Relationships between fibrinogen, plasminogen activator inhibitor-1, and their gene polymorphisms in current smokers with essential hypertension

The 4G/5G Polymorphism of Plasminogen Activator Inhibitor Type 1 is a Predictor of Moderate-to-Severe Thyroid Eye Disease

Introduction

Thyroid eye disease (TED) is an autoimmune disease of the orbits. Once developed, complete cure is rare. Plasminogen activator inhibitor type 1 (PAI-1) contributes to remodeling of connective tissue and has a central role in the pathogenesis of TED. We aimed to test if the 4G/5G polymorphism of PAI-1 is a predictor of the development of moderate-to-severe TED.

Methods

A total of 185 patients with Graves’ disease, 87 of them with TED, 98 without TED, as well as 201 healthy controls, were studied. Genomic DNA was isolated from peripheral blood samples. The 4G/5G polymorphism of the PAI-1 gene was analyzed by allele-specific PCR, and the distribution of genotypes was calculated in each group. Plasma PAI-1 and thyroid hormone levels were measured by ELISA and ECLIA, respectively.

Results

The 4G/4G genotype was associated with the development of moderate-to-severe TED (OR = 2.54; 95% CI: 1.26–5.14; p < 0.01). The 4G/5G polymorphism of PAI-1 was not a predictor of plasma PAI-1 levels.

Conclusion

The 4G/4G genotype of PAI-1 is a risk factor for the development of moderate-to-severe TED. Patients with Graves’ disease who harbor this genotype may be candidates for special attention towards the development of TED.

PAI-1 gain-of-function genotype, factors increasing PAI-1 levels, and airway obstruction: The GALA II Cohort

BACKGROUND

PAI-1 gain-of-function variants promote airway fibrosis and are associated with asthma and with worse lung function in subjects with asthma.

OBJECTIVE

We sought to determine whether the association of a gain-of-function polymorphism in plasminogen activator inhibitor-1 (PAI-1) with airway obstruction is modified by asthma status, and whether any genotype effect persists after accounting for common exposures that increase PAI-1 level.

METHODS

We studied 2070 Latino children (8-21y) with genotypic and pulmonary function data from the GALA II cohort. We estimated the relationship of the PAI-1 risk allele with FEV1/FVC by multivariate linear regression, stratified by asthma status. We examined the association of the polymorphism with asthma and airway obstruction within asthmatics via multivariate logistic regression. We replicated associations in the SAPPHIRE cohort of African Americans (n=1056). Secondary analysis included the effect of the at-risk polymorphism on postbronchodilator lung function.

RESULTS

There was an interaction between asthma status and the PAI-1 polymorphism on FEV₁ /FVC (P=.03). The gain-of-function variants, genotypes (AA/AG), were associated with lower FEV₁ /FVC in subjects with asthma (β=-1.25, CI: -2.14,-0.35, P=.006), but not in controls. Subjects with asthma and the AA/AG genotypes had a 5% decrease in FEV₁ /FVC (P<.001). In asthmatics, the risk genotype (AA/AG) was associated with a 39% increase in risk of clinically relevant airway obstruction (OR=1.39, CI: 1.01, 1.92, P=.04). These associations persisted after exclusion of factors that increase PAI-1 including tobacco exposure and obesity.

CONCLUSIONS AND CLINICAL RELEVANCE

The decrease in the FEV₁ /FVC ratio associated with the risk genotype was modified by asthma status. The genotype increased the odds of airway obstruction by 75% within asthmatics only. As exposures known to increase PAI-1 levels did not mitigate this association, PAI-1 may contribute to airway obstruction in the context of chronic asthmatic airway inflammation.

Coronary Artery Atherosclerosis in Hypertensive Patients: The Role of Fibrinogen Genetic Variability

INTRODUCTION AND OBJECTIVES

We examined whether the rs180070 and rs2070011 polymorphisms of the fibrinogen gene could affect the risk of coronary artery disease in hypertensive patients by modifying the inflammatory process and coagulation.

METHODS

A total of 744 participants underwent coronary angiography due to symptoms of stable angina, while hypertension was present in 332 patients.

