Efficacy and safety of a combination of fluvastatin and bezafibrate in patients with mixed hyperlipidaemia (FACT study)

Review: Fibrates: therapeutic review

As agonists of the peroxisome proliferator-activated receptor α (PPARα), fibrates are established, effective and well-tolerated agents in the management of atherogenic dyslipidaemia. Key actions of fibrates include a reduction in elevated triglyceride levels (by up to 50%) and a rise in high-density lipoprotein cholesterol (HDL-C) concentrations (typically by 5—15%). Fibrates promote a shift from small, dense low-density lipoprotein (LDL) to larger more buoyant particles, which are less susceptible to oxidation and possess higher binding affinity for removal by the non-atherogenic LDL receptor pathway. Thus, fibrates can correct lipid abnormalities commonly observed in patients with type 2 diabetes and metabolic syndrome. Clinical evidence has demonstrated the value of fibrate therapy in secondary and primary prevention settings, as well as in patients with type 2 diabetes. However, FIELD, the largest fibrate study to date in diabetic patients, predominantly in a primary prevention setting, showed a non-significant 11% reduction in the primary end point of coronary heart disease death and non-fatal myocardial infarction with fenofibrate, although total cardiovascular events, corresponding to the secondary end point, were significantly reduced by 11% (p=0.035). It is possible that risk reduction with fenofibrate may have been attenuated by the two-fold greater drop-in use of statin therapy in the placebo group. However, the interesting results of fenofibrate on attenuation of microangiographic symptomatology potentially suggest a new recommendation for fibrate therapy, although further studies are required to validate these findings.

A selective peroxisome proliferator-activated receptor δ agonist PYPEP suppresses atherosclerosis in association with improvement of the serum lipoprotein profiles in human apolipoprotein B100 and cholesteryl ester transfer protein double transgenic mice

OBJECTIVE

Although peroxisome proliferator-activated receptor (PPAR) δ agonists have been shown to improve the serum lipoprotein profiles in humans, the impact of the changes in these lipoprotein profiles on atherosclerosis remains to be elucidated. The aim of this study was to investigate the relationship between the selective PPARδ agonist-induced alterations of serum lipoprotein profiles and the development of atherosclerosis in human apolipoprotein B100 and cholesterol ester transfer protein double transgenic (hApoB100/hCETP-dTg) mice with human-like hypercholesterolemic dyslipidemia.

METHODS

hApoB100/hCETP-dTg mice fed an atherogenic diet received a novel PPARδ agonist (PYPEP) or vehicle for 18 weeks, followed by evaluation of atherosclerosis. Serum samples were collected during the treatment period at least at 3-week intervals to determine the lipoprotein levels and the levels of an inflammatory marker, macrophage chemotactic protein-1 (MCP-1), and to analyze the lipoprotein profile by fast protein liquid chromatography. The cholesterol efflux capacity of high-density lipoprotein (HDL) was examined using [(3)H]-cholesterol labeled macrophages.

RESULTS

Compared with vehicle treatment, PYPEP treatment caused increases in the serum levels of HDL cholesterol and apolipoprotein A-I (ApoA-I), as well as reductions in the serum non-HDL cholesterol and MCP-1 levels. The HDL fraction from the PYPEP-treated group maintained its cholesterol efflux capacity and showed an increased population of smaller HDL particles. PYPEP substantially suppressed atherosclerotic lesion progression, and the lesion areas had significant correlations with non-HDL cholesterol, HDL cholesterol, ApoA-I and MCP-1 by Pearson's correlation analysis. A multiple regression analysis revealed that non-HDL cholesterol and ApoA-I were significantly associated with the atherosclerotic lesion area.

CONCLUSION

A novel PPARδ agonist, PYPEP, suppressed atherosclerotic lesion progression by improving the serum lipoprotein profiles, including increased levels of ApoA-I and functional HDL particles, as well as a reduced non-HDL cholesterol level, in hApoB100/hCETP-dTg mice with human-like hypercholesterolemic dyslipidemia.

Safety and efficacy of fibrate-statin combination therapy compared to fibrate monotherapy in patients with dyslipidemia: a meta-analysis

BACKGROUND

Dyslipidemia is a major risk factor for the development of cardiovascular disease. Treatment with fibrate, statins, or other lipid-lowering drugs prevents primary or recurrent cardiovascular events. However, all lipid-lowering drugs have side effects, which may become more severe if combination therapy is prescribed.

METHODS

We performed a meta-analysis of published data to compare the safety and efficacy of fibrates alone, compared to fibrate-statin combinations, in patients with dyslipidemia. Six articles were assessed in terms of the efficacy of therapy and nine from the viewpoint of therapeutic safety.

RESULTS

In terms of efficacy, fibrate-statin combinations afforded significantly greater reductions in the levels of total cholesterol (SE=-2.248; 95% CI 1.986-2.510), LDL cholesterol (SE=-2.274; 95% CI 2.015-2.533), and triglycerides (SE=-0.465; 95% CI 0.272-0.658) compared to fibrate alone. In terms of safety, treatment with fibrate alone was associated with a significant decrease in the number of kidney-related adverse events (RR=-0.547; 95% CI 0.368-0.812), compared to treatment with fibrate-statin combinations.

CONCLUSION

We suggest that treatment with a fibrate-statin combination affords clinical benefits that are superior to treatment with fibrate alone, but increases the risk of side effects (particularly renal). Therapy should thus be carefully monitored.

Bezafibrate improves postprandial hypertriglyceridemia and associated endothelial dysfunction in patients with metabolic syndrome: a randomized crossover study

Background

Postprandial elevation of triglyceride-rich lipoproteins impairs endothelial function, which can initiate atherosclerosis. We investigated the effects of bezafibrate on postprandial endothelial dysfunction and lipid profiles in patients with metabolic syndrome.

Methods

Ten patients with metabolic syndrome were treated with 400 mg/day bezafibrate or untreated for 4 weeks in a randomized crossover study. Brachial artery flow-mediated dilation (FMD) and lipid profiles were assessed during fasting and after consumption of a standardized snack. Serum triglyceride and cholesterol contents of lipoprotein fractions were analyzed by high-performance liquid chromatography.

Results

Postprandial FMD decreased significantly and reached its lowest value 4 h after the cookie test in both the bezafibrate and control groups, but the relative change in FMD from baseline to minimum in the bezafibrate group was significantly smaller than that in the control group (-29.0 ± 5.9 vs. -42.9 ± 6.2 %, p = 0.04). Bezafibrate significantly suppressed postprandial elevation of triglyceride (incremental area under the curve (AUC): 544 ± 65 vs. 1158 ± 283 mg h/dl, p = 0.02) and remnant lipoprotein cholesterol (incremental AUC: 27.9 ± 3.5 vs. 72.3 ± 14.1 mg h/dl, p < 0.01). High-performance liquid chromatography analysis revealed that postprandial triglyceride content of the chylomicron and very low-density lipoprotein fractions was significantly lower in the bezafibrate group than in the control group (p < 0.05).

Conclusion

Bezafibrate significantly decreased postprandial endothelial dysfunction, and elevations of both exogenous and endogenous triglycerides in patients with metabolic syndrome, suggesting that bezafibrate may have vascular protective effects in these patients.

Clinical trial registration

Unique Identifiers: UMIN000012557

Safety and efficacy of statin treatment alone and in combination with fibrates in patients with dyslipidemia: a meta-analysis

BACKGROUND

Dyslipidemia is a major risk factor for cardiovascular disease and is treated with many effective lipid-lowering agents. Statins are often used alone or in combination with fibrates. Combination therapy is more effective due to their comparative actions, but the increased incidence of side effects should be considered carefully.

RESEARCH DESIGN AND METHODS

A meta-analysis of published data was conducted to compare the safety and efficacy of statins alone versus statins plus fibrates in patients with dyslipidemia. In total, nine articles were assessed for efficacy analysis and ten articles were assessed for safety analysis.

