Secretion of plasminogen activator inhibitor-1 from cultured human umbilical vein endothelial cells is induced by very low density lipoprotein

Clot or Not? Reviewing the Reciprocal Regulation Between Lipids and Blood Clotting

Both hyperlipidemia and thrombosis contribute to the risks of atherosclerotic cardiovascular diseases, which are the leading cause of death and reduced quality of life in survivors worldwide. The accumulation of lipid-rich plaques on arterial walls eventually leads to the rupture or erosion of vulnerable lesions, triggering excessive blood clotting and leading to adverse thrombotic events. Lipoproteins are highly dynamic particles that circulate in blood, carry insoluble lipids, and are associated with proteins, many of which are involved in blood clotting. A growing body of evidence suggests a reciprocal regulatory relationship between blood clotting and lipid metabolism. In this review article, we summarize the observations that lipoproteins and lipids impact the hemostatic system, and the clotting-related proteins influence lipid metabolism. We also highlight the gaps that need to be filled in this area of research.

The impact of the PCSK-9/VLDL-Receptor axis on inflammatory cell polarization

BACKGROUND

Studies have shown that lipoproteins, such as LDL and VLDL, as well as its major protein component ApoE2 impact on macrophage polarization important in atherosclerosis. Proprotein convertase subtilisin/kexin 9 (PCSK9) is a key regulator of lipoprotein receptor expression. The present study investigated the effect of the VLDL/VLDL-receptor (VLDL-R) axis on mononuclear cell polarization, as well as the role of PCSK9 and PCSK9 inhibitors (PCSK9i) within this network.

METHODS

Human monocytic THP-1 cells and human monocyte-derived macrophages isolated from peripheral blood mononuclear cells (PBMC) were treated with either LPS/IFN-γ to induce a pro-inflammatory phenotype, or with IL-4/IL-13 to induce an anti-inflammatory phenotype. Cells were then subjected to further treatments by lipoproteins, PCSK9, PCSK9i and lipoprotein receptor blockers.

RESULTS

LPS/IFN-γ treatment promoted a pro-inflammatory state with an increased expression of pro-inflammatory mediators such as TNF-α, CD80 and IL-1β. VLDL co-treatment induced a switch of this pro-inflammatory phenotype to an anti-inflammatory phenotype. In pro-inflammatory cells, VLDL significantly decreased the expression of pro-inflammatory markers e.g., TNF-α, CD80, and IL-1β. These effects were eliminated by PCSK9 and restored by co-incubation with a specific anti-PCSK9 monoclonal antibody (PCSK9i). Migration assays demonstrated that pro-inflammatory cells displayed a significantly higher invasive capacity when compared to untreated cells or anti-inflammatory cells. Moreover, pro-inflammatory cell chemotaxis was significantly decreased by VLDL-mediated acquisition of the anti-inflammatory phenotype. PCSK9 significantly lessened this VLDL-mediated migration inhibition, which was reversed by the PCSK9i.

CONCLUSION

VLDL promotes mononuclear cell differentiation towards an anti-inflammatory phenotype. PCSK9, via its capacity to inhibit VLDL-R expression, reverses the VLDL-mediated anti-inflammatory action, thereby promoting a pro-inflammatory phenotype. Thus, PCSK9 targeting therapies may exert anti-inflammatory properties within the vessel wall.

Hypertriglyceridemia: A Neglected Risk Factor for Ischemic Stroke?

Hypertriglyceridemia is caused by defects in triglyceride metabolism and generally manifests as abnormally high plasma triglyceride levels. Although the role of hypertriglyceridemia may not draw as much attention as that of plasma cholesterol in stroke, plasma triglycerides, especially nonfasting triglycerides, are thought to be correlated with the risk of ischemic stroke. Hypertriglyceridemia may increase the risk of ischemic stroke by promoting atherosclerosis and thrombosis and increasing blood viscosity. Moreover, hypertriglyceridemia may have some protective effects in patients who have already suffered a stroke via unclear mechanisms. Therefore, further studies are needed to elucidate the role of hypertriglyceridemia in the development and prognosis of ischemic stroke.

Positive correlation of serum angiopoietin-like protein 3 levels with metabolic syndrome in patients with coronary artery disease

Objectives:

Angiopoietin-like protein 3 (ANGPTL3) regulates triglyceride metabolism by reversibly inhibiting the lipoprotein lipase activity. Metabolic syndrome (MetS) is an independent risk factor for further cardiovascular disease. This study evaluated the relationship between the fasting serum ANGPTL3 levels and MetS in patients with coronary artery disease (CAD).

Materials and Methods:

Fasting blood samples were obtained from 90 patients with CAD. Serum ANGPTL3 levels were measured using a commercial enzyme-linked immunosorbent assay kit. MetS and its components were defined using the diagnostic criteria of the International Diabetes Federation.

Results:

Fifty-three patients (58.9%) had MetS. The hypertension (P = 0.001), diabetes (P < 0.001), body weight (P = 0.027), body mass index (P = 0.001), waist circumference (P < 0.001), systolic blood pressure (P = 0.001), fasting glucose (P < 0.001), triglycerides (P < 0.001), blood urea nitrogen (P = 0.044), C-reactive protein (P = 0.010), insulin (P = 0.040), homeostasis model assessment of insulin resistance (P = 0.002), and ANGPTL3 level (P = 0.001) of CAD patients who had MetS were higher, and the high-density lipoprotein cholesterol (P = 0.001) and estimated glomerular filtration rate (P = 0.016) were lower. A binary logistic regression analysis of the significant variables also revealed that the ANGPTL3 level (odds ratio: 1.023, 95% confidence interval: 1.008–1.038, P = 0.002) was an independent predictor of MetS in patients with CAD.

Conclusion:

The results of our study indicated that the fasting ANGPTL3 level was positively associated with MetS among patients with CAD.

Randomization to Omega-3 Fatty Acid Supplementation and Endothelial Function in COPD: The COD-Fish Randomized Controlled Trial

Rationale

Studies suggest a pathogenic role of endothelial dysfunction in chronic obstructive lung disease (COPD). Omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation improves endothelial function in other diseases but has not been examined in COPD.

Objective

We hypothesized that n-3 PUFA supplementation would improve systemic endothelial function in COPD. We performed a pilot randomized, placebo-controlled, double-blind, phase 2 superiority trial (NCT00835289).

Methods

Adults with moderate and severe stable COPD (79% with emphysema on computed tomography [CT]) were randomized to high-dose fish oil capsules or placebo daily for 6 months. The primary endpoint was percentage change in brachial artery flow-mediated dilation (FMD) from baseline to 6 months. Secondary endpoints included peripheral arterial tonometry, endothelial microparticles (EMPs), 6-minute walk distance, respiratory symptoms, and pulmonary function.

