Plasma lipids and cerebral small vessel disease

Brain artery diameters and risk of dementia and stroke

INTRODUCTION

We tested the association of brain artery diameters with dementia and stroke risk in three distinct population-based studies using conventional T2-weighted brain magnetic resonance imaging (MRI) images.

METHODS

We included 8420 adults > 40 years old from three longitudinal population-based studies with brain MRI scans. We estimated and meta-analyzed the hazard ratios (HRs) of the brain and carotids and basilar diameters associated with dementia and stroke.

RESULT

Overall and carotid artery diameters > 95th percentile increased the risk for dementia by 1.74 (95% confidence interval [CI], 1.13-2.68) and 1.48 (95% CI, 1.12-1.96) fold, respectively. For stroke, meta-analyses yielded HRs of 1.59 (95% CI, 1.04-2.42) for overall arteries and 2.11 (95% CI, 1.45-3.08) for basilar artery diameters > 95th percentile.

DISCUSSION

Individuals with dilated brain arteries are at higher risk for dementia and stroke, across distinct populations. Our findings underline the potential value of T2-weighted brain MRI-based brain diameter assessment in estimating the risk of dementia and stroke.

Association between serum triglycerides and stroke type, severity, and prognosis. Analysis in 6558 patients

BACKGROUND AND OBJECTIVES

Hypertriglyceridemia (HT) may increase the risk of stroke. Limited studies have shown that stroke severity and infarction size are smaller in patients with HT. We explored the relationship between triglyceride levels and stroke risk factors, severity and outcome in a large prospective database.

DESIGN

Prospective Cross-sectional study.

SETTING

We retrospectively interrogated the Qatar Stroke Database in all patients admitted between 2014-2022 with acute ischemic stroke and evaluated the relationship between triglyceride, diabetes, stroke severity (measured on NIHSS), stroke type (TOAST classification) and the short- (mRS at 90 days) and long-term outcomes (MACE at 1 year) in patients with HT.

PARTICIPANTS

Six thousand five hundred fifty-eight patients ≥20 years were included in this study RESULTS: Six thousand five hundred fifty-eight patients with ischemic stroke [mean age 54.6 ± 12. 9; male 82.1%) were included. Triglyceride levels upon admission were low-normal (≤1.1 mmol/L) in 2019 patients, high-normal (1.2-1.7 mmol/L) in 2142 patients, borderline-high (1.8-2.2 mmol/L) in 1072 patients and high (≥2.3 mmol/L) in 1325 patients. Higher triglyceride levels were associated with stroke and increased likelihood of having diabetes, obesity, active smoking, and small vessel/lacunar stroke type. An inverse relationship was noted whereby higher triglyceride levels were associated with lower stroke severity and reduced likelihood of poorer outcome (mRS 3-6) at discharge and 90 days. Long-term MACE events were less frequent in patients with higher triglyceride levels. After adjusting age, gender, diabetes, prior stroke, CAD, and obesity, multivariate analysis showed that hypertension and triglyceride levels were higher in mild ischemic strokes patients.

CONCLUSIONS

Increasing triglycerides are associated with higher risk of small vessel disease and requires further prospective cohort studies for confirmation.

Risk factors and cognitive correlates of white matter hyperintensities in ethnically diverse populations without dementia: The COSMIC consortium

INTRODUCTION

White matter hyperintensities (WMHs) are an important imaging marker for cerebral small vessel diseases, but their risk factors and cognitive associations have not been well documented in populations of different ethnicities and/or from different geographical regions.

METHODS

We investigated how WMHs were associated with vascular risk factors and cognition in both Whites and Asians, using data from five population-based cohorts of non-demented older individuals from Australia, Singapore, South Korea, and Sweden (N = 1946). WMH volumes (whole brain, periventricular, and deep) were quantified with UBO Detector and harmonized using the ComBat model. We also harmonized various vascular risk factors and scores for global cognition and individual cognitive domains.

RESULTS

Factors associated with larger whole brain WMH volumes included diabetes, hypertension, stroke, current smoking, body mass index, higher alcohol intake, and insufficient physical activity. Hypertension and stroke had stronger associations with WMH volumes in Whites than in Asians. No associations between WMH volumes and cognitive performance were found after correction for multiple testing.

CONCLUSION

The current study highlights ethnic differences in the contributions of vascular risk factors to WMHs.

Associations of Lipoprotein(a) Level with Cerebral Small Vessel Disease in Patients with Alzheimer's Disease

BACKGROUND

This study aimed to examine the association of lipoprotein(a) [Lp(a)] level with the burden of cerebral small vessel disease (CSVD) in patients with Alzheimer's disease (AD).

METHODS

Data from 111 consecutive patients with AD admitted to Nanjing First Hospital from 2015 to 2022 were retrospectively analyzed in this study. Serum Lp(a) concentrations were grouped into tertiles (T1-T3). Brain magnetic resonance imaging (MRI) was rated for the presence of CSVD, including enlarged perivascular spaces (EPVS), lacunes, white-matter lesions, and cerebral microbleeds (CMBs). The CSVD burden was calculated by summing the scores of each MRI marker at baseline. A binary or ordinal logistic regression model was used to estimate the relationship of serum Lp(a) levels with CSVD burden and each MRI marker.

RESULTS

Patients with higher tertiles of Lp(a) levels were less likely to have any CSVD (T1, 94.6%; T2, 78.4%; T3, 66.2%; p = 0.013). Multivariable analysis found that Lp(a) levels were inversely associated with the presence of CSVD (T2 vs. T1: adjusted odds ratio [aOR] 0.132, 95% confidence interval [CI] 0.018-0.946, p = 0.044; T3 vs. T1: aOR 0.109, 95% CI 0.016-0.737, p = 0.023) and CSVD burden (T3 vs. T1: aOR 0.576, 95% CI 0.362-0.915, p = 0.019). The independent relationship between Lp(a) levels and individual CSVD features was significant for moderate-to-severe EPVS in the centrum semiovale (T2 vs. T1: aOR 0.059, 95% CI 0.006-0.542, p = 0.012; T3 vs. T1: aOR 0.029, 95% CI 0.003-0.273, p = 0.002) and CMBs (T3 vs. T1: aOR 0.144, 95% CI 0.029-0.716, p = 0.018).

CONCLUSIONS

In this study, serum Lp(a) level was inversely associated with CSVD in AD patients.

Molecular biomarkers for vascular cognitive impairment and dementia

As disease-specific interventions for dementia are being developed, the ability to identify the underlying pathology and dementia subtypes is increasingly important. Vascular cognitive impairment and dementia (VCID) is the second most common cause of dementia after Alzheimer disease, but progress in identifying molecular biomarkers for accurate diagnosis of VCID has been relatively limited. In this Review, we examine the roles of large and small vessel disease in VCID, considering the underlying pathophysiological processes that lead to vascular brain injury, including atherosclerosis, arteriolosclerosis, ischaemic injury, haemorrhage, hypoperfusion, endothelial dysfunction, blood-brain barrier breakdown, inflammation, oxidative stress, hypoxia, and neuronal and glial degeneration. We consider the key molecules in these processes, including proteins and peptides, metabolites, lipids and circulating RNA, and consider their potential as molecular biomarkers alone and in combination. We also discuss the challenges in translating the promise of these biomarkers into clinical application.

Association of Plasma Lipids with White Matter Hyperintensities in Patients with Acute Ischemic Stroke

Purpose

White matter hyperintensities (WMH) are the common marker of cerebral small vessel disease (CSVD). Dyslipidemia plays a notable role in the pathogenesis of CSVD. However, the relationship between dyslipidemia and WMH is poorly elucidated. This study aims to investigate the association between serum lipid fractions and WMH in patients with acute ischemic stroke (AIS).

Patients and Methods

A total of 901 patients with AIS were included in this study. The burden of WMH, including deep white matter hyperintensities (DWMH), periventricular white matter hyperintensities (PVWMH), and total WMH load, were evaluated on magnetic resonance imaging (MRI) by the Fazekas scale. All the WMH burden were set as dichotomous variables. Serum levels of triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c) were collected. The association of serum lipid fractions with WMH burden was analyzed using univariate and multivariate logistic regression models.

Results

The average age of the participants was 67.6±11.6 years, and 584 cases (64.8%) were male. About 33.5% (n = 302) patients were smoker, and 23.5% (n = 212) patients had a history of alcohol consumption. The proportion of previous diabetes, ischemic cardiomyopathy and hypertension was 39.0% (n = 351), 21.2% (n = 191) and 75.9% (n = 684), respectively. The average of serum HDL-c, TC, TG, LDL-c levels for all participants were 1.26 ± 0.28 mmol/l, 4.54 ± 1.06 mmol/l, 1.67 ± 1.09 mmol/l, 3.08 ± 0.94 mmol/l. There were no statistical associations between HDL-c, TG, TC, LDL-c and each type of WMH burden (P > 0.05) in multivariate logistic regression analysis. Similar findings were found in subgroup analysis based on gender classification.

Conclusion

Serum lipid levels were not associated with the presence of any type of WMH in patients with AIS.

