Relationship between triglycerides and factor VIIc and plasminogen activator inhibitor type-1: lack of threshold value

Metabolites Associated With the Risk of Incident Venous Thromboembolism: A Metabolomic Analysis

Background Venous thromboembolism ( VTE ) is a complex thrombotic disorder that constitutes a major source of mortality and morbidity. To improve understanding of the cause of VTE , we conducted a metabolomic analysis in a case-control study including 240 incident VTE cases and 6963 controls nested within 3 large prospective population-based cohorts, the Nurses' Health Study, the Nurses' Health Study II , and the Health Professionals Follow-Up Study. Methods and Results For each individual, we measured 211 metabolites and collected detailed information on lifestyle factors. We performed logistic regression and enrichment analysis to identify metabolites and biological categories associated with incident VTE risk, accounting for key confounders, such as age, sex, smoking, alcohol consumption, body mass index, and comorbid diseases (eg, cancers). We performed analyses of all VTEs and separate analyses of pulmonary embolism. Using the basic model controlling for age, sex, and primary disease, we identified 60 nominally significant VTE - or pulmonary embolism-associated metabolites ( P<0.05). These metabolites were enriched for diacylglycerols ( P_permutation<0.05). However, after controlling for multiple testing, only 1 metabolite (C5 carnitine; odds ratio, 1.25; 95% confidence interval, 1.10-1.41; P_corrected=0.03) remained significantly associated with VTE . After further adjustment for body mass index, no metabolites were significantly associated with disease after accounting for multiple testing, and no metabolite classes were enriched for nominally significant associations. Conclusions Although our findings suggest that circulating metabolites may influence the risk of incident VTE , the associations we observed were confounded by body mass index. Larger studies involving additional individuals and with broader metabolomics coverage are needed to confirm our findings.

Plasminogen Activator Inhibitor 1 Activity and Other Coronary Risk Factors

Because only some coronary risk factors have been evaluated for an association with plasma plasminogen activator inhibitor 1 (PAI-1) activity, this cross-sectional study examined the association between 27 coronary risk factors and PAI-1 in 24 healthy persons without coronary heart disease (control persons) and 22 patients who had survived myocardial infarction (cases). The coronary risk factors included major coronary risk factors such as age, anthropometric measures such as intraabdominal fat, and biochemical analytes such as serum concentration of triglyceride and plasma von Willebrand factor activity. The associations were analyzed in univariate and multiple linear regression analyses. For the control persons, triglyceride and von Willebrand factor were significantly associated with PAI-1 activity (p=0.0002, R2=0.55). In contrast for the 24 cases, age and intraabdominal adipose tissue were significantly associated with PAI-1 (p=0.0011, R2=0.51). Coronary risk factors explained more than half the variation of PAI-1 activity for both study groups. However, healthy persons and patients with previous myocardial infarction differed regarding coronary risk factors associated with PAI-1.

The association of clot lysis time with total obesity is partly independent from the association of PAI-1 with central obesity in African adults

INTRODUCTION

Preliminary evidence indicates that the association of fibrinolytic potential, measured as clot lysis time (CLT), with body composition may differ from that of plasminogen activator inhibitor type-1 (PAI-1). We therefore investigated the association between fibrinolytic markers (plasminogen activator inhibitor type-1 activity (PAI-1act) and CLT) and body composition using detailed body composition analyses.

MATERIALS AND METHODS

Data from 1288 Africans were cross-sectionally analyzed. Body composition analysis included BMI, waist circumference (WC); waist to height ratio (WHtR), skinfolds and body fat percentage measured with air-displacement plethysmography and bioelectrical impedance analysis.

RESULTS

PAI-1act and CLT were significantly higher in women than in men, despite adjustment for differences in body composition. PAI-1act and CLT showed similar linear positive relationships with body composition (BMI, WC, WHtR, skinfolds) in men. In women CLT also showed a linear relationship with body composition, while PAI-1act levels plateaued at higher BMI and did not differ across skinfold categories. PAI-1act showed stronger correlations with body composition markers in men than it did in women, while no sex differences existed for CLT. PAI-1act associated more strongly with central obesity, while CLT associated with total body fat.

