Association of blood pressure with fibrinolytic potential in the Framingham offspring population

Parental history of hypertension is associated with coagulation–fibrinolytic balance disorders

It has been previously shown that essential hypertension (EH) is associated with coagulation-fibrinolytic balance disorders. Our study was conducted in order to investigate disturbances in coagulation-fibrinolysis in offsprings of hypertensive parents. Two groups were studied: 44 healthy normotensive individuals (17 male, 27 female, age range 12-22 years) with a documented family history of hypertension and 33 individuals (14 male, 19 female, age range 11-21 years) without a family history of essential hypertension. The following parameters were determined in both groups: plasminogen activator inhibitor-1 antigen, tissue plasminogen activator antigen, fibrinogen, fibrin degradation products, thrombomodulin, protein S antigen, protein C activity, von Willebrand factor Ag, factor VII and factor XII activity. Additionally, systolic and diastolic blood pressure, insulin levels, blood lipids and heart rate were determined. The two groups were not found to have differences with respect to age, gender, body mass index, blood lipids and insulin levels. Hypertensive offsprings had significantly higher plasma levels of plasminogen activator inhibitor-1 antigen, fibrinogen, fibrin degradation products, protein S antigen and factor XII activity, while no differences were observed to the other haemostatic variables studied. Hence, offsprings of hypertensives had significantly higher diastolic blood pressure and heart rate. In conclusion, alterations regarding blood pressure, heart rate and fibrinolytic function exist in offsprings of hypertensive parents compared to individuals without family history of hypertension.

PAI-1 in human hypertension: relation to hypertensive groups

BACKGROUND

Although the renin-angiotensin system and insulin resistance (IR) have been identified as major regulators of plasminogen activator inhibitor type-1 (PAI-1), their roles in hypertensive subjects is not clearly defined.

METHODS

We examined the effect of dietary salt restriction on PAI-1 levels in 239 hypertensive subjects from three centers. Subjects were placed on a 200 and 10 mmol/day sodium diets for 1-week periods. Plasma renin activity (PRA) and PAI-1 levels were measured on the last day of both diets and fasting insulin, glucose, and aldosterone (ALDO) levels, only on the low salt diet.

RESULTS

Sodium restriction increased PAI-1 levels from 32.1 +/- 2.5 ng/mL to 39.8 +/- 3.2 ng/mL (P = .009). There was a strong positive correlation between PAI-1 levels and PRA (r = 0.228, P = .0004), IR (r = 0.222, P = .001), triglycerides (r = 0.275, P < .001), and ALDO (P = .018 for linear trend). The patients were divided into low renin (low IR and ALDO levels), nonmodulators (normal PRA, high IR, and low ALDO levels), and modulators (normal PRA, intermediate IR, and normal ALDO levels) groups to assess the relative contribution of each factor to PAI-1 levels. Modulators had significantly (P = .019) higher PAI-1 levels compared to the low renin and nonmodulators who had similar PAI-1 levels.

CONCLUSIONS

Plasma renin activity, IR, and ALDO all correlate with PAI-1 levels in the hypertensive subjects. However, the data suggest that ALDO may be an important factor contributing to the variability of PAI-1 levels in individual hypertensive subjects.

Acute effects of transdermal 17beta-estradiol on hemostatic variables after 24-hour treatment

The aim of this study was to investigate the acute effects of transdermal 17beta-estradiol (Estraderm) on plasma levels of coagulatory and fibrinolytic factors in postmenopausal normotensive and hypertensive women. Eleven normotensive and 13 hypertensive women were included in this placebo-controlled crossover study. In a randomized order each subject was treated with a patch of 100 microg 17beta-estradiol or placebo for 24 hours. Serum levels of tissue type plasminogen activator (tPA) activity, plasminogen activator inhibitor-I (PAI-1) activity, tPA antigen, PAI-I antigen, FVII, FX, and fibrinogen were assayed after both treatments. There was no significant difference in serum levels of hemostatic variables after treatment with estrogen compared to levels after placebo treatment in either of the groups. Nor was there any measurable difference when comparing hypertensive and normotensive subjects.

