, p = 0.034). The ALPS-index was negatively correlated with the basal ganglia (BG)-ePVS score (r = -0.242, p = 0.038) while there was no significant difference in the centrum semiovale (CSO)-ePVS score. Further analysis showed that there are more high-grade ePVS in the BG compared to the carotid plaque group than in the non-carotid plaque group (84.6% vs. 40.9%, p = 0.001). Conclusions: ALPS-index reflects the glymphatic system of the brain, which is associated with early high-risk cerebrovascular diseases. There may be damage in the function of the glymphatic system which induces the expansion of the perivascular space (PVS) in the BG in individuals with carotid plaque.

Extracranial carotid atherosclerosis is associated with increased neurofibrillary tangle accumulation

OBJECTIVE

We sought to determine whether extracranial carotid atherosclerotic disease (ECAD) is associated with increased key neurodegenerative pathology such as neurofibrillary tangle (NFT), beta-amyloid plaque, or cerebral amyloid angiopathy (CAA) accumulation, findings associated with Alzheimer's disease (AD) and other dementias.

METHODS

Our prospective, longitudinal, clinicopathologic study, the AZSAND (Arizona study of aging and neurodegenerative disorders) and Brain and Body Donation Program, recorded the presence or absence of clinically diagnosed ECAD and performed semiquantitative density estimates of NFT, beta-amyloid plaque, and CAA at death. After adjusting for potential confounding factors determined by logistic regression analysis, histopathology density scores were evaluated in individuals with ECAD (n = 66) and those without ECAD (n = 125).

RESULTS

We found that the presence of ECAD was associated with a 21% greater NFT burden at death compared with no ECAD (P = .02). Anatomically, an increased NFT burden was seen throughout the brain regions evaluated but was significant in the temporal lobe (P < .05) and entorhinal cortex (P = .02). In addition, we found that subjects who had undergone carotid endarterectomy (CEA), the surgical treatment of ECAD (n = 32), had decreased NFT densities compared with those with ECAD who had not undergone CEA (n = 66; P = .04). In contrast to NFT, ECAD was not associated with beta-amyloid plaques or CAA density.

CONCLUSIONS

These findings indicate that ECAD is associated with the NFT burden in the temporal lobe and entorhinal cortex, which has clinical significance for AD and non-AD dementias and cognitive dysfunction. Further understanding of whether ECAD increases the risk of neurodegenerative brain changes is highly relevant because ECAD is a treatable disease that has not, otherwise, been evaluated for nor specifically treated as a dementia risk factor.

The Association between Carotid Intima-Media Thickness and Cognitive Impairment: A Systematic Review and Meta-Analysis

BACKGROUND

Emerging evidence suggests that cognitive impairment (CI) and different etiologies of dementia, including Alzheimer's disease (AD), are associated with vascular risk factors and atherosclerosis. In clinical practice, carotid intima-media thickness (CIMT) measured by ultrasonography may be a marker of atherosclerosis. Many studies report increased CIMT in patients with dementia and CI although a firm association has not yet been established.

AIM

This systematic review and meta-analysis were conducted to study the relationship between CIMT, dementia, and CI.

METHODS

The literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and included the following databases: Medline, Embase, Cochrane Library, and Epistemonikos. The search spanned from 2000 to 2020 and was limited to English and Scandinavian languages.

RESULTS

The main analysis of CIMT in subjects with CI compared to subjects with no cognitive impairment (NCI) included 12 studies; 1,089 subjects with CI and 5,223 with NCI. There was no significant difference in CIMT between the CI and NCI groups. However, subgroup analyses revealed significantly higher CIMT in the mild cognitive impairment (MCI) and dementia groups than the NCI group. In addition, patients with dementia had increased CIMT compared to patients with MCI, and patients with AD demonstrated higher CIMT than those with vascular cognitive impairment (VCI).

CONCLUSION

CIMT may be higher in subjects with CI than in cognitively healthy subjects although no significant difference was observed in our main analysis. CIMT was higher in the dementia group than the MCI group and in the AD group compared to the VCI group.

A comprehensive review on RAGE-facilitated pathological pathways connecting Alzheimer’s disease, diabetes mellitus, and cardiovascular diseases

Background

Alzheimer’s disease (AD), cardiovascular disease (CVD), and diabetes are some of the most common causes of morbidity and mortality among the aging populations and cause a heavy burden on the worldwide healthcare system. In this review, we briefly highlighted cellular inflammation-based pathways of diabetes mellitus and CVD through receptor for advanced glycation end products AGEs or RAGE leading to Alzheimer’s disease and interrelation between these vascular and metabolic disorders. The articles were retrieved from Google Scholar, Science Direct, and PubMed databases using the following terms: Alzheimer’s; AGEs; RAGE; RAGE in Alzheimer’s; AGEs in Alzheimer’s; RAGE in diabetes; RAGE related pathways of CVD; RAGE in hypertension; RAGE and RAS system; RAGE and oxidative stress.

Main body of the abstract

AD is a neurodegenerative disease characterized by cognitive dysfunction and neuronal cell death. Vascular complications like hypertension, coronary artery disease, and atherosclerosis as well as metabolic syndromes like obesity and diabetes are related to the pathophysiology of AD. RAGE plays significant role in the onset and progression of AD. Amyloid plaques and neurofibrillary tangles (NFT) are two main markers of AD that regulates via RAGE and other RAGE/ligands interactions which also induces oxidative stress and a cascade of other cellular inflammation pathways leading to AD. Though AD and diabetes are two different disorders but may be inter-linked by AGEs and RAGE. In long-term hyperglycemia, upregulated AGEs interacts with RAGE and produces reactive oxygen species which induces further inflammation and vascular complications. Aging, hypercholesterolemia, atherosclerosis, hypertension, obesity, and inflammation are some of the main risk factors for both diabetes and dementia. Chronic hypertension and coronary artery disease disrupt the functions of the blood-brain barrier and are responsible for the accumulation of senile plaques and NFTs.

Short conclusion

RAGE plays a role in the etiology of Aβ and tau hyperphosphorylation, both of which contribute to cognitive impairment. So far, targeting RAGE may provide a potential sight to develop therapies against some metabolic disorders.