CONCLUSIONS

Observed differences may be related to differences in adipose tissue type, distribution and sequence of accumulation between sexes. PAI-1act is strongly influenced by accumulation of visceral adipose tissue, whereas CLT is associated with obesity independent of type and sequence of body fat accumulation in this African adult study population.

Effects of different protein sources on plasminogen inhibitor-1 and factor VII coagulant activity added to a fat-rich meal in type 2 diabetes

BACKGROUND

Exaggerated postprandial triglyceride concentration is believed to be atherogenic, and to influence the risk of thrombosis. Both elevated plasminogen inhibitor 1 (PAI-1) and increased factor VII coagulant activity (FVIIc) are potential important contributors to the increased risk of cardiovascular disease in type 2 diabetes.

AIM

We aimed to investigate the effect of adding four different protein types (i.e. casein, whey, cod, and gluten) to a fat-rich meal on postprandial responses of PAI-1 and FVIIc in type 2 diabetic patients.

METHODS

Twelve type 2 diabetic patients ingested four isocaloric test meals in random order. The test meals contained 100 g of butter and 45 g of carbohydrate in combination with 45 g of casein (Cas-meal), whey (Whe-meal), cod (Cod-meal), or gluten (Glu-meal), respectively. Plasma concentrations of PAI-1 and FVIIc were measured before meal, and at regular intervals for 8-h postprandially.

RESULTS

The postprandial PAI-1 concentration decreased significantly by 49% to 56% in response to the four test meals. There were no significant differences between the outcomes from the four test-meals. The FVIIc levels decreased by 8% to 11% after the meals. Again, we observed no significant differences in outcomes between the four protein-enriched meals.

CONCLUSIONS

The four proteins casein, whey, cod, and gluten, added to a fat-rich meal, all decreased the PAI-1 and FVIIc concentrations postprandially in type 2 diabetic subjects. However, postprandial levels of PAI-1 and FVIIc were not acutely influenced by the protein source.

Omega-3 polyunsaturated fatty acids: a necessity for a comprehensive secondary prevention strategy

Long-chain omega-3 polyunsaturated fatty acid (PUFA) supplementation has been used for the secondary prevention of fatal and nonfatal myocardial infarction (MI). However, the benefit of this therapy is frequently confused with other established treatments in the therapeutic strategy among such patients. We review the data on omega-3 PUFA use in secondary care and consider indications for its use which include post-MI and raised triglycerides. We suggest that the available evidence supports the use of omega-3 supplementation as part of the comprehensive secondary care package for post-MI patients.

Co-administration of ezetimibe and simvastatin in acute myocardial infarction

BACKGROUND

Recent trials in acute myocardial infarction indicate that intensive and early statin therapy that lowers low-density lipoprotein cholesterol (LDL-C) to < or = 70 mg dL(-1) is beneficial. The combination of statins with ezetimibe, a newly developed cholesterol-absorption inhibitor, can lead to a further reduction in LDL-C of up to 26%. In this study, we examined the rapidity and intensity of the lipid-lowering effect of ezetimibe co-administered with simvastatin immediately after myocardial infarction.

MATERIALS AND METHODS

Sixty patients admitted for acute myocardial infarction were randomized to receive either simvastatin 40 mg (SIMVA), a combination of simvastatin 40 mg and ezetimibe 10 mg (EZE/SIMVA), or no lipid-lowering drugs (NLLD) and had their lipid levels assessed 2, 4 and 7 days later.

RESULTS

At baseline, cardiovascular risk factors were similar in all three groups [mean (SD) LDL-C of 141 (36) mg dL(-1)]. At days 2 , 4 and 7 there was no significant change in mean LDL-C levels in the NLLD group (-10%, -6%, and -9%, all P > 0.09), while there were significant reductions with SIMVA (-15%, -27%, and -25%, respectively, all P < 0.001 vs. day 0) and even greater reductions with co-administration of EZE/SIMVA (-27%, -41%, and -51%, respectively, all P < 0.001 vs. day 0). The percentages of patients achieving LDL-C below 70 mg dL(-1) at days 4 and 7 were substantially greater with EZE/SIMVA (45% and 55%, respectively) than with SIMVA (5% and 10%, respectively), while no NLLD patient reached this goal. Triglyceride levels showed a progressive increase in the NLLD group (+45% at day 7, P < 0.05 vs. day 0), no change in the SIMVA group, but a decrease in the EZE/SIMVA group (-17% at day 7, P < 0.05 vs. day 0). No significant difference in HDL-C levels, tolerability, or clinical events was observed between the three groups.

