Management of dyslipidemias with fibrates, alone and in combination with statins: role of delayed-release fenofibric acid

Evaluation of the Pharmacokinetic Drug-Drug Interaction between Micronized Fenofibrate and Pitavastatin in Healthy Volunteers

Dyslipidemia is a major risk factor for development of atherosclerosis and cardiovascular disease (CVD). Effective lipid-lowering therapies has led to CVD risk reduction. This study evaluated the possible pharmacokinetic interactions between fenofibrate, a peroxisome proliferators-activated receptors α agonist, and pitavastatin, a 3-hydoxy-3-methylglutaryl-coenzyme A reductase inhibitor, in healthy Korean subjects. The study design was an open-label, randomized, multiple-dose, three-period, and six-sequence crossover study with a 10-day washout in 24 healthy volunteers. It had three treatments: 160 mg of micronized fenofibrate once daily for 5 days; 2 mg of pitavastatin once daily for 5 days; and 160 mg of micronized fenofibrate with 2 mg of pitavastatin for 5 days. Serial blood samples were collected at scheduled intervals for up to 48 h after the last dose in each period to determine the steady-state pharmacokinetics of both drugs. Plasma concentrations of fenofibric acid and pitavastatin were measured using a validated high-performance liquid chromatography with the tandem mass spectrometry method. A total of 24 subjects completed the study. Pitavastatin, when co-administered with micronized fenofibrate, had no effect on the C_max,ss and AUC_τ,ss of fenofibric acid. The C_max,ss and AUC_τ,ss of pitavastatin were increased by 36% and 12%, respectively, when co-administered with fenofibrate. Combined treatment with pitavastatin and micronized fenofibrate was generally well tolerated without serious adverse events. Our results demonstrated no clinically significant pharmacokinetic interactions between micronized fenofibrate and pitavastatin when 160 mg of micronized fenofibrate and 2 mg of pitavastatin are co-administered. The treatments were well tolerated during the study, with no serious adverse events.

Comparative study of the effect of atorvastatin and fenofibrate on high-density lipoprotein cholesterol levels in patients with type 2 diabetes

Diabetes is the most common metabolic disease. Type 2 diabetes is a variable combination of insulin resistance and disorder in insulin secretion, leading to disorder of lipids and plasma lipoproteins. The most common pattern of dyslipidemia in diabetic is high triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C). This study was conducted to find a more effective drug to increase HDL-C. In this study, 80 patients (26 males and 54 females) with type 2 diabetes received fenofibrate in cross-sectional way for 2 months, and they did not take antilipid drugs for 2 month. Then, they underwent atorvastatin for 2 months and HDL-C was measured before and after taking drugs. Patients did not change their diet during this study. Effect of atorvastatin and fenofibrate on HDL-C levels in patients with type 2 diabetes was evaluated. The mean HDL-C and total cholesterol (TC) before and after taking drugs were 36.5 mg/dL and 174.56 mg/dL, respectively. After atorvastatin, the mean HDL-C and TC were 43.30 and 150.144 mg/dL, respectively, and after fenofibrate, 43.40 were mg/dL and 146.36 mg/dL, respectively. Atorvastatin caused increase in HDL-C by 18.44% and reduction in TC by 13.82% and fenofibrate increase in HDL-C by18.62% and reduction in TC by 16.05%. No difference was seen between atorvastatin and fenofibrate in terms of effect on the HDL-C excess (P = 0.449). In addition, no difference was seen between atorvastatin and fenofibrate in terms of effect on TC reduction (P = 0.992). In conclusion various factors are involved in increasing the HDL, such as race, sex, nutrition, physical activity and, of course, medications. The effect of medications is also different on races and genetics. The value of increase in HDL-C after Fenofibrate and Atorvastatin was associated with gender so that it caused more increase of HDL-C in females.

Pharmacological Options in Atherosclerosis: A Review of the Existing Evidence

Coronary heart disease (CHD) is the leading cause of mortality worldwide and high low-density lipoprotein (LDL) cholesterol levels have been shown to be key in the pathogenesis of this condition. Lipid control has therefore been the subject of decades of research and has led to many large and robust randomized controlled trials, as well as the highest grossing drug of all time—Lipitor (atorvastatin). Statin therapy has long been indicated for secondary and more recently primary prevention. However, despite the large-scale use of statins, CHD prevalence remains high, and some patients do not respond to statin therapy. There has been a large push to find and test alternative lipid-lowering agents, these include fibrates, cholesterol absorption inhibitors, and proprotein convertase subtilisin/kexin type 9 (PCSK-9) inhibitors. It is the aim of this review to assess the literature surrounding each of these groups of drugs.