Subclinical Carotid Artery Atherosclerosis and Cognitive Function: A Mini-Review

Carotid artery atherosclerosis, the result of a multitude of vascular risk factors, is a promising marker for use in risk stratification. Recent evidence suggests that carotid artery atherosclerosis affects cognitive function and is an independent risk factor for the development of cognitive impairment. Both atherosclerosis and cognitive impairment develop over a prolonged period (years), and due to the aging population, markers to identify persons at risk are needed. Carotid artery atherosclerosis can easily be visualized using non-invasive ultrasound, potentially enabling early and intensified risk factor management to preserve cognitive function or delay further decline. However, the burden of atherosclerosis and temporal exposure required to pose a risk of cognitive impairment is unclear. This mini-review aims to explore the available evidence on the association between carotid atherosclerosis and cognition, and furthermore identify the remaining gaps in knowledge.

Cerebral Hypoxia: Its Role in Age-Related Chronic and Acute Cognitive Dysfunction

Postoperative cognitive dysfunction (POCD) has been reported with widely varying frequency but appears to be strongly associated with aging. Outside of the surgical arena, chronic and acute cerebral hypoxia may exist as a result of respiratory, cardiovascular, or anemic conditions. Hypoxia has been extensively implicated in cognitive impairment. Furthermore, disease states associated with hypoxia both accompany and progress with aging. Perioperative cerebral hypoxia is likely underdiagnosed, and its contribution to POCD is underappreciated. Herein, we discuss the various disease processes and forms in which hypoxia may contribute to POCD. Furthermore, we outline hypoxia-related mechanisms, such as hypoxia-inducible factor activation, cerebral ischemia, cerebrovascular reserve, excitotoxicity, and neuroinflammation, which may contribute to cognitive impairment and how these mechanisms interact with aging. Finally, we discuss opportunities to prevent and manage POCD related to hypoxia.

Potentially Inappropriate Prescriptions of Antipsychotics for Patients With Dementia

Dementias are neurodegenerative and progressive diseases of the central nervous system. The objective of this study was to determine the frequency of potentially inappropriate prescriptions of antipsychotics in a group of patients diagnosed with dementia in Colombia. This was a cross-sectional study based on a population database for drug dispensing that identified prescriptions of antidementia drugs, antipsychotics, and other drugs for patients with a diagnosis of dementia. Descriptive statistics and bivariate and multivariate analyses were performed. A total of 11,372 patients with dementia were identified; 66.6% were women, and the mean age was 80.5 ± 9.6 years. Alzheimer's disease was the most frequent diagnosis (76.6%). A total of 69.0% of patients received antidementia drugs. A total of 37.1% of patients received some antipsychotic, especially atypical antipsychotics (31.0%). Increased age, being treated with memantine, simultaneously presenting with anxiety, depression, and psychotic disorders, and concomitantly receiving anticonvulsants, bronchodilators and benzodiazepines were associated with a greater probability of being prescribed antipsychotics. More than one-third of patients with dementia received antipsychotic prescriptions, which are considered potentially inappropriate because they can worsen cognitive decline and favor the occurrence of adverse events.

Incidence of Hearing Impairment and Changes in Pure-Tone Average Across Generations

Importance

Age-adjusted prevalence of hearing impairment (HI) decreased across generations in the 20th century, suggesting that HI is partially preventable. It is not known whether HI incidence differs by generation.

Objectives

To examine whether HI incidence and change in pure-tone average (PTA) differ by generation and identify factors underlying these differences.

Design, Setting, and Participants

This cohort study used data from the Epidemiology of Hearing Loss Study (EHLS) and Beaver Dam Offspring Study (BOSS), a pair of studies of adults in Beaver Dam, Wisconsin. Baseline examinations occurred from 1993 to 1995 in the EHLS and 2005 to 2008 in BOSS, with two 5-year follow-up examinations in each cohort. This longitudinal cohort study assessed 3651 participants without HI at baseline who had follow-up data.

Main Outcomes and Measures

The primary outcome was incident HI measured by pure-tone audiometry, defined as PTA greater than 25-dB hearing level (dB HL) in either ear. Associations of 5-year incidence were estimated by relative risks (RRs) and 10-year cumulative incidence with generation, as categorized by commonly used sociodemographic descriptors of year of birth, by hazard ratios (HRs). The 10-year change in PTA was investigated using a generation × time interaction term in generalized estimating equation models.

Results

Among the 3651 participants (mean [SD] age at baseline 53.1 [10.6] years; 2255 [61.8%] female; and 3567 [97.7%] non-Hispanic White), the 5-year HI incidence was 14.1% (95% CI, 13.0%-15.3%) and the 10-year cumulative incidence was 26.0% (95% CI, 24.6%-27.6%). The incidence increased with age. The risk of 5-year incident HI decreased by generation (RR, 0.80; 95% CI, 0.66-0.97) when adjusting for multiple covariates. The decreased risk was similar in the 10-year period (HR, 0.86; 95% CI, 0.73-1.01). The PTA change rate (per 5 years of follow-up) decreased by generation, with the Greatest Generation (born 1901-1924) experiencing the highest rate (7.03 dB HL). The rates were all significantly lower for the other generations (Silent Generation [born 1925-1945], 3.30 dB HL; Baby Boom Generation [born 1946-1964], 3.36 dB HL; and Generation X [born 1965-1984], 2.33 dB HL).

Conclusions and Relevance

This study suggests that the risk of HI and rate of PTA change is lower for the Silent Generation and Baby Boom Generation compared with the Greatest Generation. Part of this lower risk is likely associated with changes in modifiable factors. A potential continued benefit may exist for Generation X. Combined with the reduced risk of HI for the Silent Generation and Baby Boom Generation, this finding implies that the future HI burden may be lower than current estimates suggest.

Association of Carotid Intima-Media Thickness and Other Carotid Ultrasound Features With Incident Dementia in the ARIC-NCS

Background

Increased carotid intima‐media thickness, interadventitial diameter, presence of carotid plaque, and lower distensibility are predictors for cardiovascular disease. These indices likely relate to cerebrovascular disease, and thus may constitute a form of vascular contributions to dementia and Alzheimer disease–related dementia. Therefore, we assessed the relationship of carotid measurements and arterial stiffness with incident dementia in the ARIC (Atherosclerosis Risk in Communities) study.

