Kaori Miwa

Chronic kidney disease is associated with dementia independent of cerebral small-vessel disease

Objective: To determine whether chronic kidney disease (CKD) is associated with incident dementia independent of cerebral small-vessel disease (SVD) in patients with vascular risk factors. Methods: Using data from a Japanese cohort of participants with vascular risk factors in an ongoing observational study from 2001, we evaluated the association between CKD at baseline and incident dementia. Baseline brain MRI was used to determine SVD (lacunar infarction, white matter hyperintensities), medial-temporal atrophy, and subcortical atrophy. Cox proportional hazards analyses were performed for predictors of dementia adjusting for age, sex, APOE ε4 allele, educational level, baseline Mini-Mental State Examination score, cerebrovascular events, vascular risk factors, and MRI findings. Results: Of the 600 subjects (mean age 68 ± 8.3 years, 57% male, 12.8 ± 2.6 years of education; CKD: 29%), 50 patients with incident dementia (Alzheimer disease: 24; vascular dementia: 18; mixed-type dementia: 5; other types: 3) were diagnosed during the median 7.5-year follow-up. CKD at baseline was associated with an increased risk of all-cause dementia in models adjusted for age, sex, educational level, and APOE ε4 allele. The associations of CKD at baseline remained significant even after additional adjusting for MRI findings and confounding variables (hazard ratio: 1.96 [1.08–3.58], p = 0.026). Conclusions: CKD is independently related to the risk of all-cause dementia in patients with vascular risk factors. Our results reinforce the hypothesis that CKD exerts deleterious effects on dementia incidence.

Relations of Blood Inflammatory Marker Levels With Cerebral Microbleeds

Background and Purpose— Cerebral microbleeds (CMB) are observed in the elderly and have been regarded as one of the manifestations of small vessel disease. Although inflammatory processes have attracted much attention not only in large-artery disease, but also in small vessel disease, their involvement in CMB remains to be determined. The purpose of this study is to clarify relations between inflammatory marker levels and CMB. Methods— Four hundred thirty-one patients without histories of cerebrovascular diseases were prospectively enrolled. The presence and number of CMB were assessed on gradient-echo magnetic resonance imaging. As common inflammatory markers, serum levels of high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and interleukin-18 (IL-18) were evaluated. Results— CMB were found in 65 patients (15%). In 35 patients, at least one CMB was found in deep locations, but 30 patients had strictly lobar CMB. Levels of hsCRP, IL-6, and IL-18 were higher in patients with CMB than in those without. Logistic regression analyses showed that each 1SD increase in each inflammatory marker level was significantly associated with the presence of CMB after adjustment for age and sex, and after additional adjustment for cardiovascular risk factors, silent lacunar infarction, and white matter hyperintensity. The OR (95% CI) of hsCRP, IL-6, and IL-18 was 1.81 (1.35–2.46), 1.73 (1.18–2.61), and 2.41 (1.44–4.52), respectively. Furthermore, the inflammatory marker levels were associated with both deep and lobar CMB. Conclusions— Higher levels of hsCRP, IL-6, and IL-18 are associated with CMB, in both deep and lobar locations, suggesting the involvement of inflammation in CMB.

Multiple or mixed cerebral microbleeds and dementia in patients with vascular risk factors

Objective: To investigate whether cerebral microbleeds (CMBs) are independently associated with incident dementia in patients with vascular risk factors. Methods: Using data from a Japanese cohort of participants with vascular risk factors in an observational study from 2001, we evaluated the association between CMBs at baseline and incident dementia. Baseline brain MRI was used to determine small-vessel disease (CMBs, lacunar infarcts, and white matter hyperintensities) and brain atrophy. Cox proportional hazards analyses were performed for predictors of dementia adjusting for age, sex, APOE ε4 allele, educational level, baseline Mini-Mental State Examination score, cerebrovascular events, vascular risk factors, and MRI findings. Results: Of the 524 subjects (mean age 68 ± 8.3 years, 57.6% male, 12.8 ± 2.6 years of schooling, 21.6% CMBs), 44 patients with incident dementia (20 Alzheimer disease, 18 vascular dementia, 3 mixed-type, and 3 other) were diagnosed during the median 7.5-year follow-up. In multivariate analysis, the presence of overall CMBs was not associated with an increased risk of incident all-cause dementia (p = 0.15). However, multiple CMBs (≥2) or mixed (lobar and deep) CMBs were associated with the increased risk of all-cause dementia, whereas strictly lobar CMBs showed no association with any dementia. Conclusions: Multiple CMBs or mixed CMBs independently showed higher risk of all-cause dementia. Our results reinforce the hypothesis that CMBs exert deleterious effects on dementia incidence, suggesting that this association may be mediated by vascular burden.

