Gender differences in blood thrombogenicity in hyperlipidemic patients and response to pravastatin

Pravastatin for lowering lipids

BACKGROUND

A detailed summary and meta-analysis of the dose-related effect of pravastatin on lipids is not available.

OBJECTIVES

Primary objective To assess the pharmacology of pravastatin by characterizing the dose-related effect and variability of the effect of pravastatin on the surrogate marker: low-density lipoprotein (LDL cholesterol). The effect of pravastatin on morbidity and mortality is not the objective of this systematic review. Secondary objectives • To assess the dose-related effect and variability of effect of pravastatin on the following surrogate markers: total cholesterol; high-density lipoprotein (HDL cholesterol); and triglycerides. • To assess the effect of pravastatin on withdrawals due to adverse effects.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials (RCTs) up to September 2021: CENTRAL (2021, Issue 8), Ovid MEDLINE, Ovid Embase, Bireme LILACS, the WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

Randomized placebo-controlled trials evaluating the dose response of different fixed doses of pravastatin on blood lipids over a duration of three to 12 weeks in participants of any age with and without evidence of cardiovascular disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included, and extracted data. We entered lipid data from placebo-controlled trials into Review Manager 5 as continuous data and withdrawal due to adverse effects (WDAEs) data as dichotomous data. We searched for WDAEs information from all trials. We assessed all trials using Cochrane's risk of bias tool under the categories of sequence generation, allocation concealment, blinding, incomplete outcome data, selective reporting, and other potential biases.

MAIN RESULTS

Sixty-four RCTs evaluated the dose-related efficacy of pravastatin in 9771 participants. The participants were of any age, with and without evidence of cardiovascular disease, and pravastatin effects were studied within a treatment period of three to 12 weeks. Log dose-response data over the doses of 5 mg to 160 mg revealed strong linear dose-related effects on blood total cholesterol and LDL cholesterol, and a weak linear dose-related effect on blood triglycerides. There was no dose-related effect of pravastatin on blood HDL cholesterol. Pravastatin 10 mg/day to 80 mg/day reduced LDL cholesterol by 21.7% to 31.9%, total cholesterol by 16.1% to 23.3%,and triglycerides by 5.8% to 20.0%. The certainty of evidence for these effects was judged to be moderate to high. For every two-fold dose increase there was a 3.4% (95% confidence interval (CI) 2.2 to 4.6) decrease in blood LDL cholesterol. This represented a dose-response slope that was less than the other studied statins: atorvastatin, rosuvastatin, fluvastatin, pitavastatin and cerivastatin. From other systematic reviews we conducted on statins for its effect to reduce LDL cholesterol, pravastatin is similar to fluvastatin, but has a decreased effect compared to atorvastatin, rosuvastatin, pitavastatin and cerivastatin. The effect of pravastatin compared to placebo on WADES has a risk ratio (RR) of 0.81 (95% CI 0.63 to 1.03). The certainty of evidence was judged to be very low.

AUTHORS' CONCLUSIONS

Pravastatin lowers blood total cholesterol, LDL cholesterol and triglyceride in a dose-dependent linear fashion. This review did not provide a good estimate of the incidence of harms associated with pravastatin because of the lack of reporting of adverse effects in 48.4% of the randomized placebo-controlled trials.

Sex-Related Differences in Platelet Aggregation: A Literature Review Supplemented with Local Data from a Group of Generally Healthy Individuals

The process of platelet aggregation is often influenced by several factors including sex and age. A literature review confirmed the existence of sex-related differences in platelet aggregation. Although 68 out of 78 papers found such differences, there are still some controversies regarding these differences, which can be due to multiple factors (age, trigger, concomitant disease, sample handling, etc.). These outcomes are discussed in line with novel results obtained from a local study, in which blood samples from a total of 53 overall healthy women and men with ages ranging from 20 to 66 years were collected. Aggregation was induced with seven different triggers (ristocetin, thrombin receptor activating peptide 6 [TRAP-6], arachidonic acid [AA], platelet-activating factor 16 [PAF-16], ADP, collagen, or thromboxane A₂ analog U-46619) ex vivo. In addition, three FDA-approved antiplatelet drugs (vorapaxar, ticagrelor, or acetylsalicylic acid [ASA]) were also tested. In general, women had higher aggregation responses to some agonists (ADP, TRAP), as well as lower benefit from inhibitors (ASA, vorapaxar). The aggregatory responses to AA and TRAP decreased with age in both sexes, while responses to ADP, U-46619, and PAF were affected by age only in women. In conclusion, more studies are needed to decipher the biological importance of sex-related differences in platelet aggregation in part to enable personalized antiplatelet treatment.

