Monocyte suppressing action of fenofibrate

Since atherosclerosis has been proven to be an inflammatory disease, it is obvious that the proper treatment for dyslipidemia should not only correct lipid parameters but also inhibit inflammation. Monocytes and monocyte-derived proinflammatory cytokines are widely known to be involved in the formation and rupture of the atherosclerotic plaque. The aim of our study was to assess the effect of fenofibrate, a commonly used hypolipidemic drug, on the release of interleukin 1beta (IL-1beta), interleukin 6 (IL-6) and monocyte chemoattractant protein 1 (MCP-1) by monocytes from patients with combined hyperlipidemia. Fourteen patients with biochemically confirmed type IIb dyslipidemia who did not respond to a low-fat diet were treated with micronized fenofibrate for 1 month. The control group included 12 healthy, normolipidemic, age-matched subjects. To accurately evaluate the levels of the inflammatory cytokines, we excluded patients with any inflammatory disease. Monocytes were isolated from peripheral blood before and after the treatment. IL-1beta, IL-6 and MCP-1 release was measured by enzyme-linked immunosorbent assay (ELISA) after lipopolysaccharide stimulation. IL-1beta, IL-6 and MCP-1 levels were significantly higher in hyperlipidemic patients compared to the control (143.9 +/- 6.5 vs. 74.4 +/- 4.4 pg/ml; 8212 +/- 285 vs. 6110 +/- 170 pg/ml; 19.6 +/- 0.9 vs. 12.3 +/- 0.6 ng/ml, respectively). Thirty-day fenofibrate treatment decreased the release of IL-1beta by 43% (143.9 +/- 6.5 vs. 86.2 +/- 5.9 pg/ml), of IL-6 by 22% (8212 +/- 285 vs. 6330 +/- 234 pg/ml), and of MCP-1 by 29% (19.6 +/- 0.9 vs. 14.0 +/- 0.8 ng/ml). The evaluated cytokines were markedly elevated in patients with type IIb dyslipidemia. Effective fenofibrate therapy had a significant inhibitory effect on the release of monocyte-derived inflammatory cytokines.     

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

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

Combined Treatment with Fibrates and Small Doses of Atorvastatin in Patients with Mixed Hyperlipidemia

Summary

Combined statin and fibrate therapy is often imperative for the improvement of the serum lipid profile in patients with mixed hyperlipidemia. However, the potential risk of myopathy has limited the widespread use of such therapy. Preferably this treatment should involve low optimally tolerable doses of hypolipidemic drugs. Thus, we undertook a study to determine the safety and efficacy of combination therapy with fibrates and small doses of atorvastatin. Twenty-two patients with mixed hyperlipidemia were started on a fibrate regimen (micronised fenofibrate 200mg/day or ciprofibrate 100mg/day). Because after 12 weeks of therapy the fibrate failed to normalise the serum lipid profile, small doses of atorvastatin (5mg/day) were added for a further 12 weeks.

The administration of the fibrates resulted in a significant decrease in total and LDL-cholesterol levels, as well as in triglycerides, and an increase in HDL-cholesterol levels. The addition of atorvastatin (5mg/day) resulted in a further decrease in total and LDL-cholesterol levels. Consequently, the hypolipidemic therapy target was achieved in most of the patients. Combination therapy was well tolerated and no significant increases in serum liver and muscle enzymes were noticed.

We conclude that the careful administration of small doses of atorvastatin in patients with mixed dyslipidemia receiving fibrates is associated with a significant amelioration of lipid abnormalities.     

Efficacy of combination of atorvastatin and micronised fenofibrate in the treatment of severe mixed hyperlipidemia