Association of Interleukin-6 With the Progression of Carotid Atherosclerosis A 9-Year Follow-Up Study

Background and Purpose— Limited information is available on the long-term effects of interleukin-6 (IL-6) on systemic atherosclerosis. The purpose of the present study was to clarify the relationship between chronic elevation of IL-6 and the long-term progression of carotid atherosclerosis. Methods— We prospectively evaluated 210 patients with ≥1 vascular risk factors for 9.0±1.0 years. Carotid mean-maximal intima-media thickness (mmIMT), the serum high-sensitivity C-reactive protein (hs-CRP) level, and the serum IL-6 level were measured at baseline and every 3 years. The associations between the progression of mmIMT and the long-term average levels of hs-CRP and IL-6 were analyzed. Results— Carotid mmIMT increased throughout the study period (0.031±0.026 mm/y). Baseline mmIMT was significantly associated with baseline hs-CRP (P=0.002) and baseline IL-6 (P<0.001) levels. Progression of mmIMT was positively correlated with average hs-CRP (P=0.001) and average IL-6 (P<0.001) levels. When adjusted for age, sex, traditional risk factors, and baseline mmIMT, mmIMT progression remained significantly associated only with the average IL-6 level (standardized &bgr;=0.17; P=0.02), but not with the average hs-CRP level (standardized &bgr;=0.10; P=0.18). Conclusions— Chronic elevation of serum IL-6 was associated with the progression of atherosclerosis in patients with vascular risk factors. IL-6 could be used as a quantitative marker and a potential therapeutic target for accelerated atherosclerosis.

Basilar Artery Diameter Is an Independent Predictor of Incident Cardiovascular Events

Objective—Basilar arterial (BA) dolichoectasia is associated with cerebral small-vessel disease and stroke. However, the association between moderate dilation of the BA and cerebral small-vessel disease or subsequent cardiovascular events remains unclear. This study aims to clarify the factors related to BA diameter and to clarify whether the BA diameter is an independent predictor of cardiovascular events. Approach and Results—The study subjects comprised 493 outpatients with atherosclerotic risk factors. BA diameter, lacunar infarct, severity of deep white matter hyperintensities, and intracranial steno-occlusive lesions were assessed with MRI and magnetic resonance angiography. Then, we prospectively evaluated the association between BA diameter and cardiovascular events. The BA diameter ranged from 1.1 to 5.2 mm, and only 0.8% of the patients had dolichoectasia. Male sex, the presence of lacunar infarcts, the severity of deep white matter hyperintensities, the fetal-type variation of the circle of Willis, and intracranial steno-occlusive lesions were independently associated with BA diameter. In the mean follow-up of 6.0 years, 91 patients developed cardiovascular events. BA diameter was independently associated with total cardiovascular events after adjusting for age, sex, and conventional risk factors (hazard ratio, 1.55 per 1 mm increase in BA diameter; P=0.009). Conclusions—Increased BA diameter within the normal range is related to both large-vessel disease and cerebral small-vessel disease, and it could be a new predictor of cardiovascular events.

Serum inflammatory proteins and frontal lobe dysfunction in patients with cardiovascular risk factors

Background:  Recent studies have shown that the levels of circulating inflammatory markers are associated with cognitive decline and cerebral small‐vessel disease. Frontal lobe dysfunction is believed to be a relatively characteristic neuropsychological symptom in vascular cognitive impairment caused by cerebral small‐vessel disease. The purpose of this study was to investigate whether the levels of serum inflammatory markers are associated with frontal lobe dysfunction, particularly executive dysfunction.

Association of inflammatory markers and carotid intima-media thickness with the risk of cardiovascular events in high-risk patients.

Objective: Both inflammatory markers and carotid intima-media thickness (IMT) are associated with future cardiovascular disease (CVD). We investigated whether inflammatory markers can be predictors for incident CVD independent of carotid IMT in atherosclerotic high-risk patients and evaluated the joint effect of inflammatory markers and IMT in CVD prediction. Methods: We performed a prospective cohort study of 770 patients who had one or more atherosclerotic risk factors. Serum high-sensitive C-reactive protein (hsCRP), interleukin (IL)-6, IL-18, and carotid IMT were assessed at baseline and the incidence of CVD was determined. Results: During 4.3 years of mean follow-up, CVD occurred in 104 patients (14%). In univariate analyses, higher levels of hsCRP, IL-6, and IL-18 were significantly related to an increased risk of CVD. However, only IL-6, but not hsCRP or IL-18, was associated with incident CVD after adjustment for conventional risk factors and carotid IMT (hazard ratio of upper half to lower half, 1.87; 95% confidence interval, 1.20–2.93). Measuring IL-6 level in combination with carotid IMT improves the prediction of incident CVD. Conclusions: Elevated IL-6 is associated with the risk of CVD independently of carotid IMT in atherosclerotic high-risk patients.