Risk factors and cognitive correlates of white matter hyperintensities in ethnically diverse populations without dementia: the COSMIC consortium

INTRODUCTION

White matter hyperintensities (WMH) are an important imaging marker for cerebral small vessel diseases, but their risk factors and cognitive associations have not been well-documented in populations of different ethnicities and/or from different geographical regions.

METHOD

Magnetic resonance imaging data of five population-based cohorts of non-demented older individuals from Australia, Singapore, South Korea, and Sweden (N = 1,946) were examined for WMH and their associations with vascular risk factors and cognition.

RESULT

Factors associated with larger whole brain WMH volumes included diabetes, hypertension, stroke, current smoking, body mass index, higher alcohol intake and insufficient physical activity. Participants with moderate or higher physical activity had less WMH than those who never exercised, but the former two groups did not differ. Hypertension and stroke had stronger associations with WMH volumes in the White, compared to Asian subsample.

DISCUSSION

The current study highlighted the ethnic differences in the contributions of vascular risk factors to WMH.

Pathophysiology and probable etiology of cerebral small vessel disease in vascular dementia and Alzheimer's disease

Vascular cognitive impairment and dementia (VCID) is commonly caused by vascular injuries in cerebral large and small vessels and is a key driver of age-related cognitive decline. Severe VCID includes post-stroke dementia, subcortical ischemic vascular dementia, multi-infarct dementia, and mixed dementia. While VCID is acknowledged as the second most common form of dementia after Alzheimer's disease (AD) accounting for 20% of dementia cases, VCID and AD frequently coexist. In VCID, cerebral small vessel disease (cSVD) often affects arterioles, capillaries, and venules, where arteriolosclerosis and cerebral amyloid angiopathy (CAA) are major pathologies. White matter hyperintensities, recent small subcortical infarcts, lacunes of presumed vascular origin, enlarged perivascular space, microbleeds, and brain atrophy are neuroimaging hallmarks of cSVD. The current primary approach to cSVD treatment is to control vascular risk factors such as hypertension, dyslipidemia, diabetes, and smoking. However, causal therapeutic strategies have not been established partly due to the heterogeneous pathogenesis of cSVD. In this review, we summarize the pathophysiology of cSVD and discuss the probable etiological pathways by focusing on hypoperfusion/hypoxia, blood-brain barriers (BBB) dysregulation, brain fluid drainage disturbances, and vascular inflammation to define potential diagnostic and therapeutic targets for cSVD.

Incidence of Retinal Artery Occlusion and Related Mortality in Korea, 2005 to 2018

IMPORTANCE

It remains unclear whether comorbidities in patients with retinal artery occlusion (RAO), a rare retinal vascular disorder, differ by subtype and whether mortality is higher.

OBJECTIVE

To examine the nationwide incidence of clinically diagnosed, nonarteritic RAO, causes of death, and mortality rate in patients with RAO compared with that in the general population in Korea.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, population-based cohort study examined National Health Insurance Service claims data from 2002 to 2018. The population of South Korea was 49 705 663, according to the 2015 census. Data were analyzed from February 9, 2021, to July 30, 2022.

MAIN OUTCOMES AND MEASURES

The nationwide incidence of any RAO, including central RAO (CRAO; International Statistical Classification of Diseases and Related Health Problems, Tenth Revision [ICD-10] code, H34.1) and noncentral RAO (other RAO; ICD-10 code, H34.2) was estimated using National Health Insurance Service claims data from 2002 to 2018, with 2002 to 2004 as the washout period. Furthermore, the causes of death were evaluated and the standardized mortality ratio was estimated. The primary outcomes were the incidence of RAO per 100 000 person-years and the standardized mortality ratio (SMR).

RESULTS

A total of 51 326 patients with RAO were identified (28 857 [56.2%] men; mean [SD] age at index date: 63.6 [14.1] years). The nationwide incidence of any RAO was 7.38 (95% CI, 7.32-7.44) per 100 000 person-years. The incidence rate of noncentral RAO was 5.12 (95% CI, 5.07-5.18), more than twice that of CRAO (2.25 [95% CI, 2.22-2.29]). Mortality was higher in patients with any RAO than in the general population (SMR, 7.33 [95% CI, 7.15-7.50]). The SMR for CRAO (9.95 [95% CI, 9.61-10.29]) and for noncentral RAO (5.97 [95% CI, 5.78-6.16]) showed a tendency toward a gradual decrease with increasing age. The top 3 causes of death in patients with RAO were diseases of the circulatory system (28.8%), neoplasms (25.1%), and diseases of the respiratory system (10.2%).

CONCLUSIONS AND RELEVANCE

This cohort study found that the incidence rate of noncentral RAO was higher than that of CRAO, whereas SMR was higher for CRAO than noncentral RAO. Patients with RAO show higher mortality than the general population, with circulatory system disease as the leading cause of death. These findings suggest that it is necessary to investigate the risk of cardiovascular or cerebrovascular disease in patients newly diagnosed with RAO.

Association Between Behavioral, Biological, and Genetic Markers of Cardiovascular Health and MRI Markers of Brain Aging: A Cohort Study

BACKGROUND AND OBJECTIVE

The life's simple 7 approach was proposed to define cardiovascular health (CVH) metrics. We sought to investigate the associations between behavioral, biological, and genetic markers for CVH and vascular brain aging in older adults.

METHODS

This population-based cohort study included participants who had repeated brain MRI measures from 2001 to 2003 to 2007-2010 (i.e., count of perivascular spaces, volumes of white matter hyperintensity [WMH] and gray matter, and lacunes). At baseline, global, behavioral, and biological CVH metrics were defined and scored following the life's simple 7 approach and categorized into unfavorable, intermediate, and favorable profiles according to tertiles. The metabolic genetic risk score was calculated by counting 15 risk alleles associated with hypertension, diabetes, or dyslipidemia. Data were analyzed using linear mixed-effects and Cox proportional hazards models, adjusting for age, sex, and education.

RESULTS

The study sample consisted of 317 participants (age 60 years or older; 61.8% women). Favorable and intermediate (vs unfavorable) global CVH profiles were related to slower WMH progression, with β-coefficients (95% CI) being -0.019(-0.035-0.002) and -0.018(-0.034-0.001), respectively. Favorable and intermediate (vs unfavorable) biological CVH profiles were significantly related to slower WMH increase only in people aged 60-72 years. CVH profiles were not related to progression of other brain measures. Furthermore, a higher metabolic genetic risk score (range: 6-21) was associated with faster WMH increase (β-coefficient = 0.005; 95% CI: 0.003-0.008). There were statistical interactions of metabolic genetic risk score with global and behavioral CVH profiles on WMH accumulation. A higher metabolic genetic risk score was related to faster WMH accumulation, with β-coefficients being 0.015(0.007-0.023), 0.005(0.001-0.009), and 0.003(-0.001 to 0.006) among people with unfavorable, intermediate, and favorable global CVH profiles, respectively; the corresponding β-coefficients were 0.013(0.006-0.020), 0.006(0.003-0.009), and 0.002(-0.002 to 0.006) among people with unfavorable, intermediate, and favorable behavioral CVH profiles.

DISCUSSION

Intermediate to favorable global CVH profiles in older adults are associated with slower vascular brain aging. The association of metabolic genetic risk load with accelerated vascular brain aging was evident among people with unfavorable to intermediate, but not favorable, CVH profiles. These findings highlight the importance of adhering to favorable CVH profiles, especially healthy behaviors, in vascular brain health.

Mapping blood traits to structural organization of the brain in rhesus monkeys

Hematological and biochemical blood traits have been linked to brain structural characteristics in humans. However, the relationship between these two domains has not been systematically explored in nonhuman primates, which are crucial animal models for understanding the mechanisms of brain function and developing therapeutics for various disorders. Here we investigated the associations between hematological/biochemical parameters and the brain's gray matter volume and white matter integrity derived from T1-weighted and diffusion magnetic resonance imaging in 36 healthy macaques. We found that intersubject variations in basophil count and hemoglobin levels correlated with gray matter volumes in the anterior cingulum, prefrontal cortex, and putamen. Through interactions between these key elements, the blood parameters' covariation network was linked with that of the brain structures, forming overarching networks connecting blood traits with structural brain features. These networks exhibited hierarchical small-world architecture, indicating highly effective interactions between their constituent elements. In addition, different subnetworks of the brain areas or fiber tracts tended to correlate with unique groups of blood indices, revealing previously unknown brain structural organization. These results provide a quantitative characterization of the interactions between blood parameters and brain structures in macaques and may increase the understanding of the body-brain relationship and the pathogenesis of relevant disorders.

Prevalence and risk factors of MRI-defined brain infarcts among Chinese adults

Background

Few studies have explored the prevalence and risk factors of brain infarcts (BI) detected by magnetic resonance imaging (MRI) in China. The purpose was to evaluate the prevalence and risk factors of brain infarcts (BI) detected by magnetic resonance imaging (MRI) in 1.4 million Chinese adults.

Methods

This was a multicenter cross-sectional study conducted on 1,431,527 participants aged ≥18 years (mean age: 46.4 years) who underwent MRI scans in health examinations from 28 provinces of China in 2018. MRI-defined BI was defined as focal parenchymal lesions ≥3 mm. Multivariable logistic regression analyses were performed to evaluate risk factors associated with MRI-defined BI.