RESULTS

In the efficacy analysis, a combination of statins and fibrates provided significantly greater reductions in total cholesterol (SE = 0.430; 95% CI 0.315-0.545), LDL cholesterol (SE = 0.438; 95% CI 0.321-0.555) and triglycerides (SE = 0.747; 95% CI 0.618-0.876), and a significantly greater increase in HDL cholesterol (SE = 0.594; 95% CI 0.473-0.715) than treatment with statins alone. In the safety analysis, treatment with statins alone was associated with a significant reduction in the numbers of total adverse events (RR = 0.665; 95% CI 0.539-0.819), liver-related adverse events (RR = 0.396; 95% CI 0.206-0.760) and kidney-related adverse events (RR = 0.146; 95% CI 0.075-0.285).

CONCLUSION

We suggest that treatment with statins plus fibrates provides clinical benefits over treatment with statins alone but increased risks, especially of hepatic or renal side effects, should be monitored carefully.

Balanced pan-PPAR activator bezafibrate in combination with statin: comprehensive lipids control and diabetes prevention?

All fibrates are peroxisome proliferators-activated receptors (PPARs)-alpha agonists with ability to decrease triglyceride and increase high density lipoprotein- cholesterol (HDL-C). However, bezafibrate has a unique characteristic profile of action since it activates all three PPAR subtypes (alpha, gamma and delta) at comparable doses. Therefore, bezafibrate operates as a pan-agonist for all three PPAR isoforms. Selective PPAR gamma agonists (thiazolidinediones) are used to treat type 2 diabetes mellitus (T2DM). They improve insulin sensitivity by up-regulating adipogenesis, decreasing free fatty acid levels, and reversing insulin resistance. However, selective PPAR gamma agonists also cause water retention, weight gain, peripheral edema, and congestive heart failure. The expression of PPAR beta/ delta in essentially all cell types and tissues (ubiquitous presence) suggests its potential fundamental role in cellular biology. PPAR beta/ delta effects correlated with enhancement of fatty acid oxidation, energy consumption and adaptive thermogenesis. Together, these data implicate PPAR beta/delta in fuel combustion and suggest that pan-PPAR agonists that include a component of PPAR beta/delta activation might offset some of the weight gain issues seen with selective PPAR gamma agonists, as was demonstrated by bezafibrate studies. Suggestively, on the whole body level all PPARs acting as one orchestra and balanced pan-PPAR activation seems as an especially attractive pharmacological goal. Conceptually, combined PPAR gamma and alpha action can target simultaneously insulin resistance and atherogenic dyslipidemia, whereas PPAR beta/delta properties may prevent the development of overweight. Bezafibrate, as all fibrates, significantly reduced plasma triglycerides and increased HDL-C level (but considerably stronger than other major fibrates). Bezafibrate significantly decreased prevalence of small, dense low density lipoproteins particles, remnants, induced atherosclerotic plaque regression in thoracic and abdominal aorta and improved endothelial function. In addition, bezafibrate has important fibrinogen-related properties and anti-inflammatory effects. In clinical trials bezafibrate was highly effective for cardiovascular risk reduction in patients with metabolic syndrome and atherogenic dyslipidemia. The principal differences between bezafibrate and other fibrates are related to effects on glucose level and insulin resistance. Bezafibrate decreases blood glucose level, HbA1C, insulin resistance and reduces the incidence of T2DM compared to placebo or other fibrates. Currently statins are the cornerstone of the treatment and prevention of cardiovascular diseases related to atherosclerosis. However, despite the increasing use of statins as monotherapy for low density lipoprotein- cholesterol (LDL-C) reduction, a significant residual cardiovascular risk is still presented in patients with atherogenic dyslipidemia and insulin resistance, which is typical for T2DM and metabolic syndrome. Recently, concerns were raised regarding the development of diabetes in statin-treated patients. Combined bezafibrate/statin therapy is more effective in achieving a comprehensive lipid control and residual cardiovascular risk reduction. Based on the beneficial effects of pan-PPAR agonist bezafibrate on glucose metabolism and prevention of new-onset diabetes, one could expect a neutralization of the adverse pro-diabetic effect of statins using the strategy of a combined statin/fibrate therapy.

Balanced pan-PPAR activator bezafibrate in combination with statin: comprehensive lipids control and diabetes prevention?

All fibrates are peroxisome proliferators-activated receptors (PPARs)-alpha agonists with ability to decrease triglyceride and increase high density lipoprotein- cholesterol (HDL-C). However, bezafibrate has a unique characteristic profile of action since it activates all three PPAR subtypes (alpha, gamma and delta) at comparable doses. Therefore, bezafibrate operates as a pan-agonist for all three PPAR isoforms. Selective PPAR gamma agonists (thiazolidinediones) are used to treat type 2 diabetes mellitus (T2DM). They improve insulin sensitivity by up-regulating adipogenesis, decreasing free fatty acid levels, and reversing insulin resistance. However, selective PPAR gamma agonists also cause water retention, weight gain, peripheral edema, and congestive heart failure. The expression of PPAR beta/ delta in essentially all cell types and tissues (ubiquitous presence) suggests its potential fundamental role in cellular biology. PPAR beta/ delta effects correlated with enhancement of fatty acid oxidation, energy consumption and adaptive thermogenesis. Together, these data implicate PPAR beta/delta in fuel combustion and suggest that pan-PPAR agonists that include a component of PPAR beta/delta activation might offset some of the weight gain issues seen with selective PPAR gamma agonists, as was demonstrated by bezafibrate studies. Suggestively, on the whole body level all PPARs acting as one orchestra and balanced pan-PPAR activation seems as an especially attractive pharmacological goal. Conceptually, combined PPAR gamma and alpha action can target simultaneously insulin resistance and atherogenic dyslipidemia, whereas PPAR beta/delta properties may prevent the development of overweight. Bezafibrate, as all fibrates, significantly reduced plasma triglycerides and increased HDL-C level (but considerably stronger than other major fibrates). Bezafibrate significantly decreased prevalence of small, dense low density lipoproteins particles, remnants, induced atherosclerotic plaque regression in thoracic and abdominal aorta and improved endothelial function. In addition, bezafibrate has important fibrinogen-related properties and anti-inflammatory effects. In clinical trials bezafibrate was highly effective for cardiovascular risk reduction in patients with metabolic syndrome and atherogenic dyslipidemia. The principal differences between bezafibrate and other fibrates are related to effects on glucose level and insulin resistance. Bezafibrate decreases blood glucose level, HbA1C, insulin resistance and reduces the incidence of T2DM compared to placebo or other fibrates. Currently statins are the cornerstone of the treatment and prevention of cardiovascular diseases related to atherosclerosis. However, despite the increasing use of statins as monotherapy for low density lipoprotein- cholesterol (LDL-C) reduction, a significant residual cardiovascular risk is still presented in patients with atherogenic dyslipidemia and insulin resistance, which is typical for T2DM and metabolic syndrome. Recently, concerns were raised regarding the development of diabetes in statin-treated patients. Combined bezafibrate/statin therapy is more effective in achieving a comprehensive lipid control and residual cardiovascular risk reduction. Based on the beneficial effects of pan-PPAR agonist bezafibrate on glucose metabolism and prevention of new-onset diabetes, one could expect a neutralization of the adverse pro-diabetic effect of statins using the strategy of a combined statin/fibrate therapy.

Comparative effectiveness of statin plus fibrate combination therapy and statin monotherapy in patients with type 2 diabetes: use of propensity-score and instrumental variable methods to adjust for treatment-selection bias

PURPOSE

Type 2 diabetes is associated with increased cardiovascular risk. The comparative effectiveness of statin plus fibrate combination therapy and statin monotherapy in reducing risk of cardiovascular disease in real-world settings is unknown.

METHODS

A retrospective database analysis was performed using a large managed care claims database of patients identified with type 2 diabetes based on diagnosis codes from January 2002 through December 2003 and continuously enrolled for the entire study period, 5.5 years. A statin plus fibrate combination therapy group (patients who used statins less than 6 months and augmented with fibrates for more than 6 months) and a statin monotherapy group (patients who used statins persistently) among patients with type 2 diabetes were followed for 3 years to examine the relationship between the intervention and cardiovascular events using a multivariable logistic regression model, propensity score method, and instrumental variable approach.

