A single pretreatment with clofibric acid attenuates carbon tetrachloride-induced necrosis, but not steatosis, in rat liver.

The present study investigated whether a single pretreatment with clofibric acid suppresses liver injury in rats after CCl4 intoxication. Rats received a single pretreatment with clofibric acid (100 mg/kg, i.p.) 1 h prior to a CCl4 (1 mL/kg, p.o.) challenge, and were euthanized 24 h after the CCl4 administration. A single pretreatment with clofibric acid effectively suppressed increases in the serum aminotransferase activities and the severity of necrosis following the CCl4 challenge, whereas the pretreatment did not protect against CCl4-induced fatty liver. The clofibric acid pretreatment did not affect blood concentrations of CCl4 in the early stage after CCl4 dosing, or the level of the CCl4 reaching the liver 1 h after the CCl4 challenge. Moreover, the clofibric acid pretreatment did not affect the intensity of the covalent binding of the [14C]CCl4 metabolite to microsomal proteins and lipids. The clofibric acid pretreatment did not alter microsomal cytochrome P450 2E1 activity. Based on these results, we conclude that protection against CCl4-induced hepatocellular necrosis by a clofibric acid pretreatment does not require its repeated administration, and that a single and brief pre-exposure to clofibric acid prior to CCl4 dosing markedly suppresses necrosis without affecting the development and progression of steatosis.

Fibrates for primary prevention of cardiovascular disease events.

BACKGROUND: Fibrates are effective for modifying atherogenic dyslipidaemia, and particularly for lowering serum triglycerides. However, evidence that fibrates reduce mortality and morbidity associated with cardiovascular disease (CVD), or overall mortality and morbidity, in the primary prevention of CVD is lacking. OBJECTIVES: This Cochrane Review and meta-analysis aimed to evaluate the clinical benefits and harms of fibrates versus placebo or usual care or fibrates plus other lipid-modifying drugs versus other lipid-modifying drugs alone for the primary prevention of cardiovascular disease (CVD) morbidity and mortality. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO), and Web of Science (all from inception to 19 May 2016). We searched four clinical trial registers (last searched on 3 August 2016) with the help of an experienced professional librarian. We searched the databases to identify randomised controlled trials (RCTs) evaluating the clinical effects of fibrate therapy in the primary prevention of CVD events. We did not impose any language restrictions. SELECTION CRITERIA: We aimed to include all RCTs comparing the effects of fibrate monotherapy versus placebo or usual care, or fibrates plus other lipid-modifying drugs versus other lipid-modifying drugs alone. Included studies had a follow-up of at least six months for the primary prevention of CVD events. We excluded trials with clofibrate, because it was withdrawn from the market in 2002. DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts for potential study inclusion. Two review authors independently retrieved the full-text papers and extracted data. Disagreements were resolved by consensus. We calculated risk ratios (RRs) and accompanying 95% confidence intervals (CIs) for aggregate data on primary and secondary outcomes. We tested for heterogeneity with the Cochrane Q-test and used the I2 statistic to measure inconsistency of treatment effects across studies. Using the GRADE approach, we assessed the quality of the evidence and used the GRADE profiler software (GRADEpro GDT) to import data from Review Manager 5 to create 'Summary of findings' tables. MAIN RESULTS: We identified six eligible trials including 16,135 individuals. The mean age of trial populations varied across trials; between 47.3 and 62.3 years. Four trials included individuals with diabetes mellitus type 2 only. The mean treatment duration and follow-up of participants across trials was 4.8 years. We judged the risks of selection and performance bias to be low; risks of detection bias, attrition bias, and reporting bias were unclear. Reporting of adverse effects by included trials was very limited; that is why we used discontinuation of therapy due to adverse effects as a proxy for adverse effects. Patients treated with fibrates had a reduced risk for the combined primary outcome of CVD death, non-fatal myocardial infarction, or non-fatal stroke compared to patients on placebo (risk ratio (RR) 0.84, 95% confidence interval (CI) 0.74 to 0.96; participants = 16,135; studies = 6; moderate-quality of evidence). For secondary outcomes we found RRs for fibrate therapy compared with placebo of 0.79 for combined coronary heart disease death or non-fatal myocardial infarction (95% CI 0.68 to 0.92; participants = 16,135; studies = 6; moderate-quality of evidence); 1.01 for overall mortality (95% CI 0.81 to 1.26; participants = 8471; studies = 5; low-quality of evidence); 1.01 for non-CVD mortality (95% CI 0.76 to 1.35; participants = 8471; studies = 5; low-quality of evidence); and 1.38 for discontinuation of therapy due to adverse effects (95% CI 0.71 to 2.68; participants = 4805; studies = 3; I2 = 74%; very low-quality of evidence). Data on quality of life were not available from any trial. Trials that evaluated fibrates in the background of statins (2 studies) showed no benefits in preventing cardiovascular events. AUTHORS' CONCLUSIONS: Moderate-quality evidence suggests that fibrates lower the risk for cardiovascular and coronary events in primary prevention, but the absolute treatment effects in the primary prevention setting are modest (absolute risk reductions < 1%). There is low-quality evidence that fibrates have no effect on overall or non-CVD mortality. Very low-quality evidence suggests that fibrates are not associated with increased risk for adverse effects.

