Effect of micronized fenofibrate on plasma lipoprotein levels and hemostatic parameters of hypertriglyceridemic patients with low levels of high-density lipoprotein cholesterol in the fed and fasted state

Postprandial Hyperlipidemia: Its Pathophysiology, Diagnosis, Atherogenesis, and Treatments

Postprandial hyperlipidemia showing postprandial increases in serum triglyceride (TG) is associated with the development of atherosclerotic cardiovascular disease (ASCVD). To diagnose postprandial hyperlipidemia, the oral fat loading test (OFLT) should be performed; however, this test is very time-consuming and is difficult to perform. Elevated serum TG levels reflect an increase in TG-rich lipoproteins (TRLs), such as chylomicrons (CM), very low-density lipoproteins (VLDL), and their remnants (CM remnants [CMRs] and VLDL remnants [VLDLRs]). Understanding of elevation in CMR and/or VLDLR can lead us to understand the existence of postprandial hyperlipidemia. The measurement of apo B48, which is a constituent of CM and CMR; non-fasting TG, which includes TG content in all lipoproteins including CM and CMR; non-high-density lipoprotein cholesterol (non-HDL-C), which includes TRLs and low-density lipoprotein; and remnant cholesterol are useful to reveal the existence of postprandial hyperlipidemia. Postprandial hyperlipidemia is observed in patients with familial type III hyperlipoproteinemia, familial combined hyperlipidemia, chronic kidney disease, metabolic syndrome and type 2 diabetes. Postprandial hyperlipidemia is closely related to postprandial hyperglycemia, and insulin resistance may be an inducing and enhancing factor for both postprandial hyperlipidemia and postprandial hyperglycemia. Remnant lipoproteins and metabolic disorders associated with postprandial hyperlipidemia have various atherogenic properties such as induction of inflammation and endothelial dysfunction. A healthy diet, calorie restriction, weight loss, and exercise positively impact postprandial hyperlipidemia. Anti-hyperlipidemic drugs such pemafibrate, fenofibrate, bezafibrate, ezetimibe, and eicosapentaenoic acid have been shown to improve postprandial hyperlipidemia. Anti-diabetic drugs including metformin, alpha-glucosidase inhibitors, pioglitazone, dipeptidyl-peptidase-4 inhibitors and glucagon-like peptide 1 analogues have been shown to ameliorate postprandial hyperlipidemia. Although sodium glucose cotransporter-2 inhibitors have not been proven to reduce postprandial hyperlipidemia, they reduced fasting apo B48 and remnant lipoprotein cholesterol. In conclusion, it is important to appropriately understand the existence of postprandial hyperlipidemia and to connect it to optimal treatments. However, there are some problems with the diagnosis for postprandial hyperlipidemia. Postprandial hyperlipidemia cannot be specifically defined by measures such as TG levels 2 h after a meal. To study interventions for postprandial hyperlipidemia with the outcome of preventing the onset of ASCVD, it is necessary to define postprandial hyperlipidemia using reference values such as IGT.

Genetics of Triglyceride-Rich Lipoproteins Guide Identification of Pharmacotherapy for Cardiovascular Risk Reduction

OBJECTIVE

Despite aggressive reduction of low-density lipoprotein cholesterol (LDL-C), there is a residual risk of cardiovascular disease (CVD). Hypertriglyceridemia is known to be associated with increased CVD risk, independently of LDL-C. Triglycerides are one component of the heterogenous class of triglyceride-rich lipoproteins (TGRLs).

METHODS/RESULTS

Growing evidence from biology, epidemiology, and genetics supports the contribution of TGRLs to the development of CVD via a number of mechanisms, including through proinflammatory, proapoptotic, and procoagulant pathways.

CONCLUSION

New genetics-guided pharmacotherapies to reduce levels of triglycerides and TGRLs and thus reduce risk of CVD have been developed and will be discussed here.

Effects of fibrinogen synthesis inhibition on vascular cognitive impairment during traumatic brain injury in mice

Traumatic brain injury (TBI) is associated with increased blood content of fibrinogen (Fg), called hyperfibrinogenemia (HFg), which results in enhanced cerebrovascular permeability and leads to short-term memory (STM) reduction. Previously, we showed that extravasated Fg was deposited in the vasculo-astrocyte interface and was co-localized with cellular prion protein (PrP^C) during mild-to-moderate TBI in mice. These effects were accompanied by neurodegeneration and STM reduction. However, there was no evidence presented that the described effects were the direct result of the HFg during TBI. We now present data indicating that inhibition of Fg synthesis can ameliorate TBI-induced cerebrovascular permeability and STM reduction. Cortical contusion injury (CCI) was induced in C57BL/6J mice. Then mice were treated with either Fg antisense oligonucleotide (Fg-ASO) or with control-ASO for two weeks. Cerebrovascular permeability to fluorescently labeled bovine serum albumin was assessed in cortical venules following evaluation of STM with memory assessement tests. Separately, brain samples were collected in order to define the expression of PrP^C via Western blotting while deposition and co-localization of Fg and PrP^C, as well as gene expression of inflammatory marker activating transcription factor 3 (ATF3), were characterized with real-time PCR. Results showed that inhibition of Fg synthesis with Fg-ASO reduced overexpression of AFT3, ameliorated enhanced cerebrovascular permeability, decreased expression of PrP^C and Fg deposition, decreased formation of Fg-PrP^C complexes in brain, and improved STM. These data provide direct evidence that a CCI-induced inflammation-mediated HFg could be a triggering mechanism involved in vascular cognitive impairment seen previously in our studies during mild-to-moderate TBI.

Fibrinogen and Neuroinflammation During Traumatic Brain Injury

Many neurodegenerative diseases such as Alzheimer's disease (AD), multiple sclerosis, and traumatic brain injury (TBI) are associated with systemic inflammation. Inflammation itself results in increased blood content of fibrinogen (Fg), called hyperfibrinogenemia (HFg). Fg is not only considered an acute phase protein and a marker of inflammation, but has been shown that it can cause inflammatory responses. Fibrin deposits have been associated with memory reduction in neuroinflammatory diseases such as AD and TBI. Reduction in short-term memory has been seen during the most common form of TBI, mild-to-moderate TBI. Fibrin deposits have been found in brains of patients with mild-to-moderate TBI. The vast majority of the literature emphasizes the role of fibrin-activated microglia as the mediator in the neuroinflammation pathway. However, the recent discovery that astrocytes, which constitute approximately 30% of the cells in the mammalian central nervous system, manifest different reactive states warrants further investigations in the causative role of HFg in astrocyte-mediated neuroinflammation. Our previous study showed that Fg deposited in the vasculo-astrocyte interface-activated astrocytes. However, little is known of how Fg directly affects astrocytes and neurons. In this review, we summarize studies that show the effect of Fg on different types of cells in the vasculo-neuronal unit. We will also discuss the possible mechanism of HFg-induced neuroinflammation during TBI.

