Association of Hyperhomocysteinemia with Stroke Recurrence after Initial Stroke

The Role of Methionine-Rich Diet in Unhealthy Cerebrovascular and Brain Aging: Mechanisms and Implications for Cognitive Impairment

As aging societies in the western world face a growing prevalence of vascular cognitive impairment and Alzheimer's disease (AD), understanding their underlying causes and associated risk factors becomes increasingly critical. A salient concern in the western dietary context is the high consumption of methionine-rich foods such as red meat. The present review delves into the impact of this methionine-heavy diet and the resultant hyperhomocysteinemia on accelerated cerebrovascular and brain aging, emphasizing their potential roles in cognitive impairment. Through a comprehensive exploration of existing evidence, a link between high methionine intake and hyperhomocysteinemia and oxidative stress, mitochondrial dysfunction, inflammation, and accelerated epigenetic aging is drawn. Moreover, the microvascular determinants of cognitive deterioration, including endothelial dysfunction, reduced cerebral blood flow, microvascular rarefaction, impaired neurovascular coupling, and blood-brain barrier (BBB) disruption, are explored. The mechanisms by which excessive methionine consumption and hyperhomocysteinemia might drive cerebromicrovascular and brain aging processes are elucidated. By presenting an intricate understanding of the relationships among methionine-rich diets, hyperhomocysteinemia, cerebrovascular and brain aging, and cognitive impairment, avenues for future research and potential therapeutic interventions are suggested.

Hyperhomocysteinemia Increases Vascular Risk in Stroke Patients with Chronic Kidney Disease

AIMS

We aimed to assess the prognostic impact of hyperhomocysteinemia (HHcy) on the recurrent vascular event risk in stroke patients with or without chronic kidney disease (CKD).

METHODS

In this prospective observational study, 621 patients (mean age, 69.5 years; male, 62.2%) with ischemic stroke or transient ischemic attack were consecutively enrolled within 1 week of onset and followed-up for 1 year. HHcy was defined as elevated levels of fasting total homocysteine ＞15 µmol/L. CKD was defined as an estimated glomerular filtration rate of ＜60 mL/min/1.73 m2 or a history of renal replacement therapy. The primary outcome was a composite of major adverse cardiovascular events (MACEs), including nonfatal stroke, nonfatal acute coronary syndrome, major peripheral artery disease, and vascular death.

RESULTS

The prevalence of HHcy was 18.5%. Patients with HHcy were more likely to have intracranial (37.4% versus 24.8%; p=0.008) and extracranial (20.9% versus 13.0%; p=0.037) artery stenosis than were those without HHcy. At 1 year, patients with HHcy were at a greater risk of MACE than were those without HHcy (annual rate, 17.8% versus 10.4%; log-rank p=0.033). In the Cox proportional hazard regression models, HHcy was independently associated with an increased risk of MACE in patients with CKD (adjusted hazard ratio [HR], 2.06; 95% confidence interval [CI], 1.02-4.20), whereas HHcy was not predictive of MACE in those without CKD (adjusted HR, 1.00; 95% CI, 0.30-3.32).

CONCLUSIONS

Elevated levels of serum homocysteine can be an important modifiable risk factor in stroke patients with CKD, but not in those without CKD.