Methods and Results

A total of 12 459 ARIC participants with carotid arterial ultrasounds in 1990 to 1992 were followed through 2017 for dementia. Dementia cases were identified using in‐person and phone cognitive status assessments, hospitalization discharge codes, and death certificate codes. Cox proportional hazards models were used to estimate the hazard ratios (HRs) for incident dementia. Participants were aged 57±6 at baseline, 57% were women, and 23% were Black individuals. Over a median follow‐up time of 24 years, 2224 dementia events were ascertained. After multivariable adjustments, the highest quintile of carotid intima‐media thickness and interadventitial diameter in midlife was associated with increased risk of dementia (HR [95% CIs], 1.25 [1.08–1.45]; and 1.22 [1.04–1.43], respectively) compared with its respective lowest quintile. Presence of carotid plaque did not have a significant association with dementia (HR [95% CI], 1.06 [0.97–1.15]). Higher distensibility was associated with lower risk of dementia (HR [95% CI] highest versus lowest quintile, 0.76 [0.63–0.91]).

Conclusions

Greater carotid intima‐media thickness, interadventitial diameter, and lower carotid distensibility are associated with an increased risk of incident dementia. These findings suggest that both atherosclerosis and carotid stiffness may be implicated in dementia risk.

Breast Arterial Calcification Is Not Associated with Mild Cognitive Impairment or Incident All-Cause Dementia Among Postmenopausal Women: The MINERVA Study

Background: Since vascular risk factors are implicated in cognitive decline, and breast arterial calcification (BAC) is related to vascular risk, we postulated that BAC may be associated with cognitive impairment and dementia. Methods: We used a multiethnic cohort of 3,913 asymptomatic women 60-79 years of age recruited after mammography screening at a large health plan in 2012-2015. A BAC mass score (mg) was derived from digital mammograms. Cognitive function was measured at baseline using the Montreal Cognitive Assessment (MoCA) and incident all-cause dementia (n = 49 events; median follow-up = 5.6 years) were ascertained with validated ICD-9 and ICD-10 codes. We used cross-sectional linear regression of MoCA scores on BAC, then multinomial logistic regression predicting mild cognitive impairment not progressing to dementia and incident all-cause dementia and, finally, Cox regression of incident all-cause dementia. Results: No association by linear regression was found between MoCA scores and BAC presence in unadjusted or adjusted analysis. Women with severe (upper tertile) BAC had a MoCA score lower by 0.58 points (standard error [SE] = 0.18) relative to women with no BAC. However, this difference disappeared after multivariate adjustment. No significant associations were found in multinomial logistic regression for either BAC presence or gradation in unadjusted or adjusted analysis. No significant associations were found between BAC presence with incident all-cause dementia (fully adjusted hazard ratio = 0.74; 95% confidence interval: 0.39-1.39). Likewise, no significant association with incident all-cause dementia was noted for BAC gradation. Conclusions: Our results do not support the hypothesis that BAC presence or gradation may contribute to cognitive impairment or development of all-cause dementia.

Association of Carotid Plaque and Serum Lipoprotein-Associated Phospholipase A2 (LP-PLA2) with Postoperative Delirium in Geriatric Patients Undergoing Hip Replacement: A Prospective Cohort Study

BACKGROUND The aim of this study was to investigate the relationships among carotid plaque (CP), serum lipoprotein-associated phospholipase (LP-PLA2), and POD in elderly patients. MATERIAL AND METHODS Sixty-two elderly patients undergoing hip replacement with spinal-epidural anesthesia were divided into CP and non-CP groups based on the preoperative presence or absence of carotid atherosclerotic plaques, as assessed by ultrasound. POD was diagnosed by means of the Confusion Assessment Method (CAM). Blood samples were collected (preoperatively, postoperatively, and postoperative day 2) for the assessment of serum LP-PLA2 by enzyme-linked immunosorbent assay. The CP group was further divided into POD and no-POD subgroups based on the occurrence of POD. RESULTS The incidence of POD was higher in the CP group than in the non-CP group (P0.05), it was higher in the CP group than in the non-CP group postoperatively and on postoperative day 2 (P0.05), but was significantly higher in the POD subgroup than in the no-POD subgroup on postoperative day 2 (P<0.05). Furthermore, the LP-PLA2 level on postoperative day 2 was an independent risk factor for POD (odds ratio: 1.03, 95% confidence interval: 1.00-1.07). CONCLUSIONS The preoperative presence of carotid plaque is closely associated with a higher incidence of POD. The potential mechanism may involve the increased expression of LP-PLA2 in the serum, which can lead to plaque destabilization and subsequent inflammatory cascades.

Carotid atherosclerosis among middle-aged individuals predicts cognition: A 10-year follow-up study

BACKGROUND AND AIMS

There is a lack of studies simultaneously evaluating the impact of structural and functional atherosclerosis on cognition. We investigated the long-term predictive and interaction effects of structural and functional carotid atherosclerosis markers on future cognitive decline.

METHODS

Five hundred and twenty-eight middle-aged participants enrolled in the carotid atherosclerosis examination in Kaohsiung Atherosclerosis Longitudinal Study (KALS) between 2006 and 2009 were tested for cognition between 2016 and 2019. The Montreal Cognitive Assessment (MoCA) was used for the cognitive test. Baseline structural atherosclerosis was assessed by carotid intima-media thickness (cIMT) and plaque, whereas functional atherosclerosis was evaluated by carotid stiffness (β, Ep, and pulse wave velocity). Participants in the top quartile of cIMT and those with plaques were considered to have advanced structural atherosclerosis, whereas participants with all three stiffness parameters in the top quartile were defined to have advanced functional atherosclerosis.

RESULTS

The mean participant age at baseline was 53.88 ± 8.37 years. Each case of advanced structural atherosclerosis and advanced functional atherosclerosis was associated with low 10-year MoCA scores with p < 0.001 and p = 0.03, respectively. An interaction effect was observed between structural and functional atherosclerosis on the MoCA score 10 years later (p = 0.02). Participants with both advanced structural and functional markers showed a marked impact on future cognitive function, especially executive and language domains.