Harnessing Clinical Trial and Real-World Data Towards an Understanding of Sex Effects on Drug Pharmacokinetics, Pharmacodynamics and Efficacy

Increasing clinical data on sex-related differences in drug efficacy and toxicity has highlighted the importance of understanding the impact of sex on drug pharmacokinetics and pharmacodynamics. Intrinsic differences between males and females, such as different CYP enzyme activity, drug transporter expression or levels of sex hormones can all contribute to different responses to medications. However, most studies do not include sex-specific investigations, leading to lack of sex-disaggregated pharmacokinetic and pharmacodynamic data. Based available literature, the potential influence of sex on exposure-response relationship has not been fully explored for many drugs used in clinical practice, though population-based pharmacokinetic/pharmacodynamic modelling is well-placed to explore this effect. The aim of this review is to highlight existing knowledge gaps regarding the effect of sex on clinical outcomes, thereby proposing future research direction for the drugs with significant sex differences. Based on evaluated drugs encompassing all therapeutic areas, 25 drugs demonstrated a clinically meaningful sex differences in drug exposure (characterised by ≥ 50% change in drug exposure) and this altered PK was correlated with differential response.

Effect of pravastatin treatment on circulating adiponectin: a meta-analysis of randomized controlled trials

Objective

Pravastatin has been suggested to increase circulating adiponectin in humans. However, results of randomized controlled trials (RCTs) are inconsistent. We aimed to systematically evaluate the influence of pravastatin on circulating adiponectin in humans by performing a meta-analysis of RCTs.

Materials and methods

Studies were identified via systematic searching of PubMed, Embase, and Cochrane’s Library databases. A random effect model was used to pool the results. Meta-regression and subgroup analyses were applied to explore the source of heterogeneity.

Results

Eight RCTs with nine comparisons of 595 participants were included. Pravastatin treatment was associated with a significant increased level of circulating adiponectin as compared with controls (weighted mean difference [WMD] =0.63 µg/mL; 95% CI, 0.17–1.09 µg/mL; P=0.007) with moderate heterogeneity (I2=28%). These results were confirmed by meta-analysis of double-blinded placebo-controlled RCTs (WMD =0.82 µg/mL; P=0.01). Meta-regression analyses indicated that proportions of males in each study were positively correlated with the effect of pravastatin on adiponectin (coefficient: 0.015, P=0.03). Subgroup analyses confirmed that pravastatin significantly increased adiponectin in studies of males (WMD =1.41 µg/mL; P=0.008), but not in those of females (WMD =−0.04 µg/mL; P=0.94).

Conclusion

Pravastatin treatment is associated with increased circulating adiponectin. Gender difference may exist regarding the effect of pravastatin treatment on adiponectin.

Gender Differences in Associations Between Intraprocedural Thrombotic Events During Percutaneous Coronary Intervention and Adverse Outcomes

Women are frequently reported to have increased morbidity after presentation with acute coronary syndromes and myocardial infarction; however, whether a greater thrombotic tendency contributes to gender differences in clinical outcomes of urgent percutaneous coronary intervention is unknown. Intraprocedural Thrombotic Events (IPTEs) are defined as new or increasing thrombus, abrupt vessel closure, no reflow or slow reflow, or distal embolization at any time during percutaneous coronary intervention. IPTEs were evaluated in this pooled analysis of 6,591 patients with stent implantation and blinded quantitative coronary angiography (QCA) analysis, from the ACUITY and HORIZONS-AMI trials. We compared major adverse cardiac events (MACE) at in-hospital, 30-day, and 1-year follow-up and major bleeding at 30 days according to gender and the presence or absence of IPTE. IPTE was identified in 507 patients (7.7%), with 119 of 1,744 (6.8%) occurring in women and 388 of 4,847 (8.0%) in men (p = 0.12). IPTE, but not gender, was independently associated with MACE at in-hospital and 30-day follow-up. At 1-year follow-up, the adjusted hazard of MACE was higher in women and in patients with IPTE; however, the risk of MACE associated with IPTE was similar among women and men. There was no significant interaction between IPTE and gender for 1-year MACE or 30-day bleeding. IPTE predicted major bleeding only in women. In conclusion, in acute coronary syndromes, women have increased risk of adverse outcome at 1 year. IPTEs are common, occur at similar frequency, and are associated with similar degree of increased MACE in both genders at short- and long-term follow-up. Higher thrombotic propensity does not offer a mechanistic explanation for the worse outcomes noted in women.