RESULTS

The statin plus fibrate combination therapy group of 318 and the statin monotherapy group of 9928 were identified from 75,515 diabetics. After adjusting for factors that can impact cardiovascular outcomes, the combination therapy group did not significantly experience a reduction in cardiovascular disease, as compared with the statin monotherapy group (OR = 0.77; p = 0.083). The statin plus fibrate combination therapy group was significantly associated with a reduction in cardiovascular events after propensity matching (OR = 0.53; p = 0.002). Using the physician prescribing preference instrument to adjust for unmeasured confounding, we did not find evidence that subjects in the statin plus fibrate combination therapy group versus stain monotherapy group experienced a significant reduction in cardiovascular events (p = 0.124).

CONCLUSIONS

We did not find a difference in effectiveness regarding cardiovascular outcomes between the statin plus fibrate combination therapy and the statin monotherapy after controlling for hidden bias.

Management of type IIb dyslipidemia

Although the Japan Atherosclerosis Society guideline for the diagnosis and prevention of atherosclerosis cardiovascular diseases for the Japanese population provides targets for low-density lipoprotein (LDL) cholesterol, triglycerides, and high-density lipoprotein (HDL) cholesterol to prevent cardiovascular disease in patients with dyslipidemia, there is no guideline specifically targeting the treatment of type IIb dyslipidemia, which is one of the most common types of dyslipidemia, along with type IIa and type IV dyslipidemia. Type IIb dyslipidemia is important because it sometimes accompanies atherogenic lipid profiles, such as small, dense LDL, remnants, low HDL cholesterolemia. It is also associated with type 2 diabetes mellitus, metabolic syndrome, and chronic kidney disease (CKD), and most patients with familial combined hyperlipidemia (FCHL) show this phenotype; therefore, it is assumed that patients with type IIb dyslipidemia have a high risk for cardiovascular disease. Thus, the management of type IIb dyslipidemia is very important for the prevention of cardiovascular disease, so we have attempted to provide a guideline for the management of type IIb dyslipidemia.

Effect of fibrates on lipid profiles and cardiovascular outcomes: a systematic review

OBJECTIVE

Fibrates might represent a viable treatment option for patients who do not meet their target low-density lipoprotein levels on statins or who are resistant or intolerant to statins. New data from fibrate trials can be synthesized with the existing literature to better estimate their effects.

METHODS

We systematically searched the literature to identify randomized, double-blind, placebo-controlled trials examining the effect of fibrates on lipid profiles or cardiovascular outcomes. We estimated the effect of fibrates on the incidence of nonfatal myocardial infarction and all-cause mortality using random effects models.

RESULTS

Compared with placebo, fibrates were associated with greater reductions in total cholesterol (range: -101.3 mg/dL to -5.0 mg/dL) and triglycerides (range: -321.3 mg/dL to -20.8 mg/dL), and a greater increase in high-density lipoprotein (range: +1.1 mg/dL to +17.9 mg/dL) in all trials. Fibrates tended to be associated with a greater reduction in low-density lipoprotein (range: -76.3 mg/dL to +38.7 mg/dL) than placebo, although these results were not consistent across all trials. Fibrates were more efficacious than placebo at preventing nonfatal myocardial infarction (odds ratio=0.78; 95% confidence interval, 0.69-0.89), but not all-cause mortality (odds ratio=1.05; 95% confidence interval, 0.95-1.15).

CONCLUSION

In addition to improving lipid profiles, fibrates are associated with an important decrease in nonfatal myocardial infarction, but do not substantially affect all-cause mortality. Potential applications include treatment for patients with statin resistance or isolated hypertriglyceridemia, or as an adjunct to other lipid-lowering therapies.

Bezafibrate induces myotoxicity in human rhabdomyosarcoma cells via peroxisome proliferator-activated receptor alpha signaling

Fibrates, the ligands of peroxisome proliferator-activated receptor alpha (PPARalpha), are used as a class of lipid-lowering drugs in clinical practice for the treatment of dyslipidemia. Fibrates are well tolerated in most cases concomitantly with occasional adverse reactions including muscular toxicity, which is enhanced by the combination with statins. This study was designed to investigate the effects of bezafibrate as a PPARalpha agonist on human embryo rhabdomyosarcoma (RD) cells and possible mechanisms responsible for bezafibrate-mediated myopathy. The results revealed that bezafibrate caused a dose-dependent decrease in cell viability, which was fortified in association with atorvastatin at a pharmacological dose. Bezafibrate at toxic doses of 300 and 1000microM upregulated PPARalpha at the mRNA level, counteracted by a PPARalpha antagonist (MK886). Bezafibrate at a toxic dose induced typical apoptotic characteristics related to the inhibition of phosphorylation of Akt which was blocked by PPARalpha antagonist. Toxic doses of bezafibrate initiated a significant increase in pyruvate dehydrogenase kinase 4 mRNA and protein levels, compromised by MK886. These results suggest the critical roles of PPARalpha signaling in bezafibrate-induced myotoxicity and the involvement of apoptosis through Akt pathway.

Combination therapy with an HMG-CoA reductase inhibitor and a fibric acid derivative: a critical review of potential benefits and drawbacks

It has been clearly shown that lowering low density lipoprotein-cholesterol (LDL-C) [most often with an HMG-CoA reductase inhibitor] decreases the risk of a cardiovascular event. However, this risk reduction was, at most, 35% in clinical trials, meaning that many events could not be prevented. Moreover, reaching target lipid values as recommended by the current guidelines is often difficult, mainly in high-risk situations such as secondary prevention or type 2 diabetes mellitus. As the two main classes of lipid-lowering drugs (HMG-CoA reductase inhibitors and fibric acid derivatives) have complementary effects on lipid parameters, it seems logical to combine both treatments particularly in patients with combined hyperlipidemia. In fact, combination therapy with an HMG-CoA reductase inhibitor and a fibric acid derivative induces a further decrease in LDL-C levels compared with monotherapy and improves other lipid values such as high density lipoprotein-cholesterol (HDL-C) and triglyceride (TG) levels. Unfortunately, there are currently no available randomized, prospective clinical data on the reduction of the incidence of cardiovascular events with such a combination. This is mainly because the use of HMG-CoA reductase inhibitor and fibric acid derivative combinations was initially described as dangerous. It is true that such a combination increases the risk of muscle toxicity that already exists with monotherapy. Muscle toxicity can eventually lead to life-threatening rhabdomyolysis and some precautions of use are required; however, the risk seems actually lower than what has been initially reported. The use of combined therapy with an HMG-CoA reductase inhibitor and a fibric acid derivative requires the respect of some rules such as avoiding the prescription in patients with concomitant conditions like renal failure and avoiding the use of gemfibrozil as a fibric acid derivative in such a combination. It is now imperative to design clinical trials to determine the clinical efficacy and precise safety of this combined treatment especially in patients with abnormalities in every parameter of the lipid triad (LDL, HDL and TG) and a high vascular risk such as patients with type 2 diabetes mellitus.

High density lipoprotein cholesterol: an evolving target of therapy in the management of cardiovascular disease

Since the pioneering work of John Gofman in the 1950s, our understanding of high density lipoprotein cholesterol (HDL-C) and its relationship to coronary heart disease (CHD) has grown substantially. Numerous clinical trials since the Framingham Study in 1977 have demonstrated an inverse relationship between HDL-C and one’s risk of developing CHD. Over the past two decades, preclinical research has gained further insight into the nature of HDL-C metabolism, specifically regarding the ability of HDL-C to promote reverse cholesterol transport (RCT). Recent attempts to harness HDL’s ability to enhance RCT have revealed the complexity of HDL-C metabolism. This review provides a detailed update on HDL-C as an evolving therapeutic target in the management of cardiovascular disease.