CONCLUSION

Carotid atherosclerosis in middle-aged individuals can predict their cognitive function in 10 years. Integrated information regarding both arterial wall and stiffness could help improve the predictive power for cognitive decline.

Macular Ganglion Cell-Inner Plexiform Layer as a Marker of Cognitive and Sensory Function in Midlife

BACKGROUND

Neurodegenerative diseases are public health challenges in aging populations. Early identification of people at risk for neurodegeneration might improve targeted treatment. Noninvasive, inexpensive screening tools are lacking but are of great potential. Optical coherence tomography (OCT) measures the thickness of nerve cell layers in the retina, which is an anatomical extension of the brain and might be indicative of common underlying neurodegeneration. We aimed to determine the association of macular ganglion cell-inner plexiform layer (mGCIPL) thickness with cognitive and sensorineural function in midlife.

METHOD

This cross-sectional study included 1,880 Beaver Dam Offspring Study participants (aged 27-93 years, mean 58) who participated in the 10-year follow-up examination. We assessed cognitive function and impairment, hearing sensitivity thresholds and impairment, central auditory processing, visual impairment, and olfactory impairment. We measured mGCIPL using the Cirrus 5000 HD-OCT Macular Cube Scan. Multivariable linear and logistic regression models adjusted for potential confounders were used to determine associations between mGCIPL thickness and cognitive and sensorineural functions, as well as for comparing participants with a thin mGCIPL (1 SD below average) to the remainder in those functions.

RESULTS

Thinner mGCIPL was associated with worse cognitive function, worse central auditory function, and visual impairment. We found an association of mGCIPL thickness with hearing sensitivity in women only and no association with impairment in hearing, olfaction, and cognition. Results on the thin group comparisons were consistent.

CONCLUSIONS

mGCIPL thickness is associated with cognitive and sensorineural function and has the potential as a marker for neurodegeneration in middle-aged adults.

Association Between Asymptomatic Vulnerable Carotid Plaques and Cognitive Impairment in Rural Adults

Background: The prevalence of cognitive impairment is growing and higher in rural areas. The association between carotid plaque and cognitive impairment remains uncertain, and few studies focused on the cognitive function of the rural population. We designed this study to investigate the association between carotid plaque and cognitive impairment in a rural community. Methods: We enrolled 3,336 participants who underwent carotid ultrasound and cognitive function measurements, free of cerebrovascular diseases, and without neurological deficits, from the China National Stroke Screen Survey program. Cognitive function was evaluated by the Montreal Cognitive Assessment (Beijing version). We used multivariable logistic regression to assess the association between asymptomatic carotid plaques and the presence of cognitive impairment. Results: Nine hundred seventy-six participants had cognitive impairment in this study. After adjustment for potential confounding factors, asymptomatic carotid plaques (odds ratio was 1.35; 95% confidence interval, 1.15-1.58), especially vulnerable carotid plaques (odds ratio was 1.54; 95% confidence interval, 1.28-1.85), were associated with cognitive impairment. Conclusion: In this community-based and observational study, asymptomatic vulnerable carotid plaque is an independent and significant risk factor for cognitive impairment in rural residents.

Evaluation of cognitive function in systemic sclerosis patients: a pilot study

OBJECTIVE

To investigate cognitive dysfunction in adult patients with systemic sclerosis (SSc) who had no known clinical neurological manifestations and to relate it with other disease severity parameters.

METHODS

In the present study, 20 SSc consecutive female patients, who met the 2013 American College of Rheumatology SSc criteria, were compared with 20 healthy age-, gender-, and educational status-matched volunteer hospital workers. Mean age and duration of illness were 41.8 ± 12.52 and 6.9 ± 5.4 years respectively. Mini-Mental State Examination (MMSE), Wechsler Adult Intelligence scale (WAIS-III), and P300 component of event-related potentials (ERPs) were used to evaluate cognitive function in SS subjectively and objectively respectively.

RESULTS

Sixty-five percent (13 out of 20) of SSc patients had MMSE score < 25, and cognitive impairment. Despite the lack of clinically apparent neurological manifestations, SSc patients had significantly low MMSE score, high Deterioration Index (DI), and prolonged P300 latency compared with that of the control group (P = 0.0001; 0.010 and 0.008 respectively). A significant positive association was found between (DI) and the Medsger severity vascular score (r = 0.518; P = 0.012).There were few differences between limited and diffuse SSc.

CONCLUSIONS

To our knowledge, few studies highlighted that subclinical cognitive impairment can occur in the course of SSc disease. Early diagnosis of cognitive impairment should be investigated either subjectively (using psychometrics tests as MMSE or WAIS-III) or objectively using P300 evoked related potentials. Medsger severity vascular score seems to be closely related to cognitive impairment.Key points• Cognitive impairment can be associated with Medsger Vascular severity score and the duration of illness.• Further larger studies will be needed to estimate the effect of disease activity on cognitive function, to further delineate the differences between limited and diffuse SSc in this area, and to understand the underlying pathophysiological mechanisms causing cognitive impairment in patients with SSc.• To investigate impaired cognitive function in patients with SSc, even in the absence of clinically apparent neurological and vascular disease.

Metabolic Syndrome and Cardiovascular Disease Impacts on the Pathophysiology and Phenotype of HIV-Associated Neurocognitive Disorders

Evidence from epidemiological studies on the general population suggests that midlife cardiovascular disease (CVD) and/or metabolic syndrome (MetS) are associated with an increased risk of cognitive impairment and dementia later in life. In the modern combined antiretroviral therapy (cART) era, as in the general population, CVD and MetS were strongly and independently associated with poorer cognitive performances of sustained immunovirologically controlled persons living with human immunodeficiency viruses (PLHIVs). Those findings suggest that CV/metabolic comorbidities could be implicated in the pathogenesis of HIV-associated neurocognitive disorders (HAND) and might be more important than factors related to HIV infection or its treatment, markers of immunocompetence, or virus replication. The association between CVD/MetS and cognition decline is driven by still not well-understood mechanisms, but risk might well be the consequence of increased brain inflammation and vascular changes, notably cerebral small-vessel disease. In this review, we highlight the correspondences observed between the findings concerning CVD and MetS in the general population and virus-suppressed cART-treated PLHIVs to evaluate the real brain-aging processes. Indeed, incomplete HIV control mainly reflects HIV-induced brain damage described during the first decades of the pandemic. Given the growing support that CVD and MetS are associated with HAND, it is crucial to improve early detection and assure appropriate management of these conditions.

