Low cholesterol as a risk factor for primary intracerebral hemorrhage: A case-control study

Characterization of a mutant samhd1 zebrafish model implicates dysregulation of cholesterol biosynthesis in Aicardi-Goutières syndrome

Aicardi-Goutières syndrome (AGS1-9) is a genetically determined encephalopathy that falls under the type I interferonopathy disease class, characterized by excessive type I interferon (IFN-I) activity, coupled with upregulation of IFN-stimulated genes (ISGs), which can be explained by the vital role these proteins play in self-non-self-discrimination. To date, few mouse models fully replicate the vast clinical phenotypes observed in AGS patients. Therefore, we investigated the use of zebrafish as an alternative species for generating a clinically relevant model of AGS. Using CRISPR-cas9 technology, we generated a stable mutant zebrafish line recapitulating AGS5, which arises from recessive mutations in SAMHD1. The resulting homozygous mutant zebrafish larvae possess a number of neurological phenotypes, exemplified by variable, but increased expression of several ISGs in the head region, a significant increase in brain cell death, microcephaly and locomotion deficits. A link between IFN-I signaling and cholesterol biosynthesis has been highlighted by others, but not previously implicated in the type I interferonopathies. Through assessment of neurovascular integrity and qPCR analysis we identified a significant dysregulation of cholesterol biosynthesis in the zebrafish model. Furthermore, dysregulation of cholesterol biosynthesis gene expression was also observed through RNA sequencing analysis of AGS patient whole blood. From this novel finding, we hypothesize that cholesterol dysregulation may play a role in AGS disease pathophysiology. Further experimentation will lend critical insight into the molecular pathophysiology of AGS and the potential links involving aberrant type I IFN signaling and cholesterol dysregulation.

Use of Lipid-Lowering Drugs After Intracerebral Hemorrhage

Hyperlipidemia is common in patients with intracerebral hemorrhage (ICH). Accumulating evidence indicates that patients with ICH are at risk for future hemorrhage recurrence, cardiovascular disease, and ischemic stroke and highlights the importance of secondary prevention of vascular events after ICH. Although the benefits of intensive treatment of hyperlipidemia for reducing ischemic cardiac and vascular events in patients with ischemic stroke are well established, the benefit versus harm in patients with ICH are less clear. Epidemiological studies suggest that hyperlipidemia is protective against ICH and that intensive lowering of lipids is associated with increased risk for ICH. Similarly, although currently available lipid-lowering treatments have been thoroughly studied in patients with ischemic cardiac and vascular disease, only few randomized trials of these therapies included a very small number of patients with history of ICH. Thus, limiting any definitive conclusions regarding the safety and net benefit of these treatments in ICH populations. Currently, there is no consensus regarding the optimal strategy for management of hyperlipidemia after ICH. In this article, we review relevant literature to outline the competing risks and benefits of lipid-lowering treatments in this vulnerable patient population. We suggest a treatment paradigm based on available data but note that data from dedicated randomized trials are needed to build the necessary evidence to guide optimal lipid-lowering strategy in patients with a history of ICH.

Associations between low-density lipoprotein cholesterol and haemorrhagic stroke

OBJECTIVE

To investigate the associations between the blood concentrations of low-density lipoprotein cholesterol (LDL-C) and the clinical features of haemorrhagic stroke.

METHODS

This study analysed the data from patients with acute haemorrhagic stroke at a comprehensive stroke centre from 2013 to 2018. Patients were stratified into three groups according to their baseline LDL-C levels: < 70, 70 to < 100 and ≥ 100 mg/dL. We used multivariate logistic regression models to analyse the associations between LDL-C and the risks of having severe neurological deficits (National Institute Health Stroke Scale [NIHSS] scores ≥ 15) and unfavourable outcomes (modified Rankin Scale [mRS] scores>2) at discharge.