China stroke surveillance report 2021

Since 2015, stroke has become the leading cause of death and disability in China, posing a significant threat to the health of its citizens as a major chronic non-communicable disease. According to the China Stroke High-risk Population Screening and Intervention Program, an estimated 17.8 million [95% confidence interval (CI) 17.6-18.0 million] adults in China had experienced a stroke in 2020, with 3.4 million (95% CI 3.3-3.5 million) experiencing their first-ever stroke and another 2.3 million (95% CI 2.2-2.4 million) dying as a result. Additionally, approximately 12.5% (95% CI 12.4-12.5%) of stroke survivors were left disabled, as defined by a modified Rankin Scale score greater than 1, equating to 2.2 million (95% CI 2.1-2.2 million) stroke-related disabilities in 2020. As the population ages and the prevalence of risk factors like diabetes, hypertension, and hyperlipidemia continues to rise and remains poorly controlled, the burden of stroke in China is also increasing. A large national epidemiological survey initiated by the China Hypertension League in 2017 showed that the prevalence of hypertension was 24.7%; the awareness, treatment, and control rates in hypertensive patients were: 60.1%, 42.5%, and 25.4%, respectively. A nationally representative sample of the Chinese mainland population showed that the weighted prevalence of total diabetes diagnosed by the American Diabetes Association criteria was 12.8%, suggesting there are 120 million adults with diabetes in China, and the awareness, treatment, and control rates in diabetic patients were: 43.3%, 49.0%, and 49.4%, respectively. The "Sixth National Health Service Statistical Survey Report in 2018" showed that the proportion of the obese population in China was 37.4%, an increase of 7.2 points from 2013. Data from 1599 hospitals in the Hospital Quality Monitoring System and Bigdata Observatory Platform for Stroke of China (BOSC) showed that a total of 3,418,432 stroke cases [mean age ± standard error (SE) was (65.700 ± 0.006) years, and 59.1% were male] were admitted during 2020. Of those, over 80% (81.9%) were ischemic stroke (IS), 14.9% were intracerebral hemorrhage (ICH) strokes, and 3.1% were subarachnoid hemorrhage (SAH) strokes. The mean ± SE of hospitalization expenditures was Chinese Yuan (CNY) (16,975.6 ± 16.3), ranging from (13,310.1 ± 12.8) in IS to (81,369.8 ± 260.7) in SAH, and out-of-pocket expenses were (5788.9 ± 8.6), ranging from (4449.0 ± 6.6) in IS to (30,778.2 ± 156.8) in SAH. It was estimated that the medical cost of hospitalization for stroke in 2020 was CNY 58.0 billion, of which the patient pays approximately CNY 19.8 billion. In-hospital death/discharge against medical advice rate was 9.2% (95% CI 9.2-9.2%), ranging from 6.4% (95% CI 6.4-6.5%) for IS to 21.8% for ICH (95% CI 21.8-21.9%). From 2019 to 2020, the information about 188,648 patients with acute IS receiving intravenous thrombolytic therapy (IVT), 49,845 patients receiving mechanical thrombectomy (MT), and 14,087 patients receiving bridging (IVT + MT) were collected through BOSC. The incidence of intracranial hemorrhage during treatment was 3.2% (95% CI 3.2-3.3%), 7.7% (95% CI 7.5-8.0%), and 12.9% (95% CI 12.3-13.4%), respectively. And in-hospital death/discharge against medical advice rate was 8.9% (95% CI 8.8-9.0%), 16.5% (95% CI 16.2-16.9%), and 16.8% (95% CI 16.2-17.4%), respectively. A prospective nationwide hospital-based study was conducted at 231 stroke base hospitals (Level III) from 31 provinces in China through BOSC from January 2019 to December 2020 and 136,282 stroke patients were included and finished 12-month follow-up. Of those, over 86.9% were IS, 10.8% were ICH strokes, and 2.3% were SAH strokes. The disability rate [% (95% CI)] in survivors of stroke at 3-month and 12-month was 14.8% (95% CI 14.6-15.0%) and 14.0% (95% CI 13.8-14.2%), respectively. The mortality rate [% (95% CI)] of stroke at 3-month and 12-month was 4.2% (95% CI 4.1-4.3%) and 8.5% (95% CI 8.4-8.6%), respectively. The recurrence rate [% (95% CI)] of stroke at 3-month and 12-month was 3.6% (95% CI 3.5-3.7%) and 5.6% (95% CI 5.4-5.7%), respectively. The Healthy China 2030 Stroke Action Plan was launched as part of this review, and the above data provide valuable guidelines for future stroke prevention and treatment efforts in China.