Arterial stiffness relates to executive dysfunction in later life

Cardiovascular disease in older people is often linked with cognitive impairment, particularly in domains of executive function and processing speed. Our aims examined whether carotid-femoral pulse wave velocity (PWV) related to subtle changes of executive function and processing speed. Fifty-six individuals with subjective mood and/or cognitive concerns underwent PWV and neuropsychological assessments of processing speed (Trail Making Test Part A) and executive functioning (Delis Kaplan Executive Function System Stroop Task; Trail Making Test Part B, TMT-B). Individuals with high PWV (≥12.0m/s) had poorer performance on TMT-B, compared to low PWV (<12.0m/s), and a moderate negative correlation (r = -0.38, p = .004) between PWV and TMT-B performance. Our results confirm that in older adults at-risk for cognitive decline, early markers of CVD are associated with subtle decrements in rapid set-shifting (executive function), supporting efforts towards early detection of CVD as a secondary prevention strategy for older individuals with cognitive decline.

Effect of S-equol and Soy Isoflavones on Heart and Brain

BACKGROUND

Observational studies in Asia show that dietary intake of soy isoflavones had a significant inverse association with coronary heart disease (CHD). A recent randomized controlled trial (RCT) of soy isoflavones on atherosclerosis in the US, however, failed to show their benefit. The discrepancy may be due to the much lower prevalence of S-equol producers in Westerners: Only 20-30% of Westerners produce S-equol in contrast to 50-70% in Asians. S-equol is a metabolite of dietary soy isoflavone daidzein by gut microbiome and possesses the most antiatherogenic properties among all isoflavones. Several short-duration RCTs documented that soy isoflavones improves arterial stiffness. Accumulating evidence shows that both atherosclerosis and arterial stiffness are positively associated with cognitive decline/dementia. Therefore, potentially, soy isoflavones, especially S-equol, are protective against cognitive decline/dementia.

METHODS/RESULTS

This narrative review of clinical and epidemiological studies provides an overview of the health benefits of soy isoflavones and introduces S-equol. Second, we review recent evidence on the association of soy isoflavones and S-equol with CHD, atherosclerosis, and arterial stiffness as well as the association of atherosclerosis and arterial stiffness with cognitive decline/ dementia. Third, we highlight recent studies that report the association of soy isoflavones and S-equol with cognitive decline/dementia. Lastly, we discuss the future directions of clinical and epidemiological research on the relationship of S-equol and CHD and dementia.

CONCLUSIONS

Evidence from observational studies and short-term RCTs suggests that S-equol is anti-atherogenic and improves arterial stiffness and may prevent CHD and cognitive impairment/ dementia. Well-designed long-term (≥ 2years) RCTs should be pursued.

Association of Cadmium and Lead Exposure With the Incidence of Contrast Sensitivity Impairment Among Middle-aged Adults

Importance

Contrast sensitivity (CS) is an important indicator of visual function that affects daily life, including mobility, visually intensive tasks, safety, and autonomy. Understanding the risk factors for CS impairment could prevent decreases in visual function.

Objective

To determine the incidence of and factors associated with CS impairment in a large cohort.

Design, Setting, and Participants

The Beaver Dam Offspring Study is an ongoing longitudinal cohort study of aging involving adults in Beaver Dam, Wisconsin. Participants who were free of CS impairment in both eyes at baseline were included (N = 1983). Baseline data collection occurred from June 8, 2005, through August 4, 2008, when the participants ranged from 21 to 84 years of age. Two follow-up examinations occurred at 5-year intervals: one was conducted between July 12, 2010, and March 21, 2013, and the other between July 1, 2015, and November 13, 2017. Data analysis was performed from November 27, 2017, to February 27, 2018.

Main Outcomes and Measures

Contrast sensitivity testing was conducted with Pelli-Robson letter sensitivity charts, and incident impairment was defined as a log CS score less than 1.55 in either eye at any follow-up examination. Cadmium and lead levels were measured in whole blood with inductively coupled plasma mass spectrometry. Associations between baseline characteristics and CS impairment incidence were examined using Cox proportional hazard models and quantified as hazard ratios (HRs) with 95% CI.

Results

Of the 1983 participants included, 1028 (51.8%) were female and 955 (48.2%) were male, with a mean (SD) age of 48 (9.3) years. The 10-year cumulative incidence of CS impairment was 24.8% (95% CI, 22.9-26.8), similar in women (24.9%) and men (24.6%), and highest in the oldest age group (65-84 years) at 66.3%. In multivariable models, cadmium level in the highest quintile (HR, 1.35; 95% CI, 1.02-1.78), older age (HR, 1.36; 95% CI, 1.25-1.47), larger waist circumference (HR, 1.06; 95% CI, 1.01-1.11), and more plaque sites (1-3 sites: HR, 1.43; 95% CI, 1.07-1.92; 4-6 sites: HR, 2.75; 95% CI, 1.26-6.05) were among the factors associated with increased risk, while male sex (HR, 0.77; 95% CI, 0.60-0.98) and any alcohol consumption (HR, 0.61; 95% CI, 0.43-0.88) were associated with decreased risk. Results were similar when smoking status replaced cadmium exposure in the models. Lead level was not associated with increased risk.

Conclusions and Relevance

This study's findings suggest that incident CS impairment was common in the 10-year follow-up, with cadmium, but not lead, exposure associated with increased risk. The associations of diminished CS with other modifiable risk factors found appear to imply that changes in behavior may reduce future incidence of CS impairment.

Carotid circumferential wall stress is not associated with cognitive performance among individuals in late middle age: The Maastricht Study

BACKGROUND AND AIMS

Arterial remodelling aims at normalising circumferential wall stress (CWS). Greater CWS in the carotid artery has previously been associated with the prevalence and severity of cerebral small vessel disease, a major cause of ageing-related cognitive decline. Here we test the hypothesis that greater carotid CWS is associated with poorer cognitive performance.