RESULTS

Six-hundred and six patients were analysed. Their median age was 58 years. Among the patients, 75 (12%) patients had LDL-C levels < 70 mg/dL, 194 (32%) patients had LDL-C levels between 70 to < 100 mg/dL and the other 337 (56%) patients had LDL-C levels ≥ 100 mg/dL. Patients with higher LDL-C levels were less likely to suffer severe neurological deficits (LDL-C: 70 to < 100 vs. < 70 mg/dL, adjusted odds ratio [OR]: 0.29, 95% CI: 0.15-0.57; LDL-C: ≥ 100 vs. < 70 mg/dL, adjusted OR = 0.27, 95% CI: 0.15-0.51) and to have unfavourable outcomes at discharge (LDL-C: 70 to < 100 vs. < 70 mg/dL, adjusted OR = 0.50, 95% CI: 0.29-0.87 and LDL-C: ≥ 100 vs. < 70 mg/dL, adjusted OR = 0.46, 95% CI: 0.28-0.78).

CONCLUSIONS

An LDL-C level < 70 mg/dL was independently associated with severe neurological deficits of haemorrhagic stroke and may increase the risks of unfavourable outcomes at discharge.

Association between Anemia and Stroke in Females: A Nationwide, Population-Based Cohort Study in Taiwan

Optimal stroke prevention strategies for women should take into account specific sex-related stroke risk factors. Anemia is a common medical condition in females, particularly in women of reproductive age. This study investigated whether anemia is an independent risk factor for stroke in females in a population-based cohort study. We investigated newly diagnosed anemic female patients with no history of central nervous system disease, psychiatric disorders, traumatic brain injury, major operations or hemorrhagic diseases identified from the Taiwan National Health Insurance Research Database. Non-anemic matched controls (1:1) were selected based on a propensity score estimated using a logistic regression model that included demographic characteristics and comorbidities. A competing risk analysis was applied to estimate the stroke risk in anemic patients compared to that of their matched controls. In our study, the adjusted sub-distribution hazard ratios (aSHRs) of overall, hemorrhagic and ischemic stroke in anemic female patients aged <50 years were 1.35 (95% confidence interval (CI): 1.19-1.52, p < 0.001), 1.31 (95% CI, 1.09-1.56, p < 0.003), and 1.35 (95% CI, 1.15-1.58, p < 0.001), respectively, compared to non-anemic female controls. However, a positive association between anemia and stroke was not found for those aged ≥50 years. Similar results were observed when the follow-up age was limited to 50 years to reduce the potential effects of menopause on stroke. In conclusion, the present population-based cohort study found that anemia is a potential risk factor for overall, hemorrhagic and ischemic stroke in females of reproductive age.

Association between Serum Lipid and Hematoma Expansion after Spontaneous Intracerebral Hemorrhage in Chinese Patients

OBJECTIVES

Although several studies have shown that interventions to lower blood lipid concentration may reduce the risk of coronary arterial disease and ischemic stroke, the correlation between serum lipid levels and hemorrhagic stroke remains controversial. To clarify any possible association between serum lipid and hematoma expansion, we examined various serum lipid indices in patients with and without early hematoma expansion.

METHODS

Data of 572 intracerebral hemorrhage (ICH) patients from the cerebral small vessel disease cohort of Peking Union Medical College Hospital were retrospectively analyzed. Patients who finished the baseline brain computed tomography (CT) examination within 6 h post-ictus and the follow-up CT within 48 h after initial CT were included in the study. Hematoma expansion was delimited as an enlargement of hemorrhage volume over 33% or 12.5 mL between baseline and subsequent CT. Both uni- and multivariate logistic regression analyses were conducted to explore the association between early hematoma growth and various serum lipid indices, including triglycerides, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), non-HDL-C, ratios of LDL-C/HDL-C and LDL-C/TC, as well as other demographic and clinical features.