Results

Thirty-three of 40 randomized participants completed all measurements. Change in FMD after 6 months did not differ between the fish oil and placebo arms (-1.1%, 95% CI -5.0-2.9, p=0.59). CD31⁺ EMPs increased in the fish oil arm (0.9%, 95% CI 0.1-1.7, p=0.04). More participants in the fish oil arm reported at least a 4-point improvement in the St George's Respiratory Questionnaire (SGRQ) compared to placebo (8 versus 1; p=0.01). There were no significant changes in other secondary endpoints. There were 4 serious adverse events determined to be unrelated to the study (3 in the fish oil arm and 1 in the placebo arm).

Conclusion

Randomization to n-3 PUFAs for 6 months did not change systemic endothelial function in COPD. Changes in EMPs and SGRQ suggest n-3 PUFAs might have biologic and clinical effects that warrant further investigation.

Environmental and Genetic Risk Factors Associated with Venous Thromboembolism

Venous thromboembolism (VTE) includes deep vein thrombosis and pulmonary embolism, and a combination of environmental and genetic risk factors contributes to VTE risk. Within environmental risk factors, some are provoking (e.g., cancer, surgery, trauma or fracture, immobilization, pregnancy and the postpartum period, long-distance travel, hospitalization, catheterization, and acute infection) and others are nonprovoking (e.g., age, sex, race/ethnicity, body mass index and obesity, oral contraceptive or hormone therapy use, corticosteroid use, statin use, diet, physical activity, sedentary time, and air pollution). Additionally, VTE has a strong genetic basis, with approximately 50 to 60% of the variance in VTE incidence attributed to genetic effects. Some genetic susceptibility variants that contribute to risk have been identified in candidate genes, mostly related to the clotting system and responsible for inherited hypercoagulable states (e.g., factor V Leiden, prothrombin, fibrinogen gamma, or blood group non-O). Other susceptibility single-nucleotide polymorphisms have been identified from genome-wide association studies, such as the two new loci in TSPAN15 (rs78707713) and SCL44A2 (rs2288904) genes. Risk factors are not always associated with VTE in isolation; however, and an understanding of how environmental and genetic factors interact may provide insight into the pathophysiology of VTE, possibly identifying opportunities for targeted prevention and treatment.

Recurrence of superficial vein thrombosis in patients with varicose veins

Objective

To investigate which factors other than history of superficial vein thrombosis (SVT) are associated with recurrent spontaneous SVT episodes in patients with varicose veins (VVs).

Materials and methods

Patients with a history of spontaneous SVT and VVs were followed up for a mean period of 55 months. Demographics, comorbidities, and thrombophilia screening test were analyzed. Patients were grouped according to the clinical–etiology–anatomy–pathophysiology classification. A multiple logistic regression analysis with the forward likelihood ratio method was undertaken.

Results

Thirteen patients out of 97 had a recurrence SVT episode during the follow-up period. All those patients were identified to have a thrombophilia defect. Protein C and S, antithrombin, and plasminogen deficiencies were more frequently present in patients without recurrence. Gene mutations were present in 38% in the nonrecurrence group and 77% in the recurrence group. After logistic regression analysis, patients with dislipidemia and mutation in prothrombin G20210A (FII) had an increased risk for recurrence by 5.4-fold and 4.6-fold, respectively. No deep vein thrombosis or pulmonary embolism occurred.

Conclusions

Dislipidemia and gene mutations of F II are associated with SVT recurrence in patients with VVs. A selection of patients may benefit from anticoagulation in the short term and from VVs intervention in the long term.

Lipids and Diabetic Retinopathy

The relationship between lipids and the development and/or severity of diabetic retinopathy (DR) is complex. Large epidemiologic studies suggest an inconsistent and overall modest association between serum triglycerides or major cholesterol species and the severity of DR; however, certain specific lipoprotein species may have stronger associations with DR severity, suggesting a pathophysiological role for lipoproteins analogous to that seen in atherosclerosis. In this lipoprotein-mediated DR pathogenesis model, damage to the blood-retinal barrier allows extravasation of lipoprotein species, which are modified in the intraretinal environment, creating substantial local damage. Additionally, hypolipidemic therapy with statins and fibrates--particularly the latter--have been shown to modulate DR in large-scale studies. Since serum lipid profile changes do not necessarily correlate with DR modulation, the efficacy of these agents may be due to their tissue-specific changes in lipoproteins and/or their anti-inflammatory, antioxidative, antiangiogenic, and antiapoptotic functions.

Estrogen regulates endothelial migration via plasminogen activator inhibitor (PAI-1)

Endothelial plasminogen activator inhibitor (PAI-1) controls vascular remodeling, angiogenesis and fibrinolysis. PAI-1 blood levels in women are related to estrogen. The aim of this study was to characterize the signaling pathways through which estrogen regulates PAI-1 in endothelial cells. Furthermore, we aimed to investigate whether PAI-1 is implicated in the control of endothelial migration by estrogen. Cultured human umbilical vein endothelial cells (HUVECs) and ovariectomized rats were used to test the effects of 17β-estradiol (E(2)) on PAI-1 expression and its role on endothelial migration. At physiological concentrations, E(2) increases the expression of PAI-1 in HUVEC within 6-12 h through activation of a signaling cascade initiated by estrogen receptor α and involving G proteins, phosphatidylinositol-3-OH kinase and Rho-associated kinase II. ROCK-II activation turns into an over-expression of c-Jun and c-Fos that is required for E(2)-induced expression of PAI-1. Estrogen-induced PAI-1 expression is implicated in HUVEC horizontal migration. PAI-1 regulation is found also in vivo, in female rats, where ovariectomy is associated with reduced PAI-1 expression, while estrogen replacement counteracts this change. In conclusion, E(2) increases PAI-1 synthesis in human endothelial cells and in rodent aorta through a G protein-initiated signaling that targets early-immediate gene expression. This regulatory pathway is implicated in endothelial cell migration. These findings describe new mechanisms of action of estrogens in the vessels, which may be important for vascular remodeling and hemostasis.