Effects of triptolide on pharmacokinetics of fenofibrate in rats and its potential mechanism

Triptolide and fenofibrate are often used together for the treatment of nephrotic syndrome in Chinese clinics. This study investigates the effects of triptolide on the pharmacokinetics of fenofibrate in rats and it potential mechanism. The pharmacokinetics of fenofibrate (20 mg/kg) with or without triptolide pretreatment (2 mg/kg/day for seven days) were investigated. Additionally, the inhibitory effects of triptolide on the metabolic stability of fenofibrate were investigated using rat liver microsome incubation systems. The results indicated that the C_max (35.34 ± 7.52 vs. 30.43 ± 6.45 μg/mL), t_1/2 (6.17 ± 1.15 vs. 4.90 ± 0.82 h) and AUC_(0-t) (468.12 ± 35.84 vs. 416.35 ± 32.68 mg h L^-1) of fenofibric acid decreased significantly (p < .05). The T_max of fenofibric acid increased significantly (p < .05) from 5.12 ± 0.36 to 6.07 ± 0.68 h. Additionally, the metabolic stability of fenofibrate was prolonged from 35.8 ± 6.2 to 48.6 ± 7.5 min (p < .05) with the pretreatment of triptolide. In conclusion, these results indicated that triptolide could affect the pharmacokinetics of fenofibric acid, possibly by inhibiting the metabolism of fenofibrate in rat liver when they were co-administered.

Effect of Fenofibrate on Serum Inflammatory Markers in Patients With High Triglyceride Values

Background: Atherosclerosis is the leading cause of death in developed countries. Although the mechanisms that underlie this process are not well defined, it has been proposed that atherosclerosis is mainly an inflammatory disease. In this context, a number of inflammatory markers have been studied for their ability to predict future cardiovascular events in asymptomatic individuals or patients with established atherosclerotic disease.

Methods and Results: The aim of our study was to evaluate the effect of micronized fenofibrate on serum inflammatory markers, such as C-reactive protein, fibrinogen, and plasma platelet-activating factor acetylhydrolase (PAF-AH) in patients with high triglyceride values. An analysis of baseline values revealed that hypertriglyceridemic patients (n = 58) exhibit an atherogenic phenotype, characterized not only by elevated lipid values but also by high concentrations of serum inflammatory markers. Along with the improvement in serum lipid profile (reduction in triglycerides and total cholesterol, low-density lipoprotein, and nonhigh-density lipoprotein-cholesterol, with a concomitant increase in high-density lipoprotein-cholesterol levels), fenofibrate administration significantly reduced the values of serum inflammatory markers by 34%, 9.5%, and 24.8% for C-reactive protein, fibrinogen, and plasma PAF-AH, respectively. However, with the exception of PAF-AH, these reductions in inflammatory markers were not correlated with the changes in lipid values.

Conclusions: In addition to its well-known hypolipidemic effects, fenofibrate may also possess significant anti-inflammatory properties that can contribute its antiatherogenic effect.

Novel electrosprayed nanospherules for enhanced aqueous solubility and oral bioavailability of poorly water-soluble fenofibrate

Purpose

The purpose of the present research was to develop a novel electrosprayed nanospherule providing the most optimized aqueous solubility and oral bioavailability for poorly water-soluble fenofibrate.

Methods

Numerous fenofibrate-loaded electrosprayed nanospherules were prepared with polyvinylpyrrolidone (PVP) and Labrafil^® M 2125 as carriers using the electrospray technique, and the effect of the carriers on drug solubility and solvation was assessed. The solid state characterization of an optimized formulation was conducted by scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopic analyses. Oral bioavailability in rats was also evaluated for the formulation of an optimized nanospherule in comparison with free drug and a conventional fenofibrate-loaded solid dispersion.

Results

All of the electrosprayed nanospherule formulations had remarkably enhanced aqueous solubility and dissolution compared with free drug. Moreover, Labrafil M 2125, a surfactant, had a positive influence on the solubility and dissolution of the drug in the electrosprayed nanospherule. Increases were observed as the PVP/drug ratio increased to 4:1, but higher ratios gave no significant increases. In particular, an electrosprayed nanospherule composed of fenofibrate, PVP, and Labrafil M 2125 at the weight ratio of 1:4:0.5 resulted in a particle size of <200 nm with the drug present in the amorphous state. It demonstrated the highest solubility (32.51±2.41 μg/mL), an excellent dissolution (~85% in 10 minutes), and an oral bioavailability ~2.5-fold better than that of the free drug. It showed similar oral bioavailability compared to the conventional solid dispersion.

Conclusion

Electrosprayed nanospherules, which provide improved solubility and bioavailability, are promising drug delivery tools for oral administration of poorly water-soluble fenofibrate.

Impact of fibrate therapy on plasma plasminogen activator inhibitor-1: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The aim of this systematic review was to perform a meta-analysis of randomized controlled trials (RCTs) examining the efficacy of fibrate therapy in reducing plasma concentration or activity of plasminogen activator inhibitor 1 (PAI-1).

METHODS

Scopus and MEDLINE databases were searched (up to October 15, 2014) to identify RCTs investigating whether fibrates lower plasma PAI-1 concentration or activity. A random-effects model and the generic inverse variance method were used for quantitative data synthesis. Sensitivity analyses were conducted using the one-study remove approach. Random-effects meta-regression was performed to assess the impact of potential moderators on the estimated effect sizes.

RESULTS

A total of 14 RCTs examining the effects of gemfibrozil (6 trials), bezafibrate (4 trials), and fenofibrate (5 trials) were included. Meta-analysis suggested that fibrate therapy did not significantly reduce plasma PAI-1 concentration (weighed mean difference [WMD]: -11.39 ng/mL, 95% CI: -26.64, 3.85, p=0.143) or activity (WMD: 2.02 U/mL, 95% CI: -0.87, 4.90, p=0.170). These results remained unchanged after subgroup analysis according to duration of treatment (<12 and ≥12 weeks) and type of fibrate administered (fenofibrate, bezafibrate or gemfibrozil). The estimated effects of fibrate therapy on plasma concentration and activity of PAI-1 were independent of treatment duration and changes in plasma triglyceride levels in the meta-regression analysis.

CONCLUSION

This meta-analysis of RCTs suggested that fibrate therapy does not reduce plasma concentration or activity of PAI-I. The putative benefits of fibrate therapy in patients with cardiovascular disease appear to be exerted via mechanisms independent of effects on PAI-1.

Enhanced oral bioavailability of fenofibrate using polymeric nanoparticulated systems: physicochemical characterization and in vivo investigation

Background

The intention of this research was to prepare and compare various solubility-enhancing nanoparticulated systems in order to select a nanoparticulated formulation with the most improved oral bioavailability of poorly water-soluble fenofibrate.