RESULTS

Out of 157 patients included in the analysis, hematoma growth occurred in 45 (28.7%). Only higher baseline systolic blood pressure was found to be correlated with an increased risk of hematoma growth based on both univariate (odds ratio [OR] 1.014, 95% confidence interval [CI]: 1.002-1.026, P = .024) and multivariate logistic regression analyses (OR 1.022, 95%CI: 1.008-1.037, P = .003). No associations were detected between the various serum lipid indices examined and other clinical features with a likelihood of early hematoma growth between groups or within various subgroups defined by different characteristics including age, gender, baseline Glasgow Coma Scale score, systolic blood pressure, intraventricular extension, and hematoma location.

CONCLUSIONS

No association between various indices of serum lipid and hematoma growth was identified among patients and subgroups with spontaneous ICH in the Chinese population; these findings may help to guide lipid management after ICH. However, further multi-centered, larger scale studies are expected to verify our results.

The Benefits and Risks of Statin Therapy in Ischemic Stroke: A Review of the Literature

Statins are effective cholesterol-lowering drugs for reducing the risks of mortality and morbidity of cardiovascular diseases. Increasing evidence has shown that statin use is associated with a significant beneficial effect in patients with ischemic stroke. Both pre-stroke and post-stroke statin use has been found to be beneficial in ischemic stroke. Furthermore, good adherence is associated with a better clinical outcome, and statin withdrawal is associated with a poor functional outcome in patients with ischemic stroke. High-intensity statin therapy is advocated for the treatment of ischemic stroke. However, there are concerns regarding the adverse effects associated with statin use in ischemic stroke such as intracranial hemorrhage. In this review, we summarize the beneficial effect of statin use in ischemic stroke and discuss the potential risks associated with statin therapy.

APOB gene polymorphisms may affect the risk of minor or minimal bleeding complications in patients on warfarin maintaining therapeutic INR

The purpose of this study was to investigate influence of gene polymorphisms of APOB and APOE on risk of bleeding complications at therapeutic INR, during warfarin treatment in Korean patients with mechanical cardiac valves. The study included 142 patients from the EwhA-Severance Treatment Group (EAST) of Warfarin. A total of 12 SNPs was investigated. Five SNPs of APOB (c.13013G>A, c.1853C>T, c.1594C>T, c.293C>T, and c.7545C>T) and five SNPs of APOE (g.4798T>G, g.6406G>A, g.10413T>C, c.388T>C, and c.526C>T) were selected. In addition to selected SNPs, VKORC1 g.6399C>T, and CYP2C9 c.1075A>C, which were known to have significant effects on warfarin stable doses, were also included in the study. Two SNPs of APOB (c.293C>T and c.1853C>T) were associated with bleeding complications. T allele carriers of c.293C>T had 8.6 times (95% CI 2.9-25.5, p < 0.001) increased risk of bleeding, and attributable risk was 88.3%. C allele carriers of c.1853C>T had 6.4 times (95% CI 2.3-17.9, p < 0.001) increased risk of bleeding after adjusting for covariates (attributable risk of 84.3%). AUROC values of models that included c.1853C>T and c.293C>T were 0.771 and 0.802, respectively. Among demographic characteristics, age was the only significant factor. This study revealed that APOB was associated with bleeding complications in patients with warfarin treatment after mechanical cardiac valves.

Minimization of Intraparenchymal Hemorrhagic Stroke Size by Optimization of Serum Lipids

Introduction

Intraparenchymal hemorrhages (IPHs) are the most common type of hemorrhagic stroke. One of the main associated risk factors is total cholesterol (TC) above 200. A severely decreased level of TC potentially interferes with the stabilization of the cell membrane and can potentially lead to a larger hemorrhage. Previous population-based studies have confirmed an association between low TCs and a high incidence of hemorrhagic stroke. It has been established that a TC below 200 decreases the potential for cardiovascular disease. This study suggests that the balance that needs to be achieved between these two extremes presents a unique possibility for an optimal therapeutic range of total cholesterol levels.

