Effect of statins on platelet function in patients with hyperlipidemia.

INTRODUCTION: It is generally assumed that cholesterol reduction by statins is the predominant therapeutic result underlying their beneficial effects in cardiovascular disease. However, the action of statins may be partially independent of their effects on plasma cholesterol levels, as they combine lipid lowering with positive effects on hemorheological conditions and endothelial function. We evaluated the impact of statin treatment on platelet adhesion to fibrinogen (spontaneous and ADP-activated), along with ADP, collagen or ristocetin-induced aggregation in type II hyperlipidemic patients. MATERIAL AND METHODS: The study group included 70 persons: 50 patients affected by type II hyperlipidemia without concomitant diseases and 20 healthy volunteers. The effects of 8-week statin treatment (atorvastatin 10 mg/day, simvastatin 20 mg/day, or pravastatin 20 mg/day) on platelet activation were evaluated. RESULTS: Regardless of the type of statin, a significant decrease in ADP-induced platelet aggregation was observed: for atorvastatin 50.6 ±12.8% vs. 41.1 ±15.8% (p < 0.05), for simvastatin 57.2 ±18.0% vs. 44.7 ±22.1% (p = 0.05), and for pravastatin 55.8 ±19.5% vs. 38.8 ±23.3% (p < 0.05). There was no significant effect of statins on collagen or ristocetin-induced platelet aggregation and adhesion. CONCLUSIONS: Therapy with statins beneficially modifies ADP-induced platelet aggregation in patients with hyperlipidemia and does not affect spontaneous or ADP-induced platelet adhesion to fibrinogen and platelet aggregation induced by collagen or ristocetin.

[Estimation of the correlation between hemostatic parameters and serum lipids in patients with hyperlipidemia type II after simvastatin therapy]. / Ocena korelacji miedzy parametrami hemostazy a lipidogramem surowicy u chorych na hiperlipidemie typu II po leczeniu simwastatyna.

UNLABELLED: The aim of the study was to evaluate the correlation between hemostatic parameters such as: the activity of antithrombin III and factor X, thrombin generation, clot bound thrombin, fibrinogen and serum lipids in patients (pts) with hyperlipidemia (hlp) type II after 2-months treatment with simvastatin in dose 20 mg/day. MATERIAL AND METHODS: The study involved 22 pts with hip with the initial concentrations of total cholesterol (TC) > 230 mg/dL, LDL-cholesterol (LDL-C) > 130 mg/dL, triglicerides (TG) < 400 mg/dL, 22 healthy volunteers as the control group. The hemostatic parameters and serum lipids were estimated before and after active therapy. TC, HDL-C, TG were determined by enzymatic method, LDL-C was calculated by Friedewald'a formula. Thrombin generation and clot bound thrombin levels were estimated by spectrophotometric method with usage of chromogenic substrate S-2238, the activity of factor X and antithrombin III--by amidolytic methods. For correlation we used coefficient of linear correlation. RESULTS: After 2-months therapy with simvastatin in patients with hlp II it was observed significantly decrease of activity of factor X (20.94 +/- 19.04 vs. 9.44 +/- 7.31 mU/mL), thrombin generation (79.62 +/- 36.68 vs. 67.99 +/- 37.69 U/mL), clot bound thrombin (49.73 +/- 21.17 vs. 37.08 +/- 26.10 U/mL) and increase of antithrombin III activity (13.03 +/- 6.11 vs. 20.64 +/- 4.18 U/mL). The mean concentrations of fibrinogen didn't change during statin treatment (336.00 +/- 71.4 vs. 357.26 +/- 98.86 mg/dL). After simvastatin treatment it wasn't observed any significant correlation between the changes of hemostatic parameters and serum lipids. CONCLUSIONS: The short therapy of simvastatin therapy beneficial modifies hemostatic parameters. Lack of linear correlation between lipids changes concentrations and hemostatic parameters during simvastatin treatment suggests hypolipemic independent influence of statin on the coagulation system.

[The comparison of simvastatin and atorvastatin effects on hemostatic parameters in patients with hyperlipidemia type II]. / Porównanie wplywu simwastatyny i atorwastatyny na wybrane parametry ukladu krzepniecia u chorych z hiperlipidemia typu II.

The studies results of statin influence on hemostasis are various. The aim of our study was to evaluate the effects of simvastatin and atorvastatin on hemostatic parameters, such as activity of factor X, antithrombin III, fibrinogen concentration and Lp(a). 72 patients (pts) aged 40-65 were involved in the study; 49 of them suffered from hyperlipidemia II (hlp II) with the initial concentration of total cholesterol (TC) >200 mg/dL, cholesterol LDL (LDL-C) >145 mg/dL, triglycerides (TG) <400 mg/dL. The control group consisted of 20 healthy persons. The pts with hlp II who underwent 4 weeks long lipid lowering diet were randomized into two groups: I--27 pts treated with simvastatin (20 mg/d), II--22 pts treated with atorvastatin (10 mg/d). The active statin therapy lasted 8 weeks. The activity of factor X and antithrombin III (AT III) was estimated by amidolytic methods, fibrinogen concentration (Fb) by the Clauss method, Lp(a)-immunoenzymatic method. The mean values of factor X activity and Fb serum concentration were higher in pts with hip II than in the control group, the AT III activity was lower. The Lp(a) concentration didn't differ between groups. Statin treatment was associated with significant reduction of factor X activity. Both simvastatin and atorvastatin markedly increased AT III (87%, 98%) in comparison to the initial values. No changes of Lp(a) concentration were observed during statin therapy. Atorvastatin therapy significantly increased the Fb concentration (12.3%). Simvastatin treatment didn't influence Fb concentration.

[Evaluation of thrombin generation and clot bound thrombin in plasma of hyperlipidemic patients treated with statins]. / Ocena stopnia generacji trombiny i wiazania trombiny ze skrzepem w osoczu ludzi z hiperlipidemia typu II leczonych statynami.

Thrombin is a crucial enzyme in blood coagulation cascade having both pro- and antithrombotic properties. Disorders of hemostatic balance increase possibility of clot formation and play significant role in the development of atherosclerosis. Statins applied in prevention of cardiovascular diseases, have not only hypolipemic activity but also many pleiotropic effects. The aim of this study was to evaluate the level of thrombin generation and clot bound thrombin in patients with hyperlipidemia type II (hlpII) before and after statins treatment. 81 patients were involved in this study: 59 patients with hlp II and 22 healthy. Patients with hlp II were treated with pravastatin (20 mg/day; n=10), simvastatin (20 mg/day; n=22), atorvastatin (10 mg/day; n=27). The treatment in each of groups lasted 8 weeks. Thrombin generation and clot bound thrombin level were estimated before and after therapy by means of spectrophotometric method with usage of chromogenic substrate S-2238. Our results demonstrate that therapy with atorva- simva- and pravastatin improves lipid levels in plasma and investigated hemostasis parameters. All three statins statistically significantly decrease total generated thrombin. Atorva- and simvastatin also significantly decrease activity both free generated thrombin and clot bound thrombin. No correlation between lipidogram and hemostatic parameters after treatment with statins suggests that observed changes are pleiotropic effect of statins treatment.