Methods

The most appropriate excipients for different nanoparticulated preparations were selected by determining the drug solubility in 1% (w/v) aqueous solutions of each carrier. The polyvinylpyrrolidone (PVP) nanospheres, hydroxypropyl-β-cyclodextrin (HP-β-CD) nanocorpuscles, and gelatin nanocapsules were formulated as fenofibrate/PVP/sodium lauryl sulfate (SLS), fenofibrate/HP-β-CD, and fenofibrate/gelatin at the optimized weight ratios of 2.5:4.5:1, 1:4, and 1:8, respectively. The three solid-state products were achieved using the solvent-evaporation method through the spray-drying technique. The physicochemical characterization of these nanoparticles was accomplished by powder X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Their physicochemical properties, aqueous solubility, dissolution rate, and pharmacokinetics in rats were investigated in comparison with the drug powder.

Results

Among the tested carriers, PVP, HP-β-CD, gelatin, and SLS showed better solubility and were selected as the most appropriate constituents for various nanoparticulated systems. All of the formulations significantly improved the aqueous solubility, dissolution rate, and oral bioavailability of fenofibrate compared to the drug powder. The drug was present in the amorphous form in HP-β-CD nanocorpuscles; however, in other formulations, it existed in the crystalline state with a reduced intensity. The aqueous solubility and dissolution rates of the nanoparticles (after 30 minutes) were not significantly different from one another. Among the nanoparticulated systems tested in this study, the initial dissolution rates (up to 10 minutes) were higher with the PVP nanospheres and HP-β-CD nanocorpuscles; however, neither of them resulted in the highest oral bioavailability. Irrespective of relatively retarded dissolution rate, gelatin nanocapsules showed the highest apparent aqueous solubility and furnished the most improved oral bioavailability of the drug (~5.5-fold), owing to better wetting and diminution in crystallinity.

Conclusion

Fenofibrate-loaded gelatin nanocapsules prepared using the solvent-evaporation method through the spray-drying technique could be a potential oral pharmaceutical product for administering the poorly water-soluble fenofibrate with an enhanced bioavailability.

Fenofibrate ameliorates insulin resistance, hypertension and novel oxidative stress markers in patients with metabolic syndrome

SUMMARY

OBJECTIVE

The benefits of fenofibrate, a peroxisome proliferator-activated receptor α agonist, against cardiovascular risk factors have been established. To clarify the underlying mechanisms of these benefits, we examined the effects of fenofibrate on insulin resistance, hypertension, inflammation, oxidative stress and coagulation markers in patients with metabolic syndrome.

METHODS

Eleven Japanese patients with metabolic syndrome underwent physical examinations and blood tests before and after treatment with fenofibrate 200 mg daily for 8 weeks.

RESULTS

Fenofibrate significantly decreased systolic blood pressure, pulse wave velocity, serum insulin, insulin resistance (calculated from the homeostasis model assessment), total cholesterol, triglyceride, remnant-like particles cholesterol, uric acid, D-dimer, fibrinogen, serum amyloid A/low-density lipoprotein (LDL) and apoA1/LDL levels. It also significantly increased levels of high molecular weight adiponectin, thrombomodulin and high-density lipoprotein cholesterol in these patients. Plasminogen activator inhibitor-1, C-reactive protein, fasting plasma glucose and thrombin-antithrombin complex levels did not change.

LIMITATION

Small sample size.

CONCLUSION

Short-term fenofibrate administration not only improved lipid profiles, but also ameliorated insulin resistance, hypertension and oxidative stress markers in patients with metabolic syndrome, suggesting that fenofibrate can decrease the risk of arteriosclerosis through various pathways.

Effect of ABT-335 (fenofibric acid) on meal-induced oxidative stress in patients with metabolic syndrome

OBJECTIVE

Examine the effect of ABT-335 (fenofibric acid) on postprandial lipemia and susceptibility of plasma lipoproteins to Cu(++)-mediated oxidation in patients with metabolic syndrome.

METHODS AND RESULTS

This is a randomized double-blind, placebo-controlled study with cross-over and includes a 4-week wash-out period between the two treatment periods. At the end of each 8-week treatment period, subjects were challenged with a standardized mixed meal followed by blood collection over the ensuing 6 h. Plasma lipoproteins were isolated by a combination of ultracentrifugation and FPLC for the continuous monitoring of conjugated dienes formation as an assessment of oxidative susceptibility. Fasting plasma TG was reduced by 20% (p < 0.0002) and there was a modest reduction in hsCRP (6.1%, p < 0.06). There was no change in either HDLc or LDLc in these subjects. Postprandial lipemia was reduced with ABT-335 as demonstrated by a 28.5% reduction (p < 0.0005) in incremental area under the curve for TG during the 6-h period after the meal challenge. Lag times for both fasting LDL (+16%) and postprandial LDL (+28%) were increased with the ABT-335 therapy, suggestive of reduced oxidative susceptibility. Co-incubation with autologous HDL did not reduced LDL oxidative susceptibility in these patients.

CONCLUSION

ABT-335 therapy reduced fasting and postprandial triglycerides in patients with metabolic syndrome. Autologous HDL may be dysfunctional in these patients as co-incubation with HDL failed to reduce oxidative susceptibility of LDL. During ABT-335 therapy, LDL was less susceptible to Cu(++)-mediated oxidative modification, in spite of the lack of changes in LDLc levels.

Current role of fenofibrate in the prevention and management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a common health problem with a high mortality burden due to its liver- and vascular-specific complications. It is associated with obesity, high-fat diet as well as with type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS). Impaired hepatic fatty acid (FA) turnover together with insulin resistance are key players in NAFLD pathogenesis. Peroxisome proliferator-activated receptors (PPARs) are involved in lipid and glucose metabolic pathways. The novel concept is that the activation of the PPARα subunit may protect from liver steatosis. Fenofibrate, by activating PPARα, effectively improves the atherogenic lipid profile associated with T2DM and MetS. Experimental evidence suggested various protective effects of the drug against liver steatosis. Namely, fenofibrate-related PPARα activation may enhance the expression of genes promoting hepatic FA β-oxidation. Furthermore, fenofibrate reduces hepatic insulin resistance. It also inhibits the expression of inflammatory mediators involved in non-alcoholic steatohepatitis pathogenesis. These include tumor necrosis factor-α, intercellular cell adhesion molecule-1, vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1. Consequently, fenofibrate can limit hepatic macrophage infiltration. Other liver-protective effects include decreased oxidative stress and improved liver microvasculature function. Experimental studies showed that fenofibrate can limit liver steatosis associated with high-fat diet, T2DM and obesity-related insulin resistance. Few studies showed that these benefits are also relevant even in the clinical setting. However, these have certain limitations. Namely, these were uncontrolled, their sample size was small, fenofibrate was used as a part of multifactorial approach, while histological data were absent. In this context, there is a need for large prospective studies, including proper control groups and full assessment of liver histology.