Obesity, haemostasis and the fibrinolytic system

Obese patients are at risk for the development of cardiovascular diseases, which can in part be explained by disturbances in the haemostatic and fibrinolytic systems. Indeed, obese subjects tend to have higher values of fibrinogen, factor VII, factor VIII, von Willebrand factor and plasminogen activator inhibitor compared to non-obese subjects. Abdominal obesity, in particular, has been shown to be associated with disturbances in fibrinogen, factor VIII and von Willebrand factor, while less consistent results have been found for factor VII. Recently it has been demonstrated that the adipocyte itself is able to produce plasminogen activator inhibitor-1, possibly explaining the high levels found in obesity. Different studies have investigated the association between haemostatic and fibrinolytic parameters and the insulin resistance syndrome, often present in obese subjects. Fibrinogen has been found to be related to insulin, but it has been suggested that this relationship is not independent of the accompanying inflammatory reaction. Results from studies on the relationship between insulin resistance and factor VII, factor VIII and von Willebrand factor levels are inconsistent. In contrast, plasminogen activator inhibitor-1 has been found to correlate with all components of the insulin resistance syndrome, and can be considered as a true component of this metabolic syndrome. Weight loss seems to have a beneficial effect on factor VII--probably mediated through a reduction in triglycerides. Data on factor VIII and von Willebrand factor are scarce but weight loss does not seem to have an effect. Fibrinogen does not seem to be reduced by modest weight loss and a more substantial weight loss seems necessary to lower fibrinogen levels. In contrast, both modest and substantial weight loss have been found to significantly reduce plasminogen activator inhibitor-1 levels. In conclusion, the increased cardiovascular risk observed in obesity could in part be explained by the association between insulin resistance and components of the fibrinolytic and haemostatic systems. Whether this relationship is truly causal or indirect needs to be elucidated further.

Losartan and perindopril effects on plasma plasminogen activator inhibitor-1 and fibrinogen in hypertensive type 2 diabetic patients

BACKGROUND

This study compared the effects of losartan and perindopril on plasma plasminogen activator inhibitor-1 (PAI-1) and fibrinogen in hypertensive type 2 diabetic patients.

METHODS

We studied 85 nonsmoking outpatients, aged 46 to 64 years, with mild to moderate essential hypertension (diastolic blood pressure [BP] > 90 and < 110 mm Hg) and well controlled type 2 diabetes mellitus. After a 4-week washout placebo period, patients were randomized to received perindopril 4 mg once daily (n = 42) or losartan 50 mg once daily (n = 43) for 12 weeks according to a double-blind, parallel-group design. At the end of the placebo and active treatment periods, BP was measured and plasma PAI-1 and fibrinogen were evaluated.

RESULTS

Both perindopril and losartan reduced systolic and diastolic BP values (-16/15 mm Hg and -15/14, respectively; P < .001 v placebo), with no difference between the two treatments. Plasma PAI-1 was reduced by perindopril (-10 ng/dL, P = .028 v placebo) but not by losartan (+4 ng/dL, NS), the difference between the two treatments being statistically significant (P < .01). Plasma fibrinogen showed no significant change with both drugs, although a decreasing trend was noted with perindopril.

CONCLUSIONS

These findings indicate that perindopril but not losartan decreases PAI-1 in hypertensive type 2 diabetic patients, which suggests that the PAI-1 lowering effect is unrelated with AT, receptor blockade and could rather be due to the fact that the endothelial receptors that mediate PAI-1 expression in response to angiotensin II are not type 1 receptor subtypes. Different effects of the two drugs on the bradykinin system might also be implicated.

Screening for traditional risk factors for cardiovascular disease: a review for oral health care providers

BACKGROUND

Cardiovascular disease, or CVD, is associated with a very high rate of morbidity and mortality among people in the United States. Primary and secondary prevention measures will help reduce cardiovascular events and increase the overall health of the patient population.

METHODS

The author conducted MEDLINE and Internet searches and reviewed publications from professional organizations for the most up-to-date information on CVD and associated risk factors.

RESULTS

More than 450,000 articles and monographs on CVD were published in English between January 1990 and May 2001. Of these, approximately 45,000 discussed CVD and risk factors. The author selected and reviewed more than 550 publications on the basis of their relevance to epidemiology, etiology, and primary and secondary prevention of CVD.