CONCLUSIONS

The co-administration of ezetimibe 10 mg with simvastatin 40 mg, by inhibiting cholesterol absorption and production, allowed more patients with acute myocardial infarction to reach LDL-C < or = 70 mg dL(-1) as early as the fourth day of treatment. The effects of such rapid and intense reduction in LDL-C on cardiovascular morbidity and mortality need to be evaluated in future clinical endpoint studies.

Plasminogen activator inhibitor-1 and tissue-plasminogen activator in minority adolescents with type 2 diabetes and obesity

Increased plasminogen activator inhibitor-1 (PAI-1) and decreased tissue-plasminogen activator (t-PA) activities lead to impaired fibrinolysis, which is critical for cardiovascular disease. We studied these hemostatic factors at fasting state and after an oral fat load in 12 type 2 diabetic and 17 nondiabetic obese adolescents, matched for age, sex, body mass index, and sexual maturation. Plasma PAI-1, t-PA, and glucose as well as serum C-peptide, insulin, total cholesterol, triglyceride, and HDL and LDL cholesterol levels were measured at 0, 2, 4, and 6 h after the fat load. Metabolic responses were expressed as the area under the curve (AUC). PAI-1 activities were significantly greater in patients than in control subjects [fasting, 23.4 +/- 2.6 versus 12.9 +/- 2.0 U/mL (p < 0.004); AUC, 101.7 +/- 12.1 versus 57.6 +/- 6.5 U . h [corrected] . mL(-1) (p < 0.003)]. Fasting t-PA activities were significantly lower in the patients than in the control subjects (0.8 +/- 0.3 versus 6.5 +/- 2.7 U/mL; p < 0.001). Triglyceride was the only lipid parameter that was significantly different in the patients than in the control subjects [fasting, 1.5 +/- 0.2 versus 0.9 +/- 0.1 mM (p < 0.05); AUC, 15.7 +/- 2.9 versus 7.9 +/- 0.6 mmol . h(-1) . L(-1) (p < 0.02)]. The PAI-1 activities decreased significantly during the loading tests (p < 0.0001), whereas the t-PA activities did not change. Insulin resistance estimated by the homeostasis model assessment was greater in the patients than in the control subjects (14.4 +/- 2.8 versus 4.6 +/- 0.7; p < 0.0001). We conclude that elevated PAI-1 and diminished t-PA activities, suggestive of suppressed fibrinolysis, are present in our adolescents with type 2 diabetes; adding another risk factor for cardiovascular disease and acute high fat load does not further negatively affect this suppressed fibrinolysis.

Visceral obesity and hemostatic profile in patients with type 2 diabetes: the effect of gender and metabolic compensation

BACKGROUND

Type 2 diabetes (T2DM) patients are characterized by a very high risk of cardiovascular diseases. Among the factors that are responsible for this phenomenon are abdominal obesity and hemostatic abnormalities.

AIM OF THE STUDY

To examine the association of the markers of coagulation and fibrinolysis with the parameters of abdominal obesity and metabolic compensation in T2DM patients.

METHODS

46 T2DM patients participated in the study: 24 men (mean age 61.1 +/- 7.9 years) and 22 postmenopausal women (mean age 62.6 +/- 8.7 years). In each patient the content and distribution of fatty tissue was measured by a dual energy X-ray absorptiometry method (DEXA). The central abdominal fat/gynoid hip fat (CAF/GF) ratio was calculated. The following hemostatic parameters were measured: fibrinogen (Fb), factor VII (fVII), antithrombin III (ATIII), C protein (pC), tissue plasminogen activator inhibitor (PAI-1) and alpha 2 antiplasmin (alpha2 AP). In addition, the biochemical indices of metabolic compensation were measured: HbA1c, glucose levels and lipids.