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.

Fenofibrate: a review of its use in dyslipidaemia

Fenofibrate is a fibric acid derivative indicated for the treatment of severe hypertriglyceridaemia and mixed dyslipidaemia in patients who have not responded to nonpharmacological therapies. The lipid-modifying effects of fenofibrate are mediated by the activation of peroxisome proliferator-activated receptor-α. Fenofibrate also has nonlipid, pleiotropic effects (e.g. reducing levels of fibrinogen, C-reactive protein and various pro-inflammatory markers, and improving flow-mediated dilatation) that may contribute to its clinical efficacy, particularly in terms of improving microvascular outcomes. Fenofibrate improves the lipid profile (particularly triglyceride [TG] and high-density lipoprotein-cholesterol [HDL-C] levels) in patients with dyslipidaemia. Compared with statin monotherapy, fenofibrate monotherapy tends to improve TG and HDL-C levels to a significantly greater extent, whereas statins improve low-density lipoprotein-cholesterol (LDL-C) and total cholesterol levels to a significantly greater extent. Fenofibrate is also associated with promoting a shift from small, dense, atherogenic LDL particles to larger, less dense LDL particles. Combination therapy with a statin plus fenofibrate generally improves the lipid profile to a greater extent than monotherapy with either agent in patients with dyslipidaemia and/or type 2 diabetes mellitus or the metabolic syndrome. In the pivotal FIELD and ACCORD trials in patients with type 2 diabetes, fenofibrate did not significantly reduce the risk of coronary heart disease events to a greater extent than placebo, and simvastatin plus fenofibrate did not significantly reduce the risk of major cardiovascular (CV) events to a greater extent than simvastatin plus placebo. However, the risk of some nonfatal macrovascular events and the incidence of certain microvascular outcomes were reduced significantly more with fenofibrate than with placebo in the FIELD trial, and in the ACCORD trial, patients receiving simvastatin plus fenofibrate were less likely to experience progression of diabetic retinopathy than those receiving simvastatin plus placebo. Subgroup analyses in the FIELD and ACCORD Lipid trials indicate that fenofibrate is of the greatest benefit in decreasing CV events in patients with atherogenic dyslipidaemia. Fenofibrate is generally well tolerated when administered alone or in combination with a statin. Thus, in patients with dyslipidaemia, particularly atherogenic dyslipidaemia, fenofibrate is a useful treatment option either alone or in combination with a statin.

Fenofibrate plus simvastatin (fixed-dose combination) for the treatment of dyslipidaemia

INTRODUCTION

Statin use results in a significant reduction of cardiovascular disease (CVD) risk. However, patients still have residual CVD risk, even if they are receiving optimal statin treatment.

AREAS COVERED

This review, based on a Pubmed/Scopus search, discusses the available evidence regarding the use of a fixed-dose fenofibrate plus simvastatin combination. This combination is useful for patients with mixed dyslipidaemia because it improves the overall lipoprotein profile. Although in clinical trials the rate of adverse events was not significantly greater than monotherapy, patients who receive combination treatment should be monitored carefully. Furthermore, in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Study, this combination did not result in a significant reduction of CVD events compared with simvastatin monotherapy. However, a possible benefit in this trial was observed in the subgroup of patients with high triglyceride and low high-density lipoprotein cholesterol levels.

EXPERT OPINION

The fixed-dose fenofibrate plus simvastatin combination treatment produces additive results and is safe when patients are properly monitored. Existing evidence appears to support the addition of fenofibrate to simvastatin treatment for the reduction of residual CVD risk in patients with atherogenic dyslipidaemia. However, this combination did not lead to better clinical outcomes in the absence of dyslipidaemia.

High-density lipoprotein (HDL) cholesterol: leveraging practice-based biobank cohorts to characterize clinical and genetic predictors of treatment outcome

Over the past decade, large multicenter trials have unequivocally demonstrated that decreasing low-density lipoprotein (LDL) cholesterol can reduce both primary and secondary cardiovascular events in patients at risk. However, even in the context of maximal LDL lowering, there remains considerable residual cardiovascular risk. Some of this risk can be attributed to variability in high-density lipoprotein (HDL) cholesterol. As such, there is tremendous interest in defining determinants of HDL homeostasis. Risk prediction models are being constructed based upon (1) clinical contributors, (2) known molecular determinants and (3) the genetic architecture underlying HDL cholesterol levels. To date, however, no single resource has combined these factors within the context of a practice-based data set. Recently, a number of academic medical centers have begun constructing DNA biobanks linked to secure encrypted versions of their respective electronic medical record. As these biobanks combine resources, the clinical community is in a position to characterize lipid-related treatment outcome on an unprecedented scale.

Fenofibrate: treatment of hyperlipidemia and beyond

Fenofibrate is a PPAR-alpha agonist indicated for the treatment of hypertriglyceridemia and mixed dyslipidemia, and is approved for the treatment of hypercholesterolemia, lipid abnormalities commonly observed in patients at high risk of cardiovascular disease, including Type 2 diabetes and/or metabolic syndromes. Treatment with fenofibrate lowers triglycerides, raises HDL-cholesterol and decreases concentrations of small LDL-cholesterol particles and apolipoprotein B. Fenofibrate is particularly effective for reducing postprandial VLDL and LDL particle concentrations, and the increased oxidative stress and inflammatory response that occurs after a fatty meal. In addition, nonlipid pleiotropic effects mediated by PPAR-alpha are likely to contribute to the reduction in atherosclerosis progression and cardiovascular events, and have beneficial effects on diabetes-related microvascular diseases. While current approaches to treating dyslipidemia to prevent cardiovascular diseases focus on statin therapy, it is increasingly clear that substantial residual risk persists. The clinical significance of combination therapy with fenofibrate and a statin to macrovascular and microvascular risk is being evaluated in a large outcomes study.

Therapeutic effects of fibrates in postprandial lipemia

Hypertriglyceridemia is observed in many metabolic diseases such as the metabolic syndrome, diabetes mellitus, or mixed dyslipidemia frequently leading to premature coronary heart disease (CHD). Additionally, several studies have shown that postprandial hypertriglyceridemia is pronounced in patients with CHD, metabolic syndrome, hypertension, and other pathologic conditions. The triglyceride-rich lipoprotein remnants accumulating in the postprandial state seem to be involved in atherogenesis and in events leading to thrombosis. Since abnormal postprandial lipemia is associated with pathologic conditions, its treatment is of clinical importance.Fibrates are of significant help in managing hypertriglyceridemia. This review summarizes the effect of fibric acid derivatives on postprandial lipemia. Fibrates decrease the production of and enhance the catabolism of triglyceride-rich lipoproteins through the activation of peroxisome proliferator-activated receptor-alpha. Results of clinical studies with fibrates have confirmed their action in decreasing postprandial triglyceride levels by increasing lipoprotein lipase activity, decreasing apolipoprotein CIII production, and by increasing fatty acid oxidation in the liver.It is concluded that fibrates are effective agents in lowering the postprandial increase in remnant lipoprotein particles and retinyl palmitate. Furthermore, fibrates can also affect the postprandial lipid profile by increasing hepatic lipase levels and in some cases, by reducing cholesterol ester transfer protein activity. The main target of fibrate therapy is to improve fasting hypertriglyceridemia, which is an essential component associated with improving postprandial lipemia. Fibrates are well tolerated by patients and adverse effects have been reported rarely after their administration.