Elevated levels of total homocysteine after ischemic stroke: a potential marker for in-hospital outcomes

OBJECTIVES

Our goal was to determine the risk conferred by elevated total homocysteine (tHcy) levels on recurrent stroke and cardiovascular disease (CVD) events after an ischemic stroke (IS), using data from the Chinese Stroke Center Alliance (CSCA).

METHODS

The study consisted of 746,854 total participants with IS. Subjects were split into groups as well as quartiles according to tHcy level. Groups included a hyperhomocysteinemia (HHcy) group with tHcy ≥15 μmol/l and a normohomocysteinemia group (nHcy) with tHcy <15 μmol/l. The determined groups and quartiles underwent multiple logistic regression models with nHcy or quartile 1 as reference groups, respectively. The information from these analyses was adjusted for potential covariates and used to investigate the association between blood tHcy and in-hospital outcomes. Information collected at discharge included in-hospital stroke recurrence and CVD events.

RESULTS

The mean [SD] age of participants was 66.2 [12.0] and 37.4% (n = 279,571) were female. The median hospital duration was 11.0 days (interquartile range, 8.0-14.0 days) and 343,346 (46.0%) patients were identified as HHcy cases (tHcy ≥15 μmol/). According to the tHcy quartile, the cumulative rates of stroke recurrence (from lowest quartile to highest) were 5.2%, 5.6%, 6.1%, and 6.6% (P < 0.0001). Similarly, those of CVD events were 5.8%, 6.1%, 6.7%, and 7.2% (P < 0.0001). Compared with the nHcy group, the HHcy group was associated with increased risks of in-hospital stroke recurrence (21912 [6.4%] vs. 22048 [5.5%], with the adjusted odds ratio (OR) 1.08, 95% CI: 1.05 to 1.10) as well as CVD events (24001 [7.0%] vs. 24236 [6.0%], with the adjusted OR: 1.08, 95% CI: 1.06 to 1.10) among patients with IS in the fully adjusted model.

CONCLUSION

HHcy was associated with increased in-hospital stroke recurrence and CVD events among patients with IS. In low-folate regions, tHcy levels may potentially predict in-hospital outcomes after IS.

Low estimated glomerular filtration rate explains the association between hyperhomocysteinemia and in-hospital mortality among patients with ischemic stroke/transient ischemic attack or intracerebral hemorrhage: Results from the Chinese Stroke Center Alliance

OBJECTIVES

To investigate the association between hyperhomocysteinemia (HHcy) and in-hospital mortality following ischemic stroke (IS), transient ischemic attack (TIA), or intracerebral hemorrhage (ICH).

METHODS

Data on patients with ischemic cerebrovascular disease (IS/TIA) or ICH enrolled in the Chinese Stroke Center Alliance (CSCA) from 2015 to 2019 were extracted. Patient characteristics and in-hospital mortality were analyzed and multiple adjusted logistic regression analyses performed to investigate the association between blood tHcy (total homocysteine) and in-hospital mortality in patients with HHcy (tHcy ⩾ 15 µmol) and patients with normohomocysteinemia (nHcy) (tHcy < 15 µmol).

RESULTS

A total of 823,622 participants were included. Mean (SD) age was 65.9 (12.1), and 62.5% (n = 514,888) were male. A total of 379,807 (46.0%) patients were identified as having HHcy, and 70,364 (8.5%) patients had an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m². An eGFR < 60 mL/min/1.73 m² was the strongest independent risk factor for HHcy in both patients with IS/TIA (adjusted odds ratio (aOR) 2.67, 95% confidence interval (CI): 2.49-2.86), and those with ICH (2.94, 2.46-3.50). On multivariable logistic regression, after adjusting for potential confounding factors, HHcy was associated with in-hospital mortality (aOR: 1.25, 95% CI: 1.13-1.37 for patients with IS/TIA; aOR: 1.40, 95% CI: 1.12-1.76 for patients with ICH). However, after additionally adjusting for eGFR, this association disappeared among patients with both IS/TIA (aOR: 1.09, 95% CI: 0.99-1.20) and those with ICH (aOR: 1.17, 9% CI: 0.96-1.43).