The Opportunities and Challenges of Peroxisome Proliferator-Activated Receptors Ligands in Clinical Drug Discovery and Development

Peroxisome proliferator-activated receptors (PPARs) are a well-known pharmacological target for the treatment of multiple diseases, including diabetes mellitus, dyslipidemia, cardiovascular diseases and even primary biliary cholangitis, gout, cancer, Alzheimer's disease and ulcerative colitis. The three PPAR isoforms (α, β/δ and γ) have emerged as integrators of glucose and lipid metabolic signaling networks. Typically, PPARα is activated by fibrates, which are commonly used therapeutic agents in the treatment of dyslipidemia. The pharmacological activators of PPARγ include thiazolidinediones (TZDs), which are insulin sensitizers used in the treatment of type 2 diabetes mellitus (T2DM), despite some drawbacks. In this review, we summarize 84 types of PPAR synthetic ligands introduced to date for the treatment of metabolic and other diseases and provide a comprehensive analysis of the current applications and problems of these ligands in clinical drug discovery and development.

Pharmacological Intervention to Modulate HDL: What Do We Target?

The cholesterol concentrations of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) have traditionally served as risk factors for cardiovascular disease. As such, novel therapeutic interventions aiming to raise HDL cholesterol have been tested in the clinical setting. However, most trials led to a significant increase in HDL cholesterol with no improvement in cardiovascular events. The complexity of the HDL particle, which exerts multiple physiological functions and is comprised of a number of subclasses, has raised the question as to whether there should be more focus on HDL subclass and function rather than cholesterol quantity. We review current data regarding HDL subclasses and subclass-specific functionality and highlight how current lipid modifying drugs such as statins, cholesteryl ester transfer protein inhibitors, fibrates and niacin often increase cholesterol concentrations of specific HDL subclasses. In addition this review sets out arguments suggesting that the HDL3 subclass may provide better protective effects than HDL2.

Treatment Strategy for Dyslipidemia in Cardiovascular Disease Prevention: Focus on Old and New Drugs

Prevention and treatment of dyslipidemia should be considered as an integral part of individual cardiovascular prevention interventions, which should be addressed primarily to those at higher risk who benefit most. To date, statins remain the first-choice therapy, as they have been shown to reduce the risk of major vascular events by lowering low-density lipoprotein cholesterol (LDL-C). However, due to adherence to statin therapy or statin resistance, many patients do not reach LDL-C target levels. Ezetimibe, fibrates, and nicotinic acid represent the second-choice drugs to be used in combination with statins if lipid targets cannot be reached. In addition, anti-PCSK9 drugs (evolocumab and alirocumab) provide an effective solution for patients with familial hypercholesterolemia (FH) and statin intolerance at very high cardiovascular risk. Recently, studies demonstrated the effects of two novel lipid-lowering agents (lomitapide and mipomersen) for the management of homozygous FH by decreasing LDL-C values and reducing cardiovascular events. However, the costs for these new therapies made the cost–effectiveness debate more complicated.

Peroxisome Proliferator-Activated Receptors in Female Reproduction and Fertility

Reproductive functions may be altered by the exposure to a multitude of endogenous and exogenous agents, drug or environmental pollutants, which are known to affect gene transcription through the peroxisome proliferator-activated receptors (PPARs) activation. PPARs act as ligand activated transcription factors and regulate metabolic processes such as lipid and glucose metabolism, energy homeostasis, inflammation, and cell proliferation and differentiation. All PPARs isotypes are expressed along the hypothalamic-pituitary-gonadal axis and are strictly involved in reproductive functions. Since female fertility and energy metabolism are tightly interconnected, the research on female infertility points towards the exploration of potential PPARs activating/antagonizing compounds, mainly belonging to the class of thiazolidinediones (TZDs) and fibrates, as useful agents for the maintenance of metabolic homeostasis in women with ovarian dysfunctions. In the present review, we discuss the recent evidence about PPARs expression in the hypothalamic-pituitary-gonadal axis and their involvement in female reproduction. Finally, the therapeutic potential of their manipulation through several drugs is also discussed.