Dissolution and Solubility Behavior of Fenofibrate in Sodium Lauryl Sulfate Solutions

The solubility of fenofibrate in pH 6.8 McIlvaine buffers containing varying concentrations of sodium lauryl sulfate was determined. The dissolution behavior of fenofibrate was also examined in the same solutions with rotating disk experiments. It was observed that the enhancement in intrinsic dissolution rate was approximately 500-fold and the enhancement in solubility was approximately 2000-fold in a pH 6.8 buffer containing 2% (w/v) sodium lauryl sulfate compared to that in buffer alone. The micellar solubilization equilibrium coefficient (k*) was estimated from the solubility data and found to be 30884+/-213 L/mol. The diffusivity for the free solute, 7.15x10(-6) cm2/s, was calculated using Schroeder's additive molal volume estimates and Hayduk-Laurie correlation. The diffusivity of the drug-loaded micelle, estimated from the experimental solubility and dissolution data and the calculated value for free solute diffusivity, was 0.86x10(-6) cm2/s. Thus, the much lower enhancement in dissolution of fenofibrate compared to its enhancement in solubility in surfactant solutions appears to be consistent with the contribution to the total transport due to enhanced micellar solubilization as well as a large decrease (approximately 8-fold) in the diffusivity of the drug-loaded micelle.

Fish oil and fenofibrate for the treatment of hypertriglyceridemia in HIV-infected subjects on antiretroviral therapy: results of ACTG A5186

INTRODUCTION

Fish oil has been shown to reduce serum triglyceride (TG) concentrations. In HIV-infected patients on antiretroviral therapy, high TG concentrations likely contribute to increased risk of cardiovascular disease. AIDS Clinical Trials Group A5186 examined the safety and efficacy of fish oil plus fenofibrate in subjects not achieving serum TG levels < or =200 mg/dL with either agent alone.

METHODS

One hundred subjects on highly active antiretroviral therapy with serum TG concentrations > or =400 mg/dL and low-density lipoprotein cholesterol < or =160 mg/dL were randomized to 3 g of fish oil twice daily or 160 mg of fenofibrate daily for 8 weeks. Subjects with a fasting TG level >200 mg/dL at week 8 received a combination of fish oil and fenofibrate in the same doses from week 10 to week 18.

RESULTS

Median baseline TG was 662 mg/dL in the fish oil group and 694 mg/dL in the fenofibrate group (P = not significant). Fish oil reduced TG levels by a median of 283 mg/dL (46%), fenofibrate reduced them by 367 mg/dL (58%), and combination therapy reduced them by 65.5%. Combination therapy achieved TG levels of < or =200 mg/dL in 22.7% subjects. Fish oil had no measurable effect on immunologic parameters or the pharmacokinetics of lopinavir.

CONCLUSIONS

Fish oil was safe when administered alone or combined with fenofibrate and significantly reduced TG levels in HIV-infected subjects with hypertriglyceridemia.

Polymorphisms in the peroxisome proliferator activated receptor alpha gene are associated with levels of apolipoprotein CIII and triglyceride in African-Americans but not Caucasians

BACKGROUND

We tested whether single nucleotide polymorphisms (SNPs) in the PPARalpha gene (PPARA) are associated with variations in levels of plasma apolipoprotein CIII (apoCIII) levels, as well as other lipids and lipoproteins, in African-Americans and Caucasians.

METHODS AND RESULTS

We initially identified an intronic SNP (rs4253728) in PPARA that was associated with plasma apoCIII level (p<0.05) in a subset of 435 individuals from the total study population (n=944; 335 African-Americans and 609 Caucasians). This SNP was then genotyped in a second subset of 476 individuals (total 911 subjects with available data), and a previously described PPARA coding SNP (L162V) which was shown to be in moderate linkage disequilibrium with the intronic SNP (r(2)=0.18) was genotyped in 928 subjects from the same study population. The minor allele frequencies for both SNPs were significantly lower in African-Americans compared with Caucasians (7.2% vs. 27.3% for rs4253728, 1.5% vs. 6.1% for L162V, both p<0.0001). African-Americans had significantly lower levels of TG and apoCIII compared with Caucasians after adjusting for age, sex, body mass index (BMI), waist circumference and other baseline characteristics. However, racial differences in TG levels were attenuated after adjusting for apoCIII levels. The minor alleles for both PPARA SNPs were associated with higher TG and apoCIII levels. Race modified the associations of L162V with TG (p for interaction=0.0056) and apoCIII (p for interaction=0.0011). Levels of both TG and apoCIII were lower in African-American but not Caucasian homozygotes for the major allele compared with carriers of the minor allele. Similar results were obtained for the intronic SNP, but the findings were no longer significant in a model that also contained L162V.

CONCLUSIONS

Two PPARA SNPs, L162V and rs4253728 (intronic), are less prevalent in African-Americans than in Caucasians and in African-Americans only are associated with higher apoCIII and TG levels.

Ciprofibrate increases paraoxonase activity in patients with metabolic syndrome

AIMS

Diabetic dyslipidaemia with decreased high-density lipoprotein-cholesterol (HDL-C) concentration plays a key role in enhanced atherosclerosis. The antioxidant effect of HDL is due to the influence of human paraoxonase 1 (PON1) and several authors have described decreased activity of this enzyme in Type 2 diabetics and subjects with metabolic syndrome. The goal of this study was to examine the effect of daily ciprofibrate on serum PON1 and lipoprotein concentrations in patients with metabolic syndrome.

METHODS

Fifty-one patients with metabolic syndrome were enrolled into the study. We examined the effect of 100 mg day(-1) ciprofibrate treatment on lipid concentrations, oxidized low-density lipoprotein (LDL), PON1 concentrations and activity. We also investigated the calculated size of LDL-cholesterol (LDL-C).

