Determinants of plasminogen activator inhibitor-1 in South Asians with ischaemic stroke

Sex Differences in Hemostatic Factors in Patients With Ischemic Stroke and the Relation With Migraine-A Systematic Review

Background: Women are more affected by stroke than men. This might, in part, be explained by sex differences in stroke pathophysiology. The hemostasis system is influenced by sex hormones and associated with female risk factors for stroke, such as migraine.

Aim: To systematically review possible sex differences in hemostatic related factors in patients with ischemic stroke in general, and the influence of migraine on these factors in women with ischemic stroke.

Results: We included 24 studies with data on sex differences of hemostatic factors in 7247 patients with ischemic stroke (mean age 57–72 years, 27–57% women) and 25 hemostatic related factors. Levels of several factors were higher in women compared with men; FVII:C (116% ± 30% vs. 104% ± 30%), FXI (0.14 UI/mL higher in women), PAI-1 (125.35 ± 49.37 vs. 96.67 ± 38.90 ng/mL), D-dimer (1.25 ± 0.31 vs. 0.95 ± 0.24 μg/mL), and aPS (18.7% vs. 12.0% positive). In contrast, protein-S (86.2% ± 23.0% vs. 104.7% ± 19.8% antigen) and P-selectin (48.9 ± 14.4 vs. 79.1 ± 66.7 pg/mL) were higher in men. Most factors were investigated in single studies, at different time points after stroke, and in different stroke subtypes. Only one small study reported data on migraine and hemostatic factors in women with ischemic stroke. No differences in fibrinogen, D-dimer, t-PA, and PAI-1 levels were found between women with and without migraine.

Conclusion: Our systematic review suggests that sex differences exist in the activation of the hemostatic system in ischemic stroke. Women seem to lean more toward increased levels of procoagulant factors whereas men exhibit increased levels of coagulation inhibitors. To obtain better insight in sex-related differences in hemostatic factors, additional studies are needed to confirm these findings with special attention for different stroke phases, stroke subtypes, and not in the least women specific risk factors, such as migraine.

Association of PAI-1 rs1799889 Polymorphism with Susceptibility to Ischemic Stroke: a Huge Meta-Analysis based on 44 Studies

BACKGROUND

the PAI-1 rs1799889 polymorphism has been reported to be associated with susceptibility to ischemic stroke. However, the results of previous studies have been inconsistent or controversial. Hence, we performed a systematic review and meta-analysis to evaluate the association of PAI-1 rs1799889 polymorphism with ischemic stroke risk.

METHODS

A comprehensive literature search was performed on PubMed, Web of Science, Scopus, SciELO, CNKI, and CBD databases up to November 05, 2019. Pooled odds ratio (OR) with 95% confidence interval (CI) were used to access the strength of this association in fixed- or random-effects model.

RESULTS

A total of 44 case-control studies with 8,620 cases and 10,260 controls were selected. Pooled data showed a significant association between PAI-1 rs1799889 polymorphism and ischemic stroke risk in the overall populations (GG vs. AA: OR = 0.791, 95% CI 0.633-0.988, p = 0.039; GA vs. AA: OR = 0.807, 95% CI 0.683-0.953, p = 0.012; and GG+GA vs. AA: OR = 0.795, 95% CI 0.637-0.993, p = 0.043). Subgroup analysis by ethnicity revealed a significant association in Asian and Mixed populations, but not in Caucasians. Moreover, stratified analysis by country of origin revealed an increased risk of ischemic stroke in Chinese populations, but not among Dutch (Netherlands) and Swedish.

CONCLUSIONS

This meta-analysis result suggested that PAI-1 rs1799889 polymorphism was associated with an increased risk of ischemic stroke, especially in Asian and Mixed populations.

Insulin resistance syndrome in South Asians

Although South Asians express increased features (conventional) of insulin resistance syndrome, these do not fully explain the increased mortality both from ischaemic heart disease and ischaemic stroke in South Asians compared to Whites. Thrombotic risk factors for vascular disease, as a part of insulin resistance syndrome in South Asians, are being investigated and are an important moiety. The management of the epidemic of ischaemic vascular disease in South Asians is a major global endeavour.