Modulation of Hypercholesterolemia-Induced Oxidative/Nitrative Stress in the Heart

Hypercholesterolemia is a frequent metabolic disorder associated with increased risk for cardiovascular morbidity and mortality. In addition to its well-known proatherogenic effect, hypercholesterolemia may exert direct effects on the myocardium resulting in contractile dysfunction, aggravated ischemia/reperfusion injury, and diminished stress adaptation. Both preclinical and clinical studies suggested that elevated oxidative and/or nitrative stress plays a key role in cardiac complications induced by hypercholesterolemia. Therefore, modulation of hypercholesterolemia-induced myocardial oxidative/nitrative stress is a feasible approach to prevent or treat deleterious cardiac consequences. In this review, we discuss the effects of various pharmaceuticals, nutraceuticals, some novel potential pharmacological approaches, and physical exercise on hypercholesterolemia-induced oxidative/nitrative stress and subsequent cardiac dysfunction as well as impaired ischemic stress adaptation of the heart in hypercholesterolemia.

A Grape Seed Procyanidin Extract Ameliorates Fructose-Induced Hypertriglyceridemia in Rats via Enhanced Fecal Bile Acid and Cholesterol Excretion and Inhibition of Hepatic Lipogenesis

The objective of this study was to determine whether a grape seed procyanidin extract (GSPE) exerts a triglyceride-lowering effect in a hyperlipidemic state using the fructose-fed rat model and to elucidate the underlying molecular mechanisms. Rats were fed either a starch control diet or a diet containing 65% fructose for 8 weeks to induce hypertriglyceridemia. During the 9th week of the study, rats were maintained on their respective diet and administered vehicle or GSPE via oral gavage for 7 days. Fructose increased serum triglyceride levels by 171% after 9 weeks, compared to control, while GSPE administration attenuated this effect, resulting in a 41% decrease. GSPE inhibited hepatic lipogenesis via down-regulation of sterol regulatory element binding protein 1c and stearoyl-CoA desaturase 1 in the fructose-fed animals. GSPE increased fecal bile acid and total lipid excretion, decreased serum bile acid levels and increased the expression of genes involved in cholesterol synthesis. However, bile acid biosynthetic gene expression was not increased in the presence of GSPE and fructose. Serum cholesterol levels remained constant, while hepatic cholesterol levels decreased. GSPE did not modulate expression of genes responsible for esterification or biliary export of the newly synthesized cholesterol, but did increase fecal cholesterol excretion, suggesting that in the presence of GSPE and fructose, the liver may secrete more free cholesterol into the plasma which may then be shunted to the proximal small intestine for direct basolateral to apical secretion and subsequent fecal excretion. Our results demonstrate that GSPE effectively lowers serum triglyceride levels in fructose-fed rats after one week administration. This study provides novel insight into the mechanistic actions of GSPE in treating hypertriglyceridemia and demonstrates that it targets hepatic de novo lipogenesis, bile acid homeostasis and non-biliary cholesterol excretion as important mechanisms for reducing hypertriglyceridemia and hepatic lipid accumulation in the presence of fructose.

Current guidelines for high-density lipoprotein cholesterol in therapy and future directions

Many studies have suggested that a significant risk factor for atherosclerotic cardiovascular disease (ASCVD) is low high-density lipoprotein cholesterol (HDL-C). Therefore, increasing HDL-C with therapeutic agents has been considered an attractive strategy. In the prestatin era, fibrates and niacin monotherapy, which cause modest increases in HDL-C, reduced ASCVD events. Since their introduction, statins have become the cornerstone of lipoprotein therapy, the benefits of which are primarily attributed to decrease in low-density lipoprotein cholesterol. Findings from several randomized trials involving niacin or cholesteryl ester transfer protein inhibitors have challenged the concept that a quantitative elevation of plasma HDL-C will uniformly translate into ASCVD benefits. Consequently, the HDL, or more correctly, HDL-C hypothesis has become more controversial. There are no clear guidelines thus far for targeting HDL-C or HDL due to lack of solid outcomes data for HDL specific therapies. HDL-C levels are only one marker of HDL out of its several structural or functional properties. Novel approaches are ongoing in developing and assessing agents that closely mimic the structure of natural HDL or replicate its various functions, for example, reverse cholesterol transport, vasodilation, anti-inflammation, or inhibition of platelet aggregation. Potential new approaches like HDL infusions, delipidated HDL, liver X receptor agonists, Apo A-I upregulators, Apo A mimetics, and gene therapy are in early phase trials. This review will outline current therapies and describe future directions for HDL therapeutics.