RESULTS

During the 3-month study, it was observed that following treatment with ciprofibrate, the serum triglyceride concentration decreased significantly (from 2.76 +/- 0.9 mmol l(-1) to 2.27 +/- 1.6 mmol l(-1); -18%; P < 0.001), while HDL-C increased significantly (from 0.95 +/- 0.2 mmol l(-1) to 1.2 +/- 0.3 mmol l(-1); 26%; P < 0.001). The oxidatively modified LDL-C concentration decreased significantly (from 137 +/- 19 U l(-1) to 117 +/- 20 U l(-1); P < 0.001), while HDL-associated apolipoprotein A1 significantly increased (from 1.35 +/- 0.2 g l(-1) to 1.75 +/- 0.3 g l(-1); P < 0.001). The LDL-C/LDL-apoB ratio, which reflects the size of LDL, increased significantly (from 0.96 +/- 0.05 to 1.05 +/- 0.06; P < 0.05). Serum PON1 activity was significantly elevated (from 108 +/- 34 U l(-1) to 129 +/- 31 U l(-1); P < 0.05), while standardized values for HDL-C remained significantly unchanged (PON1/HDL-C) (from 114 +/- 21 to 107 +/- 20; NS).

CONCLUSION

Three months of treatment with ciprofibrate favourably affected the lipid profile, increased LDL resistance to oxidation and improved antioxidant status by increasing serum paraoxonase activity in these patients.

Fenofibrate

Fenofibrate is a fibric acid derivative indicated for use in the treatment of primary hypercholesterolaemia, mixed dyslipidaemia and hypertriglyceridaemia in adults who have not responded to nonpharmacological measures. Its lipid-modifying effects are mediated by activation of peroxisome proliferator-activated receptor-alpha. Fenofibrate also has nonlipid (i.e. pleiotropic) effects (e.g. it reduces fibrinogen, C-reactive protein and uric acid levels and improves flow-mediated dilatation). Fenofibrate improves lipid levels (in particular triglyceride [TG] and high-density lipoprotein-cholesterol [HDL-C] levels) in patients with primary dyslipidaemia. Its lipid-lowering profile means that fenofibrate is particularly well suited for use in atherogenic dyslipidaemia (characterised by high TG levels, low HDL-C levels and small, dense low-density lipoprotein [LDL] particles), which is commonly seen in patients with the metabolic syndrome and type 2 diabetes mellitus. Indeed, fenofibrate improves the components of atherogenic dyslipidaemia in patients with these conditions, including a shift from small, dense LDL particles to larger, more buoyant LDL particles. Greater improvements in lipid levels are seen when fenofibrate is administered in combination with an HMG-CoA reductase inhibitor (statin) or in combination with ezetimibe, compared with monotherapy with these agents. In the DAIS study, fenofibrate significantly slowed the angiographic progression of focal coronary atherosclerosis in patients with type 2 diabetes. In terms of clinical outcomes, although no significant reduction in the risk of coronary events was seen with fenofibrate in the FIELD trial in patients with type 2 diabetes, treatment was associated with a significantly reduced risk of total cardiovascular disease (CVD) events, primarily through the prevention of non-fatal myocardial infarction and coronary revascularisation. Subgroup analyses revealed significant reductions in total CVD events and coronary heart disease events in patients with no previous CVD, suggesting a potential role for primary prevention with fenofibrate in patients with early type 2 diabetes. Improvements were also seen in microvascular outcomes with fenofibrate in the FIELD trial. Fenofibrate is generally well tolerated, both as monotherapy and when administered in combination with a statin. Combination therapy with fenofibrate plus a statin appears to be associated with a low risk of rhabdomyolysis; no cases of rhabdomyolysis were reported in patients receiving such therapy in the FIELD trial. Thus, fenofibrate is a valuable lipid-lowering agent, particularly in patients with atherogenic dyslipidaemia.

Increase in aortic pulse wave velocity is associated with abnormal postprandial triglyceride response

BACKGROUND

Aortic pulse wave velocity (aPWV), an index of aortic distensibility, and postprandial hypertriglyceridemia are recognized as independent cardiovascular risk factors.

HYPOTHESIS

The aim of this study was to evaluate the relationship between postprandial hypertriglyceridemia and changes in aPWV.

METHODS

We prospectively studied 45 patients (mean age 48 [14] years, 28.9% men), who were submitted to a standardized fat meal (FM) test. According to their triglyceride (TG) levels 2, 4, 6, and 8 h after the FM, the patients were divided into two groups: Group 1 (31 patients) with postprandial TG levels < or = 219 mg/dl, and Group 2 (14 patients) with TG levels > 219 mg/dl at one of the aforementioned time intervals. Before and 6 h after the FM, aPWV was measured noninvasively.

RESULTS

Baseline characteristics in the two groups were similar, except for higher TG, pulse pressure, waist-to-hip ratio, percentage of patients who smoked or had arterial hypertension, and lower high-density lipoprotein cholesterol levels in Group 2. Postprandially, aPWV was higher in Group 2 [11.2(2.7) vs. 9.1(2.1) m/s, p = 0.004]. Changes in aPWV correlated with TG changes from baseline to 6 h after FM (r = 0.539, p < 0.001) and with the areas under the TG curve (r = 0.617, p < 0.001). A postprandial TG increase of 100 mg/dl resulted in a 0.88 m/s rise of aPWV.

CONCLUSION

An increase in aPWV 6 h after an FM test correlates positively with abnormal postprandial hypertriglyceridemia. These relationships, reported here for the first time, could be of practical use for better evaluation of patient prognosis.

Modulation of Hepatic Inflammatory Risk Markers of Cardiovascular Diseases by PPAR–α Activators

Atherosclerosis is a long-term chronic inflammatory disease associated with increased concentrations of inflammatory hepatic markers, such as CRP and fibrinogen, and of peripheral origin, such as tumor necrosis factor (TNF)-α and interleukin (IL)-6. Peroxisome proliferator-activated receptor (PPAR-)-α is a ligand-activated transcription factor that regulates expression of key genes involved in lipid homeostasis and modulates the inflammatory response both in the vascular wall and the liver. PPAR-α is activated by natural ligands, such as fatty acids, as well as the lipid-lowering fibrates. PPAR-α agonists impact on different steps of atherogenesis: (1) early markers of atherosclerosis, such as vascular wall reactivity, are improved, (2) however, reduced expression of adhesion molecules on the surface of endothelial cells, accompanied by decreased levels of inflammatory cytokines, such as TNF-α, IL-1, and IL-6, leads to a decreased leukocyte recruitment into the arterial wall; (3) in later stages of the atherosclerotic process, PPAR-α agonists may promote plaque stabilization and reduce cardiovascular events, via effects on metalloproteinases, such as MMP9. Moreover, PPAR-α activation by fibrates also impairs proinflammatory cytokine-signaling pathways in the liver resulting in the modulation of the acute phase response reaction via mechanisms independent of changes in lipoprotein levels. Effective coronary artery disease (CAD) prevention requires the use of agents that act beyond low-density lipoprotein cholesterol-lowering. PPAR-α agonists appear to comprehensively address some of the abnormalities of the most common clinical phenotypes of the high CAD risk patient of the 21st century such as in the metabolic syndrome and type 2 diabetes: low high-density lipoprotein cholesterol, high triglycerides, small, dense low-density lipoprotein, and a proinflammatory, procoagulant state.