Impact of HMG-CoA reductase inhibitor (statin) use on blood loss during robot-assisted and open radical prostatectomy

BACKGROUND AND PURPOSE

In addition to their lipid lowering effects, HMG-CoA reductase inhibitors (statins) have been shown to exert antithrombotic effects through downregulation of the coagulation cascade. Because statin use is widespread, it is important to understand the impact of these drugs on blood loss (BL) during surgery. We studied the impact of statin use on BL during robot-assisted radical prostatectomy (RARP) and open radical prostatectomy (ORP).

PATIENTS AND METHODS

A retrospective review was conducted of a database approved by the Institutional Review Board for patients who underwent RARP or ORP at a single academic institution. Patients were categorized as statin-users or statin-naïve at the time of surgery. Patient demographic information was recorded as was perioperative data, including preoperative and postoperative hematocrit (Hct) value. BL was defined as % Hct change presurgery vs postsurgery. In addition, the outcome of ≥10% drop in Hct was studied. The t test and chi-square analysis were used to compare variables across statin use groups. Univariate and multivariable logistic regression analyses were used to identify factors that impacted BL.

RESULTS

From 1987 to 2010, 3578 patients underwent prostatectomy for prostate cancer (RARP=945 and ORP=2633). Of these, 676 men were identified as statin-users and 2902 as statin-naïve. Mean patient age was 60.2±7.0 years. Statin-users were found to be older (P<0.001), have lower mean preoperative prostate-specific antigen (PSA) levels (P=0.002), and have higher pathologic Gleason sum scores (P<0.001). For ORP, statin use was associated with increased BL with Hct % change of 20.7% for users vs18.6% for nonusers, (P<0.001). For RARP, no significant change in Hct was seen with statin use with % changes of 12.6% and 12.5%, respectively (P=0.9). When controlling for age, Gleason sum, surgeon, date of surgery and PSA level, statin use was associated with increased BL (P=0.04).

CONCLUSION

Even when controlling for age, Gleason sum, surgeon, date of surgery, and PSA, statin use is associated with increased BL during RP. This information may impact preoperative planning and patient counseling for men who are taking statins while preparing for RP.

The effect of rosuvastatin treatment on the mean platelet volume in patients with uncontrolled primary dyslipidemia with hypolipidemic diet treatment

Platelet activation and aggregation are central processes in the pathophysiology of coronary heart disease. Mean platelet volume (MPV), a determinant of platelet activation, is a newly emerging risk marker for atherothrombosis. Rosuvastatin, a new hydrophilic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin), is approved as an adjunct to diet in patients with dyslipidemia. In this study, we evaluated the effects of rosuvastatin on the MPV levels in patients with uncontrolled primary dyslipidemia with hypolipidemic treatment. We selected 30 age, sex and body mass index matched patients with uncontrolled primary dyslipidemia and hypolipidemic diet treatment and 30 normolipidemic healthy subjects. Dyslipidemic patients were treated with 10 mg/day rosuvastatin for 12 weeks. Metabolic parameters and MPV were measured at baseline and after rosuvastatin treatment in dyslipidemic group. At baseline, the dyslipidemic group had significantly higher MPV levels than in the healthy control group (8.4 +/-1.2 fl vs. 8.1 +/-0 1.0 fl, p < 0.005). The level of MPV decreased significantly after rosuvastatin treatment from a mean of 8.4 +/- 1.2 fl to 8.1 +/- 1.3 fl, (p < 0.001). The changes in MPV levels with rosuvastatin treatment were not correlated to changes in plasma lipids (p > 0.05). In addition to its well-known hypolipidemic effect, rosuvastatin also possesses significant anti-platelet activation properties. This antiplatelet effect of rosuvastatin treatment could play a role in reducing cardiovascular complications in primary hyperlipidemic patients.