HDL3, but not HDL2, stimulates plasminogen activator inhibitor-1 release from adipocytes: the role of sphingosine-1-phosphate

Sphingosine-1-phosphate (S1P) is a bioactive lysophospholipid that regulates numerous key cardiovascular functions. High-density lipoproteins (HDLs) are the major plasma lipoprotein carriers of S1P. Fibrinolysis is a physiological process that allows fibrin clot dissolution, and decreased fibrinolytic capacity may result from increased circulating levels of plasminogen activator inhibitor-1 (PAI-1). We examined the effect of S1P associated with HDL subfractions on PAI-1 secretion from 3T3 adipocytes. S1P concentration in HDL3 averaged twice that in HDL2. Incubation of adipocytes with increasing concentrations of S1P in HDL3, but not HDL2, or with S1P complexed to albumin stimulated PAI-I secretion in a concentration-dependent manner. Quantitative RT-PCR revealed that S1P(1-3) are expressed in 3T3 adipocytes, with S1P(2) expressed in the greatest amount. Treatment of adipocytes with the S1P(1) and S1P(3) antagonist VPC23019 did not block PAI-1 secretion. Inhibiting S1P(2) with JTE-013 or reducing the expression of the gene coding for S1P(2) using silencing RNA (siRNA) technology blocked PAI-1 secretion, suggesting that the S1P(2) receptor mediates PAI-1 secretion from adipocytes exposed to HDL3 or S1P. Treatment with the phospholipase C (PLC) inhibitor U73122, the protein kinase C (PKC) inhibitor RO-318425, or the Rho-associated protein kinase (ROCK) inhibitor Y27632 all significantly inhibited HDL3- and S1P-mediated PAI-1 release, suggesting that HDL3- and/or S1P-stimulated PAI-1 secretion from 3T3 cells is mediated by activation of multiple, downstream signaling pathways of S1P(2).

Sedentary subjects have higher PAI-1 and lipoproteins levels than highly trained athletes

Physical exercise protects against the development of cardiovascular disease, partly by lowering plasmatic total cholesterol, LDL-cholesterol and increased HDL-cholesterol levels. In addition, it is now established that reduction plasmatic adiponectin and increased C-reactive protein (CRP) and plasminogen activator inhibitor-1 (PAI-1) levels play a role in the maintenance of an inflammatory state and in the development of cardiovascular disease. This study aimed to examine plasma lipid profile and inflammatory markers levels in individual with sedentary lifestyle and/or highly trained athletes at rest.

METHODS

Fourteen male subjects (sedentary lifestyle n = 7 and highly trained athletes n = 7) were recruited. Blood samples were collected after an overnight fast (approximately 12 h). The plasmatic lipid profile (Triglycerides, HDL-cholesterol, LDL-cholesterol, total cholesterol, LDL-oxidized and total cholesterol/HDL-c ratio), glucose, adiponectin, C - reactive protein and PAI-1 levels were determined.

RESULTS

Total cholesterol, LDL-cholesterol, TG and PAI-1 levels were lower in highly trained athletes group in relation to sedentary subjects (p < 0.01). In addition, we observed a positive correlation between PAI-1 and total cholesterol (r = 0.78; p < 0.0009), PAI-1 and LDL-c (r = 0.69; p < 0.006) and PAI-1 and TG levels (r = 0.56; p < 0.03). The plasma concentration of adiponectin, CRP, glucose, HDL-cholesterol and total cholesterol/HDL-c ratio levels were not different. These results indicate that lifestyle associated with high intensity and high volume exercise induces changes favourable in the lipid profile and PAI-1 levels and may reduce risk cardiovascular diseases.

Acute ingestion of long-chain (n-3) polyunsaturated fatty acids decreases fibrinolysis in men with metabolic syndrome

Individuals with metabolic syndrome (MetS) often have elevated plasma plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (t-PA), contributing to an increased risk of cardiovascular disease. PAI-1 and t-PA may be affected by chronic (n-3) long-chain PUFA [(n-3)LCPUFA] supplementation; however, the acute impact of fat ingestion on these risk factors has not been established. Our objective was to investigate the acute effect of (n-3)LCPUFA on plasma PAI-1, t-PA, and platelet aggregation. We conducted a randomized crossover study in which men (n = 8, > or =45 y) with MetS consumed water or a high-saturated fat beverage (1 g fat/kg body weight) with either a high or low content of (n-3)LCPUFA. Blood samples were collected over 8 h to measure triacylglycerol (TAG), PAI-1, t-PA, and platelet aggregation. Both fat loads resulted in a significant increase in whole blood TAG concentration, plasma PAI-1 and t-PA concentrations, and PAI-1 activity, as well as a significant decrease in t-PA activity during the postprandial period. Interestingly, PAI-1 concentration and activity increased more following the high (n-3)LCPUFA compared with the low (n-3)LCPUFA beverage (P < 0.05). Furthermore, the high (n-3)LCPUFA beverage resulted in a lower t-PA activity (P < 0.05), whereas the effects of the 2 fat loads on the plasma t-PA concentration and platelet aggregation did not differ. Overall, acute intake of a high (n-3)LCPUFA beverage shifted the balance between plasma PAI-1 and t-PA, which might indicate a lower capacity for fibrinolysis.

A study on the action of vitamin E supplementation on plasminogen activator inhibitor type 1 and platelet nitric oxide production in type 2 diabetic patients

BACKGROUND AND AIM

Type 2 diabetic (T2DM) patients show decreased fibrinolysis, mainly linked to high plasminogen activator inhibitor type 1 (PAI-1) production, together with a reduced bioavailability of nitric oxide and an impairment in Na(+)/K(+)-ATPase activity possibly involved in increased cardiovascular risk. Vitamin E is the major natural lipid-soluble antioxidant in human plasma. The present work was conducted in order to measure PAI-1, ICAM and VCAM-1 plasma levels, platelet nitric oxide production and membrane Na(+)/K(+)-ATPase activity in type 2 diabetic subjects treated with vitamin E (500 IU/day) for 10 weeks and then followed for other 20 weeks.

METHODS AND RESULTS

Thirty-seven T2DM patients (24 males and 13 females) were studied. None of them were affected by any other disease or diabetic complications. Significant differences were detected for PAI-1 antigen (p<0.001), PAI-1 activity (p<0.001), nitric oxide (NO) production (p<0.001), and Na(+)/K(+)-ATPase activity (p<0.001) among the 4 phases of the study. A significant decrease both in ICAM and VCAM-1 plasma levels was also found at the 10th week compared with baseline (respectively p<0.001 and p<0.05).

CONCLUSION

Our data suggest that vitamin E counteracts endothelial activation in T2DM patients possibly representing a new tool for endothelial protection.