Does combination therapy with statins and fibrates prevent cardiovascular disease in diabetic patients with atherogenic mixed dyslipidemia?

Type 2 diabetes mellitus (T2DM) is associated with the development and progression of cardiovascular disease (CVD). Statins have an established efficacy in the management of dyslipidemia primarily by decreasing the levels of low-density lipoprotein cholesterol and thus decreasing CVD risk. They also have a favorable safety profile. Despite the statin-mediated benefit of CVD risk reduction a residual CVD risk remains, especially in T2DM patients with high triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C) values. Fibrates decrease TG levels, increase HDL-C concentrations, and improve many other atherosclerosis-related variables. Fibrate/statin co-administration improves the overall lipoprotein profile in patients with mixed dyslipidemia and may reduce the residual CVD risk during statin therapy. However, limited data exists regarding the effects of statin/fibrate combination on CVD outcomes in patients with T2DM. In the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study the statin/fibrate combination did not significantly reduce the rate of CVD events compared with simvastatin/placebo in patients with T2DM. However, it did show a possible benefit in a pre-specified analysis in the subgroup of patients with high TG and low HDL-C levels. Furthermore, in the ACCORD study the simvastatin/fenofibrate combination significantly reduced the rate of progression of retinopathy compared with statin/placebo administration in patients with T2DM. The present review presents the available data regarding the effects of statin/fibrate combination in patients with T2DM and atherogenic mixed dyslipidemia.

Cardiovascular disease risk reduction by raising HDL cholesterol--current therapies and future opportunities

Since the first discovery of an inverse correlation between high-density lipoprotein-cholesterol (HDL-C) levels and coronary heart disease in the 1950s the life cycle of HDL, its role in atherosclerosis and the therapeutic modification of HDL-C levels have been major research topics. The Framingham study and others that followed could show that HDL-C is an independent cardiovascular risk factor and that the increase of HDL-C of only 10 mg·L(-1) leads to a risk reduction of 2-3%. While statin therapy and therefore low-density lipoprotein-cholesterol (LDL-C) reduction could lower coronary heart disease considerably; cardiovascular morbidity and mortality still occur in a significant portion of subjects already receiving therapy. Therefore, new strategies and therapies are needed to further reduce the risk. Raising HDL-C was thought to achieve this goal. However, established drug therapies resulting in substantial HDL-C increase are scarce and their effect is controversial. Furthermore, it is becoming increasingly evident that HDL particle functionality is at least as important as HDL-C levels since HDL particles not only promote reverse cholesterol transport from the periphery (mainly macrophages) to the liver but also exert pleiotropic effects on inflammation, haemostasis and apoptosis. This review deals with the biology of HDL particles, the established and future therapeutic options to increase HDL-C and discusses the results and conclusions of the most important studies published in the last years. Finally, an outlook on future diagnostic tools and therapeutic opportunities regarding coronary artery disease is given.

A review of time courses and predictors of lipid changes with fenofibric acid-statin combination

Fibrates activate peroxisome proliferator activated receptor α and exert beneficial effects on triglycerides, high-density lipoprotein cholesterol, and low density lipoprotein subspecies. Fenofibric acid (FA) has been studied in a large number of patients with mixed dyslipidemia, combined with a low- or moderate-dose statin. The combination of FA with simvastatin, atorvastatin and rosuvastatin resulted in greater improvement of the overall lipid profile compared with the corresponding statin dose. The long-term efficacy of FA combined with low- or moderate- dose statin has been demonstrated in a wide range of patients, including patients with type 2 diabetes mellitus, metabolic syndrome, or elderly subjects. The FA and statin combination seems to be a reasonable option to further reduce cardiovascular risk in high-risk populations, although trials examining cardiovascular disease events are missing.