METHODS

We studied 722 individuals (60 ± 8 years, 55% men, 42.5% highly educated, blood pressure 137 ± 19/77 ± 11 mmHg, n = 197 with type 2 diabetes) who completed a neuropsychological assessment and underwent vascular ultrasound to measure the intima-media thickness (IMT) and interadventitial diameter (IAD) of the left common carotid artery at a plaque-free site. From IMT and IAD, lumen diameter (LD) was calculated. These structural measures were then combined with local carotid pulse pressure and brachial mean arterial pressure to obtain a measure of pulsatile (CWS_pulsatile) and average (CWS_mean) mechanical load on the vessel wall. Cognitive domains assessed were memory, executive function and attention, and processing speed.

RESULTS

After adjustment for age, sex, and education, regression analyses showed that neither CWS_pulsatile nor CWS_mean were associated with measures of cognitive performance (p-values ≥0.31). This null association did not differ by age or educational level, and was observed in both individuals with and without carotid plaque, diabetes and/or hypertension. In addition, none of the individual measures of carotid structure (i.e. IMT, IAD, and LD) was related to cognitive performance.

CONCLUSIONS

The present cross-sectional study shows that carotid CWS is not associated with cognitive performance, at least not among relatively highly educated individuals in late middle age with adequately controlled cardiovascular risk factors.

Prevalence of and Risk Factors for Cognitive Impairment Among Elderly Without Cardio- and Cerebrovascular Diseases: A Population-Based Study in Rural China

This study aimed to evaluate the prevalence of cognitive impairment and the distribution of its risk factors among residents aged ≥60 years without cardiovascular and cerebrovascular diseases in rural areas of northern China screened with the Chinese version of the Mini-Mental State Examination (MMSE). Between 2012 and 2013, a questionnaire survey was conducted to collect basic information from participants. Cognitive function was assessed using the MMSE. In the univariate analysis, risk factors for cognitive disorders were female sex, low education and central obesity, while drinking was found to be a protective factor. In the multivariate analysis, risk factors were old age (odds ratio [OR], 1.888; 95% confidence interval [CI]: 1.256–2.838; P = 0.002 for the 70-year-old group compared with the 60-year-old group; OR, 3.593; 95% CI, 2.468–5.230; P < 0.001 for the ≥75-year-old group compared with the 60-year-old group), low education (OR, 3.779; 95% CI: 2.218–6.440; P < 0.001 for the illiterate group compared with the group with ≥9 years of education; OR, 1.667; 95% CI, 1.001–2.775; P = 0.05 for the group with less than primary school compared with the group with ≥9 years of education), and higher blood pressure (BP; OR, 1.655; 95% CI: 1.076–2.544; P = 0.002 for individuals with stage III hypertension compared with those with normal BP). These findings suggest that it is crucial to manage and control level of BP, and improve educational attainment in order to reduce the prevalence and burden of cognitive impairment among low-income residents in rural China.

An Epidemiologic Study of the Association between Free Recall Dichotic Digits Test Performance and Vascular Health

BACKGROUND

Associations between vascular health-related factors and hearing loss defined using audiometric pure-tone thresholds have been found. Studies have not focused on a potential relationship between vascular health-related factors and central auditory processing.

PURPOSE

The aim of this study was to evaluate, on a population level, the relationship of vascular health-related factors with central auditory function.

RESEARCH DESIGN

A cross-sectional, population study.

STUDY SAMPLE

Subjects were participants in the Epidemiology of Hearing Loss Study (EHLS) or the Beaver Dam Offspring Study (BOSS)-prospective studies of aging and sensory loss. BOSS participants were the adult offspring of participants in the EHLS. Participants who completed the Dichotic Digits Test (DDT) during the fourth examination period of the EHLS (2008-2010) or the second examination period of the BOSS (2010-2013) were included (n = 3,655, mean age = 61.1 years).

DATA COLLECTION AND ANALYSIS

The DDT-free recall test was conducted using 25 sets of triple-digit pairs at a 70 dB HL presentation level. The total number of correctly repeated digits from the right and left ears was converted to a percentage correct and used as an outcome. The percentage correct in the left ear was subtracted from the percentage correct in the right ear and used as an outcome. Vascular health-related measures obtained during the examination included blood pressure, mean carotid intima-media thickness, femoral pulse wave velocity (PWV), hemoglobin A1C, and non-high-density lipoprotein (HDL) cholesterol, and, in the EHLS participants, C-reactive protein and interleukin-6. Information on vascular health-related history and behaviors was self-reported. General linear modeling produced estimates of the age- and sex-adjusted least squares means for each vascular factor, and multiple linear regression was used for multivariable modeling of each outcome.

RESULTS

After multivariable adjustment, participants with diabetes had a significantly lower (worse) mean DDT-free recall total score (-2.08 percentage points, p < 0.001) than those without diabetes. Participants who exercised at least once per week had a significantly higher (better) mean DDT-free recall total score (+1.07 percentage points, p < 0.01) than those who did not exercise at least once per week. Alcohol consumption was associated with a higher DDT-free recall total score (+0.15 percentage points per +25 g ethanol, p < 0.01). In multivariable modeling of the right-left ear difference in DDT-free recall scores, participants with a history of cardiovascular disease (CVD) or higher PWV demonstrated significantly larger differences (CVD: +3.11 percentage points, p = 0.02; PWV: +0.36 percentage points per 1 m/sec, p < 0.01). Higher levels of non-HDL cholesterol were associated with smaller right-left ear differences (-0.22 percentage points per 10 mg/dL, p = 0.01). Adjustment for handedness did not affect the results.

CONCLUSIONS

Vascular health-related factors may play a role in central auditory function.