CONCLUSION

HHcy was associated with in-hospital mortality among the patients with IS/TIA or ICH but this association disappeared after controlling for eGFR, suggesting HHcy was acting as a marker of poor renal function which itself was the predictor of poor outcome. Our results suggest the prevention and management of renal impairment may be an important measure in the reduction of mortality in patients with HHcy after IS/TIA or ICH.

Nomogram-Based Prediction of the Futile Recanalization Risk Among Acute Ischemic Stroke Patients Before and After Endovascular Therapy: A Retrospective Study

Background and Purpose

Futile recanalization (FRC) is common among large artery occlusion (LAO) patients after endovascular therapy (EVT). We developed nomogram models to identify LAO patients at a high risk of FRC pre- and post-EVT to help neurologists select the optimal candidates for EVT.

Methods

From April 2020 to July 2022, EVT and mTICI score ≥2b LAO patients were recruited. Nomogram models was developed by two-step approach for predicting the outcomes of LAO patients. First, the least absolute shrinkage and selection operator (LASSO) regression analysis was to optimize variable selection. Then, a multivariable analysis was to construct an estimation model with significant indicators from the LASSO. The accuracy of the model was verified using receiver operating characteristic (ROC), calibration curve, and decision curve analyses (DCA), along with validation cohort (VC).

Results

Using LASSO, age, sex, hypertension history, baseline NIHSS, ASPECTS and baseline SBP upon admission were identified from the pre-EVT variables. Model 1 (pre-EVT) showed good predictive performance, with an area under the ROC curve (AUC) of 0.815 in the training cohort (TrC) and 0.904 in VC. Under the DCA, the generated nomogram was clinically applicable where risk cut-off was between 15%-85% in the TrC and 5%-100% in the VC. Moreover, age, ASPECTS upon admission, onset duration, puncture-to-recanalization (PTR) duration, and lymphocyte-to-monocyte ratio (LMR) were screened by LASSO. Model 2 (post-EVT) also demonstrated good predictive performance with AUCs of 0.888 and 0.814 for TrC and VC, respectively. Under the DCA, the generated nomogram was clinically applicable if the risk cut-off was between 13-100% in the TrC and 22-85% of VC.

Conclusion

In this study, two nomogram models were generated that showed good discriminative performance, improved calibration, and clinical benefits. These nomograms can potentially accurately predict the risk of FRC in LAO patients pre- and post-EVT and help to select appropriate candidates for EVT.

Association between plasma total homocysteine (tHcy) and strokes: A meta-analysis

Objective

Inconsistent findings have been reported regarding the association between elevated plasma total homocysteine (tHcy) and the risk of different types of strokes. We conducted this meta-analysis to identify the association between tHcy and different kinds of strokes or recurrences of strokes, and provide evidence for preventing.

Methods

Relevant studies published before May 1, 2022 in databases such as PubMed, EMBASE, the Cochrane Library, CNKI, and Wanfang were retrieved. Two researchers independently searched and extracted the data, and used Stata 16.0 statistical software for analysis. Results were presented as the odds risk (OR) and the corresponding 95% confidence intervals (CI).

Results

In total, 24 articles were included, involving 51,426 subjects, of which 4,983 had stroke events during follow-up. Relative to lower tHcy, higher tHcy were associated with increased stroke (OR = 1.95, 95% CI: 1.59–2.37), ischemic stroke (OR = 1.71, 95% CI: 1.39–2.11), hemorrhagic stroke (OR = 1.99, 95% CI: 1.03–3.84), and recurrent stroke (OR = 1.25, 95% CI: 1.12–1.39), respectively.

Conclusions

This study shows that elevated tHcy increases the risk of stroke, including ischemic stroke and hemorrhagic stroke, and is closely related to the recurrence of stroke. It is recommended to pay attention to the detection of tHcy in the management of stroke patients in the future, and take effective measures to prevent and delay the progression of stroke.