CORONARY EFFECT OF FIBRATES ON PROTEINS AND ENZYMES WHICH HYDROLYZE TRIACYLGLYCEROLS.

Clofibric acid derivatives called fibrates, are quite commonly used lipid-lowering drugs, so it is necessary to know beneficial and adverse effects of these compounds on the body. The European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) has concluded that benefits of four fibrates such as: bezafibrate, ciprofibrate, fenofibrate and gemfibrozil continue outweigh their risk in treatment of people with blood lipid disorders. According to recommendations of the CHMP fibrates should not be used as first-line drugs, except in patients with severe hypertriglyceridemia and patients who cannot use statins. In this paper, we focused on effect of clofibric acid derivatives on lipid metabolism, in particular on apoproteins and regulatory enzymes.

A Strategy Using Photodynamic Therapy and Clofibric Acid to Treat Peritoneal Dissemination of Ovarian Cancer.

BACKGROUND: The current study examined the effectiveness of concurrent therapy using photodynamic therapy (PDT) and clofibric acid (CA) to treat peritoneal carcinomatosis resulting from ovarian cancer. MATERIALS AND METHODS: Nude rats were used to create a model of peritoneal carcinomatosis resulting from ovarian cancer and the effectiveness of PDT with 5-aminolevulinic acid methyl ester hydrochloride (methyl-ALA-PDT) was determined. The survival time of rats receiving that therapy was compared to the survival time of a control group. Rats with peritoneal carcinomatosis resulting from ovarian cancer were divided into 3 groups: a group that received debulking surgery (DS) alone, a group that received DS+methyl-ALA-PDT, and a group that received DS+methyl-ALA-PDT+CA. The survival time of the 3 groups was compared. Protoporphyrin, a metabolite of methyl-ALA, produces a photochemical action when activated by light. The level of protoporphyrin (the concentration) that reached organs in the abdomen was measured with HPLC. RESULTS: Rats receiving methyl- ALA-PDT had a significantly longer survival time compared to the controls. Rats with peritoneal carcinomatosis that received DS+methyl-ALA-PDT+CA had a significantly longer survival time compared to the rats that received DS alone. Some of the rats that received concurrent therapy survived for a prolonged period. Protoporphyrin was highly concentrated in peritoneal metastases, but only small amounts reached major organs in the abdomen. PDT was not found to result in necrosis in the intestines. CONCLUSIONS: The results indicated that concurrent therapy consisting of PDT with methyl-ALA and CA is effective at treating peritoneal carcinomatosis resulting from ovarian cancer without damaging organs.

Fibrates reduce triacylglycerol content by upregulating adipose triglyceride lipase in the liver of rats.