Molecular mechanisms responsible for the antiinflammatory and protective effect of HDL on the endothelium

In addition to their role in reverse cholesterol transport, high-density lipoproteins (HDL) exert several beneficial effects, including the prevention and correction of endothelial dysfunction. HDL promote endothelium proliferation and diminish endothelial apoptosis; they play a key role in vasorelaxation by increasing the release of nitric oxide and prostacyclin through the induction of the expression and the activity of endothelial nitric oxide synthase and the coupling of cyclooxygenase 2 and prostacyclin synthase. In addition, HDL affect coagulation, fibrynolisis, platelet adhesion, adhesion molecules, and protease expression, and they exert antioxidant activity. These effects are achieved at the gene expression level and are dependent on the activation of several intracellular signaling pathways, including PI3K/Akt, ERK1/2, PKC, and p38MAPK. The complexity of the signaling pathways modulated by HDL reflects the different effects of the components of this class of lipoproteins such as apolipoproteins or lipids on endothelial cell gene expression and the subsequent modulation of endothelial function observed. The in vivo relevance of these findings to endothelial recovery during physiological or pathological conditions remains to be addressed; nevertheless, the results of clinical studies with synthetic HDL, ApoA-I mimetics, and drugs that are becoming available that selectively affect HDL plasma levels and biological functions support the importance of the correction of endothelial function by HDL.

PAI-1 and the Metabolic Syndrome

The link between plasminogen activator inhibitor (PAI)-1 and the metabolic syndrome with obesity was established many years ago. Increased PAI-1 level can be now considered a true component of the syndrome. The metabolic syndrome is associated with an increased risk of developing cardiovascular disease, and PAI-1 overexpression may participate in this process. The mechanisms of PAI-1 overexpression during obesity are complex, and it is conceivable that several inducers are involved at the same time at several sites of synthesis. Interestingly, recent in vitro and in vivo studies showed that besides its role in atherothrombosis, PAI-1 is also implicated in adipose tissue development and in the control of insulin signaling in adipocytes. These findings suggest PAI-1 inhibitors serve in the control of atherothrombosis and insulin resistance.

Impact of native VLDL on tissue factor pathway inhibitor in endothelial cells and interactions between TFPI and lipoprotein lipase

Tissue factor pathway inhibitor (TFPI) is a potent inhibitor of tissue factor (TF)-induced blood coagulation. A positive association between very low density lipoproteins (VLDLs) and TFPI has been reported in vivo. In contrast, one in vitro study indicates that TFPI may enhance lipoprotein lipase (LPL) activity, thereby increasing triglyceride hydrolysis. The current study was conducted to investigate how native VLDL influenced the synthesis and release of TFPI in endothelial cells, and how TFPI affected the LPL-induced hydrolysis of VLDL in vitro and at the endothelial surface. A spontaneously transformed immortal endothelial cell line (ECV304) and primary coronary artery cells (CoEc) were used, and VLDL was isolated from healthy volunteers by density gradient ultracentrifugation. Sequential free fatty acid (FFA) measurements were used to evaluate the kinetics of the LPL-induced hydrolysis. The levels of TFPI mRNAs in the stimulated cells were determined by quantitative real-time reverse transcription-ploymerase chain reaction (qPCR) using the ABI PRISM 7700 Sequence Detection System. Stimulation of ECV304 cells for 24 hours with native VLDL (0-100 microg/mL) caused a dose-dependent increase of TFPI in the medium (6.7-23.8 ng/10(6) cells, P < 0.001), without affecting the cellular content of TFPI. The expression of TFPI mRNA was significantly upregulated after 10 minutes of stimulation with n-VLDL. Both recombinant TFPI (r-TFPI) and LPL showed a dose-dependent binding to ECV 304 cells without saturation, and no competitive binding interactions between LPL and TFPI were observed at the endothelial surface. The addition of increasing concentrations of r-TFPI to ECV 304 cells, preincubated with LPL, did not affect the hydrolysis of VLDL triglycerides. The maximal reaction velocity (V(max)) of LPL-induced hydrolysis of n-VLDL was not affected by the addition of increasing concentrations of r-TFPI to the reaction mixture in vitro. The current experimental study indicates an upregulation of TFPI synthesis and release by VLDL. LPL-induced hydrolysis of VLDL in vitro was not influenced by TFPI neither in suspension nor at the endothelial surface.

Plasma triglycerides, an independent predictor of cardiovascular disease in men: A prospective study based on a population with prevalent metabolic syndrome

BACKGROUND AND METHODS

We aimed to assess whether fasting plasma triglycerides independently predicted future fatal and nonfatal cardiovascular disease (CVD) in a population having a high prevalence of the metabolic syndrome. In the Turkish Adult Risk Factor Study, a population-based survey, 2682 men and women 20 years of age or over with fasting triglyceride values available and free of CVD at baseline examination in 1990, were prospectively followed up till 2003/04. Triglyceride concentrations were measured by the enzymatic dry chemistry method and stratified into sex-specific quintiles. Information on the mode of death was obtained from first-degree relatives and/or health personnel of local health office. Diagnosis of coronary heart disease and stroke among survivors was based on history, physical examination of the cardiovascular system and Minnesota coding of resting electrocardiograms. A total of 120 fatal and 221 new nonfatal CVD occurred among adults (mean age 43+/-14) during a mean 9.3 years of follow-up.

RESULTS

CVD was significantly and independently predicted by the top versus the bottom fasting triglyceride quintile in logistic regression analyses when adjusted for age, sex, BMI, systolic blood pressure, total cholesterol, lipid-lowering medication, status of smoking and of glucose regulation (relative risk [RR] in men and all adults 2.38 and 1.79, respectively, p both <0.02). This corresponded to hazard ratios (HR) of 1.43 in men and 1.28 in men and women combined. Adjustment for HDL-cholesterol instead of total cholesterol in the same model gave also significant HRs corresponding to 1.42 in men and 1.32 in sexes combined.

CONCLUSIONS

Fasting triglycerides are predictive of future CVD among men with an HR of 1.4, independent of age, diabetes, lipid-lowering medication, traditional risk factors including total cholesterol or HDL-C, in a population in which metabolic syndrome prevails. A modest independent risk increment in women did not reach significance.