Estradiol and Hyperhomocysteinemia Are Linked Predominantly Through Part Renal Function Indicators

BACKGROUND

Previous studies have shown that estrogen, kidney function, and homocysteine (Hcy) or hyperhomocysteinemia (HHcy) are related to each other. However, the underlying biological mechanisms still remain unclear. We aimed to explore the association between estradiol (E2) and HHcy in the female population, and to further evaluate the mediating role of renal function indicators.

METHODS

This unmatched case-control study consisted of 1,044 female participants who were 60.60 ± 12.46 years old. Data on general demographic characteristics, such as age, smoking and drinking status, menopause and so on were collected in a personal interview, and laboratory examinations were performed by well-trained personnel. The mediating effect model was applied to analyze the direct and indirect effects of E2 on Hcy.

RESULTS

The average levels of Hcy and E2 of the participants were 12.6 μmol/L and 14.95 pg/ml. There were statistical differences in renal indexes blood urea nitrogen (BUN), serum creatinine (Scr), uric acid (UA), glomerular filtration rate (GFR) and E2 between HHcy group and non-HHcy group. The logistic regression models showed that UA was risk factor for HHcy (P <0.001), GFR and E2 were protective factors for HHcy after adjusting for confounding factors (P <0.001). The indirect effects of E2 on Hcy through UA and GFR accounted for 14.63 and 18.29% of the total impacts of E2 on Hcy.

CONCLUSIONS

These data indicated that E2 was a protective factor of HHcy, and the effects of E2 on HHcy may be mediated by renal function indicators UA and GFR.

Systemic Inflammation Response Index and Systemic Immune-Inflammation Index Are Associated with Clinical Outcomes in Patients Treated with Mechanical Thrombectomy for Large Artery Occlusion

BACKGROUND

Inflammation plays a pivotal role in acute ischemic stroke, and various inflammatory markers are known to predict prognosis of acute ischemic stroke. This study aimed to evaluate the prognostic value of systemic inflammation response index (SIRI) and systemic immune-inflammation index (SII) after mechanical thrombectomy (MT) for acute ischemic stroke caused by large artery occlusion.

METHODS

The study enrolled 440 patients who underwent MT for large artery occlusion. SIRI and SII were calculated using laboratory data on admission. Prognosis was estimated with modified Rankin Scale at 3 months, and favorable clinical outcome was defined by a modified Rankin Scale score of 0-2. Receiver operating characteristic analysis was used to calculate the optimal cutoff values of SIRI and SII for predicting clinical outcome. Multivariate analysis was used to assess the relationship of SIRI and SII with clinical outcome.

RESULTS

In receiver operating characteristic analysis, the optimal cutoff values for SIRI and SII were 2.9 and 853, respectively (area under the curve 0.799, 95% confidence interval [CI] 0.756-0.843, P < 0.001 and area under the curve 0.679, 95% CI 0.643-0.745, P < 0.001, respectively). Multivariate analysis revealed that SIRI <2.9 (odds ratio 2.27, 95% CI 1.29-5.17, P = 0.019) and SII <853 (OR 1.82, 95% CI 1.16-3.10, P = 0.031) were independent predictors of favorable clinical outcome after MT.

CONCLUSIONS

Decreased SIRI and SII were associated with favorable clinical outcome after MT. SIRI and SII represent potential prognostic factors in patients undergoing MT for large artery occlusion.

Dietary folic acid deficiency impacts hippocampal morphology and cortical acetylcholine metabolism in adult male and female mice

OBJECTIVE

One-carbon (1C) metabolism is a metabolic network that integrates nutritional signals with biosynthesis, redox homeostasis, and epigenetics. There are sex differences in hepatic 1C metabolism, however, it is unclear whether sex differences in 1C impact the brain. The aim of this study was to investigate if sex modulates the effects of dietary folic acid deficiency, the main component of 1C, in brain tissue using a mouse model.

METHODS

Male and female C57Bl/6J mice were placed on a folic acid deficient (FD) or control diet (CD) at six weeks until six months of aged. After which brain tissue and serum were collected for analysis. In brain tissue, hippocampal volume, morphology, and apoptosis as well as cortical acetylcholine metabolism were measured.