Association Between Plasminogen Activator Inhibitor-1 Genetic Polymorphisms and Stroke Susceptibility

The plasminogen activator inhibitor-1 (PAI-1) is a candidate gene for stroke based on PAI-1's crucial role in fibrinolytic system. However, association studies have yielded conflicting results regarding the association between PAI-1 polymorphisms and stroke susceptibility. To further elucidate the putative association, we performed a systematic review and meta-analysis to provide a complete picture of the loci investigated for association of PAI-1 polymorphism with stroke risk and to derive a precise estimation. PubMed, Embase, and China National Knowledge Infrastructure (CNKI) databases were searched until June 2015 to identify eligible studies. Forty data sets from 39 studies with a total of 8336 cases and 14,403 controls were included. The most commonly investigated polymorphism was -675 4G/5G, followed by -844 G/A, 11053 T>G, HindIII C/G, and (CA)n. Overall, our meta-analysis provided evidence for the significant association of PAI-1 4G/5G polymorphism with an increased risk of adult but not pediatric ischemic stroke (adult: 4G/4G vs. 4G/5G + 5G/5G, OR = 1.21, 95 % CI = 1.04-1.42). In the subgroup analysis, significant association was detected in Asians (4G/4G vs. 4G/5G + 5G/5G, OR = 1.45, 95 % CI = 1.14-1.85) but not Caucasians. Moreover, we found that -844 G/A but not 11053 T>G polymorphism was associated with an increased risk of ischemic stroke (-844G/A: A/A vs. G/G: OR = 1.32, 95 % CI = 1.01-1.73). A tendency of PAI-1 4G/5G polymorphism towards a decreased risk of hemorrhagic stroke was observed (4G/4G + 4G/5G vs. 5G/5G, OR = 0.77, 95 % CI = 0.59-1.02, P = 0.066). Future well-designed studies in large well-characterized sample size and presenting results stratified by gender, age, and stroke subtype are warranted.

GLU298ASP and 4G/5G Polymorphisms and the Risk of Ischemic Stroke in Young Individuals

BACKGROUND

Polymorphisms in the endothelial nitric oxide synthase (eNOS) and in the plasminogen activator inhibitor -1 (PAI-1) genes have been implicated in stroke pathogenesis but results are still controversial. The aim of this study was to examine the possible contribution of Glu298Asp in the eNOS and 4G/5G in the PAI-1polymorphisms with ischemic stroke in a young Mexican population.

MATERIALS AND METHODS

In a case-control study, conducted between January 2006 and June 2010, 204 patients ≤45 years of age with ischemic stroke and 204 controls matched by age and gender, were recruited. The Glu298Asp and 4G/5G polymorphisms were determined in all participants by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

There was a significant difference in the Glu298Asp genotype distribution (P=0.001) and allele frequency between the two groups (P=0.001). The 4G/5G genotype distribution (P=0.40) and the allele frequency was similar between groups; (P=0.13). There were independent factors for ischemic stroke: Asp carriage (GluAsp+AspAsp) (P=0.02); smoking (P=0.01); hypertension (P=0.03), and familial history of atherothrombotic disease (P=0.04).

CONCLUSIONS

The Asp allele from the Gu298Asp gene represents an independent risk factor for ischemic stroke in a young Mexican population. In contrast, the 4G/5G was not associated with an increased risk for this disease in the same group of patients, as previously has been demonstrated in other populations.

The association between plasminogen activator inhibitor type 1 (PAI-1) levels, PAI-1 4G/5G polymorphism, and myocardial infarction: a Mendelian randomization meta-analysis

BACKGROUND

The circulating levels of plasminogen activator inhibitor type 1 (PAI-1) are increased in individuals carrying the 4G allele at position -675 of the PAI-1 gene. In turn, overexpression of PAI-1 has been found to affect both atheroma and thrombosis. However, the association between PAI-1 levels and the incidence of myocardial infarction (MI) is complicated by the potentially confounding effects of well-known cardiovascular risk factors. The current study tried to investigate in parallel the association of PAI-1 activity with the PAI-1 4G/5G polymorphism, with MI, and some components of metabolic syndrome (MetS).

METHODS

Using meta-analytical Mendelian randomization approaches, genotype-disease and genotype-phenotype associations were modeled simultaneously.