Toward "pain-free" statin prescribing: clinical algorithm for diagnosis and management of myalgia

Myalgia, which often manifests as pain or soreness in skeletal muscles, is among the most salient adverse events associated with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins). Clinical issues related to statin-associated myotoxicity include (1) incidence in randomized controlled trials and occurrence in postmarketing surveillance databases; (2) potential differences between statins in their associations with such adverse events; and (3) diagnostic and treatment strategies to prevent, recognize, and manage these events. Data from systematic reviews, meta-analyses, clinical and observational trials, and post-marketing surveillance indicate that statin-associated myalgia typically affects approximately 5.0% of patients, as myopathy in 0.1% and as rhabdomyolysis in 0.01%. However, studies also suggest that myalgia is among the leading reasons patients discontinue statins (particularly high-dose statin monotherapy) and that treatment with certain statins (eg, fluvastatin) is unlikely to result in such adverse events. This review presents a clinical algorithm for monitoring and managing statin-associated myotoxicity. The algorithm highlights risk factors for muscle toxicity and provides recommendations for (1) creatine kinase measurements and monitoring; (2) statin dosage reduction, discontinuation, and rechallenge; and (3) treatment alternatives, such as extended-release fluvastatin with or without ezetimibe, low-dose or alternate-day rosuvastatin, or ezetimibe with or without colesevelam. The algorithm should help to inform and enhance patient care and reduce the risk of myalgia and other potentially treatment-limiting muscle effects that might undermine patient adherence and compromise the overall cardioprotective benefits of statins.

Vascular and metabolic effects of treatment of combined hyperlipidemia: focus on statins and fibrates

Combined hyperlipidemia results from overproduction of hepatically synthesized apolipoprotein B in very low-density lipoproteins in association with reduced lipoprotein lipase activity. Thus, this condition is typically characterized by concurrent elevations in total cholesterol and triglycerides with decreased high-density lipoprotein cholesterol. High levels of apolipoprotein B-containing lipoproteins, most prominently carried by low-density lipoprotein (LDL) particles, are an important risk factor for coronary heart disease. Statin therapy is highly effective at lowering LDL cholesterol. Despite the benefits of statin treatment for lowering total and LDL cholesterol, many statin-treated patients still have initial or recurrent coronary heart disease events. In this regard, combined therapy with statins and fibrates is more effective in controlling atherogenic dyslipidemia in patients with combined hyperlipidemia than either drug alone. Furthermore, statins and fibrates activate PPARalpha in a synergistic manner providing a molecular rationale for combination treatment in coronary heart disease. Endothelial dysfunction associated with cardiovascular diseases may contribute to insulin resistance so that there may also be additional beneficial metabolic effects of combined statin/fibrates therapy. However, there has been little published evidence that combined therapy is synergistic or even better than monotherapy alone in clinical studies. Therefore, there is a great need to study the effects of combination therapy in patients. When statins are combined with gemfibrozil therapy, this is more likely to be accompanied by myopathy. However, this limitation is not observed when fenofibrate, bezafibrate, or ciprofibrate are used in combination therapy.

Reaching target lipid levels in patients at high risk of cardiovascular event: the experience of a Canadian tertiary care lipid clinic

OBJECTIVES

To determine the proportion of high risk patients followed at a tertiary care lipid clinic who met recommended lipid targets and to identify predictors of reaching goal lipid levels.

RESEARCH DESIGN AND METHODS

A retrospective cohort study of 502 high risk patients followed between 1983 and 2003. Clinical and demographic data and fasting lipid profiles were extracted from each patient's first two clinic visits as well as the most recent visit.

RESULTS

All patients in this study were at high risk of cardiovascular events due to dyslipidemia. At "Visit 1", only 55 (11.0%) of patients were at target TC/HDL-C < 4.0, and 97 (19.3%) of patients met target LDL-C < 2.5 mmol/l. At "Visit 3", 229 (45.8%) patients reached TC/HDL-C target, and 216 (43.2%) patients were at LDL-C target. The mean change in lipid values between Visit 1 and Visit 3 was significant (p = 0.0002) for LDL-C and (p < 0.0001) for TC/HDL-C. The use of statins, niacin, or salmon oil were all significantly associated with reaching TC/HDL-C target and LDL-C target, as well male gender, diabetes mellitus and peripheral vascular disease were also associated with reaching LDL-C target. Increasing age and lower body mass index were associated with reaching goal TC/HDL-C.

CONCLUSIONS

The mean absolute changes in lipid values were significant and median lipid levels approached target levels in patients followed at specialized clinic, however the majority of high risk patients are not meeting goal lipid levels.

Effect of paraoxonase 1 polymorphisms on the response of lipids and lipoprotein-associated enzymes to treatment with fluvastatin

BACKGROUND

Decreased paraoxonase 1 (PON1) and increased total serum lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) activities are suggested to be risk factors for vascular disease. Common PON1 genetic polymorphisms (Q192R and L55M) significantly affect PON1 activity and may also influence high-density lipoprotein (HDL)-associated Lp-PLA(2) activity. However, little is known about the possible effect of PON1 common genetic polymorphisms on the response of lipids as well as PON1 and Lp-PLA(2) activities to treatment with statins.

METHODS

Two hundred two hypercholesterolemic patients were treated with fluvastatin 40 mg/day. Fasting serum lipids, Q192R and L55M PON1 polymorphisms as well as PON1 and Lp-PLA(2) (total serum and HDL-associated) activities were determined before and after 6 months of treatment.

RESULTS

Fluvastatin treatment did not affect HDL-cholesterol or apolipoprotein (apo) AI but resulted in significant decreases in total cholesterol, triglycerides, low-density lipoprotein-cholesterol, apo B and apo E, as well as total serum Lp-PLA(2) activity. In contrast, PON1 activity significantly increased. None of these changes was influenced by Q192R or L55M PON1 polymorphisms. Overall, HDL-Lp-PLA(2) did not change but L55M polymorphism significantly influenced its response to fluvastatin. Specifically, LL homozygotes experienced a significant increase, while M carriers (LM or MM) experienced a non-significant decrease in HDL-Lp-PLA(2) activity (p = 0.030 between groups).

CONCLUSIONS

Q192R and L55M PON1 polymorphisms did not affect the response of lipids, PON1 and total serum Lp-PLA(2) to treatment with a statin. However, L55M PON1 polymorphism significantly modulated the response of HDL-Lp-PLA(2). It should be noted that this is an association study and therefore provides no proof but only indication that PON1 may also exert Lp-PLA(2) activity in HDL.

Dose-Dependent Effects of Docosahexaenoic Acid Supplementation on Blood Lipids in Statin-Treated Hyperlipidaemic Subjects

The objective of the study was to evaluate potential benefits of docosahexaenoic acid (DHA) rich fish oil supplementation as an adjunct to statin therapy for hyperlipidaemia. A total of 45 hyperlipidaemic patients on stable statin therapy with persistent elevation of plasma triglycerides (averaging 2.2 mmol/L) were randomised to take 4 g/day (n = 15) or 8 g/day (n = 15) of tuna oil or olive oil (placebo, n = 15) for 6 months. Plasma lipids, blood pressure and arterial compliance were assessed initially and after 3 and 6 months in 40 subjects who completed the trial. Plasma triglycerides were reduced 27% by 8 g/day DHA-rich fish oil (P < 0.05) but not by 4 g/day when compared with the placebo and this reduction was achieved by 3 months and was sustained at 6 months. Even though total cholesterol was already well controlled by the statin treatment (mean initial level 4.5 mmol/L), there was a further dose-dependent reduction with fish oil supplementation (r = -0.344, P < 0.05). The extent of total cholesterol reduction correlated (r = -0.44) with the initial total cholesterol levels (P < 0.005). In the subset with initial plasma cholesterol above 3.8 mmol/L, plasma very low density lipoprotein (VLDL), intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) were isolated and assayed for cholesterol and apolipoprotein B (apoB) at the commencement of the trial and at 3 months of intervention. Fish oil tended to lower cholesterol and apoB in VLDL and raise both in LDL. There were no changes in IDL cholesterol, IDL apoB and high-density lipoprotein cholesterol. The results demonstrate that DHA-rich fish oil supplementation (2.16 g DHA/day) can improve plasma lipids in a dose-dependent manner in patients taking statins and these changes were achieved by 3 months. Fish oil in addition to statin therapy may be preferable to drug combinations for the treatment of combined hyperlipidaemia.