RESULTS

Male and female FD mice had reduced serum levels of folate. Both males and females maintained on a FD showed a decrease in the thickness of the hippocampal CA1-CA3 region. Interestingly, there was a sex difference in the levels of active caspase-3 within the CA3 region of the hippocampus. In cortical tissue, there were increased levels of neuronal ChAT and reduced levels of AChE in FD females and male mice.

CONCLUSIONS

The results indicated that FD impacts hippocampal morphology and cortical neuronal acetylcholine metabolism. The data from our study indicate that there was only one sex difference and that was in hippocampal apoptosis. Our study provides little evidence that sex modulates the effects of dietary folate deficiency on hippocampal morphology and cortical neuronal acetylcholine metabolism.

Cerebrovascular risk factors associated with ischemic stroke in a young non-diabetic and non-hypertensive population: a retrospective case-control study

Background

Globally, rates of ischemic stroke (IS) have been rising among young adults. This study was designed to identify risk factors associated with IS incidence in young adults unaffected by hypertension or diabetes.

Methods

This was a retrospective case-control study of early-onset IS patients without diabetes and hypertension. Control patients were matched with healthy individuals based upon sex, age (±2 years), and BMI (±3 kg/m²) at a 1:3 ratio. Sociodemographic, clinical, and risk factor-related data pertaining to these patients was collected. The association between these risk factors and IS incidence was then assessed using conditional logistic regression models.

Results

We recruited 60 IS patients and 180 controls with mean ages of 44.37 ± 4.68 and 44.31 ± 4.71 years, respectively, for this study. Relative to controls, IS patients had significantly higher total cholesterol (TG), homocysteine (HCY), white blood cell (WBC), absolute neutrophil count (ANC), systolic blood pressure (SBP), and diastolic blood pressure (DBP) levels, and significantly lower high-density lipoprotein cholesterol (HDL-C) and triglyceride cholesterol (TC), free triiodothyronine (FT3), and free thyroxine (FT4) levels (all P < 0.05). After controlling for potential confounding factors, HCY and ANC were found to be significantly positively associated with IS incidence (OR 1.518, 95%CI 1.165–1.977, P = 0.002 and OR 2.418, 95%CI 1.061–5.511, P = 0.036, respectively), whereas HDL-C and FT3 levels were negatively correlated with IS incidence (OR 0.001, 95%CI 0.000–0.083, P = 0.003 and OR 0.053, 95%CI 0.008–0.326, P = 0.002, respectively).

Conclusions

In young non-diabetic and non-hypertensive patients, lower HDL-C and FT3 levels and higher HCY and ANC levels may be associated with an elevated risk of IS. Additional prospective studies of large patient cohorts will be essential to validate these findings.

Systemic immune-inflammation index (SII) but not platelet-albumin-bilirubin (PALBI) grade is associated with severity of acute ischemic stroke (AIS)

Introduction: Inflammation plays an important role in stroke. Many inflammatory markers in peripheral blood are proved to be associated with stroke severity or prognosis. But few comprehensive models or scales to evaluate the severity of stroke have been reported. Systemic immune-inflammation index (SII) and platelet-albumin-bilirubin (PALBI) grade as new markers of inflammation have shown their positive association with liver cancer. The relation between SII, or PALBI and stroke remains uncertain.Objective: To investigate the relationship between SII, PALBI grade and stroke severity.Methods: Patients with ischemic stroke with hospital admission <24 h after symptom onset were prospectively included in a stroke registry. Demographic, clinical, and laboratory data were collected immediately after admission in all patients. The National Institutes of Health Stroke Scale (NIHSS) was used to assess stroke severity upon admission. Minor stroke was defined as NIHSS score < =5, moderate-to-severe stroke as NIHSS score >5. SII, calculated as platelet × neutrophil/lymphocyte was divided into four groups according to interquartile range: lowest SII (SII < 353.9 × 10⁹/L), low SII (353.9-532.8 × 10⁹/L), high SII (532.8-783.9 × 10⁹/L), and highest SII (>783.9 × 10⁹/L) group.Results: A total of 362 patients with ischemic stroke were included, and between minor and moderate-to-severe stroke significant difference was found in SII (p < 0.0001), NLR (p < 0.0001), and PLR (p = 0.001), respectively. After multivariate regression analyses, SII groups (Odd ratio = 1.351, 95% confidence interval 1.084-1.684, p = 0.007) not PALBI was an independent risk factor for stroke severity.Conclusion: We found that SII but not PALBI, which both are markers of inflammation, was independently associated with stroke severity.