Association Between Interleukin–6 Levels and First-Ever Cerebrovascular Events in Patients With Vascular Risk Factors

Objective—The objective of this study was to examine the association of inflammatory markers with risk of first-ever cerebrovascular events (CVEs), while simultaneously evaluating subclinical vascular disease. Methods and Results—We enrolled 464 outpatients who had vascular risk factors without any preexisting cardiovascular disease. We examined the presence of silent lacunar infarction (SLI) by magnetic resonance imaging; carotid intima-media thickness by ultrasound; and measured high-sensitivity C-reactive protein, interleukin (IL)-6, and IL-18 at baseline, and assessed their associations with CVEs using Cox proportional hazards models of 4.8±2.6 years follow-up. We further calculated measures of reclassification and discrimination. In age- and sex-adjusted analysis, IL-6, but neither high-sensitivity C-reactive protein nor IL-18, was associated with CVEs. The association remained significant after adjustment for conventional risk factors, intima-media thickness, and SLI (hazard ratios: 1.80, per 1-SD increase in log IL-6, P=0.03). Compared with the patients with below median IL-6 without SLI, those with above median IL-6 and SLI had a higher risk of CVEs (hazard ratios: 4.14, P=0.0014). The combination of IL-6 and SLI resulted in the net reclassification improvement of 14.3% (P=0.04), and the integrated discrimination improvement gain of 2.1% (P=0.05). Conclusion—IL-6 levels were independently associated with CVEs and could improve reclassification in those with SLI.

Increased Total Homocysteine Levels Predict the Risk of Incident Dementia Independent of Cerebral Small-Vessel Diseases and Vascular Risk Factors

BACKGROUND Homocysteine has been identified as a potential risk factor for stroke, cerebral small-vessel diseases (SVD), and dementia. OBJECTIVE The present study aimed to investigate the predictive value of homocysteine levels on incident dementia while simultaneously controlling for MRI findings and vascular risk factors. METHODS Within a Japanese cohort of participants with vascular risk factors in an observational study, we evaluated the association between baseline total homocysteine (tHcy) levels (per 1 μmol/L and the tertile of tHcy), the prevalence of MRI-findings at baseline, and incident all-cause dementia. Baseline brain MRI was used to determine SVD (lacunas, white matter hyperintensities, and cerebral microbleeds [CMBs]) and atrophy (medial-temporal lobe atrophy and bicaudate ratio). Logistic regression analyses were used to estimate the cross-sectional association between tHcy and each of MRI findings. Cox proportional hazards analyses were performed to estimate the longitudinal association between tHcy and dementia. RESULTS In the 643 subjects (age: 67.2 ± 8.4 years, male: 59% ; education: 12.9 ± 2.6 years), multivariable analyses adjusted for several potential confounders, including estimated glomerular filtration rate (eGFR) and intima-media thickness, showed that highest tHcy tertile was associated with lacunas, CMBs, and strictly deep CMBs. During the mean 7.3-year follow-up (range: 2-13), 47 patients were diagnosed with dementia (Alzheimers disease: 24; vascular dementia: 18; mixed-type: 3; other: 2). After adjusting for age, gender, APOE ɛ4, education, BMI, MMSE, hypertension, cerebrovascular events, eGFR, and MRI-findings, tHcy level (hazard ratios [HR]: 1.08, p = 0.043) and the highest tertile of tHcy (HR: 2.50, p = 0.047) for all-cause dementia remained significant. CONCLUSIONS Our results provide additional evidence of tHcy that contributes to increased susceptibility to dementia risk.

Interleukin-6, interleukin-6 receptor gene variant, small-vessel disease and incident dementia.

Mixed neurogenerative and vascular dementia has emerged as the leading cause of dementia in the elderly. Inflammation is implicated in atherosclerosis, cerebral small‐vessel disease (SVD) as well as cognitive impairment. However, longitudinal data on the predictive value of circulating inflammatory markers including gene variants and magnetic resonance imaging (MRI) findings in incident dementia are scarce. It was investigated whether circulating interleukin‐6 (IL‐6), C‐reactive protein (CRP) and gene variants increase dementia risk.