Association between cholesterols, homocysteine and silent brain infarcts

Association between Homocysteine and Cerebral Small Vessel Disease: A Meta-Analysis

BACKGROUND

This study aimed to evaluate whether elevated homocysteine levels is associated with risk of different subtypes of cerebral small vessel disease (CSVD) by using meta-analysis.

MATERIALS AND METHODS

Electronic databases were systematically searched up to April 2018 for collecting the studies reporting homocysteine levels in CSVD or CSVD subtypes. After an inclusion and exclusion criteria, the data was extracted. All data was analyzed using Stata software v.12.0 (Stata Corp LP, College Station, TX). The standardized mean difference (SMD) and 95% confidence interval (CI) were used to compare continuous variables.

RESULTS

Eighteen studies met eligibility criteria with 5088 participants (1987 patients with CSVD and 3101 controls) included in the meta-analysis. Meta-analysis revealed that, compared with the controls group, the CSVD group had significantly higher homocysteine levels, with the SMD of .50 and 95% CI (.36-.64). Subgroup analyses suggested white matter lesion had significantly higher levels of homocysteine compared with controls (SMD = .56, 95% CI .39-.73), followed by silent brain infarction (SMD = .33, 95% CI .24-.42) and lacunar infarction (SMD = .17, 95% CI -.06 to .40).

CONCLUSIONS

This meta-analysis found that CSVD or CSVD subtypes have a significantly higher homocysteine levels than in controls. Further prospective population-based studies are needed to longitudinally evaluate the association between homocysteine levels and progression of different CSVD subtypes.

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.

Decreased Serum Bilirubin Is Associated With Silent Cerebral Infarction

Objective—

The presence of silent cerebral infarction (SCI) increases the risk of transient ischemia attack, symptomatic stroke, cardiovascular disease, and dementia. Total bilirubin (TB) levels were demonstrated to be decreased in carotid intima–media thickness, cardiovascular disease, stroke, and peripheral arterial disease. However, little information is available concerning the correlation between TB and SCI.

Approach and Results—

A cross-sectional study was conducted to evaluate the association between TB and SCI in 2865 subjects (1831 men and 1034 women) undergoing medical checkup. The participants with SCI had lower TB levels than those without SCI. The subjects with a low TB had a higher prevalence of SCI. Moreover, partial correlation showed that TB levels were tightly correlated with brachial-ankle pulse wave velocity after adjusting for confounding covariates ( r =−0.149; P <0.001). Multivariate logistic regression analysis revealed that higher TB was associated with a lower risk of SCI (odds ratio, 0.925; 95% confidence interval, 0.897–0.954; P <0.001).

Conclusions—

TB is a novel biochemical indicator for SCI regardless of classical cardiovascular risk factors. Early measurement of TB may be useful to assess the risk of SCI.

Hyperhomocysteinemia associates with small vessel disease more closely than large vessel disease

BACKGROUND

Hyperhomocysteinemia was believed to be an independent risk factor for stroke and associate with small vessel disease (SVD) related stroke and large vessel disease (LVD) related stroke differently. However it's still unclear which type of stroke associated with homocysteine (HCY) more strongly because the conclusions of previous studies were contradictory. In this study we focused on the subclinical angiopathies of stroke, i.e., SVD and LVD instead of stroke subtypes and sought to compare the associations between HCY level and different angiopathies.

METHODS

324 non-stroke patients were enrolled. Sex, age, HCY level and other vascular risk factors were collected. MRI and angiographies were used to determine the type of angiopathies and their severity, i.e., the scores of leukoaraiosis (LA), plaques and numbers of silent brain infarctions (SBI). LVD was defined as the presence of atherosclerotic plaques of cerebral arteries. SVD was defined as the presence of either LA or SBI. 230 patients were deemed to have LVD; 180 patients were deemed to have SVD. Spearman's correlation test and logistic regression were used to analyze the association between HCY level and different angiopathies.

RESULTS

The correlation between HCY level and scores of plaques was weaker than that of the scores of LA and numbers of SBI. Hyperhomocysteinemia was an independent risk factor for SVD (OR = 1.315, P <0.001), whereas the association between HCY level and LVD was not that significant (OR = 1.058, P = 0.075).

CONCLUSION

HCY level associated with SVD more strongly than LVD.

Silent Brain Infarction – A Review of Recent Observations

Silent brain infarction is a cerebral ischaemic event evident on brain imaging without any clinical symptom. Silent brain infarction is often detected in apparently healthy, elderly people and in different selected patient groups as well. Lately, several studies were carried out in order to identify the clinical conditions leading to silent brain infarction. A large number of clinical and paraclinical parameters were found to increase silent brain infarction prevalence, and the continuously growing list of risk factors revealed that the majority of them are similar to those related to stroke. Accordingly, some consider silent brain infarction the preclinical stage of clinically overt stroke. This point of view emphasizes the early recognition and management of silent brain infarction-related risk factors, and a great need for comparative studies, which could elicit the most sensitive indicators of the increased silent brain infarction risk, especially the ones that could be cost-effectively screened in the large populations as well.

High levels of serum uric acid are associated with silent brain infarction

BACKGROUND

Uric acid has been known to exert neuroprotective effects by acting as a free radical scavenger; however, several observational studies indicated that high levels of serum uric acid increased the risk of cardiovascular events or stroke. We sought to determine whether increased levels of uric acid are associated with the presence of silent brain infarction (SBI).

METHODS

We recruited a consecutive series of non-stroke individuals who visited the Healthcare System in our hospital and underwent brain MRI (n=1577). We conducted intensive interviews and laboratory examinations, including serum uric acid. We examined associations between SBI and vascular risk factors including uric acid by controlling possible confounders.

RESULTS

Of the 1577 subjects recruited, 921 were men and 656 were women, and the uric acid level was much higher in the men (6.3±1.3) than in the women (4.7±1.0). There was a strong dose-response relationship between the quartiles of uric acid and the presence of SBI in women (p=0.001), but not in men. Multivariable analysis showed that the highest quartile of uric acid level was an independent risk factor for the presence of SBI in total patients (adjusted OR, 1.79; 95% CI, 1.11-2.91). However, this association remained significant in women (adjusted OR, 2.64; 95% CI, 1.17-5.91), but not in men.

CONCLUSIONS

Our results suggest that an increased level of uric acid may be a risk factor for the presence of SBI. Serum uric acid level might be a good serum marker of underlying SBI or future stroke, especially in women.