Enhanced soluble CD40L in patients with the metabolic syndrome: Relationship with in vivo thrombin generation

AIMS/HYPOTHESIS

The metabolic syndrome is associated with proinflammatory and prothrombotic states. This study was designed to assess the behaviour of soluble CD40 ligand (sCD40L) and prothrombin fragment F (1+2), a marker of thrombin generation, in patients with the metabolic syndrome.

METHODS

We investigated 106 patients with the metabolic syndrome, diagnosed according to the ATPIII report, and 104 subjects without the metabolic syndrome.

RESULTS

Plasma values of sCD40L and F (1+2) were higher in patients with the metabolic syndrome (4.11+/-1.64 vs 2.61+/-0.89 ng/ml and 1.54+/-0.49 vs 0.87+/-0.21 nmol/l, respectively; p < 0.001) and were significantly correlated (r = 0.925, p < 0.001). Stepwise multiple linear regression analysis showed that sCD40L was significantly associated with F (1+2), female sex and waist circumference.

CONCLUSIONS/INTERPRETATION

Patients with the metabolic syndrome have enhanced values of plasma sCD40L and F (1+2). The study provides further insight into the relationship between metabolic syndrome, inflammation and thrombosis.

Statins Could Be Used to Control Replication of Some Viruses, Including HIV-1

Statins are mainly known for their plasma cholesterol-lowering properties and are widely used for the prevention of cardiovascular diseases. They however also exert pleiotropic effects through a variety of mechanisms, among which several immunosuppressive effects that are unrelated to their cholesterol-lowering activity. Interestingly, there has been recent evidence of antiviral effects, including preliminary studies on the efficacy of statins against HIV-1. This paper more particularly focuses on the specific inhibition of the binding of leukocyte function-associated antigen-1 (LFA-1) to intercellular adhesion molecule (ICAM-1) by statins, independently of the inhibition of HMGCoA reductase. Targeting the statin-binding site within LFA-1 or regulating LFA-1 affinity by inhibiting prenylation of the small GTPases could prove useful to treat inflammatory, autoimmune diseases and possibly viral infections, including HIV-1.

Statins but not fibrates are associated with a reduced risk of venous thromboembolism: a hospital-based case-control study

Previous studies of selected patients have suggested a reduction in the risk of venous thromboembolism with the use of statins. The objective of this study is to evaluate the influence of statin use on the risk of venous thromboembolic (VTE) events. The study is a case-control study (EDITH: Etude des Déterminants et Interactions de la Thrombose Veineuse), designed to investigate the genetic and environmental risk factors of VTE. A total of 377 patients consecutively hospitalized in the Brest University Hospital for a documented VTE event, between May 2000 and May 2002, and 377 age- and sex-matched controls were studied. Statin use was associated with a 58% decreased risk of VTE [odds ratio (OR) 0.42; 95% confidence interval (CI) 0.23-0.76; P = 0.002]. Adjustment for age, gender, coronary heart disease, atherosclerothrombotic disease or current use of aspirin did not alter the result. Neither fibrates (OR 1.38; 95% CI 0.76-2.52; P = 0.26), nor thienopyridines (OR 1.07; 95% CI 0.48-2.41; P = 0.85) were associated with a reduced risk of VTE. Aspirin use tended to decrease the risk of VTE, but this result was not significant (OR, 0.66; 95% CI, 0.42-1.05). The use of statins is associated with a significant reduction in the risk of VTE, irrespective of age, gender, and past history of atherosclerothrombotic disease, as well as the use of aspirin. This possible protective effect of statins warrants further investigations.

Sex- and age-related differences in the prognostic value of C-reactive protein in patients with angiographic coronary artery disease

PURPOSE

To determine whether sex and age affect serum C-reactive protein level and its prognostic value in patients with coronary artery disease.