Hepatic triacylglycerol (TAG) homeostasis is maintained by carefully regulated balance between its synthesis and disposal. Impairment in this balance causes steatosis. The aims of this study were i) to uncover whether fibrates control TAG concentration through the action of adipose triglyceride lipase (ATGL) and ii) to compare the potency of the effects on ATGL expression and TAG concentration among fenofibrate, bezafibrate, and clofibric acid in the liver of rats. Treatments of rats with the three fibrates induced ATGL and concomitantly decreased hepatic TAG concentration. The upregulation of ATGL was likely mediated through the activation of peroxisome proliferator-activated receptor α. Fibrates also expanded capacity of fatty acid ß-oxidation. Importantly, three fibric acids (fenofibric, bezafibric, and clofibric acids) that are active metabolites formed in the liver exhibited almost the same potency to elevate ATGL expression in vivo, despite the fact that there were considerable differences in this regard among fenofibrate, bezafibrate, and clofibric acid when compared on the basis of their dosage. These results suggest that ATGL represents a potential therapeutic target for ameliorating hepatic steatosis and that fibric acids are promising agents to ameliorate and/or protect against hepatic steatosis.

Tratamento otimizado antiplaquetário, antilipêmico, controle de pressão arterial e frequência cardíaca na doença coronariana crônica assintomática ou angina classe I / Optimized antiplatelet and hypolipidemic treatment, control of blood pressure and heart rate in chronic asymptomatic coronary artery disease or angina class 1

Neste artigo revisaremos o tratamento antiplaquetário e antilipêmico, controle da pressão arterial e controle da frequência cardíaca e sua influência na mortalidade e novos eventos, aplicável a todo paciente portador de doença coronariana crônica.

We review the antiplatelet and hypolipidemic treatment, blood pressure and heart rate control and its influence on mortality and new events, applicable to all patients with chronic coronary disease.

Additive effects of clofibric acid and pyruvate dehydrogenase kinase isoenzyme 4 (PDK4) deficiency on hepatic steatosis in mice fed a high saturated fat diet.

Although improving glucose metabolism by inhibition of pyruvate dehydrogenase kinase 4 (PDK4) may prove beneficial in the treatment of type 2 diabetes or diet-induced obesity, it may have detrimental effects by inhibiting fatty acid oxidation. Peroxisome proliferator-activated receptor α (PPARα) agonists are often used to treat dyslipidemia in patients, especially in type 2 diabetes. Combinational treatment using a PDK4 inhibitor and PPARα agonists may prove beneficial. However, PPARα agonists may be less effective in the presence of a PDK4 inhibitor because PPARα agonists induce PDK4 expression. In the present study, the effects of clofibric acid, a PPARα agonist, on blood and liver lipids were determined in wild-type and PDK4 knockout mice fed a high-fat diet. As expected, treatment of wild-type mice with clofibric acid resulted in less body weight gain, smaller epididymal fat pads, greater insulin sensitivity, and lower levels of serum and liver triacylglycerol. Surprisingly, rather than decreasing the effectiveness of clofibric acid, PDK4 deficiency enhanced the beneficial effects of clofibric acid on hepatic steatosis, reduced blood glucose levels, and did not prevent the positive effects of clofibric acid on serum triacylglycerols and free fatty acids. The metabolic effects of clofibric acid are therefore independent of the induction of PDK4 expression. The additive beneficial effects on hepatic steatosis may be due to induction of increased capacity for fatty acid oxidation and partial uncoupling of oxidative phosphorylation by clofibric acid, and a reduction in the capacity for fatty acid synthesis as a result of PDK4 deficiency.

Fibrates plus betaine: a winning combination?

Because most of the cardiac risk remains despite successful statin therapy there has been renewed interest in fibrate therapy for persisting hyperlipidaemia. Fibrate therapy lowers triglycerides but causes the urinary loss of betaine, which is an essential metabolite that is involved in osmoregulation, in methyl group metabolism, and which also affects lipid partitioning in the body. Loss of betaine is associated with an elevation of homocysteine and may compromise the potential benefits of fibrate therapy. However, betaine deficiency could be easily and inexpensively corrected by concurrent betaine supplementation. Clinical trials of combinations of betaine and fibrate, to complement statin therapy, are needed to determine the value of these agents in reducing the residual cardiovascular disease risk.

Treating mixed hyperlipidemia and the atherogenic lipid phenotype for prevention of cardiovascular events.