Management of dyslipidemia in the metabolic syndrome: recommendations of the Spanish HDL-Forum

In order to characterize the metabolic syndrome it becomes necessary to establish a number of diagnostic criteria. Because of its impact on cardiovascular morbidity/mortality, considerable attention has been focussed on the dyslipidemia accompanying the metabolic syndrome. The aim of this review is to highlight the fundamental aspects of the pathophysiology, diagnosis, and the treatment of the metabolic syndrome dyslipidemia with recommendations to clinicians. The clinical expression of the metabolic syndrome dyslipidemia is characterized by hypertriglyceridemia and low levels of high-density lipoprotein-cholesterol (HDL-C). In addition, metabolic syndrome dyslipidemia is associated with high levels of apolipoprotein (apo) B-100-rich particles of a particularly atherogenic phenotype (small dense low-density lipoprotein-cholesterol [LDL-C]. High levels of triglyceride-rich particles (very low-density lipoprotein) are also evident both at baseline and in overload situations (postprandial hyperlipidemia). Overall, the 'quantitative' dyslipidemia characterized by hypertriglyceridemia and low levels of HDL-C and the 'qualitative' dyslipidemia characterized by high levels of apo B-100- and triglyceride-rich particles, together with insulin resistance, constitute an atherogenic triad in patients with the metabolic syndrome. The therapeutic management of the metabolic syndrome, regardless of the control of the bodyweight, BP, hyperglycemia or overt diabetes mellitus, aims at maintaining optimum plasma lipid levels. Therapeutic goals are similar to those for high-risk situations because of the coexistence of multiple risk factors. The primary goal in treatment should be achieving an LDL-C level of <100 mg/dL (or <70 mg/dL in cases with established ischemic heart disease or risk equivalents). A further goal is increasing the HDL-C level to >or=40 mg/dL in men or 50 mg/dL in women. A non-HDL-C goal of 130 mg/dL should also be aimed at in cases of hypertriglyceridemia. Lifestyle interventions, such as maintaining an adequate diet, and a physical activity program, constitute an essential part of management. Nevertheless, when pharmacologic therapy becomes necessary, fibrates and HMG-CoA reductase inhibitors (statins) are the most effective drugs in controlling the metabolic syndrome hyperlipidemia, and are thus the drugs of first choice. Fibrates are effective in lowering triglycerides and increasing HDL-C levels, the two most frequent abnormalities associated with the metabolic syndrome, and statins are effective in lowering LDL-C levels, even though hypercholesterolemia occurs less frequently. In addition, the combination of fibrates and statins is highly effective in controlling abnormalities of the lipid profile in patients with the metabolic syndrome.

[Treatment of dyslipidemia: how and when to combine lipid lowering drugs]

Familial combined hyperlipidemia (FCH) is a frequent familial lipid disorder associated with insulin resistance, low HDL cholesterol, high triglycerides and cholesterol levels with variable phenotypes within the same family. FCH is linked to a high risk for cardiovascular diseases. Treatment goals for lipid abnormalities are changing in recent years. Lowering elevated levels of LDL e Non HDL-cholesterol levels are primary targets of therapy. Lower LDL-C than 70 mg/dL seems to be useful to lower cardiovascular risk in patients with very high risk. Many statins are available, with different potencies and drug interactions. Combination therapy of statins and bile acid sequestrants or ezitimibe may be necessary to further decrease LDL cholesterol levels in order to meet guideline goals. High triglycerides and low HDL cholesterol are also important goals in the treatment of these patients, and frequently statins alone are insufficient to normalize the lipid profile. Combination therapy with fibrates will further lower triglycerides and increase HDL cholesterol levels; this combination is also associated with higher incidence of myopathy and liver toxicity; appropriate evaluation of patients' risk and benefits is necessary. Association of statin/niacin seems be very useful in patients with FCH, especially as niacin is the best drug to increase HDL cholesterol; this association is not linked to a higher frequency of myopathy. Niacin causes flushing, that can in part be managed with use of aspirin and extended release forms (Niaspan); niacin also may increase plasma glucose and uric acid levels. Evaluation of risks and benefits for each patient is needed.

Overcoming ???Ageism??? Bias in the Treatment of Hypercholesterolaemia

Atherosclerosis is a progressive, lifelong condition that is the leading cause of death among middle-aged and elderly individuals aged > or =65 years. Up to 80% of elderly patients are found to have evidence of obstructive coronary heart disease at autopsy. Demographic trends, including the advancing median age and life expectancy of Western societies, suggest that a large share of the burden of atherosclerotic plaque is likely to be borne by elderly individuals. These trends are in part due to increases in a number of chronic diseases associated with adverse cardiovascular outcomes, including metabolic syndrome, diabetes mellitus and chronic kidney disease. Because the elderly have a higher attributable risk of coronary heart disease as a result of hypercholesterolaemia, more coronary deaths and overall events can be prevented via treatment in this age group compared with younger persons with hypercholesterolaemia. The efficacy, safety and tolerability of HMG-CoA reductase inhibitors (statins) have been confirmed in randomised, controlled, multicentre trials involving large numbers of patients aged > or =65 years. Although muscle symptoms such as myalgia are relatively common adverse events, more severe signs of myolysis such as myopathy and rhabdomyolysis are rare, but their risk is elevated by conditions (e.g. concomitant medications) that increase the systemic exposure of these agents. Statins differ in their susceptibility to increases in systemic exposure, but most statins have been demonstrated to be well tolerated and safe when administered to elderly patients. These favourable clinical findings should help clinicians counter highly prevalent 'ageism' bias in statin prescribing, whereby elderly patients, particularly those at highest cardiovascular risk, are often denied the benefits of statins without any meaningful foundation.

Effective use of combination lipid therapy

Despite the benefits of statin therapy, low-density lipoprotein (LDL) cholesterol management remains suboptimal and many patients do not achieve their recommended target goals. The aim of combination lipid drug therapy in high-risk patients is to achieve LDL cholesterol and non-high-density lipoprotein (HDL) cholesterol goals with a minimum of serious adverse effects. Although statins are the drug of first choice, statin monotherapy may be limited by intolerance of dose escalation or failure to attain non-HDL cholesterol goals in those with mixed hyperlipidemia. Statins plus bile acid resins or ezetimibe can achieve greater than 50% reduction in LDL cholesterol, with little or no increase in adverse effects. Fibrates, niacin, and omega-3 fatty acids, when added to statins, can reduce triglycerides, increase HDL cholesterol, and reduce non-HDL cholesterol to a greater extent than statin monotherapy. The safety profile of combination lipid therapy is acceptable if the global coronary heart disease risk of the patient is high, thus producing a favorable risk to benefit ratio. Careful surveillance of hepatic transaminases, avoidance of gemfibrozil in statin-fibrate combinations, and awareness of statin-concomitant drug interactions is key to safe and efficacious use of combination lipid drug therapy.

Effective use of combination lipid therapy

Despite the benefits of statin therapy, low-density lipoprotein cholesterol (LDL-C) management remains suboptimal and many patients do not achieve their recommended target goals. The aim of combination lipid drug therapy in high-risk patients is to achieve LDL-C and non-high-density lipoprotein cholesterol (HDL-C) goals with a minimum of serious adverse effects. Although statins are the drug of first choice, statin monotherapy may be limited by intolerance of dose escalation or failure to attain non-HDL-C goals in those with mixed hyperlipidemia. Statins plus bile acid resins or ezetimibe can achieve greater than 50% reduction in LDL-C, with little or no increase in adverse effects. Fibrates, niacin, and omega-3 fatty acids, when added to statins, can reduce triglycerides, increase HDL-C, and reduce non-HDL-C to a greater extent than statin monotherapy. The safety profile of combination lipid therapy is acceptable, if the global coronary heart disease risk of the patient is high, thus producing a favorable risk to benefit ratio. Careful surveillance of hepatic transaminases, avoidance of gemfibrozil in statin-fibrate combinations, and awareness of statin-concomitant drug interactions is key to safe and efficacious use of combination lipid drug therapy.

Statins and fibrates for preventing melanoma

BACKGROUND

Effective treatment for advanced melanoma is lacking. While no drug therapy currently exists for prevention of melanoma, in vitro, case-control, and animal model evidence suggest that lipid-lowering medications, commonly taken for high cholesterol, might prevent melanoma.

OBJECTIVES

To assess the effects of statin or fibrate lipid-lowering medications on melanoma outcomes.