CONCLUSIONS

Recent information regarding the pathogenesis and treatment of CVD suggests that oral health care providers can perform screening for risk factors and aid in monitoring of specific conditions that put people at an increased risk of developing and exacerbating existing CVD. Dentists need to take a proactive role in this endeavor.

CLINICAL IMPLICATIONS

As with most medical conditions, oral health care providers play an important function as it relates to the overall health of their patients. This article provides a timely update on CVD and the relationship between CVD and its risk factors, and offers suggestions for oral health care providers as to when they should interact with patients and patients' primary health care providers to possibly reduce the mortality and morbidity of CVD.

Independent relationship between microalbuminuria and plasminogen activator inhibitor-1 activity (PAI-1) activity in clinically healthy 58-year-old men

The aim of this cross-sectional study was to investigate the relationship between low-grade albuminuria (microalbuminuria) and factors of the coagulation- and fibrinolysis systems in 104 clinically healthy 58-year-old men recruited from the general population. Urinary albumin excretion was significantly associated with body mass index, systolic and diastolic blood pressure, plasminogen activator inhibitor (PAI)-1 activity, tissue plasminogen activator (tPA) antigen, tPA activity (negatively) and protein S (P<0.05). There were no associations between urinary albumin excretion and antithrombin III, fibrinogen, protein C, thrombin/antithrombin factor or von Willebrand factor. In multiple regression analysis urinary albumin excretion was independently and significantly associated with PAI-1 activity and systolic blood pressure (P<0.05). In conclusion we report that urinary albumin excretion was independently and significantly associated with PAI-1 activity in clinically healthy 58-year-old men. This relationship may contribute to the previously reported increased cardiovascular morbidity in subjects with microalbuminuria.

Effect of antihypertensive therapy using enalapril or losartan on haemostatic markers in essential hypertension: a pilot prospective randomised double-blind parallel group trial

To test the hypothesis that the hypercoagulable state in hypertension is significantly altered by anti-hypertensive therapy, we conducted a pilot prospective randomised double-blind trial of 40 untreated hypertensive patients (30 males, mean age 59 years) who were treated with either enalapril (10-20 mg per day) or losartan (50-100 mg per day) for 8 weeks. Thrombogenicity was assessed by measurement of plasma fibrinogen, soluble P-selectin (an index of platelet activation), plasminogen activator inhibitor 1 (PAI-1, an index of fibrinolysis) and von Willebrand factor (an index of endothelial dysfunction). Baseline von Willebrand factor alone was significantly higher in untreated hypertensive patients compared to controls (P<0.001). Following 8 weeks treatment with enalapril (mean dose 17 mg/day) or losartan (mean dose 77 mg/day), there was a significant reduction in mean blood pressure from 169+/-11/94+/-8 mmHg (baseline) to 147+/-14/84+/-7 mmHg (post-treatment) (P<0.001). However, there were no statistically significant changes in the levels of haemostatic markers (von Willebrand factor, fibrinogen, s-Psel and PAI-1). Our pilot study confirms previous observations of endothelial dysfunction in hypertensives. However, plasma fibrinogen and indices of platelet activation, fibrinolysis or endothelial dysfunction were not significantly affected by antihypertensive treatment with enalapril or losartan, despite satisfactory blood pressure control.

Angiotensin converting enzyme inhibitors: are they preferred first-line therapy?

In patients with hypertension, the primary goal is to reduce elevated blood pressure. All of the currently available and approved antihypertensive therapies are, by and large, equally efficacious. Some patient groups and individual patients may, however, respond differentially, and as a result one therapy may be more optimal than another. Overall, for uncomplicated hypertension and particularly for isolated systolic hypertension, diuretics should be considered for first-line therapy. However, comorbid conditions (which occur in > 50% of hypertensive patients) may prompt the need for a more ideal first-line therapy (eg, hypertension with diabetic nephropathy or with left ventricular dysfunction). Regardless, most patients with hypertension will require multidrug therapy to achieve the blood pressure goal, and an angiotensin converting enzyme (ACE) inhibitor may well be part of that therapy. Many going outcome trials comparing the newer therapies (such as ACE inhibitors) with diuretic-based therapy may redefine or clarify the use of different antihypertensive regimens.