Association between Carotid Plaque and Cognitive Impairment in Chinese Stroke Population: The SOS-Stroke Study

We aimed to investigate the association between carotid plaques and cognitive impairment among patients with acute ischemic stroke, and to assess key clinical implications. In the Acute Ischemic Stroke Study, patients who received a cognitive testing and underwent complete carotid artery ultrasound scans were included. Cognitive function was measured by the mini-mental state examination. The cross-sectional relationships between cognitive impairment and carotid plaques were evaluated using multivariate logistic regression analysis. Of the 3116 patients included in this study, 826 (26.51%) patients were diagnosed with cognitive impairment. After adjusting for potential confounders, patients with ≥2 carotid plaques (odds ratio [OR] = 1.47; 95% confidence interval [CI]: 1.19–1.82), patients with ≥2 number of carotid arteries with plaque (OR = 1.48; 95% CI: 1.19–1.84) and patients with hypoechoic plaque (OR = 2.05; 95% CI: 1.24–3.38) are more likely to have cognitive impairment. In this acute ischemic stroke population, the number of carotid plaques, the number of carotid arteries with plaque and plaque stability are all associated with cognitive impairment.

Total atherosclerotic burden measured by magnetic resonance imaging is related to five-year decline in cognitive function

OBJECTIVE

The aim of this study was to explore whether total atherosclerotic burden is related to future decline in performance on cognitive tests.

METHODS

The total atherosclerotic burden (TAS) was assessed by whole-body magnetic resonance angiography (WBMRA) in 305 subjects at age 70 in the study Prospective Investigation of Vasculature in Uppsala Seniors (PIVUS). The mini-mental state examination (MMSE) and trail making tests (TMT) A and B were evaluated at ages 75 and 80 in 190 of those subjects. No subject with a diagnosis of dementia was included in the sample.

RESULTS

MMSE did not change during the 5 years of follow-up, while TMT A and B increased by 4 and 7 s, respectively. TAS at age 70 was significantly related to the individual change in TMT B (P<0·0001) between age 75 and 80, when adjusted for sex, education level, TMT B at age 75 and Framingham score at age 70. No such relationship was seen for the change in TMT A (P = 0·10). The relationship between TAS and the change in MMSE was of borderline significance (P = 0·025).

CONCLUSION

A relationship was found between the total atherosclerotic burden and future decline in performance on TMT B, highlighting a role of global atherosclerosis in the cognitive decline seen during ageing.

Severe carotid artery stenosis evaluated by ultrasound is associated with post stroke vascular cognitive impairment

BACKGROUND

Acute ischemic stroke has been recognized as one key cause of vascular cognitive impairment (VCI). The purpose of this study was to evaluate the correlation between carotid artery stenosis and post VCI in acute ischemic stroke patients.

METHODS

In this study, B-mode ultrasound was applied to measure the degree of carotid artery stenosis. After 1 year, the stroke patients' cognitive function was assessed by the mini-mental state examination (MMSE) score. The relationship between the VCI and degree of carotid artery stenosis was evaluated by multivariate regression analysis.

RESULTS

VCI was observed in 136 (37.2%) of the 365 participants. High degree of carotid artery stenosis was significantly correlated with VCI (p < .01), and this correlation remained unchanged even adjustment for age, gender, education level, stroke features, and vascular risk factors.

CONCLUSIONS

These findings indicate that high-grade stenosis of carotid artery is positively correlated with post stroke VCI in patients with acute ischemic stroke. The evaluation of 1 year post stroke cognitive function may be a potential tool for screening stroke patients at risk of VCI.

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.

Association between subclinical carotid atherosclerosis, hyperhomocysteinaemia and mild cognitive impairment

OBJECTIVE

Evidence suggests that intima-media thickness (IMT) and plasma homocysteine (Hcy) levels are associated with one another, and both appear to be related to cognitive dysfunction. However, no connection between both factors taken together and mild cognitive impairment (MCI) has been established. This study analysed potential relationships between IMT, Hcy and MCI.

METHODS

We included 105 patients with MCI and 76 controls with no history of vascular disease. All participants underwent laboratory analyses, a carotid ultrasound, and clinical and neuropsychological assessment. We used the Mantel-Haenszel test (MHT), ANCOVA and multiple linear regression models (MLRM) to examine any associations between IMT, Hcy and cognitive state.

RESULTS

The MHT revealed a significant association between IMT and risk of MCI (z = 4.285, P < 0.0001). The OR for the upper quartile vs the lower quartile was 5.12 (95% CI: 2.12-12.36). MHT also showed a clear association between Hcy levels and risk of MCI (z = 3.01, P = 0.003). OR for the upper vs the lower quartile was 3.39 (95% CI: 1.41-8.12). Additionally, we found a correlation between IMT and Hcy (r = 0.162, P = 0.032).

CONCLUSIONS

Our results suggest that there is a connection between IMT, Hcy levels and presence of amnestic MCI in a population with no history of clinically manifest atherosclerosis. Furthermore, there is also a connection between the IMT and Hcy levels themselves.

Relation of cerebral vessel disease to Alzheimer's disease dementia and cognitive function in elderly people: a cross-sectional study

BACKGROUND

Few data on the pathology of cerebral vessel disease, dementia, and cognition are available. We examined the association of cerebral atherosclerosis and arteriolosclerosis neuropathology with probable and possible Alzheimer's disease dementia and cognitive function.

METHODS

This cross-sectional study included men and women aged 65 years or older who had yearly clinical assessments and had agreed to brain autopsy at the time of death, as part of one of two cohort studies of ageing (The Religious Orders Study and the Rush Memory and Aging Project). Individuals without dementia or with Alzheimer's disease dementia, and with complete neuropathological data, are included in our analyses. We used neuropsychological data proximate to death to create summary measures of global cognition and cognitive domains. Clinical data recorded between 1994 and 2015 were used to determine presence of Alzheimer's disease dementia. Systematic neuropathological assessments documented the severity of cerebral large vessel (atherosclerosis) and small vessel (arteriolosclerosis) disease. By use of regression analyses adjusted for demographics, gross and microscopic infarcts, and Alzheimer's disease pathology, we examined associations of vessel disease severity (mild, moderate, and severe) with odds of probable and possible Alzheimer's disease dementia and cognitive function.