SEARCH STRATEGY

We searched the Cochrane Skin Group Specialised Register (February 2003), CENTRAL (The Cochrane Library Issue 1, 2005), MEDLINE (to March 2003), EMBASE (to September 2003), CANCERLIT (to October 2002), Web of Science (to May 2003), and reference lists of articles. We approached study investigators and pharmaceutical companies for additional information (published or unpublished studies).

SELECTION CRITERIA

Trials involving random allocation of study participants, where experimental groups used statins or fibrates and participants were enrolled for at least four years of therapy.

DATA COLLECTION AND ANALYSIS

Three authors screened 109 abstracts of articles with titles of possible relevance. We then thoroughly examined the full text of 72 potentially relevant articles. We requested unpublished melanoma outcomes data from the corresponding author of each qualifying trial.

MAIN RESULTS

We identified 16 qualifying randomised controlled trials (RCTs) (seven statin, nine fibrate). Thirteen of these trials (involving 62,197 participants) provided data on incident melanomas (six statin, seven fibrate). A total of 66 melanomas were reported in groups receiving the experimental drug and 86 in groups receiving placebo or other control therapies. For statin trials this translated to an odds ratio of 0.90 (95% confidence interval 0.56 to 1.44) and for fibrate trials an odds ratio of 0.58 (95% confidence interval 0.19 to 1.82). Subgroup analyses failed to show statistically significant differences in melanoma outcomes by gender, melanoma occurrence after two years of participation in trial, stage or histology, or trial funding. Subgroup analysis by type of fibrate or statin also failed to show statistically significant differences, except for the statin subgroup analysis which showed reduced melanoma incidence for lovastatin, based on one trial only (odds ratio 0.52, 95% confidence interval 0.27 to 0.99).

AUTHORS' CONCLUSIONS

The melanoma outcomes data collected in this review of RCTs of statins and fibrates does not exclude the possibility that these drugs prevent melanoma. There was a 10% and 42% reduction for participants on statins and fibrates, respectively, however these results were not statistically significant. Until further evidence is established, limiting exposure to ultraviolet radiation remains the most effective way to reduce the risk of melanoma.

Pathophysiology of dyslipidaemia in the metabolic syndrome

The insulin resistance/metabolic syndrome is characterised by the variable coexistence of hyperinsulinaemia, obesity, dyslipidaemia, and hypertension. The pathogenesis of the syndrome has multiple origins, but obesity and sedentary lifestyle coupled with diet and still largely unknown genetic factors clearly interact to produce the syndrome. Dyslipidaemia, the hallmark of the metabolic syndrome, includes increased flux of free fatty acids, raised triglycerides, apolipoprotein B, and small dense low density lipoprotein, and decreased high density lipoprotein cholesterol. The widely prevalent nature of the metabolic syndrome emphasises the importance of its diagnosis and treatment. This review analyses the clinical and dynamic features of this syndrome in the aspect of dyslipidaemia and its management.

Comparative effects of lipid-lowering therapies

The pharmacologic regulation of lipid metabolism in patients with dyslipidemia is unequivocally associated with significant reductions in risk for cardiovascular morbidity and mortality. A number of therapeutic drug classes have been developed in an effort to ever more precisely and intensively modulate lipid metabolism. Statins, fibrates, ezetimibe, and niacin exert their effects via different mechanisms and afford physicians the opportunity to beneficially impact multiple pathways in patients. When used alone or in combination, these drugs decrease risk for the development and progression of atherosclerotic disease. There are strong clinical trial data to support of the use of lipid-lowering therapies in the settings of both primary and secondary prevention. This article (1) discusses the mechanisms of action of antilipidemic medications, (2) reviews dosing regimens and the pharmacokinetic differences among drugs of the same class, (3) assesses risk for drug interactions, and (4) reviews the clinical trial evidence used to support the use of particular antilipidemic medications in specific physiologic settings. The incidence of dyslipidemia is rising worldwide. This trend portends an ever-growing need for the aggressive and judicious use of different antilipidemic medication(s) in patients at risk for all forms of atherosclerotic vascular disease.

The triglyceride-high-density lipoprotein axis: an important target of therapy?

Coronary heart disease is the single largest cause of morbidity and mortality in the United States. The link between elevated low-density lipoprotein cholesterol (LDL-C) levels and coronary heart disease (CHD) has been clearly established. However, triglycerides (TG) are increasingly believed to be independently associated with CHD, while high-density lipoprotein cholesterol (HDL-C) is inversely associated with CHD risk. High TG and low HDL often occur together, often with normal levels of LDL-C, and can be described as abnormalities of the TG-HDL axis. This lipid abnormality is a fundamental characteristic of patients with the metabolic syndrome, a condition strongly associated with the development of both type 2 diabetes and CHD. Patients with high TG and low HDL-C should be aggressively treated with therapeutic lifestyle changes. For high-risk patients, lipid-modifying therapy that specifically addresses the TG-HDL axis should also be considered. Current pharmacologic treatment options for such patients include statins, fibrates, niacin, fish oils, and combinations thereof. Several new pharmacologic approaches to treating the TG-HDL axis are currently being investigated. More clinical trial data is needed to test the hypothesis that pharmacologic therapy targeting the TG-HDL axis reduces atherosclerosis and cardiovascular events.

Combination therapy in the management of complex dyslipidemias

PURPOSE OF REVIEW

Patients with dyslipidemias continue to be undertreated in both the primary and secondary prevention settings. Many patients have therapeutic needs that exceed simple reductions in low-density lipoprotein levels using statins. This review discusses the need for comprehensive management of all abnormalities in a given patient's lipoprotein profile and for the use of combinations of anti-lipidemic medications, when indicated.

RECENT FINDINGS

The majority of high-risk patients with manifestations of atherosclerotic disease or who have a coronary artery disease risk equivalent are not meeting their various lipoprotein targets. There is considerable reluctance to titrate statins and to use combinations of anti-lipidemic medications in patients not reaching their various lipoprotein targets. Combinations of anti-lipidemic medications can be specifically tailored to address abnormalities in multiple lipoprotein fractions. Recent clinical trials clearly demonstrate that combination therapy is well tolerated and facilitates lipoprotein goal attainment.

SUMMARY

Therapeutic approaches that incorporate the use of multiple anti-lipidemic medications should be more widely adopted in order to increase the number of patients able to meet their lipoprotein goals and to produce more substantially reduced risks for acute cardiovascular events.

Effects of baseline level of triglycerides on changes in lipid levels from combined fluvastatin + fibrate (bezafibrate, fenofibrate, or gemfibrozil)

This analysis was conducted to evaluate the effect of baseline triglyceride levels on lipid and lipoprotein changes after treatment with the combination of fluvastatin and fibrates. The analysis involved pooling data from 10 studies that included 1,018 patients with either mixed hyperlipidemia or primary hypercholesterolemia. Patients received a combination of fluvastatin and a fibrate (bezafibrate, fenofibrate, or gemfibrozil) from 16 to 108 weeks. The combination of fluvastatin and a fibrate improved lipid profiles, with reductions in triglycerides, low-density lipoprotein (LDL) cholesterol, and non-high-density lipoprotein (non-HDL) cholesterol that were dependent on baseline triglyceride levels. The greatest triglyceride reductions were observed in patients with high baseline triglyceride levels (> or =400 mg/dl) (41%, p <0.0001). The greatest LDL cholesterol and non-HDL cholesterol reductions occurred in patients with normal baseline triglyceride levels (<150 mg/dl) (35% and 33%, respectively; p <0.0001). The combined fluvastatin-fibrate therapy was well tolerated. Two patients (0.2%) (1 patient on fluvastatin 80 mg + gemfibrozil 1,200 mg and 1 patient on fluvastatin 20 mg + fenofibrate 200 mg) had creatine kinase levels > or =10 times the upper limit of normal, 11 patients (1.1%) had an elevation in alanine transaminase >3 times the upper limit of normal, and 7 patients (0.7%) had elevations in aspartate transaminase >3 times the upper limit of normal. Combined fluvastatin-fibrate therapy takes advantage of the complementary effects of the 2 agents, with the extent of triglyceride, LDL cholesterol, and non-HDL cholesterol lowering dependent on baseline triglyceride levels. The combination of fluvastatin and fibrates was well tolerated with no major safety concerns.