RESULTS

The presence of the A allele (rs180070) was associated with significantly high levels of fibrinogen in hypertensive patients (P=.05). On multivariate analysis, A homozygosity (rs180070) (β = 0.257 ± 18.6; P<.001), but not hypertension status (β = 0.05 ± 11.9; P=.29) was an independent predictor of fibrinogen levels. In hypertensive patients, higher fibrinogen levels>443mg/dL (odds ratio = 3.50; 95% confidence interval, 1.14-10.90; P=.029), but not A homozygosity (odds ratio = 3.00; 95% confidence interval, 0.78-11.90; P = .110) were independent predictors of the presence of coronary artery disease. Moreover, interleukin-6 levels were higher in A homozygotes for the rs180070 polymorphism compared with all other genotypes (P=.046). Indeed, this genotype was the only adjusted independent predictor of interleukin-6 levels (β = 0.151 ± 0.642; P=.032). It was also associated with higher D-dimer levels in hypertension compared with G allele carriers (P=.048).

CONCLUSIONS

The presence of A homozygosity (rs180070) is associated with increased levels of inflammatory mediators and a higher incidence of angiographic coronary artery disease. Importantly, fibrinogen is an independent predictor of the angiographic presence of coronary artery disease in hypertensive patients.

Plasminogen activator inhibitor-1 4G/5G polymorphism is associated with metabolic syndrome parameters in Malaysian subjects

The plasminogen activator inhibitor-1 4G/5G and tissue plasminogen activator Alu-repeat insertion/deletion polymorphisms might be genetic determinations of increased or decreased of their plasma activities. The aim of this study was to investigate the association of plasminogen activator inhibitor-1 4G/5G and tissue plasminogen activator Alu-repeat I/D polymorphisms with metabolic syndrome parameters in normal Malaysian subjects and to assess the impact of these polymorphisms on their plasma activities and antigens. The genetic polymorphisms were genotyped in 130 normal subjects. In addition, the plasma activities and antigens of plasminogen activator inhibitor-1 and tissue plasminogen activator as well as levels of insulin, glucose, and lipid profile at fasting state were investigated. The subjects with homozygous 4G/4G showed association with an increased triglyceride (p = 0.007), body mass index (p = 0.01) and diastolic blood pressure (p = 0.03). In addition, the plasminogen activator inhibitor-1 4G/5G polymorphism modulates plasma plasminogen activator inhibitor-1 activity and antigen and tissue plasminogen activator activity (p = 0.002, 0.014, 0.003) respectively. These results showed that, the plasminogen activator inhibitor-1 4G/5G polymorphism is associated with metabolic syndrome parameters, plasminogen activator inhibitor-1 and tissue plasminogen activator activities in Malaysian subjects, and may serve to increase the risk of type 2 diabetes and cardiovascular disease in Malaysian subjects.

Dihydropyridine calcium antagonists increase fibrinolytic activity: a systematic review

Calcium antagonists have been shown to be superior over other antihypertensive drugs to prevent stroke. Because this cannot be fully attributed to blood pressure lowering effects, other mechanisms seem to play a role. Previously we found in patients with subarachnoid hemorrhage that nimodipine enhances fibrinolytic activity. The purpose of this systematic review was to investigate the fibrinolytic effect of calcium antagonists in general, especially in patients with hypertension. We systematically studied the entire PUBMED and EMBASE database with the search terms 'calcium antagonist' combined with 'fibrinolysis', '(euglobulin) clot lysis time' (ECLT), 'tissue plasminogen activator' (tPA), or 'plasminogen activator inhibitor' (PAI). Twenty-six prospective studies were identified and 22 manuscripts were included (802 investigated individuals). The results show that calcium antagonists significantly increase fibrinolysis as shown by a reduction of the ECLT standardized mean differences (SMD) -0.58 (95% confidence interval (CI) -1.05 to -0.11)) and an increase of tPA activity (SMD 0.73 (95% CI 0.25 to 1.21)). This increase of fibrinolysis is apparently caused by an increase of the tPA antigen level (SMD 0.16 (95% CI -0.05 to 0.37)) and a decrease of the plasminogen activator inhibitor-1 antigen antigen (SMD -0.36 (95% CI -0.74 to 0.02)). A sensitivity analysis showed that dihydropyridines, but not phenylalkylamines, exert a fibrinolytic effect. This fibrinolytic effect is not only seen in patients with subarachnoid hemorrhage but also in hypertensive patients. In conclusions, calcium antagonists increase fibrinolytic activity. This may add to the beneficial pharmacological effect of calcium antagonists to prevent ischemic events in patients with hypertension and subarachnoid hemorrhage.