Statins reduce cardiovascular events and cardiovascular and total mortality in persons at risk for and with coronary disease, but there remains a significant residual event rate, particularly in those with the atherogenic lipid phenotype that is characterized by a low high-density lipoprotein (HDL) cholesterol and increase in non-HDL cholesterol. Large outcome trials designed to assess the value of combining statins with other agents to target HDL cholesterol and non-HDL cholesterol will not be completed for a few years, but there is ample evidence for the clinician to consider combination therapy. The choices for therapies to supplement statins include niacin, fibrates, and omega-3 fatty acids. We present the argument that after therapeutic lifestyle changes, the first priority should be the maximally tolerated effective dose of a potent statin. Evidence supports the addition of niacin as the second agent. In some situations, high-dose omega-3 fatty acid therapy could be the first agent added to statins. Although fibrate monotherapy alone or in combination with non-statin low-density lipoprotein cholesterol-lowering agents can be effective in mixed hyperlipidemia when statins are not tolerated, the combination of statin+fibrate should be considered second-line therapy until the efficacy and safety are established.

Case report. Hyperlipoproteinaemia(a): which is the optimal therapy? A case report.

This case report presents the clinical history of a patient with elevated lipoprotein(a) and small size isoform, associated with mixed hyperlipaemia, which was probably familial combined hyperlipaemia. After premature myocardial infarction, the subject was treated with fibrates. Niacin was started after recurrence. One year ago, after another episode of acute coronary syndrome, rosuvastatin was added to niacin. The atherogenicity of this lipid disorder, along with the different options for therapy is discussed.

Beyond statin therapy: a review of the management of residual risk in diabetes mellitus.

Total cholesterol and low-density lipoprotein (LDL) cholesterol exhibit an independent, strong, continuous correlation with cardiovascular events. The effectiveness of hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) in the treatment and prevention of atherosclerosis is well-established. However, despite the lowering of LDL targets and the increased use of statins, patients with type 2 diabetes mellitus (DM) continue to experience a higher proportion of adverse coronary artery disease events. This is as a result of an atherogenic dyslipidaemia, characterized by low levels of high-density lipoprotein and elevated plasma triglyceride concentrations, often with high levels of cholesterol-rich remnant particles. This article will review dyslipidaemia and its role in DM, and will discuss available treatment modalities that address residual cardiovascular risk in this disease.

Fibrates: no ACCORD on their use in the treatment of dyslipidaemia.

PURPOSE OF REVIEW: New data have emerged over the last few years about the role of fibrates in treatment of microvascular and macrovascular disease. RECENT FINDINGS: Endpoint studies have been conducted with fibrates in coronary heart disease since 1971 and results have been contradictory. Fibrates have shown benefits in patients with low HDL-cholesterol and low LDL-cholesterol. Fibrates remain topical, given their actions on the lipid triad present in the metabolic syndrome and in diabetes. In the Fenofibrate Intervention in Endpoint Lowering in Diabetes study of mixed primary and secondary prevention cohorts, fenofibrate therapy resulted in an 11% reduction in coronary or cardiovascular events in monotherapy. Despite frequent use, there was little endpoint data on fibrate-statin combination therapy until recently. The Action to Control Cardiovascular Risk in Diabetes trial of fenofibrate added to baseline simvastatin therapy in diabetes showed a nonsignificant 8% reduction in cardiovascular events. The benefits were concentrated in men, and women did slightly worse with fibrate therapy. In post-hoc analysis, slight beneficial effects of fenofibrate were seen in patients with moderate hypertriglyceridaemia (>2.3 mmol/l) and low HDL-cholesterol (<0.88 mmol/l). The safety profile of fibrate-simvastatin combination was good. SUMMARY: Fenofibrate and bezafibrate are reasonable second-line therapies for dyslipidaemia and in diabetes. They are safe in combination therapy with statins but add little endpoint benefit except possibly in patients with a significant degree of atherogenic dyslipidaemia (high triglycerides and low HDL-cholesterol). The benefits of fibrates on microvascular disease remain to be fully explored.

Management of hypertriglyceridemia in the diabetic patient.