Combination lipid-lowering therapy with statins: safety issues in the postcerivastatin era

Combination lipid-altering regimens represent an emerging clinical paradigm to meet increasingly stringent consensus lipoprotein targets for coronary prevention. This practice, together with escalating prevalences of coronary artery disease in certain ageing (western industrial) populations, polypharmacy in the elderly and the recent voluntary market withdrawal of cerivastatin, warrants a re-examination of the safety profiles of 3-hydroxy-3-methylglutaryl co-enzyme A (HMG-CoA) reductase inhibitors (i.e., statins). These agents are exceedingly well-tolerated in the vast majority of patients, very infrequently precipitating musculoskeletal symptoms and/or signs. Statins vary in their pharmacological profiles, leading to distinct levels of systemic exposure and capacities to penetrate skeletal myocytes. Pharmacokinetic interactions with certain agents increase the likelihood of statin-induced myopathy and, in exceedingly rare instances, potentially fatal rhabdomyolysis with myoglobinuria and renal failure. As with other medical decisions, the anticipated benefits of long-term statin therapy, with or without other lipid-altering agents, need to be weighed against the prospects of clinically significant drug interactions. In clinical trials and postmarketing surveillance, the two statins that are not metabolised by the cytochrome P450 3A4 system (fluvastatin and pravastatin) have exhibited very low propensities to elicit myopathy when combined with other agents. These agents should be considered initially when contemplating combination lipid-lowering regimens for coronary prevention.

Statin-fibrate combination: therapy for hyperlipidemia: a review

Statins and fibrates are well-established treatments for hyperlipidaemias and the prevention of vascular events. However, fibrate + statin therapy has been restricted following early reports of rhabdomyolysis that mainly involved gemfibrozil, originally with bovastatin, and recently, with cerivastatin. Despite this limitation, several reports describing combination therapy have been published. This review considers these studies and the relevant indications and contraindications. Statin + fibrate therapy should be considered if monotherapy or adding other drugs (e.g. cholesterol absorption inhibitors, omega-3 fatty acids ornicotinic acid) did not achieve lipid targets or is impractical. Combination therapy should be hospital-based and reserved for high-risk patients with a mixed hyperlipidaemia characterised by low density lipoprotein cholesterol (LDL) >2.6 mmol/l(100 mg/dl, high density lipoprotein cholesterol (HDL) <1.0 mmol/l (40 mg/dl) and/or triglycerides> 5.6 mmol/l (500 mg/dl. These three 'goals' are individually mentioned in guidelines. Patients should have normal renal, liver and thyroid function tests and should not be receiving therapy with cyclosporine, protease inhibitors or drugs metabolised through cytochrome P450 (especially 3A4). Combination therapy is probably best conducted using drugs with short plasma half-lives; fibrates should be prescribed in the morning and statins at night to minimise peak dose interactions. Both drug classes should be progressively titated from low doses. Regular (3-monthly) monitoring of liver function and creatine kinase is required. In conclusion, fibrate + statin therapy remains an option in high-risk patents. However, long-term studies involving safety monitoring and vascular endpoints are required to demonstrate the efficacy of this regimen.

Safety considerations for statins

PURPOSE OF REVIEW

The hydroxymethyl glutaryl coenzyme A reductase inhibitors or statins offer important benefits for the large populations of individuals at high risk for coronary heart disease. These drugs have a good safety profile. Nevertheless, differences in physicochemical and pharmacokinetic properties between statins may translate into significant differences in long-term safety. This review focuses on long-term adverse effects related to statin use, namely hepatotoxicity and myopathy. Moreover, the most common drugs used in combination with statins in long-term therapies are analyzed in terms of possible drug/drug interactions affecting the safety of statins.

RECENT FINDINGS

The withdrawal of cerivastatin from the global market in 2001, because of severe cases of rhabdomyolysis, highlighted concerns regarding the safety of the entire class. Afterwards, the role of statins and their interactions with other drugs in precipitating this condition have been carefully reviewed. In approximately 60% of the total number of cases, statin-related rhabdomyolysis was found to be related to drug/drug interactions. Recently, all cases of fatal rhabdomyolysis associated with statin use have been reported to the US Food and Drug Administration. This has shown that fatal rhabdomyolysis among statin users is a rare event, the reporting rates being much less than one death per million prescriptions in the case of all statins except cerivastatin.

SUMMARY

The safety and tolerability of the available statins support their use as the first-line treatment of patients at high risk for coronary heart disease, since the clinical benefits greatly outweigh the small risk of myopathy. Nevertheless, clinicians should be aware of the adverse effects possibly related to statin therapy, particularly in patients at high risk for coronary heart disease and requiring long-term multiple-drug therapies.

Combination therapy for combined dyslipidemia

Patients with combined dyslipidemia are at high risk for coronary artery disease and often require combination drug therapy to achieve lipid levels recommended by the US National Cholesterol Education Program's third Adult Treatment Panel (ATP III). In addition to recommendations for low-density lipoprotein (LDL) cholesterol and triglyceride levels, ATP III established non-high-density lipoprotein (HDL) cholesterol goals for individuals with triglycerides >or=2.26 mmol/L (>or=200 mg/dL). It also introduced certain criteria for the diagnosis of the metabolic syndrome, a clustering of risk factors (abdominal obesity, elevated triglycerides, low HDL cholesterol, elevated blood pressure, impaired fasting glucose) that increases cardiovascular risk and is common in patients with combined dyslipidemia. Statin monotherapy has been shown to benefit these patients, and additional benefit may be obtained by combination therapy that provides greater reductions in both LDL cholesterol and triglycerides as well as greater increases in HDL cholesterol. However, combining a statin with either niacin or a fibrate may increase the risk for myopathy and therefore requires careful monitoring and evaluation of the risk-benefit ratio for each patient. Moreover, combination therapy may be associated with increased drug costs and decreased patient compliance. Recently developed agents that may improve the effectiveness of combination therapy include ezetimibe-a cholesterol absorption inhibitor-and a formulation that combines extended-release niacin and lovastatin in a single pill. Clinical trials are needed to determine the optimal treatment in patients with combined dyslipidemia.

Fluvastatin

Fluvastatin was the first wholly synthetic statin to the market and is effective in reducing total and low density lipoprotein cholesterol, which translates into reductions in coronary heart disease events. The Lescol Intervention Prevention Study has established the effectiveness of the early use of statins in reducing recurrent events in high-risk patients with coronary heart disease post percutaneous coronary interventions. Fluvastatin is well-tolerated with few side effects. The occurrence of significant abnormalities in liver enzymes is infrequent, and the risk of myositis and rhabdomyolysis seems to be less than with other statins. There have been no reports of fatal rhabdomyolysis to date. The potential for drug interactions with fluvastatin is low. It seems safe in combination with cyclosporin and there have been few reports of rhabdomyolysis when using fluvastatin in combination with other lipid-lowering agents. It is nevertheless important to be vigilant for this potentially important side effect and, as with other statins, inform patients of the potential risk and suggestive symptoms. Fluvastatin provides a useful option in treating hypercholesterolaemia in patients at high risk of coronary heart disease.

Peroxisome proliferator-activated receptor agonists, hyperlipidaemia, and atherosclerosis

Dyslipidaemia is a major risk factor in the development of atherosclerosis, and lipid lowering is achieved clinically using fibrate drugs and statins. Fibrate drugs are ligands for the fatty acid receptor peroxisome proliferator-activated receptor (PPAR)alpha, and the lipid-lowering effects of this class of drugs are mediated by the control of lipid metabolism, as directed by PPARalpha. PPARalpha ligands also mediate potentially protective changes in the expression of several proteins that are not involved in lipid metabolism, but are implicated in the pathogenesis of heart disease. Clinical studies with bezafibrate and gemfibrozil support the hypothesis that these drugs may have a significant protective effect against cardiovascular disease. The thiazolidinedione group of insulin-sensitising drugs are PPARgamma ligands, and these have beneficial effects on serum lipids in diabetic patients and have also been shown to inhibit the progression of atherosclerosis in animal models. However, their efficacy in the prevention of cardiovascular-associated mortality has yet to be determined. Recent studies have found that PPARdelta is also a regulator of serum lipids. However, there are currently no drugs in clinical use that selectively activate this receptor. It is clear that all three forms of PPARs have mechanistically different modes of lipid lowering and that drugs currently available have not been optimised on the basis of PPAR biology. A new generation of rationally designed PPAR ligands may provide substantially improved drugs for the prevention of cardiovascular disease.

