PAI-1 activity, but not fibrinogen or von Willebrand factor, is inversely related to LDL particle size in type 2 diabetes

Apolipoprotein B vs non-high-density lipoprotein cholesterol: Association with endothelial hemostatic markers and carotid intima-media thickness

BACKGROUND

Both apolipoprotein B (apoB) and non-high-density lipoprotein cholesterol (non-HDL-C) are accepted as alternative risk factors or targets for lipid-lowering therapy, which correlate more strongly with cardiovascular events than low-density lipoprotein cholesterol.

OBJECTIVE

The aim of this cross-sectional study was to evaluate the differences in plasma levels of plasminogen activator inhibitor-1 (PAI-1) and of von Willebrand factor (vWF) as endothelial hemostatic markers and carotid intima-media thickness (C-IMT) as a morphologic marker for atherosclerotic vascular disease among dyslipidemic individuals with apoB levels higher, estimated or lower based on regression equation of apoB vs non-HDL-C.

METHODS

A total of 594 dyslipidemic subjects without atherosclerotic manifestation were divided into 3 groups (according to tertiles of apoB levels above, within, and below the line of identity): H-apoB (n = 200), E-apoB (n = 194), and L-apoB (n = 200). PAI-1, vWF, C-IMT and lipids, anthropometric parameters, markers of insulin resistance, and inflammation were measured. Differences in variables between groups were analyzed using analysis of variance.

RESULTS

There was a strong association between apoB and non-HDL-C. The correlations of apoB and of non-HDL-C with markers of endothelial damage and C-IMT were very similar. Despite these facts, individuals with higher apoB levels had significantly higher levels of PAI-1 compared with individuals with estimated (P < .05) or lower apoB (P < .001). There were no significant differences in vWF, C-IMT, markers of insulin resistance, obesity, and inflammation.

CONCLUSION

Individuals with apoB higher than predicted by non-HDL-C had significantly higher levels of PAI-1, which may contribute to the increased risk of future atherothrombotic events.

Altered Daytime Fluctuation Pattern of Plasminogen Activator Inhibitor 1 in Type 2 Diabetes Patients with Coronary Artery Disease: A Strong Association with Persistently Elevated Plasma Insulin, Increased Insulin Resistance, and Abdominal Obesity

This study was aimed at investigating daily fluctuation of PAI-1 levels in relation to insulin resistance (IR) and daily profile of plasma insulin and glucose levels in 26 type 2 diabetic (T2D) patients with coronary artery disease (CAD) (group A), 10 T2D patients without CAD (group B), 12 nondiabetics with CAD (group C), and 12 healthy controls (group D). The percentage of PAI-1 decrease was lower in group A versus group B (4.4 ± 2.7 versus 35.0 ± 5.4%; P < 0.05) and in C versus D (14.0 ± 5.8 versus 44.7 ± 3.1%; P < 0.001). HOMA-IR was higher in group A versus group B (P < 0.05) and in C versus D (P < 0.01). Simultaneously, AUCs of PAI-1 and insulin were higher in group A versus group B (P < 0.05) and in C versus D (P < 0.01), while AUC of glucose did not differ between groups. In multiple regression analysis waist-to-hip ratio and AUC of insulin were independent determinants of decrease in PAI-1. The altered diurnal fluctuation of PAI-1, especially in T2D with CAD, might be strongly influenced by a prolonged exposure to hyperinsulinemia in the settings of increased IR and abdominal obesity, facilitating altogether an accelerated atherosclerosis.

Influence of fibrinogen and C-RP on progression of peripheral arterial disease in type 2 diabetes: a preliminary report

Background

Limited studies have suggested that inflammatory biomarkers play a role in the initiation and progression of atherosclerosis in diabetic patients. This study assesses the effect of inflammatory biomarkers: fibrinogen and C-reactive protein (C-RP) on the progression of peripheral arterial disease (PAD) in type 2 diabetic (T2D) patients.

Methods

Sixty two patients with T2D and PAD (mean age 60.28 ± 27 years and diabetes duration of 8.58 ± 6.17 years) were enrolled in a cohort prospective study of 36 months. Ankle-brachial index (ABI) was measured in all patients at baseline and after 36 months. Multiple linear regression analysis was used to determine the predictivity of variables for fibrinogen, C-RP, plasma lipid fractions, fasting plasma glucose, Body Mass Index (BMI), duration of diabetes status and the age on changes in ABI value.