Materials & methods

Inclusion criteria included all adult patients with International Classification of Diseases (ICD)-9/10 code for hemorrhagic stroke, from June 2007 to June 2017. A total of 300 patients met the criteria (N=300). For each patient, the following data were collected: NIH Stroke Scale, TC level, triglyceride level, low-density lipoprotein (LDL) and high-density lipoprotein (HDL), cholesterol reducing medications, size of hemorrhage on computed tomography (CT) of the head, location of hemorrhage, and patient disposition. Statistical analysis was done using the Generalized Linear Modeling with Wald Chi-square as the statistical determinant.

Results

Intracerebral hemorrhage size is dependent on the intracranial location with brain lobes having larger bleeds. Minimum hemorrhage size was noted in TC 188-196 and this effect was statistically significant independent of location. HDL has a significant independent effect on hemorrhage size with overall minimum bleed occurring in the range of 43-51 mg/dL HDL (98-106 mg/dL for men and 43-51 mg/dL for women). This sex effect within HDL on hemorrhage size is statistically significant. There was a differential effect of HDL dependent on patient race. Asian and black patients had least IPH volume with HDL 70-79 mg/dL, while Hispanic patients had a minimum at 43-51 mg/dL. White patients required a higher HDL, 80-88 mg/dL to minimize the IPH size. The triglyceride level had a statistically significant independent effect on the bleed size with the minimum hemorrhage size occurring in the range of 205-224 mg/dL. This effect was nuanced by patient race with statistically significant minimum IPH size occurring at 144-164 mg/dL for white patients, 124-143 mg/dL for Hispanic and black patients, and 84-103 mg/dL for Asian patients. Post-hospital patient disposition was not significantly affected by any of the above predictor variables.

Conclusion

This study found TC, HDL and triglycerides in specific ranges are associated with significantly decreased hemorrhage size across all genders and hemorrhage locations. The ranges with the strongest hemorrhage-limiting effect are as follows: TC 188-196 mg/dL, HDL 43-51 mg/dL (98-106 mg/dL for men and 43-51 mg/dL for women), triglycerides 205-224 mg/dL. Lipids both below and above these ranges yield larger bleeds. It also found larger brain areas will have more extensive hemorrhage than smaller brain areas. Future work in this arena should include collaboration with cardiology to determine ideal ranges for both cardio- and neuroprotection as well as a prospective study to validate the applicability of these findings in patient care.

Polymorphism and plasma levels of apolipoprotein E and the risk of aneurysmal subarachnoid hemorrhage in a Chinese population: a case-control study

Background

Aneurysmal subarachnoid hemorrhage (aSAH) is the most common types of subarachnoid hemorrhage, which is a critical clinical problem with high morbidity, mortality, and economic impact. Recent studies have shown that APOE was a genetic risk factor of aSAH, however, the studies lack consistent conclusions and the evidence from Chinese Han population is rare.

Objective

To determine the relationship between APOE polymorphism and the incidence of aSAH in Chinese Fujian Han population and explore the possible mechanism of ApoE in the pathogenesis of aSAH.

Methods

A total of 131 patients newly diagnosed with aSAH were selected as aSAH group and 137 healthy subjects were selected as the control group. All the samples were analyzed for blood lipids and serum ApoE levels, and ApoE genotype was determined by a commercial chip and further confirmed with Sanger sequencing. An adjusted multivariate logistic regression analysis was carried out to estimate the effects of APOE polymorphism on the risk of aSAH.

Results

Compared with the controls, the serum TC, HDL-C and ApoA1 levels in aSAH were significantly lower: TC (4.52 ± 1.38 vs. 5.11 ± 0.86 mmol/L, P < 0.001), HDL-C (1.23 ± 0.46 vs. 1.44 ± 0.32 mmol/L, P < 0.001) and ApoA1 (1.20 ± 0.32 vs. 1.38 ± 0.25 g/L, P < 0.001). The distribution of ε2/ε3 genotype (19.08% vs. 9.49%, P = 0.038) and ε2 allele frequency (11.07% vs. 5.84%, P = 0.039) was significantly higher in aSAH than the healthy controls. The multivariate logistic regression identified that ApoE ε2 allele was independently associated with aSAH (OR = 2.083; and 95% CI = 1.045-4.153, P = 0.037). The serum ApoE in aSAH were significantly higher than controls (53.03 ± 24.64 vs. 45.06 ± 12.84 mg/L, P = 0.010).