METHODS

In a consecutive series of 2254 patients with angiographically defined coronary artery disease, baseline C-reactive protein and predictive value for incident death or nonfatal myocardial infarction by sex and age (<55 and > or =55 years) were compared. C-reactive protein levels were measured by fluorescence polarization immunoassay with use of a medium-sensitivity method. Patients were followed for a mean (+/-SD) of 3.1 +/- 2.2 years. Comparisons used ln-transformed C-reactive protein and linear and time-to-event regression analyses, adjusting for confounders.

RESULTS

Overall, women had higher geometric mean C-reactive protein levels than did men (1.47 vs. 1.30 mg/dL, P <0.001), even after adjustment for age, hyperlipidemia, diabetes, prior myocardial infarction, body mass index, and heart failure (P = 0.002). High C-reactive protein levels were associated with increased mortality or myocardial infarction among men (adjusted hazard ratio [HR] = 1.9; 95% confidence interval [CI]: 1.5 to 2.3) but not among women (HR = 1.0; 95% CI: 0.69 to 1.4). Among patients aged <55 years, C-reactive protein level was similarly predictive in men and women (HR = 2.2 vs. 2.7), whereas in patients > or =55 years of age, it remained predictive for men (HR = 1.8; 95% CI: 1.5 to 2.3) but not women (HR = 0.93; 95% CI: 0.63 to 1.4).

CONCLUSION

We found that the prognostic value of C-reactive protein in coronary artery disease patients varied by sex and age. This sex-age interaction may have important implications for C-reactive protein-based secondary risk assessment and requires further investigation.

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.

Effects of HMG-CoA reductase inhibitors on coagulation and fibrinolysis processes

Recent large clinical trials have demonstrated that HMG-CoA reductase inhibitors, or statins, markedly reduce morbidity and mortality when used in the primary and secondary prevention of cardiovascular disease. It has been established that the benefits of statin therapy in cardiovascular disease can be explained not only by the lipid-lowering potential of statins but also by nonlipid-related mechanisms (so-called "pleiotropic effects") that contribute to the positive effect of statins on the incidence of cardiovascular events. The coagulation and fibrinolytic systems are two separate but reciprocally linked enzyme cascades that regulate the formation and breakdown of fibrin. Numerous studies have demonstrated that disturbances of coagulation and fibrinolysis contribute to the development and progression of atherosclerosis, and that they affect the incidence of atherosclerosis-related clinical events. High plasma levels or activities of fibrinogen, factor VII, factor VIII, von Willebrand factor (vWF), soluble thrombomodulin, tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) are thought to be associated with increased morbidity and mortality related to cardiovascular disease. Experimental studies and many clinical studies have recently shown that statins produce favourable effects on haemostatic parameters, including those that are risk factors for cardiovascular disease. Statins diminish procoagulant activity, which is observed at different stages of the coagulation cascade, including tissue factor (TF) activity, conversion of prothrombin to thrombin and thrombin activity. In some studies, statins also reduced fibrinogen levels. By altering the levels and activities of tPA and PAI-1, statins seem to stimulate fibrinolysis. The data on the effects of combined treatment with statins and other drugs on haemostasis are rather limited. They suggest that statins combined with fibric acid derivatives, omega-3 fatty acids and 17beta-estradiol are superior to statins alone. The only two clinical studies performed in patients with acute coronary syndromes showed a relatively weak effect of statins on haemostasis in those patients. Although various statins may produce different effects on individual variables, there are no convincing data showing that differences in their physicochemical and pharmacokinetic properties significantly alter their net effect on excessive procoagulant activity. Apart from the lipid-lowering effect, statins suppress the synthesis of several important nonsterol isoprenoids derived from the mevalonate pathway, especially farnesyl and geranylgeranyl pyrophosphates, which via enhanced protein prenylation, are involved in the regulation of many cellular processes. It is presumed that the inhibitory effect of statins on the mevalonate pathway is involved in the regulation of some key steps of coagulation and fibrinolysis processes. In this way they probably regulate the synthesis of TF, tPA and PAI-1, and perhaps they also control the generation and activity of thrombin. The beneficial effects of statins on coagulation and fibrinolysis may be responsible for their ability to decrease the number of cardiovascular events. The lipid-independent effects of statins on haemostasis may contribute to the marked decrease in the incidence rates of mortality, hospitalisation and revascularisation in patients treated with these drugs.