Results

The age- and sex-standardized prevalence of MRI-defined BI, lacunar and non-lacunar infarcts were 5.79% (5.75–5.83%), 4.56% (4.52–4.60%), and 1.23% (1.21–1.25%), respectively. The sex-standardized prevalence of MRI-defined BI ranged from 0.46% among those aged 18–29 years to 37.33% among those aged ≥80 years. Men (6.30%) had a higher age-standardized prevalence of MRI-defined BI than women (5.28%). The highest age- and sex-standardized prevalence of MRI-defined BI was observed in the Northwest (8.34%) and Northeast (8.02%) regions, while the lowest prevalence was observed in the Southwest (4.02%). A higher risk of MRI-defined BI was associated with being male [odd ratio (OR) 1.17, 95% CI 1.15–1.19], older age (OR per 10-year increments 2.33, 2.31–2.35), overweight (1.12, 1.10–1.14) or obesity (1.18, 1.16–1.21), hypertension (1.80, 1.77–1.83), diabetes (1.24, 1.21–1.26), and dyslipidemia (1.07, 1.05–1.08).

Conclusion

MRI-defined BI is highly prevalent in China, even among young adults. MRI-defined BI was associated with being male, older age, living in the northern region, and metabolic conditions.

Biomarkers involved in the pathogenesis of cerebral small-vessel disease

Cerebral small-vessel disease (CSVD) has been found to have a strong association with vascular cognitive impairment (VCI) and functional loss in elderly patients. At present, the diagnosis of CSVD mainly relies on brain neuroimaging markers, but they cannot fully reflect the overall picture of the disease. Currently, some biomarkers were found to be related to CSVD, but the underlying mechanisms remain unclear. We aimed to systematically review and summarize studies on the progress of biomarkers related to the pathogenesis of CSVD, which is mainly the relationship between these indicators and neuroimaging markers of CSVD. Concerning the pathophysiological mechanism of CSVD, the biomarkers of CSVD have been described as several categories related to sporadic and genetic factors. Monitoring of biomarkers might contribute to the early diagnosis and progression prediction of CSVD, thus providing ideas for better diagnosis and treatment of CSVD.

Associations of Life's Simple 7 With Cerebral Small Vessel Disease

BACKGROUND

The purpose of this study is to examine the associations of Life's Simple 7 (LS7) with risks of cerebral small vessel disease (CSVD) and its magnetic resonance imaging markers.

METHODS

Community-dwelling residents in Lishui city in China from the cross-sectional survey of the PRECISE study (Polyvascular Evaluation for Cognitive Impairment and Vascular Events) were included in this study from 2017 to 2019. LS7 was analyzed as the total score, medical score (derived from the 3 metrics based on medical history and testing), and behavioral score (based on 4 metrics based on behaviors), and categorized as poor, intermediate, or ideal. A CSVD score or a modified CSVD score was derived from 4 magnetic resonance imaging markers (lacunes, microbleeds, perivascular spaces, and white matter hyperintensity) at baseline. Binary logistic regression or ordinal logistic regression model was used to estimate the relationship of LS7 scores with CSVD and magnetic resonance imaging markers.

RESULTS

A total of 3061 participants were included in this study. Compared with poor total LS7 score, ideal LS7 total score was associated with reduced adjusted odds of higher CSVD score (common odds ratio [cOR], 0.73 [95% CI, 0.58-0.90]) and higher modified CSVD score (cOR, 0.78 [95% CI, 0.64-0.95]). Compared with poor LS7 medical score, ideal LS7 medical score was associated with reduced adjusted odds of higher CSVD score (cOR, 0.65 [95% CI, 0.53-0.80]) and higher modified CSVD score (cOR, 0.67 [95% CI, 0.56-0.81]). Higher total LS7 score and LS7 medical score were associated with a lower risk of white matter hyperintensities and lacunes. Higher LS7 behavioral score was associated with lower risk of lacunes.

CONCLUSIONS

Ideal LS7 score, indicating excellent cardiovascular health, was associated with lower total CSVD burden. Optimizing the risk factors captured by LS7 may reduce the progression of CSVD.

Differential associations of lipoprotein(a) level with cerebral large artery and small vessel diseases

BACKGROUND AND PURPOSE

Cerebral large artery and small vessel diseases are related to different pathogenetic mechanisms and have different risk factor profile. Lipoprotein(a) (Lp(a)) was shown to promote atherosclerosis but data was limited on its association with cerebral small vessel diseases (cSVD). The objective of this study was to assess the associations of Lp(a) level with the two types of cerebrovascular diseases.

METHODS

Community-dwelling subjects aged 50-75 years from the baseline survey of The PolyvasculaR Evaluation for Cognitive Impairment and vaScular Events study were included. Lp(a) concentrations was measured and categorised into three groups according to the tertiles. Eligible participants were scanned by a 3.0T MRI scanner and assessed for intracranial atherosclerosis and cSVD burden based on four imaging markers.

RESULTS

This study included 3059 subjects. The average age of the participants was 61.2±6.7 years, and 53.5% (1636) were female. Compared with the first tertile, subjects with the second and third tertiles of Lp(a) concentrations were associated with an increased odds of presence of intracranial plaque (18.7% vs 15.4%, adj.OR 1.37, 95% CI 1.08 to 1.75; 18.9% vs 15.4%, adj.OR 1.34, 95% CI 1.05 to 1.72). Similar associations were observed for intracranial atherosclerotic burden. Whereas, subjects with the third tertile of Lp(a) level had a decreased odds of presence of cSVD (25.9% vs 31.7%, adj.OR 0.74, 95% CI 0.60 to 0.92) and lower cSVD burden (adj.cOR 0.76, 95% CI 0.62 to 0.94).

CONCLUSIONS

In this study, Lp(a) concentrations were positively associated with presence and burden of intracranial atherosclerosis, but was inversely associated with cSVD.

TRIAL REGISTRATION NUMBER

NCT03178448.

Brain white matter hyperintensities-predicted age reflects neurovascular health in middle-to-old aged subjects

BACKGROUND

age-related neurovascular structural and functional impairment is a major aetiology of dementia and stroke in older people. There is no single marker representative of neurovascular biological age yet.

OBJECTIVE

this study aims to develop and validate a white matter hyperintensities (WMH)-based model for characterising individuals' neurovascular biological age.

METHODS

in this prospective single-site study, the WMH-based age-prediction model was constructed based on WMH volumes of 491 healthy participants (21-89 years). In the training dataset, the constructed linear-regression model with log-transformed WMH volumes showed well-balanced complexity and accuracy (root mean squared error, RMSE = 10.20 and mean absolute error, MAE = 7.76 years). This model of neurovascular age estimation was then applied to a middle-to-old aged testing dataset (n = 726, 50-92 years) as the testing dataset for external validation.

RESULTS

the established age estimator also had comparable generalizability with the testing dataset (RMSE = 7.76 and MAE = 6.38 years). In the testing dataset, the WMH-predicted age difference was negatively associated with visual executive function. Individuals with older predicted-age for their chronological age had greater cardiovascular burden and cardiovascular disease risks than individuals with normal or delayed predicted age. These associations were independent of chronological age.

CONCLUSIONS

our model is easy to use in clinical practice that helps to evaluate WMH severity objective to chronological age. Current findings support our WMH-based age measurement to reflect neurovascular health and have potential diagnostic and prognostic value for clinical or research purposes in age-related neurovascular disorders.

Added value of femoral artery atherosclerosis for determining severity of white matter lesion by carotid atherosclerosis: a magnetic resonance imaging study

BACKGROUND

Previous studies reported that single vascular atherosclerosis was an effective indicator for white matter lesions (WMLs).

PURPOSE

To investigate the added value of femoral atherosclerosis for determining severity of WMLs by carotid atherosclerosis using three-dimensional vessel wall magnetic resonance imaging (MRI).

MATERIAL AND METHODS

Elderly individuals without cardiovascular symptoms within the previous six months were recruited. The plaque features of carotid and femoral arteries were evaluated and compared between individuals with WML score ≤ 3 and those with WML score > 3. Logistic regression and receiver operating characteristic (ROC) analyses were used to determine the value of plaque features in discriminating WMLs with score > 3.

RESULTS

In total, 112 individuals (49 men, mean age 72.0±5.6 years) were included. Participants with a WML score > 3 showed a significantly greater carotid wall area and femoral artery stenosis and higher incidence of carotid calcification and femoral artery calcification and lipid-rich necrotic cores (LRNC) compared to those with a WML score ≤ 3 (all P < 0.05). Carotid artery calcification and femoral artery calcification, LRNC, and stenosis were found to be significantly associated with severe WMLs before and after adjustment for clinical factors (odds ratio 1.51-3.79, all P < 0.05). ROC analysis showed, in discriminating severe WMLs, the area under the curve increased from 0.615 to 0.754 after combining femoral artery LRNC and stenosis with carotid calcification compared to the carotid calcification alone.

CONCLUSION

Characteristics of femoral artery atherosclerosis determined by vessel wall MRI have added value for carotid atherosclerosis in determining the severity of WMLs.