Results

Linear regression analysis defined F as a predictor for endpoint value of ABI (β = 0.469, p = 0.007). Value of C-RP determinates change of minimal value of ABI (β = 0.449, p = 0.037) and change of mean ABI per year (β = 0.442, p = 0.025).

Conclusion

Our data indicate that plasma determination of fibrinogen and C-RP might have a clinical implication in defining the process of progression of PAD in T2D population.

Simvastatin reduces circulating plasminogen activator inhibitor 1 activity in volunteers with the metabolic syndrome

BACKGROUND

The Metabolic Syndrome (MS) confers an increased risk for diabetes and cardiovascular disease. We previously showed that simvastatin has concomitant benefits in reducing low-density lipoprotein (LDL)-cholesterol and inflammation in MS subjects. The levels of plasminogen activator inhibitor 1(PAI-1), soluble P-selectin (sP-selectin), and soluble CD40 ligand (sCD40L) play an important role in the development and progression of atherosclerosis. Their levels are increased in the MS. The current study was to investigate the effects of simvastatin on PAI-1, sP-selectin, and sCD40 ligand.

METHODS

Fifty subjects with MS were randomized into either placebo or simvastatin (40 mg/day) group for 8 weeks. Blood samples were obtained at baseline and at the end of the study. PAI-1 activity and sP-selectin and sCD40L levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

There was no baseline difference in any of the parameters studied. Compared to baseline, simvastatin significantly reduced (P < 0.05) the circulating PAI-1 activity (24.3 +/- 5.2 IU/mL at baseline vs. 21.4 +/- 3.9 IU/mL after 8 weeks of treatment). Simvastatin did not alter (P < 0.05) the levels of sP-selectin (111.4 +/- 35.9 ng/mL at baseline vs. 118.5 +/- 71.2 ng/mL after 8 weeks) or sCD40L (2.0 +/- 1.6 ng/mL at baseline vs. 1.5 +/- 1.0 ng/mL after 8 weeks).

CONCLUSION

Our data indicate that simvastatin therapy has significant effects on the fibrinolytic system in MS subjects as evidenced in a reduction in PAI-1 activity.

Relationship of abdominal visceral and subcutaneous adipose tissue with lipoprotein particle number and size in type 2 diabetes

OBJECTIVE

Insulin resistance and type 2 diabetes are associated with an atherogenic lipoprotein profile. We examined the role of visceral and subcutaneous fat depots, independent of BMI, on the dyslipidemia associated with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 382 subjects with type 2 diabetes underwent abdominal computed tomography to evaluate subcutaneous (SAT) and visceral adipose tissue (VAT) distribution and had anthropometric measurements to determine BMI and waist and hip circumference. Fasting blood was obtained for lipoprotein particle number and size using nuclear magnetic resonance spectroscopy. The relationship of lipoprotein particle number and size with BMI, SAT, and VAT was examined using multivariable regression models adjusted for age, sex, diabetes therapy, duration of diabetes, smoking, statin use, and A1C levels. The relation of VAT to lipoprotein particle number and size was further evaluated after the addition of BMI, BMI plus SAT, or BMI plus homeostatis is model assessment of insulin resistance (HOMA-IR) to the model.

RESULTS

VAT was positively related to VLDL particle number (P < 0.0001), LDL particle number (P < 0.01), and VLDL size (P < 0.0001) and negatively related to LDL size (P < 0.0001) and HDL size (P < 0.0001). These relationships remained unchanged after addition of BMI and SAT to the model. After addition of HOMA-IR, VAT remained positively related to VLDL particle number (P < 0.0001) and size (P < 0.01) and negatively related to LDL and HDL particle size (P < 0.0001 for both comparisons). Neither BMI nor SAT was independently related to lipoprotein parameters.

CONCLUSIONS

In patients with type 2 diabetes, higher VAT independent of BMI was associated with higher VLDL and LDL particle number, larger VLDL particles, and smaller LDL and HDL particles. This lipoprotein pattern has been associated with increased risk for atherosclerosis and cardiovascular disease.