Effects of oxidized and glycated low-density lipoproteins on transcription and secretion of plasminogen activator inhibitor-1 in vascular endothelial cells

Plasminogen activator inhibitor-1 (PAI-1) is the major physiological inhibitor of fibrinolysis. Elevated levels of PAI-1 were frequently detected in patients with coronary artery disease (CAD) or diabetes. Low-density lipoprotein (LDL) is a classical risk factor of CAD. Oxidation and glycation increase the atherogenecity of LDL. Previous studies demonstrated that oxidized LDL (oxLDL) or glycated LDL (gly-LDL) increased the release of PAI-1 from endothelial cells (ECs). The present study examined the effects of oxLDL and gly-LDL on the transcription, expression, secretion, and subcellular distribution of PAI-1 in cultured human ECs. Treatment with LDL significantly increased the promoter activity, mRNA level, and the release of PAI-1 from ECs by two- to threefold compared to controls. Oxidation or glycation significantly enhanced the effects of LDL on PAI-1 production in ECs compared to LDL (four- to fivefold vs. controls). No significant differences were detected between the effects of oxLDL and gly-LDL. Abundant PAI-1 antigens were detected in the perinuclear region of ECs and overlapped with giantin, a marker of Golgi apparatus. Treatment with brefeldin A disturbed the stack structure of Golgi apparatus and almost completely inhibited the release of PAI-1 from ECs induced by the lipoproteins and at basal conditions. The results suggest that oxidation and glycation enhanced the effects of LDL on the production of PAI-1 in ECs through increasing the transcription of PAI-1. Intact Golgi apparatus is required for PAI-1 generation from ECs induced by LDL or its modified forms.

Impact of simvastatin on hemostatic and fibrinolytic regulators in Type 2 diabetes mellitus

Simvastatin, a widely used 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor, effectively reduced cardiac death and ischemic events in patients with coronary heart disease (CHD) and diabetes mellitus (DM). The mechanism of cardiovascular benefits of statins in DM remains unclear. We examined how simvastatin influences the levels of several in vivo markers for coagulation and fibrinolysis in 26 Type 2 DM patients. The diabetic patients received 20 mg/day of simvastatin up to 12 months. The levels of total cholesterol (TC), low density lipoprotein-cholesterol (LDL-c) and triglycerides in peripheral circulation of patients were significantly reduced after > or =6 weeks of simvastatin treatment. Levels of prothrombin fragment 1+2 (F1+2), factor VII, plasminogen activator inhibitor-1 (PAI-1) and tissue factor pathway inhibitor (TFPI) antigens, but not tissue plasminogen activator (tPA) antigen, in the pre-simvastatin plasmas of the diabetic patients were significantly higher than the levels found in plasmas of healthy subjects. Significant reductions in F1+2 and PAI-1 levels were evident > or =6 weeks after the diabetic patients received simvastatin. Levels of total tPA, TFPI, FVII, hemoglobin A1c, fasting blood glucose, and insulin in the diabetic patients' plasma were not significantly altered by simvastatin treatment. Positive correlations were found between PAI-1 versus TC, PAI-1 versus LDL-c, and FVII versus triglycerides in the plasmas of simvastatin-treated patients. The results suggest that simvastatin reduces in vivo prothrombinase activity and PAI-1 levels in type 2 DM patients. These actions may contribute to the protective properties of simvastatin against ischemic events in diabetic patients.

A polymorphism of the plasminogen activator inhibitor-1 gene promoter and the polycystic ovary syndrome

OBJECTIVE

To investigate the association of a common 5G/4G polymorphism of the plasminogen activator inhibitor-1 gene (PAI1) with occurrence and clinical characteristics of the polycystic ovary syndrome (PCOS).

STUDY DESIGN

In a case-control study, we evaluated a series of 106 Caucasian women with PCOS and 102 healthy controls. Women completed a detailed questionnaire and underwent a peripheral venous puncture, ultrasonography, and a standardized oral glucose tolerance test (OGTT). The PAI1 gene promoter polymorphism was evaluated using PCR.

RESULTS

Allele and genotype frequencies were not significantly different among women with PCOS and controls (P=0.3 and 0.6, respectively). In women with PCOS, presence of the 5G/4G polymorphism of PAI1 was not associated with changes in serum hormone levels or with clinical characteristics.

CONCLUSIONS

The 5G/4G polymorphism of the PAI1 promoter is not associated with occurrence and phenotype of the PCOS.

Molecular mechanisms of fibrinolysis

The molecular mechanisms that finely co-ordinate fibrin formation and fibrinolysis are now well defined. The structure and function of all major fibrinolytic proteins, which include serine proteases, their inhibitors, activators and receptors, have been characterized. Measurements of real time, dynamic molecular interactions during fibrinolysis of whole blood clots can now be carried out in vitro. The development of gene-targeted mice deficient in one or more fibrinolytic protein(s) has demonstrated expected and unexpected roles for these proteins in both intravascular and extravascular settings. In addition, genetic analysis of human deficiency syndromes has revealed specific mutations that result in human disorders that are reflective of either fibrinolytic deficiency or excess. Elucidation of the fine control of fibrinolysis under different physiological and pathological haemostatic states will undoubtedly lead to novel therapeutic interventions. Here, we review the fundamental features of intravascular plasmin generation, and consider the major clinical syndromes resulting from abnormalities in fibrinolysis.

Influence of long-term intervention with dietary counseling, long-chain n-3 fatty acid supplements, or both on circulating markers of endothelial activation in men with long-standing hyperlipidemia

BACKGROUND

Dietary factors and very-long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) may influence the atherothrombotic process. Elevated concentrations of circulating cell adhesion molecules, thrombomodulin (TM), von Willebrand factor (vWF), and tissue-type plasminogen activator antigen (tPAag) are related to atherothrombotic cardiovascular disease.

OBJECTIVE

The randomized Diet and Omega-3 Intervention Trial (DOIT) targeted a comparison of the effect of 3-y dietary counseling, n-3 PUFA supplementation (2.4 g/d), or both on circulating markers of endothelial activation.

DESIGN

The study included 563 elderly men with long-standing hyperlipidemia. The men were randomly assigned by factorial design into 4 groups: control (no dietary counseling and placebo capsules), dietary counseling (and placebo capsules), n-3 PUFA supplementation (no dietary counseling), and dietary counseling and n-3 PUFA supplementation.

RESULTS

Serum concentrations of fatty acids reflected good compliance. Dietary counseling was followed by significantly reduced concentrations of soluble intercellular adhesion molecule 1 (sICAM-1; P < 0.001), sTM (P = 0.004), and tPAag (P < 0.001) than in subjects without dietary counseling. After n-3 PUFA supplementation, significantly reduced concentrations of sICAM-1 (P < 0.001) and sTM (P = 0.006) were observed when compared with subjects receiving placebo capsules. An increase in tPAag was not significantly different from that observed in subjects receiving placebo capsules. For sICAM-1, a significant effect was observed for both interventions combined.