Central and Branch Retinal Artery Occlusion-Do They Harbor the Same Risk of Further Ischemic Events?

Purpose: Retinal artery occlusion (RAO) is associated with an increased risk of cardiovascular events such as ischemic stroke and myocardial infarction, but whether different RAO subtypes such as central retinal artery occlusion (CRAO) or branch retinal artery occlusion (BRAO) carry similar risk of these events is unclear. Our aim was to determine whether the risk of cardiovascular events differs between CRAO and BRAO. Methods: This single-center, retrospective study included 131 patients hospitalized in our clinic in 2010–2020 with CRAO or BRAO confirmed by ophthalmic examination. Data on demographics, previous ischemic stroke and myocardial infarction, comorbidities, the results of echocardiographic and ultrasound carotid artery examinations and laboratory tests were assessed. Data on ischemic stroke, myocardial infarction, and all-cause mortality occurring after RAO were obtained from the Polish National Health Service, which collects data on all publicly funded hospitalizations. Using these data, Kaplan-Meier analyses and Cox proportional hazard regression were performed. Results: Ischemic stroke occurred in 9.9% of patients after RAO: 10.6% in the CRAO group and 8.1% in the BRAO group (p = 0.662). Myocardial infarction occurred in 2.3% of patients after RAO: 2.1% in the CRAO group and 2.7% in the BRAO group (p = 0.843). All-cause mortality occurred in 22.9% of patients after RAO: 25.5% in the CRAO group and 16.2% in the BRAO group (p = 0.253). The composite endpoint of ischemic stroke, myocardial infarction, and all-cause mortality after RAO occurred in 28.2% of patients: 30.9% in the CRAO group and 21.6% in the BRAO group (p = 0.338). There was no difference between CRAO and BRAO in median time to ischemic stroke (32 vs. 76.4 months; p = 0.352), all-cause mortality (35.9 vs. 36.3 months; p = 0.876) or composite endpoint (37.5 vs. 41.5 months; p = 0.912) after RAO. The Kaplan-Meier analysis showed no differences between CRAO and BRAO in ischemic stroke, myocardial infarction, all-cause mortality, or the composite endpoint; similar results were obtained in analyses of patients with and without cardiovascular events before RAO. Conclusions: The prognosis for ischemic stroke, myocardial infarction, and all-cause mortality is similar in patients with CRAO and BRAO. Ischemic strokes occur with a similar frequency before and after RAO. Myocardial infarctions are observed significantly more frequently before an episode of RAO than after. The results of our study indicate that both CRAO and BRAO require expanded diagnostics to assess the risk of recurrent cardiovascular events, especially ischemic strokes, to implement appropriate prophylaxis and reduce mortality.

New candidate blood biomarkers potentially associated with white matter hyperintensities progression

We aimed to discover blood biomarkers associated with longitudinal changes in white matter hyperintensities (WMH). This study was divided into a discovery phase and a replication phase. Subjects in both studies were patients with hypertension, aged 50-70, who underwent two magnetic resonance imaging (MRI) sessions and blood extractions over a 4-year follow-up period. In the discovery phase, we screened 1305 proteins in 12 subjects with WMH progression and in 12 matched control subjects. We found that 41 proteins were differentially expressed: 13 were upregulated and 28 were downregulated. We subsequently selected three biomarkers for replication in baseline and follow-up samples in 80 subjects with WMH progression and in 80 control subjects. The selected protein candidates for the replication were MMP9 (matrix metalloproteinase-9), which was higher in cases, MET (hepatocyte growth factor receptor) and ASAH2 (neutral ceramidase), which were both lower in cases of WMH progression. Baseline biomarker concentrations did not predict WMH progression. In contrast, patients with WMH progression presented a steeper decline in MET over time. Furthermore, cases showed higher MMP9 and lower ASAH2 levels than controls at the follow-up. These results indicate that MMP9, MET, and ASAH2 are potentially associated with the progression of WMH, and could therefore be interesting candidates to validate in future studies.

High-density lipoprotein cholesterol and brain aging amongst rural-dwelling older adults: a population-based magnetic resonance imaging study

BACKGROUND AND PURPOSE

Current evidence supports the involvement of lipids in brain aging. A range of serum lipids is explored in association with brain structure and cognitive function amongst rural-dwelling older adults.

METHODS

This population-based cross-sectional study included 184 rural-dwelling adults (age ≥ 65 years, 39.1% women) in Shandong, China. In 2014-2016, data on demographics, lifestyle, health conditions and serum lipids were collected. Volumes of gray matter, white matter, ventricles, hippocampus and white matter hyperintensity were automatically estimated on brain magnetic resonance imaging. Global cognitive function was assessed with the Mini-Mental State Examination (MMSE), and mild cognitive impairment (MCI) was defined according to Petersen's criteria. Data were analyzed using the general linear regression, logistic regression and mediation models.

RESULTS

Of the 184 participants, 47 were defined with MCI. Low high-density lipoprotein cholesterol (HDL-C; <1.55 vs. ≥1.55 mmol/l) was significantly associated with reduced volumes of total white matter (multi-adjusted β = -9.77, 95% confidence interval -19.48-0.06) and hippocampus (-0.23, -0.46-0.01), a lower MMSE score (-1.49, -2.67-0.31) and a higher likelihood of MCI (multi-adjusted odds ratio 3.21, 95% confidence interval 1.42-7.29). The mediation effects of structural brain measures on the associations between a low level of HDL-C and MMSE score or MCI were not statistically significant (p > 0.05).

CONCLUSIONS

This study suggests that low HDL-C may be involved in structural brain aging and cognitive dysfunction amongst rural-dwelling older adults in China, but the association of low HDL-C with cognitive aging phenotypes appears not to be mediated by brain structure.

White matter hyperintensities and the progression from mild parkinsonian signs to parkinsonism and Parkinson's disease

This study investigated the impact of white matter hyperintensities (WMHs) on the progression from mild parkinsonian signs (MPS) to parkinsonism and Parkinson's disease (PD). Participants with MPS completed 5 years of follow-up. WMHs were divided into periventricular WMHs and deep WMHs according to magnetic resonance imaging scans. The diagnosis of MPS, parkinsonism, and PD was based on the motor portion of the Unified Parkinson's Disease Rating Scale. Cox proportional hazard models were used to identify the association between WMHs and MPS progression. Of the 636 participants, 166 (26.1%) with MPS developed parkinsonism and PD after follow-up. After adjusting for potential factors, severe WMHs were associated with an increased risk of MPS progression, moderate and severe periventricular WMHs and severe deep WMHs were associated with the risk of MPS progression, and severe WMHs were associated with the progression of gait/balance impairment, bradykinesia, and rigidity. Additionally, participants treated for vascular risk factors such as hypertension, diabetes mellitus, and hypercholesterolemia had a lower risk of MPS progression.

The central vein sign in multiple sclerosis patients with vascular comorbidities

Background:

The central vein sign (CVS) is an imaging biomarker able to differentiate multiple sclerosis (MS) from other conditions causing similar appearance lesions on magnetic resonance imaging (MRI), including cerebral small vessel disease (CSVD). However, the impact of vascular risk factors (VRFs) for CSVD on the percentage of CVS positive (CVS+) lesions in MS has never been evaluated.

Objective:

To investigate the association between different VRFs and the percentage of CVS+ lesions in MS.

Methods:

In 50 MS patients, 3T brain MRIs (including high-resolution 3-dimensional T2*-weighted images) were analyzed for the presence of the CVS and MRI markers of CSVD. A backward stepwise regression model was used to predict the combined predictive effect of VRF (i.e. age, hypertension, diabetes, obesity, ever-smoking, and hypercholesterolemia) and MRI markers of CSVD on the CVS.

Results:

The median frequency of CVS+ lesions was 71% (range: 35%–100%). In univariate analysis, age ( p < 0.0001), hypertension ( p < 0.001), diabetes ( p < 0.01), obesity ( p < 0.01), smoking ( p < 0.05), and the presence of enlarged-perivascular-spaces on MRI ( p < 0.005) were all associated with a lower percentage of CVS+ lesions. The stepwise regression model showed that age and arterial hypertension were both associated with the percentage of CVS+ lesions in MS (adjusted R2 = 0.46; p < 0.0001 and p = 0.01, respectively).

Conclusion:

The proportion of CVS+ lesions significantly decreases in older and hypertensive MS patients. Although this study was conducted in patients with an already established MS diagnosis, the diagnostic yield of the previously proposed 35% CVS proportion-based diagnostic threshold appears to be not affected. Overall these results suggest that the presence of VRF for CSVD should be taken into account during the CVS assessment.