FINDINGS

Study enrolment began in January, 1994, and two cohort studies are ongoing. 1143 individuals were included in our analyses (median age at death 88·8 years; 478 [42%] with Alzheimer's disease dementia). Moderate-to-severe atherosclerosis was present in 445 (39%) individuals, and arteriolosclerosis in 401 (35%) individuals. Each level increase in the severity of atherosclerosis or arteriolosclerosis was associated with significantly higher odds of Alzheimer's disease dementia (odds ratio [OR] for atherosclerosis 1·33, 95% CI 1·11-1·58; OR for arteriolosclerosis 1·20, 1·04-1·40). Atherosclerosis was associated with lower scores for global cognition (estimate -0·10 [SE 0·04], p=0·0096) and four cognitive domains (episodic memory -0·10 [0·04], p=0·017; semantic memory -0·11 [0·05], p=0·018; perceptual speed -0·14 [0·04], p=0·00080; and visuospatial abilities -0·13 [0·04], p=0·0080), but not working memory (-0·05 [0·04], p=0·21). Arteriolosclerosis was associated with lower scores for global cognition (estimate -0·10 [0·03], p=0·0015) and four domains (episodic memory -0·12 [0·04], p=0·00090; semantic memory -0·10 [0·04], p=0·013; working memory -0·07 [0·03], p=0·045; perceptual speed -0·12 [0·04], p=0·0012), and a non-significant association was noted for visuospatial abilities (-0·07 [0·03], p=0·052). Findings were unchanged in analyses controlling for the presence of APOE ε4 allele or vascular risk factors.

INTERPRETATION

Cerebral atherosclerosis and arteriolosclerosis are associated with Alzheimer's disease dementia, and are also associated with low scores in most cognitive domains. Cerebral vessel pathology might be an under-recognised risk factor for Alzheimer's disease dementia.

FUNDING

US National Institutes of Health.

Carotid duplex ultrasound and transcranial Doppler findings in commercial divers and pilots

The risky working environments of divers and pilots, and the possible role of extreme ambient pressure in carotid stenosis, make ischemic stroke an important occupational concern among these professionals. In this study, we aimed to evaluate the association of being exposed to hyperbaric or hypobaric conditions with carotid artery stenosis by comparing common carotid intima-media thickness (CCIMT) and blood flow velocities of cerebral arteries in divers and pilots using carotid duplex ultrasound (CDUS) and transcranial Doppler (TCD). CDUS and transtemporal TCD were performed in 29 divers, 36 pilots and 30 control participants. Medical history, blood pressure, lipid profile and blood sugar were recorded to control the previously well-known risk factors of atherosclerosis. Findings of the CDUS and TCD [including: CCIMT and blood flow velocities of internal carotid artery (ICA), common carotid artery (CCA), and middle cerebral artery (MCA)] of divers and pilots were compared with those of the control group using regression analysis models. Both right and left side CCIMT were significantly higher in divers (P < 0.05) and pilots (P < 0.05) in comparison with the control group. Carotid index [peak systolic velocity (PSV) of ICA/PSV of CCA) of divers and pilots were also higher than the control group. TCD findings were not significantly different between divers, pilots, and the control group. Increased CCIMT and carotid index in diver and pilot groups appear to be suggestive of accelerated atherosclerosis of carotid artery in these occupational groups.

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.

Neurovascular dysfunction and neurodegeneration in dementia and Alzheimer's disease

Vascular insults can initiate a cascade of molecular events leading to neurodegeneration, cognitive impairment, and dementia. Here, we review the cellular and molecular mechanisms in cerebral blood vessels and the pathophysiological events leading to cerebral blood flow dysregulation and disruption of the neurovascular unit and the blood-brain barrier, which all may contribute to the onset and progression of dementia and Alzheimer's disease (AD). Particularly, we examine the link between neurovascular dysfunction and neurodegeneration including the effects of AD genetic risk factors on cerebrovascular functions and clearance of Alzheimer's amyloid-β peptide toxin, and the impact of vascular risk factors, environment, and lifestyle on cerebral blood vessels, which in turn may affect synaptic, neuronal, and cognitive functions. Finally, we examine potential experimental treatments for dementia and AD based on the neurovascular model, and discuss some critical questions to be addressed by future studies. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock.

Insulin resistance and carotid intima-media thickness mediate the association between resting-state heart rate variability and executive function: A path modelling study

BACKGROUND

Research has linked high-frequency heart rate variability (HF-HRV) to cognitive function. The present study adopts a modern path modelling approach to understand potential causal pathways that may underpin this relationship.

METHODS

Here we examine the association between resting-state HF-HRV and executive function in a large sample of civil servants from Brazil (N=8114) recruited for the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). HF-HRV was calculated from 10-min resting-state electrocardiograms. Executive function was assessed using the trail-making test (version B).

RESULTS AND CONCLUSIONS

Insulin resistance (a marker of type 2 diabetes mellitus) and carotid intima-media thickness (subclinical atherosclerosis) mediated the relationship between HRV and executive function in seriatim. A limitation of the present study is its cross-sectional design; therefore, conclusions must be confirmed in longitudinal study. Nevertheless, findings support that possibility that HRV provides a 'spark' that initiates a cascade of adverse downstream effects that subsequently leads to cognitive impairment.

Association between Carotid Artery Stenosis and Cognitive Impairment in Stroke Patients: A Cross-Sectional Study

To investigate potential associations between carotid artery stenosis and cognitive impairment among patients with acute ischemic stroke and to provide important clinical implications. We measured the degree of carotid artery stenosis and recorded the Mini-Mental State Examination score (MMSE) at admission in 3116 acute ischemic stroke patients. The association between carotid stenosis and cognitive impairment assessed by MMSE was tested using multivariate regression analysis. Other clinical variables of interest were also studied. After adjusting for age, gender, education level, marriage, alcohol use, tobacco use, physical activity, hypertension, diabetes, hypercholesterolemia, atrial fibrillation, myocardial infarction and NIHSS (National Institutes of Health Stroke Scale) score, we found that participants with high-grade stenosis of the carotid artery had a higher likelihood of cognitive impairment compared to those without carotid artery stenosis (OR = 1.49, 95%CI: 1.05–2.11, p<0.001). Left common carotid artery stenosis was associated with cognitive impairment in the univariate analysis, although this effect did not persist after adjustment for the NIHSS score. Cognitive impairment was associated with high-grade stenosis of the right carotid artery.