CONCLUSIONS

Each intervention (dietary counseling or n-3 PUFA supplements) reduced sTM and sICAM-1 concentrations, indicating decreased endothelial activation. The tPAag increase in the groups not receiving dietary counseling (pooled), which indicates progression of atherosclerosis, was significantly counteracted by dietary counseling.

Effect of delapril-manidipine combination vs irbesartan-hydrochlorothiazide combination on fibrinolytic function in hypertensive patients with type II diabetes mellitus

The aim of this double-blind, double-dummy, parallel group study was to compare the effects of delapril-manidipine combination vs a irbesartan-hydrochlorothiazide combination on plasma tissue plasminogen activator (t-PA) and plasmogen activator inhibitor type I (PAI-l) activities in hypertensive patients with type II diabetes mellitus. After a 4-week run-in placebo period, 80 patients (37 male and 43 female), aged 41-65 years, were randomly allocated to an 8-week treatment with delapril 30 mg once daily or irbesartan 150 mg once daily. Thereafter, manidipine l0 mg once daily was added to delapril treatment and hydrochlorothiazide 12.5 mg to irbesartan treatment for a further 8 weeks. Blood pressure (BP), plasma t-PA and PAI-l activities were evaluated at the end of the run-in period, after 4-week monotherapy treatments, and at the end of the combination treatment periods. Both combination treatments, delapril-manidipine and irbesartan-hydrochlorothiazide, produced a greater reduction in systolic BP/diastolic BP (SBP/DBP) values (-27.6/21.8 mmHg and -26.4/20.2 mmHg, respectively) than the respective monotherapies (-15.2/11.7 mmHg with delapril and -16.3/11.3 mmHg with irbesartan). Delapril monotherapy significantly decreased plasma PAI-l activity (-10.4 IU/mI; P<0.05). The addition of manidipine produced a significant increase in t-PA activity (+0.27 IU/mI); P<0.05). Irbesartan monotherapy did not significantly affect the fibrinolytic balance, whereas the addition of hydrochlorothiazide worsened it, producing a significant increase in PAI-l activity (+9.5 IU/ml; P<0.05). In hypertensive patients with type II diabetes mellitus, the combination delapril-manidipine may determine a greater improvement of the fibrinolytic function than the respective monotherapy, while the association irbesartan-hydrochlorothiazide may worsen it.

Is the effect of antihypertensive drugs on platelet aggregability and fibrinolysis clinically relevant?

Hypertension is associated with decreased fibrinolytic potential, mainly expressed as elevated plasma plasminogen activator inhibitor type 1 (PAI-1) levels, and increased platelet aggregability, which may account in part for the increased risk of atherosclerosis and its clinical complications in hypertensive patients. The effects of antihypertensive drugs on this prothrombotic state have been investigated and controversial findings have been reported, possibly because of differences in study designs, patients selected, and methodology used. Scarce and conflicting data exist about the effects of diuretics and beta-adrenoceptor antagonists on the fibrinolytic system, whereas ACE inhibitors have generally been reported to improve the fibrinolytic balance by decreasing plasma PAI-1 levels, calcium channel antagonists have been shown to increase tissue plasminogen activator (tPA) activity, and angiotensin II type 1 (AT(1)) receptor antagonists seem to exert neutral effects. beta-Adrenoceptor antagonists, calcium channel antagonists, and AT(1)-receptor antagonists have been reported to exert anti-aggregatory effects on platelets, while contrasting data exist about the influence of ACE inhibitors. Clinical implications of the changes induced by antihypertensive drugs on the fibrinolytic balance and platelet function are still debated. In particular, the question of whether these changes may translate into different degrees of cardiovascular protection in hypertensive patients remains unanswered. While awaiting more information from clinical trials, the choice of antihypertensive drugs, particularly in high-risk patients, should take into account effects beyond their BP-lowering efficacy. Selected agents should have a favorable, or at least neutral, impact on fibrinolytic function and platelet activity.

Cholesterol diet enhances daily rhythm of Pai-1 mRNA in the mouse liver

Myocardial infarction frequently occurs in the morning, a phenomenon in part resulting from the downregulation of fibrinolytic activity. Plasminogen activator inhibitor-1 (PAI-1) is a key factor behind fibrinolytic activity, and its gene expression is controlled under the circadian clock gene in the mouse heart and liver. Hypercholesterolemia has been associated with impaired fibrinolysis due to enhanced PAI-1 activity, which has also been implicated in atherosclerosis. The aim of this study was to decipher whether the Pai-1 gene is still expressed daily with hypercholesterolemia. Hypercholesterolemia (1% cholesterol diet) did not significantly affect the daily expression of clock genes (Per2 and Bmal1) and clock-controlled genes (Dbp and E4bp4) in the liver (P > 0.05); however, daily expression of the Pai-1 gene and Pai-1 promoter regulating factor genes such as Nr4a1 was significantly upregulated (P < 0.01). Daily restricted feeding for 4 h during the day reset the gene expression of Per2, Pai-1, Nr4a1, and Tnf-alpha. Lesion of the suprachiasmatic nucleus, the location of the main clock system, led to loss of Per2 and Pai-1 daily expression profiles. In the present experiments, we demonstrated that hypercholesterolemia enhanced daily expression of the Pai-1, Tnf-alpha, and Nr4a1 genes in the mouse liver without affecting clock and clock-controlled genes. Therefore, the risk or high frequency of acute atherothrombotic events in the morning still seems to be a factor that may be augmented under conditions of hypercholesterolemia.

Leptin and insulin down-regulate angiopoietin-like protein 3, a plasma triglyceride-increasing factor

We reported previously that angiopoietin-like protein3 (ANGPTL3), a liver-specific secretory factor, increased plasma triglyceride (TG) via inhibition of lipoprotein lipase and free fatty acid (FFA) by activating adipose-lipolysis. The current study examined the regulation of Angptl3 by leptin and insulin, both of which are key players in the metabolic syndrome. Angptl3 expression and plasma ANGPTL3 levels were increased in leptin-resistant C57BL/6J(db/db) and -deficient C57BL/6J(ob/ob) mice, relative to the control. Leptin supplements decreased Angptl3 gene expression and plasma ANGPTL3 in C57BL/6J(ob/ob) mice. The changes of Angptl3 were associated with alterations of plasma TG and FFA levels. Leptin treatment directly suppressed Angptl3 gene expression in hepatocytes. Angptl3 gene expression and plasma protein levels were also increased in insulin-deficient streptozotocin-treated mice. Insulin treatment of hepatocytes decreased Angptl3 gene expression and protein secretion. Our results suggest that elevated ANGPTL3 by leptin- or insulin-resistance is attributed to increased plasma TG and FFA concentrations in obesity.