The association between homocysteine and ischemic stroke subtypes in Chinese: A meta-analysis

BACKGROUND

The findings on the association between elevated plasma homocysteine levels and the risk of the trial of org 10172 in acute stroke treatment (TOAST) of ischemic stroke have been inconsistent in Chinese. So far, there is no meta-analysis about the association between Hcy and the TOAST subtypes of ischemic stroke in Chinese. This study; therefore, aimed to evaluate whether elevated homocysteine levels are associated with the TOAST subtypes of ischemic stroke using a meta-analysis.

MATERIALS AND METHODS

A systematic search of electronic databases were conducted for studies reporting homocysteine levels in ischemic stroke and the TOAST of ischemic stroke to April 18, 2018. The data were extracted after the application of inclusion and exclusion criteria. All the data were analyzed using Stata software version 9.0 (Stata Corp LP, College Station, TX). The standardized mean difference (SMD) and 95% confidence interval (CI) were used to compare continuous variables.

RESULTS

Thirteen studies comprising 3114 participants (2243 patients and 871controls) met the eligibility criteria and were included in the meta-analysis. The meta-analysis revealed that the ischemic stroke group had significantly higher levels of homocysteine than controls (SMD = 1.15, 95% CI = 0.85-1.45, P < .05). The subgroup analyses suggested that the groups of patients with large-artery atherosclerosis, small-vessel occlusion, cardioembolism, stroke of other determined etiology and stroke of undetermined etiology had significantly higher levels of homocysteine compared to those in the control group (large-artery atherosclerosis: SMD = 2.12, 95% CI = 1.40-2.84, P < .05; small-vessel occlusion: SMD = 1.10, 95% CI = 0.72-1.48, P < .05; CE: SMD = 1.17, 95% CI = 0.64-1.71, P < .05; stroke of other determined etiology: SMD = 0.88, 95% CI = 0.53-1.24, P < .05; stroke of undetermined etiology: SMD = 1.50, 95% CI = 0.66-2.33, P < .05, respectively).

CONCLUSION

This meta-analysis found that ischemic stroke patients and the TOAST of ischemic stroke patients in Chinese had significantly higher homocysteine levels than the controls, suggesting that serum homocysteine levels may be a risk factor for ischemic stroke and the TOAST subtypes of ischemic stroke in Chinese.

Elevated serum neopterin and homocysteine increased the risk of ischemic stroke in patients with transient ischemic attack

Objective: To investigate the correlation between serum neopterin, homocysteine (Hcy) and the risk of developing ischemic stroke (IS) in patients with transient ischemic attack (TIA).

Methods: Ninety-two TIA patients were prospectively recruited at the First Affiliated Hospital of the Medical College, Shihezi University, Xinjiang Autonomous Region China. Of the included patients, 27 developed ischemic stroke (IS group) and other 65 cases did not (TIA group). Peripheral venous blood was obtained within 24 hours of TIA diagnosis. Serum neopterin, Hcy and serum lipid levels were tested and compared between IS and TIA groups.