The Effects of Atorvastatin Treatment on the Fibrinolytic System in Dyslipidemic Patients

Statins have pleiotrophic effects related to the pathogenesis of atherosclerosis and thrombogenicity of the vessel wall beyond lipid lowering. The aim of the present study was to examine the effect of atorvastatin treatment on the fibrinolytic system in patients with dyslipidemia. The investigation was carried out on 41 dyslipidemic patients (21 males and 20 females) with a mean age of 53.8 years (range, 30-76). The patients were divided into subgroups according to their cholesterol and triglyceride levels as hypercholesterolemic (n = 26) and mixed-type hyperlipidemic (n = 15) and their risk factors for coronary heart disease including age, sex, hypertension, obesity, smoking, and family history. The patients were started on atorvastatin 10 mg/day, and evaluated within 6-12 weeks to assess the changes in fibrinolytic parameters including global fibrinolytic capacity, plasminogen activator inhibitor type-1 and tissue plasminogen activator, and lipids. After successful lipid-lowering therapy, global fibrinolytic capacity (P = 0.003) and tissue plasminogen activator levels (P = 0.04) were found to be increased and plasminogen activator inhibitor type-1 levels (P = 0.02) decreased in dyslipidemic patients. Global fibrinolytic capacity levels increased (P < 0.001) and plasminogen activator inhibitor type-1 levels decreased (P = 0.01) in patients with hypercholesterolemia (n = 26). However, no significant changes were observed in fibrinolytic parameters in patients with mixed-type hyperlipidemia (n = 15). When the patients were separately evaluated according to risk factors, significant beneficial effects on the fibrinolytic system were observed, especially in patients without obesity and hypertension as well as in older patients and males. These findings suggest that atorvastatin treatment has a beneficial effect on the fibrinolytic system in patients with hypercholesterolemia, but not in patients with mixed-type hyperlipidemia. Further studies are needed to show whether higher doses and longer periods of lipid lowering treatment have beneficial effects in patients with mixed type hyperlipidemia and some risk factors.

Long-Term Hemostatic Effects of Cholesterol-Lowering Therapy with Atorvastatin

This study assessed hemostatic effects of an HMC-CoA reductase inhibitor, atorvastatin, on different parameters in 32 hypercholesterolemic patients of both sexes. In the patients and in 25 control subjects, plasma levels of tissue-type plasminogen activator, plasminogen activator inhibitor (PAI-1), D-dimer, prothrombin fragment 1 + 2 (F1 + 2), total cholesterol, triglycerides and fibrinogen had been measured. All these parameters were evaluated in patients after 6 and 12 months of treatment with atorvastatin at a dosage of 20 mg/day. This treatment significantly lowered the total cholesterol level in all patients. Moreover, after 6 months of atorvastatin treatment, PAI-1 and F1 + 2, which were both increased at baseline, were significantly reduced. This reduction continued after 12 months. The present results show that a reduction of hemostatic abnormalities, which exist in hypercholesterolemia, may be another important effect of the atorvastatin therapy.

Decrease of hemostatic cardiovascular risk factors by aggressive vs. conventional atorvastatin treatment in patients with Type 2 diabetes mellitus

BACKGROUND

Patients with Type 2 diabetes mellitus have increased levels of hemostatic risk variables for cardiovascular disease, such as fibrinogen, von Willebrand factor (VWF), factor (F)VIIa, d-dimer and plasminogen activator inhibitor-1 (PAI-1).

OBJECTIVES

To evaluate the effect of aggressive vs. standard dose atorvastatin on hemostatic cardiovascular risk factors in patients with Type 2 diabetes mellitus.

PATIENTS AND METHODS

The effect of 30 weeks of treatment with atorvastatin 10 and 80 mg on hemostatic cardiovascular risk factors was assessed in a randomized double-blind placebo-controlled trial on 217 patients with Type 2 diabetes mellitus and dyslipidemia.