Effect of Fenofibrate on Lipoprotein(a) in Hypertriglyceridemic Patients

We investigated the effect of fenofibrate on lipoprotein(a)levels in hypertriglyceridemic patients and the parameters relating to its effect. Patients with a triglyceride level >/=300 mg/dL or with a triglyceride level >/=200 mg/dL and a high density lipoprotein cholesterol level </=40 mg/dL were treated either with 200 mg of fenofibrate(Fenofibrate group, n = 56) or with general measures (Control group,n = 56). Lipid and lipoprotein levels were measured at baseline and 2 months. Baseline lipoprotein(a) levels were negatively correlated with triglyceride (r = 20.30, P = 0.001) and alanine aminotransferase levels (r = 20.24, P = 0.012). Fenofibrate therapy increased lipoprotein(a) level from 9.4 6 10.6 to 15.6 6 17.5 mg/dL (P = 0.000). The more triglyceride levels decreased, the more lipoprotein(a) levels increased in all subjects (r = 20.46, P = 0.000) and in Control (r =20.35, P = 0.008) and Fenofibrate groups (r = 20.35, P = 0.008). Fenofibrate elevated lipoprotein(a) level greater in patients with a normal liver function. When Fenofibrate group was divided into two subgroups according to the degree of percentage change in lipoprotein(a) level, change in triglyceride level and alanine aminotransferase level were independent predictors by forward logistic regression analysis. In summary, fenofibrate therapy increases lipoprotein(a) level,and this elevation is associated with change in triglyceride level and liver function.

Efficacy and safety profile of fenofibrate-coated microgranules 130 mg, with and without food, in patients with hypertriglyceridemia and the metabolic syndrome: An 8-week, randomized, double-blind, placebo-controlled study

BACKGROUND

The limited bioavailability of certain fenofibrate formulations necessitates administration with food, raising concerns about efficacy and compliance. There is a need for new formulations that have improved bioavailability and eliminate the requirement for administration with food.

OBJECTIVE

The aim of this study was to assess the food-related efficacy of a new formulation of micronized fenofibrate coated on inert microgranules (FF-muG) for the treatment of hypertriglyceridemia in patients exhibiting the metabolic syndrome.

METHODS

This was a randomized, double-blind, placebo-controlled, double-dummy, parallel-group study in patients who had fasting triglyceride (TG) concentrations > or =300 mg/dL and <1000 mg/dL and met National Cholesterol Education Program Adult Treatment Panel III criteria for the metabolic syndrome. A 6-week washout and diet lead-in period was followed by an 8-week treatment period. Eligible patients were randomized to receive either FF-muG 130 mg with food, FF-muG 130 mg without food, or placebo every day for 8 weeks. The primary end point was the mean percent change in TG levels from baseline to the end of treatment; changes in other lipid end points were also assessed. Safety profiles were assessed based on adverse-event reports, changes in clinical laboratory values and vital signs (including electrocardiography), and the findings of physical examinations.

RESULTS

One hundred forty-six patients took part in the study: 54 received FF-muG 130 mg with food, 42 received FF-muG 130 mg without food, and 50 received placebo. The groups were similar in terms of mean age (56 years), sex (59.5%-63.0% men; 37.0%-40.5% women), race (83.3%-100% white), mean body weight (92 kg), mean height (172 cm), mean fasting baseline TG concentrations (480 mg/dL), and other components of the metabolic syndrome. The 2 FF-muG groups (with and without food) showed similar improvements in the dyslipidemia associated with the metabolic syndrome: TG levels decreased a mean of 36.7% and 36.6%, respectively (P < 0.001 vs placebo). The overall frequency of adverse events was similar in the 2 FF-muG groups and did not differ significantly from placebo (63.0%, 61.9%, and 52.0%, respectively). Gastrointestinal disturbances (eg, diarrhea, dyspepsia) occurred more frequently in the 2 FF-muG groups compared with the placebo group (31.5%, 26.2%, and 12.0%; P = NS). Significant increases from baseline in alanine aminotransferase were seen in both FF-muG groups (mean [SEM], 3.77 [2.60] and 11.69 [7.42] U/L, respectively; P < or = 0.05 vs placebo); however, these increases were considered clinically significant in only 5 cases, none of them requiring discontinuation of study drug.

CONCLUSIONS

This study found no inequivalence in the TG-lowering effects of the 2 fenofibrate regimens compared with placebo. Both regimens were well tolerated. Thus, FF-muG 130 mg administered without regard to meals appears to be efficacious and well tolerated for the treatment of hypertriglyceridemia in patients exhibiting the metabolic syndrome.

Efficacy and safety of high-density lipoprotein cholesterol-increasing compounds: a meta-analysis of randomized controlled trials

OBJECTIVES

The aim of this research was to estimate the efficacy and safety of current high-density lipoprotein cholesterol (HDL-C)-increasing drugs.

BACKGROUND

Epidemiologic evidence has shown that HDL-C is inversely related to coronary heart disease (CHD) risk. However, the evidence for reducing CHD risk by raising HDL-C is thin, predominantly due to the paucity of effective and safe HDL-increasing drugs.

METHODS

Randomized controlled trials with fibrates and niacin, published between 1966 through February 2004 (MEDLINE), were retrieved. Information on treatment, baseline characteristics, serum lipids, end points, and side-effects were independently abstracted by two authors using a standardized protocol.

RESULTS

Data from 53 trials (16,802 subjects) using fibrates and 30 trials (4,749 subjects) using niacin were included. Random-effects model showed 11% versus 10% reduction in total cholesterol, 36% versus 20% reduction in triglycerides, 8% versus 14% reduction in low-density lipoprotein cholesterol, and 10% versus 16% increase in HDL-C for fibrates and niacin, respectively. Apart from flushes in the niacin group, both fibrates and niacin were shown to be well-tolerated and safe. Fibrates reduced the risk for major coronary events by 25% (95% confidence interval 10% to 38%), whereas current available data for niacin indicate a 27% reduction.

CONCLUSIONS

Fibrates reduce major coronary events and increase HDL-C levels without significant toxicity. Niacin has a more potent effect on HDL-C levels, whereas data on cardiovascular event rate reduction are limited. Future studies need to evaluate whether additional HDL increase by fibrates or particularly newer niacin formulations on top of statin therapy translates into further event reduction in high-risk subjects, without significant toxicity.