RESULTS

Patients of both genders were divided according to median CAF/GF ratio. The activity of PAI-1 was significantly higher in women with CAF/GF ratio >or= 0.88 as compared to those with CAF/GF < 0.88 (2.64 +/- 1.28 vs. 1.61 +/- 0.27 U/ml, p < 0.05). The activity of ATIII was significantly lower in men with CAF/GF ratio >or= 1.17, as compared to those with CAF/GF < 1.17 (105.10 +/- 10.02 vs. 113.42 +/- 10.72 %, p < 0.05). There was a significant correlation between the CAF/GF ratio and the activity of PAI-1 in women (r = 0.30, p < 0.05). In addition, in men the CAF/GF ratio was negatively correlated with ATIII activity (r = -0.44, p < 0.05). Multiple stepwise regression analysis demonstrated independent association between the CAF/ GF ratio and the activity of PAI-1 (p < 0.001), and between the CAF/GF ratio and the activity of alpha2 AP (p < 0.01). There was an independent association between the concentration of HbA1c and the concentration of Fb (p < 0.001) and between triglycerides and the activity of fVII (p < 0.01).

CONCLUSIONS

The results of our study show that the patients with T2DM and with higher markers of abdominal obesity measured by DEXA show fibrinolysis impairment and thrombinogenesis elevation compared to those with lower abdominal obesity markers. Independent factors determining hypercoagulation also include metabolic control and lipids. Hemostatic disorders place subjects with diabetes and abdominal obesity at risk of developing vascular complications.

Serum lipid levels and the risk of venous thrombosis

OBJECTIVE

Lipids, through effects on the coagulation and fibrinolytic systems, may contribute to the development of venous thrombosis. This association has been investigated in a few studies, with conflicting results.

METHODS AND RESULTS

We conducted a population-based, case-control study at a health maintenance organization in Washington State, to assess the association of serum lipid levels with the risk of venous thrombosis. Cases were 477 postmenopausal women with a first venous thrombosis during January 1995 through December 2001. Control subjects (1986) were a random sample of postmenopausal women. Medical records, computerized pharmacy databases, and a cancer registry served to collect data on lipid levels and risk factors for thrombosis. Total cholesterol levels were not associated with venous thrombosis. Only high HDL cholesterol levels were associated with a decreased risk of venous thrombosis after adjustment for hospitalization, malignancy, height and weight, postmenopausal hormone therapy, and vascular disease (for high-density lipoprotein [HDL] cholesterol levels >1.79 mmol/L versus those <1.79 mmol/L; odds ratio [OR], 0.71; 95% confidence interval [CI], 0.52 to 0.97). In contrast, elevated triglyceride levels were associated with an increased risk (OR, 2.13; 95% CI, 1.34 to 3.37) for women with triglyceride levels >1.05 mmol/L compared with women with lower levels.

CONCLUSIONS

Elevated triglyceride levels were associated with a doubling of risk of venous thrombosis in postmenopausal women, whereas elevated HDL cholesterol levels were associated with a decreased risk.

Effects of lipids and lipid-lowering therapy on hemostatic factors in patients with myocardial infarction

BACKGROUND

The risk of cardiovascular disease (CVD) is associated with specific hemostatic markers and lipid profiles, and evidence indicates that there are associations between lipid profiles and the levels of certain hemostatic factors. The disturbances in hemostasis and the risk of CVD can be ameliorated by lipid-lowering therapy.

OBJECTIVE

We investigated the associations of lipid profiles with factor (F)VIIa, von Willebrand factor (VWF), D-dimer and plasminogen activator inhibitor-1 (PAI-1), and examined whether lipid-lowering statin therapy would affect the levels of these hemostatic markers.

PATIENTS AND METHODS

This cross-sectional study analyzed 1045 postmyocardial infarction patients.

RESULTS

In multivariate regression analyses (without adjusting for clinical covariates) HDL-cholesterol (HDL-C) and HDL size were independent and significant predictors of FVIIa; HDL size was a predictor of VWF; HDL size, HDL-C and LDL size were predictors of D-dimer; and triglyceride and HDL size were predictors of PAI-1. After adjusting for clinical covariates, HDL-C, lipoprotein (Lp)(a), apolipoprotein B (apoB) and warfarin were independent and significant predictors of FVIIa; HDL size, age, diabetes mellitus, insulin, race and warfarin were predictors of VWF; HDL-C, HDL size, LDL size, age, warfarin, hypertension and gender were predictors of D-dimer; and triglyceride, HDL size, body mass index, insulin and hypertension were predictors of PAI-1. Patients on statin therapy had significantly lower levels of D-dimer than those who were not on this therapy.