Regulation and deregulation of cholesterol homeostasis: The liver as a metabolic "power station"

Cholesterol plays several structural and metabolic roles that are vital for human biology. It spreads along the entire plasma membrane of the cell, modulating fluidity and concentrating in specialized sphingolipid-rich domains called rafts and caveolae. Cholesterol is also a substrate for steroid hormones. However, too much cholesterol can lead to pathological pictures such as atherosclerosis, which is a consequence of the accumulation of cholesterol into the cells of the artery wall. The liver is considered to be the metabolic power station of mammalians, where cholesterol homeostasis relies on an intricate network of cellular processes whose deregulations can lead to several life-threatening pathologies, such as familial and age-related hypercholesterolemia. Cholesterol homeostasis maintenance is carried out by: biosynthesis, via 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) activity; uptake, through low density lipoprotein receptors (LDLr); lipoprotein release in the blood; storage by esterification; and degradation and conversion into bile acids. Both HMGR and LDLr are transcribed as a function of cellular sterol amount by a family of transcription factors called sterol regulatory element binding proteins that are responsible for the maintenance of cholesterol homeostasis through an intricate mechanism of regulation. Cholesterol obtained by hepatic de novo synthesis can be esterified and incorporated into apolipoprotein B-100-containing very low density lipoproteins, which are then secreted into the bloodstream for transport to peripheral tissues. Moreover, dietary cholesterol is transferred from the intestine to the liver by high density lipoproteins (HDLs); all HDL particles are internalized in the liver, interacting with the hepatic scavenger receptor (SR-B1). Here we provide an updated overview of liver cholesterol metabolism regulation and deregulation and the causes of cholesterol metabolism-related diseases. Moreover, current pharmacological treatment and novel hypocholesterolemic strategies will also be introduced.

Rare PPARA variants and extreme response to fenofibrate in the Genetics of Lipid-Lowering Drugs and Diet Network Study

OBJECTIVE

Fenofibrate, a peroxisome proliferator-activated receptor-α (PPARα) agonist, reduces triglyceride (TG) concentrations by 25-60%. Given significant interindividual variations in the TG response, we investigated the association of PPARA rare variants with treatment response in the Genetics of Lipid-Lowering Drugs and Diet Network study.

METHODS

We calculated the change in the TG concentration (ΔTG) among 861 GOLDN participants treated with fenofibrate (160 mg/day) for 3 weeks. From the distribution of ΔTG adjusted for age and sex, the 150 highest and 150 lowest fenofibrate responders were selected from the tails of the distribution for PPARA resequencing. The resequencing strategy was based on VariantSEQr technology for the amplification of exons and regulatory regions.

RESULTS

We identified 73 variants with an average minor allele frequency of 4.8% (range: 0.2-16%). We tested the association of rare variants located in a coding or a regulatory region (minor allele frequency<1%, 13 variants) with treatment response group by an indicator variable (presence/absence of ≥1 rare variant) using general linear mixed models to allow for adjustment for family relationship. After adjusting for baseline, fasting TG concentration carrying at least one rare variant was associated with a low fenofibrate response (odds ratio=6.46; 95% confidence interval: 1.4-30.8). Carrier status was also associated with a relative change in the total cholesterol concentration (P=0.02), but not high-density lipoprotein or low-density lipoprotein concentration.

CONCLUSION

Rare, potentially functional variants in PPARA may play a role in the TG response to fenofibrate, but future experimental studies will be necessary to replicate the findings and confirm functional effects.

Role of the PPAR-α agonist fenofibrate in severe pediatric burn

Fenofibrate is a peroxisome proliferator activated receptor alpha agonist that contains both pro and anti-inflammatory properties, and has been used in the treatment of dyslipidemia and diabetes for decades. Its receptors are expressed in the liver, skeletal muscle, cardiac, enteric, and renal cells, which allow it to provide systemic regulation of lipoprotein metabolism, fatty acid oxidation, and fatty acid transport. Hyperglycemia is a common complication found in the burn population because hepatic glucose production and catecholamine-mediated hepatic glycogenolysis are augmented. Insulin resistance occurs often in these patients and is associated with poor outcomes. In the pediatric burn population, fenofibrate has been found to ameliorate or decrease the number of hypoglycemic episodes when compared to management with insulin alone. Its mechanism of action is thought to involve an improvement in insulin signaling in skeletal muscle, as well as improvements in mitochondrial function, glucose oxidation, and insulin sensitivity. The long term use of fenofibrate in severely burned patients may improve hyperglycemia and insulin resistance, as well as improve wound healing, and reduce apoptosis, and oxidative stress.