RESULTS

According to an additive model of inheritance and the Mendelian randomization approach, the MI-related odd ratio for individuals carrying the 4G allele was 1.088 with 95% confidence interval (CI) 1.007, 1.175. Moreover, the 4G carriers had, on average, higher PAI-1 activity than 5G carriers by 1.136 units (95% CI 0.738, 1.533). The meta-regression analyses showed that the levels of triglycerides (p=0.005), cholesterol (p=0.037) and PAI-1 (p=0.021) in controls were associated with the MI risk conferred by the 4G carriers.

CONCLUSIONS

The Mendelian randomization meta-analysis confirmed previous knowledge that the PAI-1 4G allele slightly increases the risk for MI. In addition, it supports the notion that PAI-1 activity and established cardiovascular determinants, such as cholesterol and triglyceride levels, could lie in the etiological pathway from PAI-1 4G allele to the occurrence of MI. Further research is warranted to elucidate these interactions.

Global fibrinolytic activity, PAI-1 level, and 4G/5G polymorphism in Thai children with arterial ischemic stroke

BACKGROUND

Prolonged euglobulin clot lysis time (ECLT) and increased level of plasminogen activator inhibitor-1 (PAI-1) were reported to be risk factors of arterial ischemic stroke (AIS) by some studies; however, these findings were not supported by other studies. The objective of this study was to determine the association of ECLT, PAI-1 level, and polymorphisms of 4G and 5G of PAI-1 gene to the development of AIS in Thai children.

METHODS

This study included patients aged 1-18 years old. Diagnosis of AIS was confirmed by imaging study. The control group was age- and sex-matched healthy subjects. Demographic data were recorded, and blood was tested for ECLT, PAI-1 level, lipid profiles, fasting blood sugar (FBS), and 4G and 5G polymorphisms of PAI-1 gene.

RESULTS

There were 70 subjects participating in this study, consisting of 30 patients and 40 controls. Demographic data, lipid profiles, and FBS were similar between the 2 groups. Furthermore, ECLT and PAI-1 level did not differ between patient and control groups; however, both showed significant correlation (r = .352, P = .006). The 4G/5G polymorphism was the most common genotype in both patient and control groups (69.0% vs. 80.0%). However, 4G and 5G polymorphisms of PAI-1 gene did not correlate with PAI-1 level in this study (P = .797).

CONCLUSIONS

The PAI-1 level and 4G/5G polymorphism may not be a risk factor of AIS in this population. It was also found that the 4G/5G polymorphism was the most common PAI-1 genotype in this study.

A-G-4G haplotype of PAI-1 gene polymorphisms -844 G/A, HindIII G/C, and -675 4G/5G is associated with increased risk of ischemic stroke caused by small vessel disease

BACKGROUND

Plasminogen activator inhibitor type 1 (PAI-1) is the major inhibitor of fibrinolysis. It was reported that PAI-1 gene polymorphisms affected PAI-1 level and might therefore influence the risk of vascular diseases, including stroke. We studied the association of three common polymorphisms in PAI-1 gene (-844 G/A, -675 4G/5G, and HindIII G/C) with the odds of different causes of ischemic stroke.

METHODS

We studied 390 patients with ischemic stroke due to large vessel disease (n = 117), small vessel disease (n = 121), and cardioembolism (n = 152) as well as 291 controls. The etiology of ischemic stroke was established using TOAST criteria. PAI-1 polymorphisms were genotyped with restriction fragment length polymorphism and single strand conformation polymorphism method.

RESULTS

A-G-4G haplotype of PAI-1 gene was found more frequently in stroke patients with small vessel disease than in control subjects (44.9% vs 35.7%; P = 0.02). No association was found between investigated genotype or allele frequencies and distinct causes of ischemic stroke.

CONCLUSIONS

Our results demonstrate that A-G-4G PAI-1 gene haplotype is associated with increased risk of small vessel disease stroke, but this study does not support an association of -844 G/A, -675 4G/5G, and HindIII G/C PAI-1 gene polymorphisms with particular etiology of ischemic stroke.

Does body weight influence the response to intravenous tissue plasminogen activator in stroke patients?