Plasma lipidomic biomarker analysis reveals distinct lipid changes in vascular dementia

Vascular dementia (VaD) is a complex neurocognitive disorder secondary to a variety of cerebrovascular lesions. Numerous studies have shown that lipid metabolism is involved in the pathobiology of the disease. We examined the plasma lipid profiles in VaD, with the expectation of identifying reliable lipid biomarkers for VaD. 49 VaD patients and 48 healthy controls were recruited from Bankstown-Lidcombe Hospital in Sydney, Australia. Lipids were extracted by single phase 1-butanol/methanol, and untargeted analysis was performed by liquid chromatography coupled-mass spectrometry (LC–MS/MS). Univariate analysis of variance was used to examine the differences in lipid classes and individual lipids between VaD and control groups. In an independent sample of 161 subjects from the Older Australian Twins Study (OATS), elastic net penalization for the generalized linear model (Glmnet) and Random Forest were applied to the lipid levels to subcategorise the sample into vascular cognitive impairment and controls. Most lipids belonging to the classes of ceramides (Cer), cholesterol esters (ChE) and phospholipids were significantly lower in VaD plasma, while glycerides were elevated compared to controls. Levels of ChE, Cer and the two lipid classes together achieved the best accuracy in discriminating VaD from controls, with more than 80% accuracy. The probable VaD group in the OATS sample predicted by the lipid levels showed greater impairment in most cognitive domains, especially attention and processing speed and executive function from controls but did not differ in white matter hyperintensities and DTI measures. As a conclusion, plasma lipids levels, in particular Cer and ChE, are abnormal in VaD and may help discriminate them from healthy controls. Understanding the basis of these differences may provide insights into the pathobiology of VaD.

Association between atherogenic dyslipidemia and fournier’s gangrene

SUMMARY OBJECTIVE We aimed to determine whether atherogenic dyslipidemia is associated with the disease and morbidity in our patients treated for Fournier’s gangrene (FG). METHODS Sixty-two patients who were treated with the diagnosis of FG at our center between 2012 and 2017 were retrospectively screened. RESULTS The triglyceride values of the patients who required reconstructive surgery were statistically significantly higher than those of the patients for whom wound debridement and primary suturing was sufficient (p:0.001). A total of 65.7% of the patients had normal triglyceride values in the group in which wound debridement and primary suturing was sufficient, while this rate was 22.2% in the group of patients who needed reconstructive surgery; the difference was statistically significant (p: 0.002). The UFGSI score of those with triglyceride values higher than the normal range was statistically significantly higher (p:0.006). The cut-off point for the triglyceride value for which Fournier’s gangrene was more morbid and the probability of reconstructive surgery need was significantly higher, i.e., >233mg. CONCLUSION Our study has demonstrated that atherogenic dyslipidemia, especially hypertriglyceridemia, is an important factor affecting morbidity and associated with high patient care costs after hospitalization and discharge in FG.

Prospectively Collected Cardiovascular Biomarkers and White Matter Hyperintensity Volume in Ischemic Stroke Patients

BACKGROUND

Few prospective cohort studies collect detailed information on stroke characteristics among individuals who experience ischemic stroke, including white matter hyperintensity volume, and thus cannot explore how prospectively collected biomarkers prior to the stroke influence white matter hyperintensity volume. We explored the association between a large panel of prospectively collected lipid and inflammatory biomarkers and white matter hyperintensity volume among participants in the Women's Health Study with incident ischemic stroke.

METHODS

Among Women's Health Study participants with first ischemic stroke who had baseline serum biomarkers and available magnetic resonance imaging, we measured white matter hyperintensity volume using a validated semi-automated method. Linear regression was used to explore the associations between biomarkers and log-transformed white matter hyperintensity volume.

RESULTS

After multivariate adjustment, a 1% increment in HbA1c% was associated with an increase in white matter hyperintensity volume (P value = .05). Evidence of a nonlinear association between high density lipoprotein cholesterol levels and ApoA1 levels with white matter hyperintensity volume was noted (P values for nonlinearity = .01 and .001, respectively). No other biomarkers were significantly associated with white matter hyperintensity volume.

CONCLUSIONS

Chronic hyperglycemia as evidenced by HbA1c levels measured years prior to stroke is associated with white matter hyperintensity volume at the time of stroke. Additional research is needed to explain why low levels of high density lipoprotein cholesterol levels and ApoA1 may be associated with similar white matter hyperintensity volume as high levels.

Pooled cohort risk equation and subclinical cerebrovascular diseases

BACKGROUND AND PURPOSE

In 2013, the American College of Cardiology/American Heart Association (ACC/AHA) introduced a novel pooled cohort risk (PCR) model for atherosclerotic cardiovascular disease. In this study, we evaluated the relationship between the PCR score and cerebral large- and small-vessel diseases (cLVD and cSVD) in a healthy population, METHODS: We assessed consecutive health check-up volunteers from 2006 to 2013. We calculated the estimated 10-year atherosclerotic cardiovascular disease risk as the PCR score based on the 2013 ACC/AHA guidelines. We evaluated both cSVD/cLVD, including the prevalence of cLVD, lacunes and cerebral microbleed (CMB), and the volume of white matter hyperintensity (WMH). In addition to PCR score, the risk factors that were associated with outcome variables at P < 0.10 in univariate analysis were included for further multivariable linear or regression analyses.

RESULTS

A total of 2720 participants were evaluated (mean age, 57 years, male sex, 54%). In multivariable analysis, PCR score was associated with WMH volume [β = 0.361; 95% confidence interval (CI), 0.320-0.402, P < 0.001], cLVD [adjusted odds ratio (aOR), 1.66; 95% CI, 1.29-2.16, P < 0.001], lacunes (aOR, 1.80; 95% CI, 1.52-2.14, P < 0.001) and CMBs (aOR, 1.75; 95% CI, 1.40-2.19, P < 0.001). Furthermore, PCR score also showed dose-response tendencies according to the burden of cLVD, WMH, lacunes and CMB.

CONCLUSIONS

A higher PCR score based on the ACC/AHA guidelines is closely associated with a higher prevalence and burden of cLVD and cSVD.

Patients with the Subcortical Small Vessel Type of Dementia Have Disturbed Cardiometabolic Risk Profile

BACKGROUND

Population-based studies have shown that cardiometabolic status is associated with the amount of white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI). However, little is known of cardiometabolic risk factors in the subcortical small vessel type of dementia (SSVD), in which WMHs are one of the most prominent manifestations.

OBJECTIVE

To determine whether the profile of cardiometabolic risk factors differed between SSVD, Alzheimer's disease (AD), mixed dementia (combined AD and SSVD), and healthy controls.

METHODS

This was a mono-center, cross-sectional study of SSVD (n = 40), AD (n = 113), mixed dementia (n = 62), and healthy controls (n = 94). In the statistical analyses, we adjusted for covariates using ANCOVA and binary logistic regression.

RESULTS

The prevalence of hypertension was increased in SSVD and mixed dementia (p < 0.001 and p < 0.05 versus controls, respectively). Diabetes was more prevalent in SSVD patients, and body mass index was lower in AD and mixed dementia, compared to the controls (all p < 0.05). Serum total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) were reduced in the SSVD group (both p < 0.05 versus control). These differences remained after adjustment for covariates. In the SSVD group, Trail Making Test A score correlated positively with systolic blood pressure, mean arterial pressure, and pulse pressure.

CONCLUSION

All dementia groups had an altered cardiometabolic risk profile compared to the controls. The SSVD patients showed increased prevalence of hypertension and diabetes, and in line with previous population-based data, TC and LDL-C in serum were reduced.

Prospects for Diminishing the Impact of Nonamyloid Small-Vessel Diseases of the Brain

Small-vessel diseases (SVDs) of the brain are involved in about one-fourth of ischemic strokes and a vast majority of intracerebral hemorrhages and are responsible for nearly half of dementia cases in the elderly. SVDs are a heavy burden for society, a burden that is expected to increase further in the absence of significant therapeutic advances, given the aging population. Here, we provide a critical appraisal of currently available therapeutic approaches for nonamyloid sporadic SVDs that are largely based on targeting modifiable risk factors. We review what is known about the pathogenic mechanisms of vascular risk factor-related SVDs and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), the most frequent hereditary SVD, and elaborate on two mechanism-based therapeutic approaches worth exploring in sporadic SVD and CADASIL. We conclude by discussing opportunities and challenges that need to be tackled if efforts to achieve significant therapeutic advances for these diseases are to be successful.

Causal Effect of Lp(a) [Lipoprotein(a)] Level on Ischemic Stroke and Alzheimer Disease: A Mendelian Randomization Study

Background and Purpose- Stroke and Alzheimer disease are 2 major causes of neurological disability in aged people and shared overlapping predictors. In recent prospective studies, high Lp(a) [lipoprotein(a)] level is associated with high risk of stroke but low risk of Alzheimer disease. Whether this reflects a causal association remains to be established. The aim of this study is to examine the causal associations of Lp(a) concentrations on ischemic stroke, ischemic stroke subtypes, and Alzheimer disease. Methods- We used 9 single-nucleotide polymorphisms associated with Lp(a) concentrations as instrumental variables. Summary-level data on ischemic stroke and its subtypes were obtained from the Multiancestry Genome-Wide Association Study of Stroke consortium with European individuals ≤446 696 individuals. Summary-level data on Alzheimer disease were obtained from the International Genomics of Alzheimer Project With European individuals ≤54 162 individuals. Two-sample Mendelian randomization (MR) estimates were calculated with inverse-variance weighted, penalized inverse-variance weighted, simple median, weighted median, and MR Pleiotropy Residual Sum and Outlier approaches, and MR-Egger regression was used to explore pleiotropy. Results- Genetically predicted 1-SD log-transformed increase in Lp(a) concentrations was associated with a substantial increase in risk of large artery stroke (odds ratio, 1.20; 95% CI, 1.11-1.30; P<0.001) and a reduce in risk of small vessel stroke (odds ratio, 0.92; 95% CI, 0.88-0.97; P=0.001) and Alzheimer disease (odds ratio, 0.94; 95% CI, 0.91-0.97; P<0.001) using inverse-variance weighted method. No significant association was observed for total ischemic stroke or cardioembolic stroke. MR-Egger indicated no evidence of pleiotropic bias. Results were broadly consistent in sensitivity analyses using penalized inverse-variance weighted, simple median, weighted median, and MR Pleiotropy Residual Sum and Outlier approaches accounting for potential genetic pleiotropy or outliers. Conclusions- This study provides evidence to support that high Lp(a) concentrations was causally associated with an increased risk of large artery stroke but a decreased risk of small vessel stroke and Alzheimer disease. The mechanism underlying the double-edged sword effect of Lp(a) concentrations on neurological system requires further investigation.