The 4G/4G PAI-1 genotype is associated with elevated plasma PAI-1 levels regardless of variables of the metabolic syndrome and smoking status. A population-based study in Spanish population

Reported data about the effect of the 4G/5G PAI-1 polymorphism on plasma PAI-1 levels are controversial. This study was designed to determine the relative effect of the 4G/5G PAI-1 polymorphism on high plasma PAI-1 levels after adjustment for metabolic syndrome - related variables, and to test if this effect is modified by the smoking status. Six hundred and thirty one unrelated subjects (292 men; 35-74 years), from a cross-sectional population-based epidemiological survey in the province of Segovia (Spain) were studied. The higher frequency of high PAI-1 levels was found in 4G/4G subjects (5G/5G 19.4%, 4G/5G 21.6%, 4G/4G 33.7%, p = 0.003). A multiple regression model, adjusted for gender, age, BMI, waist circumference, triglycerides, HDL-cholesterol, HOMA IR and leptin, showed this adjOR: 4G/4G vs 5G/5G: 2.22, p = 0.008. When smoking status - 4G/5G PAI-1 interaction was included as an independent variable these results were not modified. Our results indicate that the 4G/4G PAI-1 genotype might be strongly associated with high PAI-1 levels regardless of metabolic syndrome-related variables and smoking status.

Effects of perindopril treatment on hemostatic function in patients with essential hypertension in relation to angiotensin converting enzyme (ACE) and plasminogen activator inhibitor-1 (PAI-1) gene polymorphisms

BACKGROUND AND AIM

An imbalance in the hemostatic system is a frequent finding in untreated essential hypertension (HT), and it has been shown that treatment with angiotensin converting entyme (ACE) inhibitors improves hemostatic function. In order to elucidate the role of genetic factors, we studied hemostasis in patients with untreated and treated HT and correlated the results with ACE I/D and plasminogen activator enhibitor-1 (PAI-1) 4G/5G gene polymorphisms.

METHODS AND RESULTS

Forty-three males with HT (mean age 31.7 +/- 6.8 years) were compared with 34 age and gender-matched controls. All of the patients were treated with perindopril (4 mg/day) and, after one and six months of therapy, their levels of plasma fibrinogen (Fb), t-PA antigen, PAI-1 antigen, von Willebrand factor (vWF), ACE activity and blood pressure were measured. ACE and PAI-1 genotypes were identified by means of the polymerase chain reaction on DNA isolated from peripheral blood lymphocytes. Untreated patients had significantly higher levels of Fb, PAI-1 (p < 0.01) and t-PA (p < 0.05) regardless of their ACE or PAI-1 genotypes. Perindopril reduced blood pressure regardless of ACE or PAI-1 genotype (p < 0.001). ACE II homozygotes showed the greatest decrease in ACE activity (p < 0.01) and a significant reduction in Fb levels (p < 0.05) after just one month of treatment. Analysis of the group as a whole revealed an increase in t-PA antigen levels after six months of treatment, regardless of ACE or PAI-1 genotype (p < 0.01).

CONCLUSIONS

Our results show that essential hypertension predisposes to the procoagulant state characterized by hyperfibrinogenemia and hypofibrinolysis. Perindopril reduced fibrinogen levels in ACE II homozygotes due to its more potent inhibitory action on the renin-angiotensin system in such patients. It improved fibrinolysis by increasing t-PA levels regardless of ACE and PAI-1 genotype.