CONCLUSION

There are significant associations of lipid profiles with hemostatic factors, the directions of which suggest novel pathways by which dyslipidemia may contribute to coronary heart disease.

Circulating levels of plasminogen activator inhibitor type-1, tissue plasminogen activator, and thrombomodulin in hemodialysis patients: biochemical correlations and role as independent predictors of coronary artery stenosis

This study investigated the relationship between the circulating levels of the endothelial cell glycoproteins plasminogen activator inhibitor type 1 (PAI-1), tissue plasminogen activator (TPA), and thrombomodulin (TM) and the major vascular risk factors described in dialysis patients. In addition, the role of these endothelial cell products as independent predictors of coronary artery disease (CAD) was analyzed. Levels of TM, TPA antigen (Ag), TPA activity, PAI-1 Ag, PAI-1 activity, TPA/PAI complexes, thrombin-antithrombin complexes, fibrinopeptide A, C-reactive protein (CRP), interleukin-1beta and tumor necrosis factor-alpha, lipids, apoproteins A1 and B, and albumin were measured in a group of 200 nondiabetic dialysis patients and 100 healthy matched volunteers. When compared with healthy controls, dialysis patients showed increased levels of CRP, TM, TPA, and PAI-1 and evidence of increased thrombin-dependent fibrin formation. Increased levels of active PAI-1 were associated to a great extent with major classic vascular risk factors and to a lesser extent with CRP and serum triglycerides. Forty-six patients (23%) had evidence of CAD. Variables associated with CAD in the univariate analysis included age, time on dialysis, male gender, number of packs of cigarettes per year, high BP, fibrinogen, apolipoprotein B, albumin, PAI-1 activity, CRP, thrombin-antithrombin complexes, and fibrinopeptide A. Logistic regression analysis found age, high-density lipoprotein cholesterol, gender, high BP, CRP, time on dialysis, and PAI-1 activity to be independent predictors of CAD. This model classified correctly 85% of patients as having CAD and showed adequate goodness of fit for all risk categories. Our data support a pathogenic link among activated inflammatory response, endothelial injury, and CAD in hemodialysis patients and suggest that assessment of circulating PAI-1 levels could be an additional tool to identify dialysis patients who are at risk for developing atheromatous cardiovascular disease.

Concurrent administration of sustained-release bezafibrate may counteract the increased thrombotic risk associated with oral estrogen therapy

Although hormone replacement therapy (HRT) can have many favorable effects on serum lipids and on vascular endothelium that presumably mediate the decreased risk for heart attack and stroke associated with HRT in observational epidemiology, oral estrogen also has various pro-coagulant effects: increases in serum triglycerides and factor VII activity, decreases in serum antithrombin III and protein S. This may explain the increased risk for venous thromboembolism observed with HRT and oral contraceptives, as well as the temporary increase in coronary risk noted when women with preexisting coronary disease initiate HRT. The well-tolerated hypolipidemic agent bezafibrate has anticoagulant actions that are diametrically opposed to the procoagulant effects of oral estrogen: namely, reductions in serum triglycerides and factor VII activity, and an increase in antithrombin III. However, bezafibrate could be expected to complement the protective effects of oral estrogen on serum lipids and on serum IGF-I activity. Thus, there is reason to believe that concurrent bezafibrate administration would minimize any thrombotic risk associated with HRT or oral contraception, while amplifying the health benefits of oral estrogen, and would make it more feasible to administer these therapies in women at increased vascular risk. These predictions require confirmation in controlled clinical studies. Certain natural hypolipidemic agents may also have potential as adjuvants to oral estrogen, but their effects on hemostasis require further investigation.

Which antiphospholipid antibody tests are most useful?

Despite an active international effort to improve diagnosis and treatment of the antiphospholipid syndrome (Hughes syndrome), there remain problems of lack of standardization and lack of prospective and multivariate epidemiologic analysis which restrict the diagnostic and predictive ability of commercially available tests. Nevertheless, current published series provide some data from which strategic approaches can be used to maximize the efficiency and usefulness of available tests. For further updates on new research and developments of interest to physicians and patients with this syndrome, the following web sites may prove helpful: www.slrapls.org, www.hematology.org, www.acforum.org, www.americanheart.org, www.rarediseases.org, www.aarda.org, and www.lupus.org.