The hypertriglyceridemia of diabetes can be classified into mild to moderate (triglycerides between 150-499 mg/dL) and severe hypertriglyceridemia (triglycerides > or =500 mg/dL). As in any other individuals with hypertriglyceridemia, secondary causes need to be excluded. The management of severe hypertriglyceridemia (chylomicronemia syndrome) includes aggressive reduction of triglycerides with intravenous insulin, fibrates, omega-3 fatty acids, and/or niacin therapy to avert the risk of pancreatitis. In patients with mild to moderate hypertriglyceridemia, the treatment of choice is statin therapy to achieve the low-density lipoprotein (LDL) and non-high-density lipoprotein (HDL) target goals. The evidence base would favor niacin therapy in combination with statin therapy to achieve the goals pertaining to LDL cholesterol and non-HDL cholesterol. The data about the combination of fibrate therapy with statin therapy are disappointing.

PPARalpha: an emerging therapeutic target in diabetic microvascular damage.

The global pandemic of diabetes mellitus portends an alarming rise in the prevalence of microvascular complications, despite advanced therapies for hyperglycemia, hypertension and dyslipidemia. Peroxisome proliferator-activated receptor alpha (PPARalpha) is expressed in organs affected by diabetic microvascular disease (retina, kidney and nerves), and its expression is regulated specifically in these tissues. Experimental evidence suggests that PPARalpha activation attenuates or inhibits several mediators of vascular damage, including lipotoxicity, inflammation, reactive oxygen species generation, endothelial dysfunction, angiogenesis and thrombosis, and thus might influence intracellular signaling pathways that lead to microvascular complications. PPARalpha has emerged as a novel target to prevent microvascular disease, via both its lipid-related and lipid-unrelated actions. Despite strong experimental evidence of the potential benefits of PPARalpha agonists in the prevention of vascular damage, the evidence from clinical studies in patients with diabetes mellitus remains limited. Promising findings from the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study on microvascular outcomes are countered by elevations in participants' homocysteine and creatinine levels that might potentially attenuate the benefits of PPARalpha activation. This Review focuses on the role of PPARalpha activation in diabetic microvascular disease and highlights the available experimental and clinical evidence from studies of PPARalpha agonists.

Effects of fibrates on cardiovascular outcomes: a systematic review and meta-analysis.

BACKGROUND: Several clinical trials have reported inconsistent findings for the effect of fibrates on cardiovascular risk. We undertook a systematic review and meta-analysis to investigate the effects of fibrates on major clinical outcomes. METHODS: We systematically searched Medline, Embase, and the Cochrane Library for trials published between 1950 and March, 2010. We included prospective randomised controlled trials assessing the effects of fibrates on cardiovascular outcomes compared with placebo. Summary estimates of relative risk (RR) reductions were calculated with a random effects model. Outcomes analysed were major cardiovascular events, coronary events, stroke, heart failure, coronary revascularisation, all-cause mortality, cardiovascular death, non-vascular death, sudden death, new onset albuminuria, and drug-related adverse events. FINDINGS: We identified 18 trials providing data for 45 058 participants, including 2870 major cardiovascular events, 4552 coronary events, and 3880 deaths. Fibrate therapy produced a 10% RR reduction (95% CI 0-18) for major cardiovascular events (p=0.048) and a 13% RR reduction (7-19) for coronary events (p<0.0001), but had no benefit on stroke (-3%, -16 to 9; p=0.69). We noted no effect of fibrate therapy on the risk of all-cause mortality (0%, -8 to 7; p=0.92), cardiovascular mortality (3%, -7 to 12; p=0.59), sudden death (11%, -6 to 26; p=0.19), or non-vascular mortality (-10%, -21 to 0.5; p=0.063). Fibrates reduced the risk of albuminuria progression by 14% (2-25; p=0.028). Serious drug-related adverse events were not significantly increased by fibrates (17 413 participants, 225 events; RR 1.21, 0.91-1.61; p=0.19), although increases in serum creatinine concentrations were common (1.99, 1.46-2.70; p<0.0001). INTERPRETATION: Fibrates can reduce the risk of major cardiovascular events predominantly by prevention of coronary events, and might have a role in individuals at high risk of cardiovascular events and in those with combined dyslipidaemia. FUNDING: National Health and Medical Research Council of Australia.