RESULTS AND CONCLUSIONS

Atorvastatin 10 and 80 mg dose-dependently reduced d-dimer (7.4% and 8.5%, respectively, P for trend = 0.004) and PAI-1 antigen levels (9.0% and 18%, respectively, P for trend = 0.021). Levels of fibrinogen, VWF, tissue-type plasminogen activator and FVIIa were not influenced by atorvastatin. In conclusion, in patients with Type 2 diabetes mellitus, atorvastatin dose-dependently improved the levels of the hemostatic risk variables d-dimer and PAI-1.

Plasminogen activator inhibitor-1: physiologic role, regulation, and the influence of common pharmacologic agents

Plasminogen activator inhibitor-1 (PAI-1) is the major inhibitor of endogenous thrombolysis, thereby promoting thrombosis. PAI-1 is also a primary contributor to the development and recurrence of acute myocardial infarction. The renin angiotensin system, hypertriglyceridemia, hyperglycemia and hyperinsulinemia, and estrogen all influence the fibrinolytic system and PAI-1 in particular. Available data strongly suggest that angiotensin-converting enzyme (ACE) inhibitors and hormone replacement therapy with estrogen beneficially reduce PAI-1 production. Metformin, an agent commonly used for non-insulin-dependent diabetes mellitus (NIDDM), appears to favorably decrease PAI-1 production in NIDDM patients but not nondiabetic patients. Among the cholesterol-lowering statins, clinical literature evaluating pravastatin provides the most compelling data to support this agent's favorable effect on PAI-1. Other available statins either have not displayed an effect on PAI-1 or do not have clear data to conclusively define their effects on the fibrinolytic system.

What is the role of intensive cholesterol lowering in the treatment of acute coronary syndromes?

Cholesterol lowering with statins reduces coronary events in a primary-prevention setting and in patients with stable coronary disease. However, where the risk of a coronary event is highest, in the early months after an episode of unstable angina or non-Q-wave infarction, the effect of statin therapy has not been evaluated until recently. The lack of an early benefit in the 3 main statin trials in stable coronary disease may have discouraged this type of investigation. Yet, evidence suggests that intensive cholesterol lowering can rapidly influence several mechanisms intimately related to the pathogenesis of acute coronary syndromes; specifically, improvement in endothelial function, decreased propensity for platelet thrombus formation, and reduced inflammation. Furthermore, 3 nonrandomized, observational studies have recently reported an improved outcome in statin-treated compared with untreated patients after acute coronary syndromes.

The role of dyslipidemia and statins in venous thromboembolism

Recent studies have proposed an association between hyperlipidemia and venous thromboembolism (VTE). We review the epidemiological evidence linking dyslipidemia with VTE and examine several possible underlying mechanisms. We discuss the possible role of HMG CoA reductase inhibitors (statins) in the prevention and treatment of VTE and suggest future directions for research.

[Effect on plasma fibrinogen of hypercholesterolaemia treatment with pravastatin]

OBJECTIVE

To determine whether hypercholesterolaemia treatment with pravastatin causes modifications in plasma fibrinogen.

DESIGN

Descriptive, prospective pharmacological intervention study, with two transversal cuts, one at the start and one after 6 months pravastatin treatment.

SETTING

Health area located in the suburbs of Valencia.

PATIENTS

Hypercholesterolaemia cases diagnosed de novo and treated with pravastatin for 6 months. Sample size was calculated for paired data with an alpha error of 0.05 and a beta error of 20%. The fibrinogen difference thought relevant was set at 40 mg/dl. Variability was deduced from a mini-sample of 15 cases, obtaining a total of 57 patients. Sex, age, height, weight, BMI, count, formula, globular sedimentation rate (GSR), glucaemia, total, HDL and LDL cholesterol, and triglycerides were recorded.

MEASUREMENTS AND MAIN RESULTS

Mean age was 55.9, height 161.9 cm and initial weight 73.9 kg (mean BMI 28.1 kg/m(2)). After six months pravastatin treatment (10/20 mg/day) we found no significant differences in glucaemia, GSR or leukocytes. There were differences in weight, that fell by 1.5 kg (0.6 kg/m(2)), systolic pressure (4.3 mmHg) and diastolic pressure (2.7 mmHg) on average. We found the following differences for lipids: 42.3 mg/dl (15.2%) drop in mean total cholesterol, 27 mg/dl (14.5%) in LDL cholesterol, and 36.2 mg/dl (21.9%) in triglycerides. We found a mean increase in HDL cholesterol of 4.4 mg/dl. There was a mean drop of 43.7 mg/dl (11.9%) in fibrinogen.