Major depression and small vessel stroke: a Mendelian randomization analysis

BACKGROUND AND PURPOSE

Although observational studies have reported a positive association between depression and ischemic stroke, causality remains inconclusive. We aimed to assess the causal relationship of major depressive disorder (MDD) with ischemic stroke, especially with the small vessel stroke (SVS) subtype.

METHODS

We used 72 independent single-nucleotide polymorphisms associated with MDD in a genome-wide association study (GWAS) from the Psychiatric Genetics Consortium as instrumental variables. The corresponding data for ischemic stroke and its subtypes of European ancestry were available from the MEGASTROKE consortium of 34,217 ischemic stroke cases and 406,111 controls. Primary Mendelian randomization estimates were calculated with inverse-variance weighted method, and several alternate methods and multiple sensitivity analyses were also performed.

RESULTS

We found that genetic predisposition to higher risk of MDD was associated with higher risk of SVS, with an odds ratio of 1.33 (95% confidence interval, 1.08-1.65; p = 0.009) per log-odds increment in MDD risk, but not with large artery stroke (OR, 1.08; 95% CI 0.83-1.41; p = 0.559), cardioembolic stroke (OR, 0.98; 95% CI 0.80-1.20; p = 0.833), or all ischemic stroke (OR, 1.03; 95% CI 0.92-1.15; p = 0.633). The association of MDD with SVS was overall robust to sensitivity analyses.

CONCLUSIONS

We provided evidence for a possible causal effect of MDD on increased risk of SVS. Future researches are required to investigate whether rational intervention on depression may help to reduce societal burden of SVS.

Plasma Metabolites Associated with Brain MRI Measures of Neurodegeneration in Older Adults in the Atherosclerosis Risk in Communities⁻Neurocognitive Study (ARIC-NCS)

Background: Plasma metabolites are associated with cognitive and physical function in the elderly. Because cerebral small vessel disease (SVD) and neurodegeneration are common causes of cognitive and physical function decline, the primary objective of this study was to investigate the associations of six plasma metabolites (two plasma phosphatidylcholines [PCs]: PC aa C36:5 and PC aa 36:6 and four sphingomyelins [SMs]: SM C26:0, SM [OH] C22:1, SM [OH] C22:2, SM [OH] C24:1) with magnetic resonance imaging (MRI) features of cerebral SVD and neurodegeneration in older adults. Methods: This study included 238 older adults in the Atherosclerosis Risk in Communities study at the fifth exam. Multiple linear regression was used to assess the association of each metabolite (log-transformed) in separate models with MRI measures except lacunar infarcts, for which binary logistic regression was used. Results: Higher concentrations of plasma PC aa C36:5 had adverse associations with MRI features of cerebral SVD (odds ratio of 1.69 [95% confidence interval: 1.01, 2.83] with lacunar infarct, and beta of 0.16 log [cm3] [0.02, 0.30] with log [White Matter Hyperintensities (WMH) volume]) while higher concentrations of 3 plasma SM (OH)s were associated with higher total brain volume (beta of 12.0 cm3 [5.5, 18.6], 11.8 cm3 [5.0, 18.6], and 7.3 cm3 [1.2, 13.5] for SM [OH] C22:1, SM [OH] C22:2, and SM [OH] C24:1, respectively). Conclusions: This study identified associations between certain plasma metabolites and brain MRI measures of SVD and neurodegeneration in older adults, particularly higher SM (OH) concentrations with higher total brain volume.

Genetic and lifestyle risk factors for MRI-defined brain infarcts in a population-based setting

OBJECTIVE

To explore genetic and lifestyle risk factors of MRI-defined brain infarcts (BI) in large population-based cohorts.

METHODS

We performed meta-analyses of genome-wide association studies (GWAS) and examined associations of vascular risk factors and their genetic risk scores (GRS) with MRI-defined BI and a subset of BI, namely, small subcortical BI (SSBI), in 18 population-based cohorts (n = 20,949) from 5 ethnicities (3,726 with BI, 2,021 with SSBI). Top loci were followed up in 7 population-based cohorts (n = 6,862; 1,483 with BI, 630 with SBBI), and we tested associations with related phenotypes including ischemic stroke and pathologically defined BI.

RESULTS

The mean prevalence was 17.7% for BI and 10.5% for SSBI, steeply rising after age 65. Two loci showed genome-wide significant association with BI: FBN2, p = 1.77 × 10-8; and LINC00539/ZDHHC20, p = 5.82 × 10-9. Both have been associated with blood pressure (BP)-related phenotypes, but did not replicate in the smaller follow-up sample or show associations with related phenotypes. Age- and sex-adjusted associations with BI and SSBI were observed for BP traits (p value for BI, p [BI] = 9.38 × 10-25; p [SSBI] = 5.23 × 10-14 for hypertension), smoking (p [BI] = 4.4 × 10-10; p [SSBI] = 1.2 × 10-4), diabetes (p [BI] = 1.7 × 10-8; p [SSBI] = 2.8 × 10-3), previous cardiovascular disease (p [BI] = 1.0 × 10-18; p [SSBI] = 2.3 × 10-7), stroke (p [BI] = 3.9 × 10-69; p [SSBI] = 3.2 × 10-24), and MRI-defined white matter hyperintensity burden (p [BI] = 1.43 × 10-157; p [SSBI] = 3.16 × 10-106), but not with body mass index or cholesterol. GRS of BP traits were associated with BI and SSBI (p ≤ 0.0022), without indication of directional pleiotropy.

CONCLUSION

In this multiethnic GWAS meta-analysis, including over 20,000 population-based participants, we identified genetic risk loci for BI requiring validation once additional large datasets become available. High BP, including genetically determined, was the most significant modifiable, causal risk factor for BI.

Age and recurrent stroke are related to the severity of white matter hyperintensities in lacunar infarction patients with diabetes

Background and purpose

White matter hyperintensities (WMH) is identified as a marker of cerebral small vessel diseases and is a major contributor to cognitive impairment, depression, gait disturbance, and urinary incontinence. However, the risk factors for WMH in patients with type 2 diabetes mellitus (T2DM) has not been well explored. Thus, in this study, we aimed to investigate the relationship between the severity of WMH and vascular risk factors in lacunar infarction patients with T2DM.

Methods

Consecutive lacunar infarction patients with T2DM were recruited in this cross-sectional study. Paraventricular WMH (P-WMH) and deep WMH (D-WMH) were separately scored by the Fazekas scale, and classified into two categories by the severity. Vascular risk factors and clinical features were compared between the mild and severe WMH. Multiple logistic regression analysis was used to determine the relationship between severity of WMH and vascular risk factors.

Results

A total of 327 participants aged 34–91 years were enrolled in this study. Compared with the patients with mild P-WMH, the patients with severe P-WMH had higher age (P=0.031), higher proportion of hypertension (P=0.042) and stroke (P<0.001). Levels of TG, LDL, and HbA1c were significantly higher in patients with mild P-WMH. Compared with the patients with mild D-WMH the patients with severe D-WMH had higher age and hyperhomocysteinemia (HCY) level (P<0.001), higher proportion of hyperlipidemia (P=0.008), and stroke (P<0.001). Multivariable logistic regression analyses showed that higher age and recurrent stroke were independently related to severe P-WMH and D-WMH in lacunar infarction patients with T2DM.

Conclusions

Age and recurrent stroke are related to the severity of P-WMH and D-WMH in lacunar infarction patients with T2DM.

Cerebral small vessel disease in Indonesia: Lacunar infarction study from Indonesian Stroke Registry 2012-2014

BACKGROUND AND PURPOSE

Stroke is the number one cause of morbidity and mortality in Indonesia. Lacunar infarction is one of cerebral small vessel disease spectrum. This study aimed to present stroke epidemiology in Indonesia and risk factors associated with cerebral small vessel disease.

METHODS

A multicenter prospective cross-sectional study of 18 hospitals in Indonesia was conducted using Stroke Case Report Form from 2012 to 2014. Stroke was diagnosed based on clinical findings confirmed with non-contrast computed tomography of the brain. Subjects were classified into two large groups: ischemic (lacunar and non-lacunar) and hemorrhagic (intracranial and subarachnoid hemorrhage). Other risk factors were assessed on admission.