BACKGROUND

The recommended dose of IV tissue plasminogen activator (t-PA) for ischemic stroke patients weighing >100 kg (ISPW >100 kg) is fixed at 90 mg. Elevated levels of plasminogen activator inhibitor-1 (PAI-1) and impaired fibrinolysis have been reported in heavy patients, suggesting that ISPW >100 kg may require higher doses of t-PA. We hypothesized that ISPW >100 kg are less likely to benefit from IV t-PA compared to patients who weigh <or=100 kg and receive a weight-based dose.

METHODS

We queried the National Institute of Neurological Disorders and Stroke t-PA study database, and performed multivariate logistic regression analyses to analyze the effects of weight (>100 vs. <or=100 kg) and t-PA dose on functional outcomes at 3 months.

RESULTS

Six percent of the t-PA and 10% of the placebo cohorts had an actual body weight >100 kg. Weight >100 kg emerged as a predictor of worse outcome (OR = 5.76; p = 0.017) and neurological deterioration (OR = 3.4; p = 0.07) after t-PA. This negative impact of body weight on outcome was not seen among placebo-treated patients. We also found a trend for an association between lower doses of t-PA and unfavorable 3-month outcomes in t-PA-treated patients (OR = 1.9; p = 0.05).

CONCLUSIONS

ISPW >100 kg seem to derive less benefit from IV t-PA than their lighter counterparts. This may be partly attributed to the use of fixed non-weight-adjusted dosing in heavier patients. The mechanism(s) underlying this observation and its potential therapeutic implications require further investigations.

Polymorphisms in platelet glycoprotein 1balpha and factor VII and risk of ischemic stroke: a meta-analysis

BACKGROUND AND PURPOSE

Platelets and components of the coagulation cascade are known to be instrumental in the pathogenesis of arterial occlusive disorders. The aim of this meta-analysis is to test the hypothesis that genetic variation in the platelet glycoprotein 1balpha and Factor VII genes influence the occurrence of ischemic stroke. All genetic association studies that examined the R353Q (rs6046) polymorphism of the Factor VII gene and 2 polymorphisms of the platelet glycoprotein (1balpha) gene (Thr/Met rs6065 and Kozak sequence -5 C/T rs2243093) in relation to ischemic stroke were examined.

METHODS

Electronic databases Embase, Medline, and HuGEnet were searched for all years up until June 2006 for all studies that evaluated any of these candidate genes and stroke.

RESULTS

Pooled ORs were calculated with 95% CIs using both fixed and random effects models. Meta-analysis for Factor VII (R353Q) did not detect any effect on ischemic stroke risk. Further estimation resulted in pooled OR(1) QQ versus RR=0.9 (95% CI: 0.4 to 1.9) and pooled OR(2) for RQ versus RR=0.9 (95% CI: 0.6 to 1.4). These results were robust and homogeneous. Pooling ORs for the platelet glycoprotein 1balpha Kozak variant -5 T/C polymorphism showed extreme heterogeneity with differing effect directions across studies. Fisher's method of pooling was therefore used to calculate a combined probability value, which was highly significant (P<0.001). The pooled OR for platelet glycoprotein 1balpha Met/Met v Thr/Thr was 1.0 to 2.0, depending on the sensitivity analyses, and for Thr/Met versus Thr/Thr, the pooled OR was between 1.3 and 1.4. These results were consistent, reasonably robust, and implied a dominant genetic effect.

CONCLUSIONS

This analysis provides strong evidence that the Factor VII R353Q gene polymorphism is not associated with ischemic stroke, that the Thr/Met polymorphism of GP1balpha is associated with ischemic stroke in a dominant genetic model, and that the Kozak sequence polymorphism of GP1balpha may be close to another causative locus that is associated with ischemic stroke.

Plasminogen activator inhibitor-1 4G/5G polymorphism and risk of ischemic stroke: a meta-analysis