Conclusion

APOE polymorphism might be associated with the incidence of aSAH in Chinese Fujian Han population. ApoE ε2 may be a risk factor for the incidence of aSAH, which may be related with the impacts of ApoE genotypes for the serum lipids, especially for the plasma levels of ApoE.

Elevated oxidative stress among coronary artery disease patients on statin therapy: A cross sectional study

BACKGROUND

Statins are a major group of drugs that reduces LDL-C levels, which are proven to have other beneficial effects such as preventing coronary events. The objective of this study was to evaluate oxidative stress and select novel coronary artery disease risk factors among coronary artery disease patients on statins.

METHODS

In this observational, cross-sectional study, we compared total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, apolipoprotein B, lipoprotein (a), homocysteine, reduced glutathione, glutathione peroxidase, superoxide dismutase, ascorbic acid, malondialdehyde and oxidized LDL among male coronary artery disease patients on statin therapy (group 2, n = 151) with sex-matched, diabetic patients (group 3, n = 80) as well as healthy controls (group 1, n = 84).

RESULTS

Total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol were significantly lower among subjects of group 2 compared to other two groups. The novel risk factors studied did not differ significantly between groups, except for a higher homocysteine level among group 2 subjects compared to the other two groups. Elevated oxidative stress, indicated by lower reduced glutathione, glutathione peroxidase, and ascorbic acid as well as higher malondialdehyde and oxidized LDL was observed among group 2 subjects. Triglycerides, HDL-cholesterol, ascorbic acid and malondialdehyde were found to be independent predictors for coronary artery disease among this study population.

CONCLUSIONS

Though coronary artery disease subjects had healthy lipid profile, oxidative stress, a recognized risk factor for coronary events, was still elevated among this patient group. Novel risk factors were not found to be major predictors for coronary artery disease among the study subjects.

Association between statin use and intracerebral hemorrhage: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Accumulating evidence suggests that statins exert neuroprotective effects, but whether their use affects the outcomes of intracerebral hemorrhage (ICH) remains controversial. Therefore, we performed a systematic review and meta-analysis to investigate whether statin use before spontaneous ICH affects unfavorable functional outcome or mortality.

METHODS

We searched the Cochrane Library, MEDLINE, EMBASE and China National Knowledge Infrastructure databases for studies examining the effects of pre-ICH statin use on unfavorable functional outcome, mortality or neuroimaging outcomes in consecutively recruited patients with spontaneous ICH, regardless of the duration or dose of statin treatment.

RESULTS

A total of 12 studies were included that examined the effects of pre-ICH statin use on post-ICH outcomes in 1652 subjects in the favors pre-statin group and 5309 in the favors no pre-ICH statin group. Meta-analysis of 11 studies suggested that pre-ICH statin use did not significantly affect mortality across all three time points tested [in-hospital, 30 days, 90 days; odds ratio (OR) 0.85, 95% confidence interval (CI) 0.70-1.03]. However, meta-analysis of seven studies showed that pre-ICH statin use did significantly decrease 90-day mortality (OR 0.72, 95% CI 0.59-0.88). Meta-analysis of six studies showed that pre-ICH statin use was not associated with significant changes in unfavorable functional outcome. Moreover, pre-ICH statin use did not significantly affect admission hematoma volume (standardized mean difference 7.75, 95% CI -5.59 to 21.09).

CONCLUSION

Available evidence suggests that statin use before spontaneous ICH does not increase short-term mortality, unfavorable functional outcome or post-ICH hematoma volume at admission.