RESULTS

We enrolled 5411 patients, of whom 3627 (67.03%) had ischemic stroke and 1784 (32.97%) had hemorrhagic stroke. Male patients were prevalent in both large groups, although found less in subarachnoid hemorrhage group. Among patients with hemorrhagic stroke, 1603 (89.54%) of them had intracerebral hemorrhage and 181 (10.46%) had subarachnoid hemorrhage. From 3627 ischemic stroke patients, 1635 (45.07%) of them had lacunar infarction. We found that age above 55 years old, male gender, hypertension, dyslipidemia, and diabetes were important risk factors associated with lacunar stroke (p < 0.05).

CONCLUSION

Ischemic stroke was the leading cause of stroke in Indonesia. In total, 45% of the total ischemic stroke patients had lacunar infarction. Important risk factors associated with lacunar infarction were hypertension, dyslipidemia, diabetes, age over 55, and male population.

Update on Vascular Cognitive Impairment Associated with Subcortical Small-Vessel Disease

Subcortical small-vessel disease (SSVD) is a disorder well characterized from the clinical, imaging, and neuropathological viewpoints. SSVD is considered the most prevalent ischemic brain disorder, increasing in frequency with age. Vascular risk factors include hypertension, diabetes, hyperlipidemia, elevated homocysteine, and obstructive sleep apnea. Ischemic white matter lesions are the hallmark of SSVD; other pathological lesions include arteriolosclerosis, dilatation of perivascular spaces, venous collagenosis, cerebral amyloid angiopathy, microbleeds, microinfarcts, lacunes, and large infarcts. The pathogenesis of SSVD is incompletely understood but includes endothelial changes and blood-brain barrier alterations involving metalloproteinases, vascular endothelial growth factors, angiotensin II, mindin/spondin, and the mammalian target of rapamycin pathway. Metabolic and genetic conditions may also play a role but hitherto there are few conclusive studies. Clinical diagnosis of SSVD includes early executive dysfunction manifested by impaired capacity to use complex information, to formulate strategies, and to exercise self-control. In comparison with Alzheimer's disease (AD), patients with SSVD show less pronounced episodic memory deficits. Brain imaging has advanced substantially the diagnostic tools for SSVD. With the exception of cortical microinfarcts, all other lesions are well visualized with MRI. Diagnostic biomarkers that separate AD from SSVD include reduction of cerebrospinal fluid amyloid-β (Aβ)42 and of the ratio Aβ42/Aβ40 often with increased total tau levels. However, better markers of small-vessel function of intracerebral blood vessels are needed. The treatment of SSVD remains unsatisfactory other than control of vascular risk factors. There is an urgent need of finding targets to slow down and potentially halt the progression of this prevalent, but often unrecognized, disorder.

Sex differences in associations between blood lipids and cerebral small vessel disease

BACKGROUND AND AIMS

Dyslipidemia predicts higher risk of coronary events and stroke and might be associated with cerebral small vessel disease (SVD). Previous studies linking blood lipids and SVD have yielded inconsistent results, which may be attributable to sex differences in lipids metabolism. The aim of this study was to investigate the relationships between blood lipids and SVD in neurologically healthy men and women.

METHODS AND RESULTS

Consecutive 817 people aged 50 years or more were enrolled and underwent magnetic resonance imaging scans to evaluate the periventricular white matter lesions (PVWMLs), deep white matter lesions (DWMLs) and silent brain infarction (SBI). Fasting total cholesterol, triglyceride, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol, apolipoprotein A-1 (apoA-1) and apolipoprotein B were assessed. Multivariable logistic regression analyses were performed to determine the associations of blood lipids with PVWMLs, DWMLs and SBI. HDL-C (for PVWMLs: OR 0.36, 95% CI 0.19-0.71; for DWMLs: OR 0.35, 95% CI 0.20-0.63) and apoA-1 (for PVWMLs: OR 0.27, 95% CI 0.11-0.66; for DWMLs: OR 0.22, 95% CI 0.10-0.48) were inversely associated with the severity of PVWMLs and DWMLs in women but not in men after adjustment for age, hypertension, diabetes, current smoking, daily drinking, body mass index and uric acid. Additionally, no blood lipids were significantly associated with SBI.

CONCLUSIONS

Our findings demonstrate that sex differences may exist in the associations between lipids and SVD. HDL-C and apoA-1 levels were inversely associated with the severity of PVWMLs and DWMLs in women.

Development and validation of a priori risk model for extensive white matter lesions in people age 65 years or older: the Dijon MRI study

OBJECTIVES

The objective was to develop and validate a risk model for the likelihood of extensive white matter lesions (extWML) to inform clinicians on whether to proceed with or forgo diagnostic MRI.

DESIGN

Population-based cohort study and multivariable prediction model.

SETTING

Two representative samples from France.

PARTICIPANTS

Persons aged 60-80 years without dementia or stroke. Derivation sample n=1714; validation sample n=789.

PRIMARY AND SECONDARY OUTCOME MEASURES

Volume of extWML (log cm³) was obtained from T2-weighted images in a 1.5 T scanner. 20 candidate risk factors for extWML were evaluated with the C-statistic. Secondary outcomes in validation included incident stroke over 12 years follow-up.

RESULTS

The multivariable prediction model included six clinical risk factors (C-statistic=0.61). A cut-off of 7 points on the multivariable prediction model yielded the optimum balance in sensitivity 63.7% and specificity 54.0% and the negative predictive value was high (81.8%), but the positive predictive value was low (31.5%). In further validation, incident stroke risk was associated with continuous scores on the multivariable prediction model (HR 1.02; 95% CI 1.01 to 1.04, P=0.02) and dichotomised scores from the multivariable prediction model (HR 1.28; 95% CI 1.02 to 1.60, P=0.03).

CONCLUSIONS

A simple clinical risk equation for WML constituted by six variables can inform decisions whether to proceed with or forgo brain MRI. The high-negative predictive value demonstrates potential to reduce unnecessary MRI in the population aged 60-80 years.

Association between hemostatic markers, serum lipid fractions and progression of cerebral small vessel disease: A 2-year follow-up study

INTRODUCTION

Little is known if hemostatic markers and serum lipid fractions can predict further radiological progression beyond vascular risk factors in cerebral small vessel disease (SVD). We investigated whether they are associated with SVD radiological progression and if they are related to different SVD clinical manifestations.

METHODS

A single-center, prospective, cohort study with 2 years of radiological follow-up was performed in consecutive patients with different SVD manifestations. The study group consisted of 123 patients: 49 with lacunar stroke (LS), 48 with vascular dementia (VaD) and 26 with vascular parkinsonism (VaP). We assessed SVD progression by a visual SVD scale. We determined the relationship between serum or plasma concentrations of tissue factor (TF), thrombomodulin, beta-thromboglobulin (BTG), fibrinogen, D-dimer and total cholesterol, HDL-C, LDL-C, triglycerides and SVD progression by logistic regression analysis.

RESULTS

34.9% patients had SVD radiological progression: 43% had isolated WMLs progression, 23.2% had new lacunes, 34.8% had both WMLs progression and new lacunes. Fibrinogen [OR 1.02 (95% CI 1.006-1.011] was significantly associated with risk of new lacunes or WMLs progression regardless of the clinical SVD manifestation. While low HDL [OR 0.96 (0.93-1)] and TF [OR 1.07 (0.99-1.1)] were marginally associated with new lacunes, BTG [OR 1.005 (0.99-1.01)] was associated with WMLs progression.

CONCLUSION

We found a relationship between fibrinogen and risk of radiological progression of SVD regardless of the clinical SVD manifestation. In addition, lower HDL and increased TF predicted development of new lacunes, and higher BTG was associated with risk of WMLs progression.

Hypercholesterolaemia and vascular dementia

Vascular dementia (VaD) is the second commonest cause of dementia. Stroke is the leading cause of disability in adults in developed countries, the second major cause of dementia and the third commonest cause of death. Traditional vascular risk factors-diabetes, hypercholesterolaemia, hypertension and smoking-are implicated as risk factors for VaD. The associations between cholesterol and small vessel disease (SVD), stroke, cognitive impairment and subsequent dementia are complex and as yet not fully understood. Similarly, the effects of lipids and lipid-lowering therapy on preventing or treating dementia remain unclear; the few trials that have assessed lipid-lowering therapy for preventing (two trials) or treating (four trials) dementia found no evidence to support the use of lipid-lowering therapy for these indications. It is appropriate to treat those patients with vascular risk factors that meet criteria for lipid-lowering therapy for the primary and secondary prevention of cardiovascular and cerebrovascular events, and in line with current guidelines. Managing the individual patient in a holistic manner according to his or her own vascular risk profile is recommended. Although the paucity of randomized controlled evidence makes for challenging clinical decision making, it provides multiple opportunities for on-going and future research, as discussed here.