Effects of atorvastatin (10 mg) on hemostatic and inflammatory parameters in hyperlipidemic patients with angiographically proven coronary artery disease

Hyperlipidemic patients with coronary heart disease were treated with atorvastatin, and its effects on hemostatic and inflammatory parameters were assessed. After 3 months of therapy, the plasma levels of plasminogen activator inhibitor, prothrombin fragment 1+2, highly sensitive C-reactive protein, von Willebrand factor, and fibrinogen were significantly reduced; no significant reductions were observed in lipoprotein(a) and tissue plasminogen activator antigen levels.

Interrelationships between the fibrinolytic system and lipoproteins in the pathogenesis of coronary atherosclerosis

The fibrinolytic system is comprised of a series of serine proteases and serine protease inhibitors which are involved in the dissolution of fibrin in the vascular lumen, but also in the migration of cells and in the remodeling of the extracellular matrix of the vascular wall. The transcription, expression and degradation of the various fibrinolytic enzymes by cells in the vascular wall is influenced by lipoproteins and this interrelationship may play a significant role in the development of the atherosclerotic plaque: the transcription of plasminogen activator inhibitor-1 is influenced by very low-density lipoproteins, the expression of both tissue plasminogen activator and plasminogen activator inhibitor-1 is influenced by low-density lipoproteins and lipoprotein(a) (Lp(a)) and the internalization of the urokinase: plasminogen activator inhibitor-1 complex occurs via the low-density lipoprotein related protein. Several clinical studies have shown correlations between fibrinolytic parameters and lipoproteins in healthy populations and in patients with dyslipidemia, but the correlation between single plasma fibrinolytic enzymes and the severity of coronary atherosclerosis is less well documented. The reduction of plasma lipids with lipid-lowering drugs also affects the concentration of fibrinolytic enzymes, although this may also be due to direct effects of the drugs on the expression of the various fibrinolytic enzymes. The reduction of fibrinolytic and proteolytic activity in the atherosclerotic plaque by their lipid-lowering effect and by their direct action on the fibrinolytic system may be one of the mechanisms by which some lipid-lowering drugs achieve plaque stabilization.

Endothelial function and postprandial lipemia

It is widely recognised that post-prandial lipoproteins play a role in the development of atherosclerosis, but the mechanisms underlying this role are unclear. An attractive working hypothesis is that the pathogenetic link is endothelial dysfunction. The available data seem to corroborate this theory and recognise triggering by oxidative stress, but some of the evidence is still contradictory.

Metabolic syndrome: an appraisal of the pro-inflammatory and procoagulant status

Inflammation and hypercoagulability predispose to atherothrombosis and seem to be important features of the metabolic syndrome. The most convincing evidence is the association with increased levels of C-reactive protein. The hemostatic abnormality that has been most consistently associated with insulin resistance is an elevated plasminogen activator inhibitor-1 level. In contrast, markers of hypercoagulability have been associated inconsistently with hyperinsulinemia and glucose intolerance. Fibrinogen clusters with inflammatory factors, which suggests involvement of adipose tissue-generated inflammatory cytokines. Elevated von Willebrand's factor and factor VIII levels aggregate with indicators of endothelial injury,whereas vitamin K-dependent coagulation proteins correlate with triglyceride levels.

Hypofibrinolysis in the insulin resistance syndrome: implication in cardiovascular diseases

Insulin resistance syndrome (IRS) is associated with increased cardiovascular morbidity and mortality. IRS is becoming one of the major health problems as its prevalence grows rapidly. Accelerated atherothrombotic process in the IRS is attributed to metabolic abnormalities, inflammation and to impaired fibrinolysis due to increased plasma plasminogen activator inhibitor type 1 (PAI-1) levels. Proinflammatory cytokines may have an important role in PAI-1 overexpression, particularly in the adipose tissue. Studies in genetically modified mice indicate that PAI-1 might be involved in the aetiopathogenesis of obesity. Modifying PAI-1 expression by PAI-1 inhibitors may open a new field of research and may reveal the true role of PAI-1 in atherosclerotic and insulin resistance processes.

Chronic hypertriglyceridemia in young watanabe heritable hyperlipidemic rabbits impairs endothelial and medial smooth muscle function

Several studies have suggested that hypertriglyceridemia is a common risk factor for coronary heart disease. Although increasing serum levels of triglyceride correlate with hypercoagulability, little is known about the contribution of hypertriglyceridemia to vascular function. We successfully segregated two lines of rabbits with genetically-determined severely high (TGH; 2764 +/- 413 mg/dl) and moderately high (TGL; 191 +/- 12 mg/dl) levels of triglyceride, but with comparable levels of total cholesterol, from Watanabe heritable hyperlipidemic rabbits. To determine whether hypertriglyceridemia was involved in alterations of vascular function, we conducted isometric tension studies and analyzed protein expression on thoracic aortic rings isolated from young (3-4 month) TGH, TGL and Japanese White rabbit (JW). No difference in percentage of plaque area in the thoracic aorta was found between TGH and TGL. Relaxing responses, evoked by sodium nitroprusside were similar in JW, TGL and TGH, but endothelium-dependent relaxation to acetylcholine was impaired in TGH compared with JW or TGL (maximal relaxation in JW; 83.5 +/- 2.7%, TGL; 79.9 +/- 5.3%, TGH; 59.1 +/- 5.7%, p<0.05). Relaxation to A23187 was also attenuated in TGH compared with JW, but not significantly different between TGL and JW. Endothelium-independent relaxation elicited by isoproterenol in TGH was significantly decreased compared with JW or TGL (maximal relaxation in JW; 95.2 +/- 2.6% TGL; 91.0 +/- 4.9%, TGH; 75.1 +/- 5.2%, p<0.05). Protein expression of angiotensin II type-1 receptor was increased in TGH and that of nitric oxide synthases-3 was attenuated in TGH compared with TGL. This is the first study showing that endothelium-dependent and -independent vascular relaxation under the condition of combined hyperlipidemia was severely impaired as compared to that under only hypercholesterolemia. These results suggest that hypertriglyceridemia aggravates functional impairment induced by hypercholesterolemia in endothelial and smooth muscle cells.