Results: Serum neopterin (6.38±1.76 ng/mL vs 5.39±1.51 ng/mL), Hcy (17.95±4.10 μmol/L vs 15.30±3.66 μmol/L), TG (1.82±0.92 mmol/L vs 1.40±0.71 mmol/L) and LDL (3.31±0.67 mmol/L vs 2.69±0.62 mmol/L) of IS group were significantly higher than those of TIA group (p<0.05). The AUC of serum neopterin, Hcy, TG and LDL for predicting the risk of developing IS in patients with TIA were 0.68 (95%CI: 0.55-0.81, 0.68 (95%CI: 0.57-0.80), 0.64 (95%CI: 0.51-0.78) and 0.75 (95%CI: 0.63-0.86), respectively.

Conclusion: Serum neopterin, Hcy, TG and LDL are promising serological markers for predicting the increased risk of developing IS for patients with TIA.

The Controversial Role of Homocysteine in Neurology: From Labs to Clinical Practice

Homocysteine (Hcy) is a sulfur-containing amino acid that is generated during methionine metabolism. Physiologic Hcy levels are determined primarily by dietary intake and vitamin status. Elevated plasma levels of Hcy can be caused by deficiency of either vitamin B12 or folate. Hyperhomocysteinemia (HHcy) can be responsible of different systemic and neurological disease. Actually, HHcy has been considered as a risk factor for systemic atherosclerosis and cardiovascular disease (CVD) and HHcy has been reported in many neurologic disorders including cognitive impairment and stroke, independent of long-recognized factors such as hyperlipidemia, hypertension, diabetes mellitus, and smoking. HHcy is typically defined as levels >15 micromol/L. Treatment of hyperhomocysteinemia with folic acid and B vitamins seems to be effective in the prevention of the development of atherosclerosis, CVD, and strokes. However, data from literature show controversial results regarding the significance of homocysteine as a risk factor for CVD and stroke and whether patients should be routinely screened for homocysteine. HHcy-induced oxidative stress, endothelial dysfunction, inflammation, smooth muscle cell proliferation, and endoplasmic reticulum (ER) stress have been considered to play an important role in the pathogenesis of several diseases including atherosclerosis and stroke. The aim of our research is to review the possible role of HHcy in neurodegenerative disease and stroke and to understand its pathogenesis.

Role of Homocysteine in the Ischemic Stroke and Development of Ischemic Tolerance

Homocysteine (Hcy) is a toxic, sulfur-containing intermediate of methionine metabolism. Hyperhomocysteinemia (hHcy), as a consequence of impaired Hcy metabolism or defects in crucial co-factors that participate in its recycling, is assumed as an independent human stroke risk factor. Neural cells are sensitive to prolonged hHcy treatment, because Hcy cannot be metabolized either by the transsulfuration pathway or by the folate/vitamin B12 independent remethylation pathway. Its detrimental effect after ischemia-induced damage includes accumulation of reactive oxygen species (ROS) and posttranslational modifications of proteins via homocysteinylation and thiolation. Ischemic preconditioning (IPC) is an adaptive response of the CNS to sub-lethal ischemia, which elevates tissues tolerance to subsequent ischemia. The main focus of this review is on the recent data on homocysteine metabolism and mechanisms of its neurotoxicity. In this context, the review documents an increased oxidative stress and functional modification of enzymes involved in redox balance in experimentally induced hyperhomocysteinemia. It also gives an interpretation whether hyperhomocysteinemia alone or in combination with IPC affects the ischemia-induced neurodegenerative changes as well as intracellular signaling. Studies document that hHcy alone significantly increased Fluoro-Jade C- and TUNEL-positive cell neurodegeneration in the rat hippocampus as well as in the cortex. IPC, even if combined with hHcy, could still preserve the neuronal tissue from the lethal ischemic effects. This review also describes the changes in the mitogen-activated protein kinase (MAPK) protein pathways following ischemic injury and IPC. These studies provide evidence for the interplay and tight integration between ERK and p38 MAPK signaling mechanisms in response to the hHcy and also in association of hHcy with ischemia/IPC challenge in the rat brain. Further investigations of the protective factors leading to ischemic tolerance and recognition of the co-morbid risk factors would result in development of new avenues for exploration of novel therapeutics against ischemia and stroke.