Differential associations of plasma lipids with incident dementia and dementia subtypes in the 3C Study: A longitudinal, population-based prospective cohort study

BACKGROUND

Vascular risk factors have been proposed as important targets for the prevention of dementia. As lipid fractions represent easily modifiable targets, we examined the longitudinal relationship of baseline lipid fractions with 13-y incident dementia and its subtypes (Alzheimer disease [AD] and mixed or vascular dementia) in older community-dwelling persons.

METHODS AND FINDINGS

Non-institutionalized persons aged 65+ y (n = 9,294) were recruited for the Three-City Study (3C Study), a population-based cohort study from the electoral rolls of the cities of Dijon, Bordeaux, and Montpellier, France, between March 1999 and March 2001. Follow-up examinations were performed every 2 y after the baseline assessment. The final study sample comprised 7,470 participants from the 3C Study (mean age ± standard deviation [SD] 73.8 ± 5.3 y, 61.0% women) who were prospectively followed up for up to 13 y. Fasting lipid fractions (triglycerides [TGs], high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], total cholesterol [TC]) were studied as continuous variables, and results are reported per SD increase of each lipid fraction. Incident dementia and its subtypes were studied as censored variables using Cox models with age as time scale. Analyses were adjusted for sex, study center, and educational level, as well as vascular risk factors and apolipoprotein E (APOE) ε4 genotype. We corrected for multiple testing, yielding a significance threshold of 0.0169. p-Values above the significance threshold but less than 0.05 were considered nominally significant. During a mean (± SD) follow-up period of 7.9 ± 3.6 y, 779 participants developed incident dementia (n = 532 AD and n = 154 mixed or vascular dementia). Higher LDL-C and TC concentrations at baseline were associated with an increased risk of AD (hazard ratio [HR] per SD increase = 1.13 [95% CI 1.04-1.22], p = 0.0045, and HR = 1.12 [1.03-1.22], p = 0.0072, respectively). These associations were largely unchanged after adjustment for vascular risk factors and were attenuated after adjustment for APOEε4 (HR per SD increase = 1.12 [1.03-1.23], p = 0.0110, and HR = 1.12 [1.02-1.23], p = 0.0171, respectively). Higher TG concentrations at baseline were associated with an increased risk of all dementia (HR per SD increase = 1.11 [1.03-1.19], p = 0.0044) and mixed or vascular dementia (HR = 1.21 [1.04-1.41], p = 0.0163). However, these associations disappeared after adjusting for vascular risk factors (HR = 1.07 [0.98-1.17], p = 0.1374, and HR = 1.17 [0.96-1.42], p = 0.1206, respectively). Main limitations of the study include interval censoring of incident dementia cases, potential selective survival bias, and the fact that variation in lipid concentrations during follow-up could not be accounted for in the analyses.

CONCLUSIONS

In a large population-based sample of older community-dwelling persons with up to 13 y of follow-up, we observed that higher LDL-C and TC concentrations were associated with an increased risk of AD. This result was independent of vascular risk factors and was attenuated after adjustment for APOEε4 carrier status. TG and HDL-C concentrations were not associated with risk of incident dementia or its subtypes after accounting for vascular risk factors.

Diabetes mellitus and white matter hyperintensity

White matter hyperintensity (WMH) is a brain lesion detected as a high-intensity area in magnetic resonance imaging T2 and fluid-attenuated inversion recovery images, and it has been suggested that WMH reflects damage to small vessels in periventricular and subcortical areas. Although WMH has been linked to the incidence of stroke, more recently it has been clarified that WMH is also associated with progression of cognitive decline and functional disability, which are components of so-called geriatric syndrome. In addition to hypertension, which is the classical risk factor for WMH, evidence has been accumulating to suggest that diabetes mellitus could also be associated with WMH progression, and some studies have shown that WMH severity is correlated with cognitive decline in patients with diabetes. The factors that accelerate WMH formation in elderly patients with diabetes remain poorly defined. It is considered that insulin resistance is an exacerbating factor, but the effects of hypertension, dyslipidemia or other vascular risk factors have yet be clarified, and further studies are required.

Differential Effect of White-Matter Lesions and Covert Brain Infarcts on the Risk of Ischemic Stroke and Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

We examined the association of white-matter hyperintensity (WMH) volume and covert brain infarcts, which are the 2 major magnetic resonance imaging markers of covert cerebrovascular disease in older adults, with long-term risk of ischemic stroke and intracerebral hemorrhage (ICH) in the general population.

METHODS

Participants were 1731 individuals aged ≥65 years from the Three-City Dijon study. We studied the association of WMH volume and brain infarct, with incident ischemic stroke overall, and by subtype, and with incident ICH.

RESULTS

High total, periventricular, and deep WMHs were associated with incident ICH. Extensive periventricular WMH volume was associated with increased risk of ischemic stroke (hazard ratio, 1.94; 95% confidence interval, 1.12-3.35), particularly cardioembolic stroke. Covert brain infarcts were associated with incident ICH but not with incident ischemic stroke or its subtypes.

CONCLUSIONS

Although of ischemic nature, both WMH volume and covert brain infarcts portend a major risk of ICH. If confirmed in independent studies, these findings could have important implications for the clinical management of covert vascular brain lesions.

Fibroblast Growth Factor 23 Is Associated With Subclinical Cerebrovascular Damage: The Northern Manhattan Study

BACKGROUND AND PURPOSE

Elevated fibroblast growth factor 23 (FGF23) regulates phosphate homeostasis and is linked with mortality, cardiovascular events, and stroke. However, the role of FGF23 as a risk factor for subclinical cerebrovascular damage is unclear.

METHODS

We used multivariable linear and logistic regression to evaluate associations between FGF23, continuously and by quartiles, with white matter hyperintensity volume, expressed as percent intracranial volume (%ICV), and subclinical brain infarction (SBI) in a community-based stroke-free sample.

RESULTS

There were 1170 stroke-free Northern Manhattan Study (NOMAS) participants with FGF23 levels and quantitative magnetic resonance imaging data on white matter hyperintensity volume and SBI. Participants with FGF23 levels in the top quartile (range=85-1425 RU/mL) had greater white matter hyperintensity volume (β=0.19 %ICV; 95% CI, 0.04-0.33 %ICV; P=0.01) compared with those in the lowest quartile (range=15-49 RU/mL), adjusted for demographics, vascular risk factors, and estimated glomerular filtration rate. These findings remained significant in those without evidence of chronic kidney disease (estimated glomerular filtration rate <60 mL/min per 1.73 m(2)). Elevated FGF23 was not associated with SBI overall after adjusting for demographic factors and estimated glomerular filtration rate, but sex modified the effect of FGF23 on odds of SBI (P for interaction=0.03). FGF23 was associated with significantly greater odds of SBI only in men (odds ratio, 1.7; 95% CI, 1.1-2.7; P=0.03) after full adjustment.

CONCLUSIONS

These cross-sectional community-based data from a diverse urban sample show an association between elevated FGF23 and small vessel disease and magnetic resonance imaging-defined brain infarction in men, independent of chronic kidney disease. Data on elevated FGF23 and subclinical cerebrovascular damage progression are needed.

Blood and CSF biomarkers in brain subcortical ischemic vascular disease: Involved pathways and clinical applicability

Vascular dementia is the second most common type of dementia after Alzheimer’s disease (AD). Subcortical ischemic vascular disease refers to a form of vascular cognitive impairment characterized by the presence of diffuse white matter hyperintensities (WMHs) and multiple lacunar infarcts. These neuroimaging findings are mainly caused by cerebral small-vessel disease (cSVD) and relate to aging and cognitive impairment, but they can also be silent and highly prevalent in otherwise healthy individuals. We aimed to review studies on blood and cerebrospinal fluid (CSF) markers related to the presence of WMHs and lacunar infarcts that have been conducted in the past in large population-based studies and in high-risk selected patients (such as those with vascular risk factors, vascular cognitive impairment, or AD). Relevant associations with the presence and progression of cSVD have been described in the blood for markers related to inflammatory processes, endothelial damage and coagulation/fibrinolysis processes, etc. Also, different combinations of CSF markers might help to differentiate between etiologic types of dementia. In the future, to translate these findings into clinical practice and use biomarkers to early diagnosis and monitoring vascular cognitive impairment would require the replication of candidate markers in large-scale, multicenter, and prospectively designed studies.

Cardiovascular risk factors and small vessel disease of the brain: Blood pressure, white matter lesions, and functional decline in older persons

Several potential vascular risk factors exist for the development and accumulation of subcortical white matter disease in older people. We have reported that in older people followed for up to 4 years white matter hyperintensity (WMH) lesions on magnetic resonance imaging nearly doubled in volume and were associated with alterations in mobility and cognitive function. Herein we review the genetic, metabolic, and vascular risk factors that have been evaluated in association with the development and pathogenesis of WMH in older persons. Our research efforts have focused on systemic hypertension, particularly in the out-of-office setting as 24-hour ambulatory blood pressure (BP) has proven to be a stronger indicator of the progression of WMH in older people and the associated functional decline than doctor’s office BP. Based on relations between 24-hour systolic BP levels, the accrual of WMH, and functional decline, we have designed the INFINITY trial, the first interventional study to use ambulatory BP to guide antihypertensive therapy to address this problem in the geriatric population.