Antiplatelet agents for the prevention of cardiovascular disease in diabetes mellitus

Patients with diabetes mellitus (DM) have accelerated atherothrombotic disease of coronary, cerebral, leg, and other vessels. The major cause of death is cardiovascular, and the risk for a myocardial infarction (MI) in a patient with DM who has never had a MI is the same as a nondiabetic individual who has already had one. In this paper, we review the major reasons for a prothrombotic state in patients with DM: alterations in the intrinsic coagulation and fibrinolytic systems and many abnormalities of platelet function. Increased platelet thromboxane production as well as activation of platelet receptors for fibrinogen and or adenosine diphosphate (ADP) are often present, and can be treated with aspirin (acetylsalicylic acid) and/or receptor blockers. Review of the major primary prevention trials in DM indicates that a significantly reduced risk for MI or major cardiovascular events may be obtained by enteric-coated aspirin, 81-325 mg/day. There is emerging consensus that this is recommended strategy in adult (aged >30 years) patients with DM who are at high vascular risk. Surveys suggest that this includes virtually every patient with type 2 DM in the US, as well as many patients with complicated type 1 DM. These recommendations are also appropriate for secondary prevention. Data supporting the use of clopidogrel as an alternative drug in the case of aspirin allergy or other contraindications are reviewed. Evidence is presented in support of using aspirin plus clopidogrel in acute coronary syndromes (ACS), and a meta-analysis of six trials of platelet glycoprotein (GP) IIb/IIIa inhibitors and aspirin in diabetic patients with ACS establishes this regimen as an effective choice. Although bleeding episodes are more common with combined antiplatelet therapy for ACS than for aspirin alone, the benefit of a significant reduction in 30-day mortality appears to outweigh the risk of major bleeding. It is concluded that major advances in our understanding of the prothrombotic state in DM have been made. Evidence from controlled clinical trials supports the use of enteric-coated aspirin, 81-325 mg/day, as a primary and a secondary prevention strategy in adults with DM with high vascular risk. In ACS, combination therapy with aspirin plus clopidogrel or alternatively, aspirin plus a platelet GP IIb/IIIa inhibitor is supported by prospective trial data. These approaches should be added to the other multifactorial preventive strategies directed at lowering the risk for major vascular events in patients with DM.

Plasminogen activator inhibitor-1, inflammation, obesity, insulin resistance and vascular risk

Elevated plasma plasminogen activator inhibitor-1 (PAI-1) level is a core feature of insulin-resistance syndrome (IRS). Atherothrombotic complications in IRS are partly attributed to impaired fibrinolysis caused by increased plasma PAI-1 levels. Although the etiology of IRS is far from being explained, the clustering of inflammation, adipose tissue accumulation and insulin resistance suggests an etiopathological link. Proinflammatory cytokines might regulate PAI-1 expression in IRS; however, more studies are needed to confirm this complex mechanism in humans. Furthermore, modifying PAI-1 expression by PAI-1 inhibitors provides a new challenge and may reveal the true role of PAI-1 in atherosclerotic and insulin resistance processes.

The renin-angiotensin system is involved in the production of plasminogen activator inhibitor type 1 by cultured endothelial cells in response to chylomicron remnants

Triglyceride-rich lipoproteins have been suggested to promote atherosclerosis. Plasminogen activator inhibitor type 1 (PAI-1) plays an important role in the events of cardiovascular pathophysiology. The renin-angiotensin system influences various vascular functions, including PAI-1 production. We examined whether or not chylomicron remnants increased PAI-1 mRNA and protein production in endothelial cells and whether or not an inhibition of the renin-angiotensin system interfered with this effect. Chylomicron remnants were isolated from functionally hepatectomized rats injected with chylomicrons. Human umbilical vein endothelial cell cultures (HUVECs) were incubated with chylomicron remnants with or without an angiotensin-converting enzyme inhibitor (temocaprilat), an angiotensin II receptor type 1 antagonist (RNH-6270), or an angiotensin II receptor type 2 antagonist (PD123319). Chylomicron remnants increased PAI-1 secretion in HUVECs (0.5 microg/ml; 128.3 +/- 6.1%, the mean +/- SEM) as well as angiotensin II (10 nmol/l; 130.7 +/- 9.5%) in 18 h, as compared with the controls, as well as stimulated PAI-1 mRNA expression to a maximum level at 4 h. Temocaprilat and RNH-6270, but not PD123319, attenuated all of these effects. Chylomicron remnants enhanced nuclear extract binding to a very low-density lipoprotein response element in the PAI-1 promoter region and activated nuclear factor-kappaB. Extracellular signal-regulated kinase (ERK 1/2) was phosphorylated in response to chylomicron remnants. These effects were inhibited by temocaprilat or RNH-6270. In conclusion, chylomicron remnants increased protein secretion and mRNA expression of PAI-1 in HUVECs. Inhibition of the renin-angiotensin system reduced this stimulation.

Molecular mechanisms of diabetic cardiovascular disease

Cardiovascular disease is a major cause of morbidity and mortality in persons with diabetes mellitus. This population represents an important target for preventive therapies aimed at reducing atherosclerosis. Recent molecular research has uncovered many of the cellular mechanisms that lead to atherosclerosis in the diabetic patient. This review, part 1 of a 2-part series, is geared toward clinicians and discusses these mechanisms as they pertain to prevention of cardiovascular disease in patients with diabetes.

Prognostic role of reversible endothelial dysfunction in hypertensive postmenopausal women

OBJECTIVES

; The aim of the present study was to assess whether optimized antihypertensive treatment is effective in modifying endothelial function and whether an improvement in flow-mediated vasodilation (FMD) in response to treatment, as an expression of reversible endothelial dysfunction, could predict a more favorable prognosis in a population of postmenopausal women.

BACKGROUND

Hypertensive postmenopausal women have been shown to have abnormal endothelium-dependent vascular function. However, FMD may change over time, according to antihypertensive treatment; the prognostic value of these changes has not been investigated.

METHODS

A total of 400 consecutive postmenopausal women with mild-to-moderate hypertension and impaired FMD underwent ultrasonography of the brachial artery at baseline and after six months, while optimal control of blood pressure was achieved using antihypertensive therapy. They were then followed up for a mean period of 67 months (range 57 to 78). Endothelial function was measured as FMD of the brachial artery, using high-resolution ultrasound.

RESULTS

After six months of treatment, FMD had not changed (< or = 10% relative to baseline) in 150 (37.5%) of 400 women (group 1), whereas it had significantly improved (>10% relative to baseline) in the remaining 250 women (62.5%) (group 2). During follow-up, we noticed 32 events (3.50 per 100 person-years) in group 1 and 15 events (0.51 per 100 person-years) in group 2 (p < 0.0001).

CONCLUSIONS

This study demonstrates that a significant improvement in endothelial function may be obtained after six months of antihypertensive therapy and clearly identifies patients who possibly have a more favorable prognosis.