Pharmacological interactions of statins

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are effective in reducing the risk of coronary events, and are generally very well tolerated. However, simvastatin, lovastatin, cerivastatin and atorvastatin are biotransformed in the liver primarily by cytochrome P450 (CYP) 3A4, and clinical experience has shown that the risk of adverse effect, such as myopathy, increases with concomitant use of statins with drugs that substantially inhibit CYP 3A4 at therapeutic doses. Indeed, pharmacokinetic interactions (e.g. increased bioavailability), myositis, and rhabdomyolysis have been reported following concurrent use of atorvastatin, cerivastatin, simvastatin or lovastatin and cyclosporine A, mibefradil or nefazodone. In contrast, fluvastatin (mainly metabolized by CYP 2C9) and pravastatin (eliminated by other metabolic routes) are less subject to this interaction. Nevertheless, an increase in pravastatin bioavailability has been reported in the presence of cyclosporine A, possibly because of an interaction at the level of biliary excretion. In summary, some statins may have lower adverse drug interaction potential than others, which is an important determinant of safety during long-term therapy.

How well tolerated are lipid-lowering drugs?

It has been clearly established that lipid-lowering treatments [such as 3-hydroxyl-3-methylglutamyl coenzyme A reductase inhibitors ('statins') or fibrates] can reduce cardiovascular events, and with one of the statins even total mortality, in high-risk populations. Intervention studies have not included the very old, but it is generally assumed that this patient group would benefit from these treatments to an extent similar to younger patients. Worries about the associations seen in observational studies between low cholesterol levels and cancer, cerebral haemorrhage or mood and behaviour change have been largely overcome by findings from the latest large drug intervention trials, which do not show any increase in these conditions with statin or fibrate treatments. The common adverse effects associated with these drugs are relatively mild and often transient in nature. Potentially more serious adverse effects, which are more clearly related to drug treatment and are probably dose-dependent, include elevations in hepatic transaminase levels and myopathy; however, these effects are uncommon and generally resolve rapidly when treatment is stopped. The risk of myopathy with fibrate treatment is increased in patients with renal impairment, and the risk of myopathy with statin treatment increases with co-administration of drugs that inhibit statin metabolism or transport. Other adverse effects are related to specific drugs, for example, clofibrate is associated with an increased risk of gallstones. Studies in elderly patients have not shown an increased risk of adverse effects with lipid-lowering drugs compared with younger patients, but in clinical practice there may be some increased risk, particularly with regards to drug interactions. Therefore, lipid-lowering drugs should be administered with extra caution to elderly patients.

Tolerability of statin-fibrate and statin-niacin combination therapy in dyslipidemic patients at high risk for cardiovascular events

Achieving recommended cholesterol and triglyceride targets for the prevention of cardiovascular events is difficult and frequently requires the use of >1 lipid-lowering medication. This study evaluated the tolerability and effectiveness of combination regimens in high-risk dyslipidemic patients resistant to monotherapy. A retrospective chart review of all patients referred to a cardiovascular risk reduction clinic over a 7.5-year period identified 136 patients who received combination therapy with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) plus fibrate (n = 106) or a statin plus niacin (n = 30) regimen. During follow-up (mean 18.5 months), 28 patients (20.6%) discontinued combination therapy: 11 (8.1%) experienced myalgia with or without elevated creatine kinase, 3 had gastrointestinal upset, and 1 had asymptomatic creatine kinase elevation. No patient had combination therapy discontinued due to elevated liver enzymes. Medications were stopped in 8 patients for reasons other than reported adverse effects or biochemical abnormalities, and 5 patients were switched to alternate monotherapy. Mean percent change from baseline to treatment with combination therapy for total cholesterol (-35%), low-density lipoprotein cholesterol (-37%), high-density lipoprotein cholesterol (+23%), triglycerides (-62%), and total cholesterol/high-density lipoprotein cholesterol ratio (-41%) were all statistically significant (p <0.01). These results demonstrate that combination statin-fibrate and statin-niacin regimens are safe and effective in managing dyslipidemias in most patients at risk for cardiovascular events who are inadequately treated with one of these agents alone.

Combined treatment with fibrates and small doses of atorvastatin in patients with mixed hyperlipidemia

Combined statin and fibrate therapy is often imperative for the improvement of the serum lipid profile in patients with mixed hyperlipidemia. However, the potential risk of myopathy has limited the widespread use of such therapy. Preferably this treatment should involve low optimally tolerable doses of hypolipidemic drugs. Thus, we undertook a study to determine the safety and efficacy of combination therapy with fibrates and small doses of atorvastatin. Twenty-two patients with mixed hyperlipidemia were started on a fibrate regimen (micronised fenofibrate 200mg/day or ciprofibrate 100 mg/day). Because after 12 weeks of therapy the fibrate failed to normalise the serum lipid profile, small doses of atorvastatin (5 mg/day) were added for a further 12 weeks. The administration of the fibrates resulted in a significant decrease in total and LDL-cholesterol levels, as well as in triglycerides, and an increase in HDL-cholesterol levels. The addition of atorvastatin (5 mg/day) resulted in a further decrease in total and LDL-cholesterol levels. Consequently, the hypolipidemic therapy target was achieved in most of the patents. Combination therapy was well tolerated and no significant increases in serum liver and muscle enzymes were noticed. We conclude that the careful administration of small doses of atorvastatin in patients with mixed dyslipidemia receiving fibrates is associated with a significant amelioration of lipid abnormalities.

Combination lipid-altering therapy: an emerging treatment paradigm for the 21st century

For the care of an expanding segment of the US population with multiple coronary risk factors, combination lipid-altering therapy is emerging as a treatment imperative. The most recent National Cholesterol Education Program's consensus guidelines emphasize long-term global coronary heart disease (CHD) risk status, designate patients with CHD risk equivalents (eg, diabetes, peripheral arterial disease, 20% or more 10-year absolute CHD risk) for aggressive lipid-altering therapy, and deem the metabolic syndrome (eg, obesity, insulin resistance, hypertension, elevated triglycerides, low levels of high-density lipoprotein cholesterol, small dense low-density lipoprotein particles) as a secondary target for intervention. With the advancing age of the US population and the high prevalence of diabetes, the metabolic syndrome, and CHD, increasing numbers of patients will require a more balanced metabolic attack attainable only through combination lipid-altering regimens. Many of these patients, as well as persons at heightened risk for cardiovascular disease because of a range of heritable conditions (eg, familial hypercholesterolemia, familial combined hyperlipidemia), will undoubtedly require binary or ternary regimens involving statins in concert with niacin, fibric-acid derivatives, or bile acid resins. Such approaches enable the clinician to exploit the complementary effects of these agents, allowing them to be administered at low, optimally tolerable doses that are consistent with superior efficacy and a lower risk of adverse events as compared with escalating doses of monotherapy.

Diabetes: statins, fibrates, or both?

Cardiovascular disease is the leading cause of mortality in patients with type 2 diabetes. Among the many factors that are involved in the pathogenesis of atherosclerosis in diabetic patients, dyslipidemia plays a major role. It is characterized by an increase in triglycerides, a decrease in high-density lipoprotein cholesterol and normal or mildly elevated low-density lipoprotein cholesterol. The management of patients with diabetic dyslipidemia is difficult because we lack studies specifically designed for diabetic patients. Thus, strategy has to rely on post hoc analyses of landmark intervention trials, which usually include only a small number of diabetic patients, or on rare trials enrolling small cohorts of diabetic patients. When lifestyle changes fail, monotherapy should be tried first with either a statin or a fibrate, depending on triglyceride level. If lipid target values are not reached, a combination therapy can then be initiated, with close follow-up of potential side effects.