CONCLUSIONS

We found an 11.9% drop of plasma fibrinogen in patients with hypercholesterolaemia treated with pravastatin.

Should intensive cholesterol lowering play a role in the management of acute coronary syndromes?

Although several large, well-controlled trials with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) demonstrate the benefits of cholesterol lowering on cardiovascular morbidity and mortality, these trials excluded patients with recent unstable angina or myocardial infarction. Thus, the potentially beneficial effects that may accrue from early statin therapy have not been apparent. Mechanistic and experimental studies show that benefits from statin therapy may include improved endothelial function, a decrease in platelet thrombus deposition, and a reduction in inflammation at the site of the lesion. Large-scale clinical trials are now under way to determine the effect of aggressive cholesterol lowering in patients with acute coronary syndromes. If the findings of the smaller studies are confirmed, statin therapy should be considered early after infarction or unstable angina.

Atorvastatin upregulates type III nitric oxide synthase in thrombocytes, decreases platelet activation, and protects from cerebral ischemia in normocholesterolemic mice

BACKGROUND AND PURPOSE

Thrombosis superimposed on atherosclerosis causes approximately two thirds of all brain infarctions. We previously demonstrated that statins protect from cerebral ischemia by upregulation of endothelial type III nitric oxide synthase (eNOS), but the downstream mechanisms have not been determined. Therefore, we investigated whether antithrombotic effects contribute to stroke protection by statins.

METHODS

129/SV wild-type and eNOS knockout mice were treated with atorvastatin for 14 days (0.5, 1, and 10 mg/kg). eNOS mRNA from aortas and platelets was measured by reverse-transcriptase polymerase chain reaction. Platelet factor 4 (PF 4) and beta-thromboglobulin (beta-TG) in the plasma were quantified by ELISA. Transient cerebral ischemia was induced by filamentous occlusion of the middle cerebral artery followed by reperfusion.

RESULTS

Stroke volume after 1-hour middle cerebral artery occlusion/23-hour reperfusion was significantly reduced by 38% in atorvastatin-treated animals (10 mg/kg) compared with controls. Serum cholesterol levels were not affected by the treatment. eNOS mRNA was significantly upregulated in a dose-dependent manner in aortas and in thrombocytes of statin-treated mice compared with controls. Moreover, indices of platelet activation in vivo, ie, plasma levels of PF 4 and beta-TG, were dose-dependently downregulated in the treatment group. Surprisingly, atorvastatin-treatment did not influence PF 4 and beta-TG levels in eNOS knockout mice.

CONCLUSIONS

The synthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor atorvastatin upregulates eNOS in thrombocytes, decreases platelet activation in vivo, and protects from cerebral ischemia in normocholesterolemic mice. Antithrombotic and stroke-protective effects of statins are mediated in part by eNOS upregulation. Our results suggest that statins may provide a novel prophylactic treatment strategy independent of serum cholesterol levels.

Pleiotropic effects of statins

The advent of statin therapy has revolutionized the ability of the clinician to manage patients at risk for the development of an ischemic event due to dyslipidemia. Large-scale clinical trials involving thousands of patients in both primary and secondary prevention have clearly demonstrated that statin therapy will reduce cardiovascular mortality across a broad spectrum of patient subgroups. Additionally, in adequately powered trials, total mortality has been successfully decreased by the use of statin therapy. However, the precise mechanism underlying the benefit of statin therapy has been controversial due to the multiplicity of potential benefits that statins have demonstrated in addition to pure lipid lowering. The causal theory of pharmacologic benefit reiterates the lipid hypothesis, which states that dyslipidemia is central to the process of atherosclerosis and the clinical benefit which accrues from statin therapy is a function of the degree of lipid lowering. The noncausal theory supports the premise that clinical benefits are related primarily to pleiotropic effects of statins (endothelial function, inflammation, coagulation and plaque vulnerability) as being the major modulators of clinical benefit. This review will focus on the potential beneficial effects of statin therapy on a number of the pleiotropic effects of statins and the potential role that these activities play in the reduction of risk for ischemic events.