Effect of Fenofibrate on Uric Acid Metabolism in Japanese Hyperlipidemic Patients

Forty Type IIb or IV hyperlipidemic patients (serum triglyceride concentrations were higher than 150 mg/dl) were treated with fenofibrate (300 mg/day) for 12 weeks. Lipid profile and uric acid metabolism were evaluated before and after the treatment; the serum concentrations of total cholesterol and triglyceride respectively decreased from 224 +/- 41.9 mg/dl to 199 +/- 35.2 mg/dl and from 205 +/- 71.7 mg/dl to 134 +/- 67.5 mg/dl (p < 0.001). The uric acid concentrations in the serum also significantly decreased from 7.0 +/- 1.58 mg/dl to 5.2 +/- 1.57 mg/dl (p < 0.001). Fenofibrate treatment did not cause any change in the serum xanthine and hypoxanthine concentrations. Instead the urinary concentrations of uric acid decreased from 7.0 +/- 1.58 mg/dl to 5.2 +/- 1.57 mg/dl (p < 0.01), while the clearance ratio of uric acid and creatinin increased from 6.1 +/- 2.56 to 9.9 +/- 3.87 (p = 0.02) by the fenofibrate treatment. Fenofibrate decreases uric acid concentrations in the serum not as a result of inhibition of uric acid production but by increasing the urinary excretion of uric acid.

Management of hypercholesterolaemia in postmenopausal women

Increased rates of coronary heart disease (CHD) occur with advancing age in both sexes, although CHD rates in women lag behind those of men by about 10 years. There is a sharp increase in CHD rate among women after approximately 50 years of age. The reasons for this are not completely understood and are undoubtedly multifactorial. Cross-sectional data from large-scale population studies suggest that around the time of the menopause, low-density lipoprotein (LDL)-cholesterol levels increase by approximately 15 to 25%. Because this increase is larger than that observed in men over the same age span and closely approximates that observed in women after oophorectomy, it is likely that reduced circulating estrogen levels associated with menopause play a role in the adverse changes in both blood lipid levels and CHD incidence. There is clear evidence that treating hypercholesterolemia reduces cardiovascular risk in women, as well as in men. In the US National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) guidelines, diet and other lifestyle changes are recommended as first-line therapy. If the treatment goals cannot be achieved through non-pharmacological measures, drug therapy should be added. Of the available lipid-lowering agents, HMG CoA reductase inhibitors (statins) are the clear choice to decrease LDL-cholesterol levels. However the favourable effects of statins on high-density lipoprotein (HDL)-cholesterol and triglyceride levels are more modest, and statins are not known to decrease lipoprotein (a) [Lp(a)] levels. Estrogen or hormone replacement therapy (ERT/HRT) and nicotinic acid improve LDL- and HDL-cholesterol levels and also decrease Lp(a) levels. However, ERT/HRT is no longer recommended as first-line therapy for decreasing CHD risk. Nicotinic acid is particularly useful for decreasing triglyceride levels (as are fibrates) and raising HDL-cholesterol levels. Bile-acid sequestrants reduce LDL-cholesterol and slightly increase HDL-cholesterol levels. Both bile acid sequestrants and ERT/HRT tend to raise triglyceride levels, therefore they should be used cautiously in women with hypertriglyceridaemia. Treatment should be individualised for each patient. It is important to evaluate the primary form of dyslipidaemia, other CHD risk factors, comorbidities, and the extent of lipid improvement needed in order to reach treatment goals. The effects of each type of therapy and potential adverse effects should also be considered.

Postprandial lipemia--effect of lipid-lowering drugs

Exaggerated postprandial hyperlipidemia has been associated with cardiovascular disease. The mechanisms underlying this association are likely to depend on a multitude of effects. Potentially atherogenic remnants of triglyceride-rich lipoproteins (TRL) accumulate in the postprandial state. In addition, TRL may promote the formation of small dense LDL. There are some indications that the postprandial period is a hypercoagulable state and endothelial function seems to be hampered after acute fat intake. Conventional lipid lowering drugs such as statins and fibrates have the potency of reducing postprandial hyperlipidemia, but the fibrates seem to be more effective in this respect. There is a complete lack of prospective studies linking inefficient postprandial lipid metabolism with clinical endpoints and there is also a need to include investigations of postprandial lipid metabolism in the evaluation of novel drugs affecting lipid metabolism and insulin resistance.

Fenofibrate raises plasma homocysteine levels in the fasted and fed states

The effect of fenofibrate (FEN), compared with placebo (PL), on total plasma homocysteine (tHcy) levels in the fasted and fed states has been examined. Twenty men with established coronary artery disease (CAD) or with at least two cardiovascular risk factors, who had elevated plasma triglyceride levels (> 2.3 mmol/l) and reduced HDL-C levels (< 0.91 mmol/l), and in whom a fibric acid derivative was clinically indicated were studied. The study was a randomized, PL controlled, double-blind study designed to test the effect of micronized FEN on postprandial lipemia. Plasma tHcy levels were investigated as a post-hoc analysis. After a 4-week dietary stabilization period, patients were randomized to PL or FEN (200 mg/day) for 8 weeks, followed by an 8-h postprandial study, consisting of 1 g fat/kg body weight (35% cream). The methionine content of cream was approximately 0.53 mg/ml. A 5-week washout period was then followed by a second 8-week treatment period (FEN or PL), at the end of which a second postprandial study was undertaken. Blood was sampled in the fasted state (0 h) and postprandially at 2, 4, 6 and 8 h. Plasma was stored at -80 degrees C for homocysteine, vitamins B(6), B(12) and folate measurements. FEN caused a marked decrease in all triglyceride-rich lipoprotein parameters, no change in LDL-C, and an increase in HDL-C levels. Fen treatment was associated with an increase in fasting tHcy (PL: 10.3+/-3.3 micromol/l to FEN: 14.1+/-3.8 micromol/l, 40.4+/-20.5%, P < 0.001) and fed tHcy levels 6 h post-fat load (PL: 11.6+/-3.3 micromol/l vs. FEN: 17.1+/-5.4 micromol/l, P < 0.001). Homocysteine levels were increased by the fat load; PL: 14% (P < 0.001) and FEN: 21%, P < 0.001 at the 2, 4, 6 and 8 h time points. Change in tHcy level on FEN was not associated with changes in plasma levels of folate, vitamins B(6) or B(12) or creatinine. Amino acid analysis revealed that methionine and cysteine were significantly increased on FEN (P < 0.005). The incidence of hyperhomocysteinemia (defined as tHcy level >14 micromol/l) was PL: 2/20 (10%) and FEN: 9/20 (45%) (chi(2) = 4.51, P = 0.034). There was no correlation between changes in plasma triglyceride levels and tHcy levels. Since tHcy is considered an emerging cardiovascular risk factor, the ability of FEN to increase plasma tHcy levels could potentially mitigate the potential of this drug to protect against cardiovascular disease.