This study investigated the hypothesis that the insertion/deletion (4G/5G) polymorphism of the plasminogen activator inhibitor type-1 gene affects the risk for ischemic stroke, since results concerning this association have been controversial. We therefore performed a meta-analysis of published data regarding this issue. A comprehensive electronic search was carried out until January 2006. The analysis was performed using random-effects models and meta-regression. Eighteen eligible studies were retrieved (15 case-control studies and three cohort studies). The case-control studies included 3104 cases and 4870 control individuals concerning the contrast of 4G/4G versus remaining genotypes. The 4G pooled allele frequencies in cases and controls were 54.21 and 54.75%, respectively. Overall, the per-allele odds ratio of the 4G allele was 0.98 (95% confidence interval, 0.858-1.121). Regarding genotypes, we derived nonsignificant odds ratios in all contrasts. The subanalysis including the three studies with a prospective design in the 4G/4G versus 5G/5G contrast derived a significant result (relative risk, 0.523; 95% confidence interval, 0.353-0.775), but the estimated effect size was insignificant when cohort and case-control studies were analyzed together (relative risk, 0.848; 95% confidence interval, 0.662-1.087). We failed to demonstrate a significant association between the 4G/5G polymorphism and ischemic stroke under basal conditions. Determination of plasminogen activator inhibitor type-1 function seems of much higher clinical value than determination of the 4G/5G polymorphism. The effect of this genotype on risk of ischemic stroke in acute stressful diseases and the role of cohort studies in genetic epidemiology, however, warrant further investigation.

An Effect of the PAI-1 4G/5G Polymorphism on Cholesterol Levels May Explain Conflicting Associations with Myocardial Infarction and Stroke

BACKGROUND AND PURPOSE

The gene-encoding plasminogen activator inhibitor type 1 (PAI-1) has a common 4G/5G 'functional' polymorphism, and people homozygous for the 4G allele have higher PAI-1 plasma concentrations. The 4G/4G genotype is associated with increased risk of myocardial infarction but paradoxically protects against stroke. We hypothesized that this paradox may be explained via an effect of the PAI-1 polymorphism on plasma lipids.

METHODS

We studied 71 consecutive Italian patients referred to our Institute for first stroke or vascular cognitive impairment. PAI-1 gene 4G/5G polymorphism, total plasma cholesterol, plasma triglycerides, sex, age, smoking, oral contraceptive use, statin therapy, hypertension, diabetes, and history of myocardial infarction were examined.

RESULTS

The 4G/4G genotype was significantly associated with high cholesterol (p = 0.003) but not with triglycerides (p = 0.39). Adjusted odds ratios were: 5.8 for 4G/4G vs. 4G/5G (95% CI, 3.1-23.0), and 15.9 for 4G/4G vs. 5G/5G (95% CI, 2.4-105.0).

CONCLUSIONS

This finding may explain the involvement of the PAI-1 polymorphism in the clustering of atherothrombotic risk factors, and why people with the 4G/4G genotype are at increased risk for myocardial infarction. Stroke is not so clearly related to hypercholesterolemia and other effects of the 4G/4G genotype (perhaps increased PAI-1 expression) may protect against stroke.

Insulin resistance syndrome (metabolic syndrome) and obesity in Asian Indians: evidence and implications

OBJECTIVES

This review describes prevalence, determinants, and possible pathophysiologic mechanisms and suggests management and research directions for insulin resistance syndrome (metabolic syndrome) in Asian Indians.

METHOD

We reviewed the topic using the terms Asian Indians, Asians, South Asians, and Indians coupled with the terms insulin resistance, hyperinsulinemia, metabolic syndrome, and obesity from the databases Pubmed (National Library of Medicine, Bethesda, MD, USA) and Current Contents (Institute for Scientific Information, Thomson Scientific, Philadelphia, PA, USA) and from non-indexed publications of the medical research and governmental institutions in India.

RESULTS

Asian Indians have a high prevalence of insulin resistance syndrome that may underlie their greater than normal tendency to develop diabetes mellitus and early atherosclerosis. Important reasons could be their excess body fat and adverse body fat patterning including abdominal adiposity even when the body mass index is within the currently defined normal limits. Some of these features have been reported at birth and childhood. Whether Asian Indians also have tendency to develop insulin resistance de novo, independent of total or regional adiposity, needs further investigation. Underlying genetic tendency or early-life adverse events may contribute to such a phenotype, but lifestyle factors alone or modulated by inherited factors appear to play an important role because obesity and dyslipidemia become worse with urbanization and migration. Systemic stress may contribute to insulin resistance syndrome in the intra-country and inter-country migrant Asian Indians.

CONCLUSIONS

High prevalences of excess body fat, adverse body fat patterning, hypertriglyceridemia, and insulin resistance beginning at a young age have been consistently recorded in Asian Indians irrespective of their geographic locations. These data suggest that primary prevention strategies should be initiated early in this ethnic group.