OBJECTIVES: In patients with mixed lipid disorders, monotherapy may not effectively control all lipid abnormalities. We undertook this study to assess the efficacy of fenofibrate in combination with atorvastatin in patients with severe mixed dyslipidemia. METHODS: This was an 18-week, open-label study conducted in our lipid clinic. After a 6-week dietary baseline phase, patients received 200 mg/day micronised fenofibrate for 6 weeks. At the end of this period the subjects discontinued this treatment and received 40 mg/day atorvastatin for 6 weeks. Finally 200 mg/day of micronised fenofibrate was added to the statin therapy. RESULTS: Administration of micronised fenofibrate reduced serum triglycerides (P < 0.01) and total cholesterol and low-density lipoprotein (LDL) cholesterol (P < 0.05 for both parameters), while it evoked a significant increase in serum high-density lipoprotein (HDL) cholesterol levels (P < 0.05). Atorvastatin monotherapy induced a more pronounced decrease of total and LDL cholesterol. However, plasma triglycerides, although significantly lower than baseline values (P < 0.05), were higher than the values observed during treatment with fenofibrate. Moreover, serum HDL cholesterol concentrations were higher during fibrate therapy than during the statin one. During the combination therapy, the decrease in triglycerides was greater than that observed with fenofibrate alone, while the decrease in LDL cholesterol was more pronounced than that observed with atorvastatin alone. CONCLUSION: The combination of atorvastatin with micronised fenofibrate in patients with severe mixed dyslipidemia may have a favourable effect on some major coronary artery disease risk factors.     

Effects of atorvastatin,simvastatin, and fenofibrate therapy on monocyte chemoattractant protein-1 secretion in patients with hyperlipidemia

OBJECTIVE: Monocytes that migrate into the arterial wall participate in the development and, eventually, rupture of the atherosclerotic plaque. The aim of this study was to evaluate the secretion of monocyte chemoattractant protein-1 (MCP-1) by monocytes from hyperlipidemic patients treated with hypolipidemic drugs, namely fenofibrate, simvastatin, or atorvastatin to determine what role is played by these drugs in the development and stabilization of the atherosclerotic plaque. METHODS: Fifty-four hyperlipidemic patients, who did not respond to a low-fat diet, were treated with fenofibrate, simvastatin, or atorvastatin (18 patients in each group) for 1 month. The control group included 18 normolipidemic, healthy, age-matched participants. Ten hyperlipidemic patients were effectively treated with hypolipidemic diet alone for 1 month. This group was compared with a control group of ten healthy subjects. To accurately evaluate the adhesion molecule levels, we excluded hyperlipidemic patients and control subjects with any inflammatory disease. Before and after treatment, monocytes were isolated from peripheral blood. After stimulation with lipopolysaccharide (LPS), MCP-1 secretion was measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: MCP-1 levels were significantly higher in hyperlipidemic patients than controls: 15.8+/-0.47, 16.7+/-0.23, and 14.9+/-0.45 compared with 12.36+/-0.42 ng/ml. Fenofibrate, atorvastatin, and simvastatin significantly decreased MCP-1 levels from 15.8+/-0.47 to 8.79+/-0.89, from 16.7+/-0.23 to 7.46+/-0.73, and from 14.9+/-0.45 to 10.3+/-0.8 ng/ml, respectively. In the diet-treated group of hyperlipidemic patients, the level of MCP-1 before therapy was significantly higher than in controls (16.89+/-0.31 vs 12.45+/-0.36 ng/ml). The diet therapy caused a significant decrease in levels of MCP-1 to 15.1+/-0.36 ng/ml. There was a correlation between the decreased levels of lipids and the decreased release of MCP-1 in the patients treated with hypolipemic drugs. CONCLUSION: The drug-induced decrease in MCP-1 secretion in hyperlipidemic patients suggests that, apart from acting on lipids, the hypolipidemic drugs studied may directly inhibit the activity of monocytes.     

Statin or fibrate chronic treatment modifies the proteomic profile of rat skeletal muscle

Statins and fibrates can cause myopathy. To further understand the causes of the damage we performed a proteome analysis in fast-twitch skeletal muscle of rats chronically treated with different hypolipidemic drugs. The proteomic maps were obtained from extensor digitorum longus (EDL) muscles of rats treated for 2-months with 10 mg/kg atorvastatin, 20 mg/kg fluvastatin, 60 mg/kg fenofibrate and control rats. The proteins differentially expressed were identified by mass spectrometry and further analyzed by immunoblot analysis. We found a significant modification in 40 out of 417 total spots analyzed in atorvastatin treated rats, 15 out of 436 total spots in fluvastatin treated rats and 21 out of 439 total spots in fenofibrate treated rats in comparison to controls. All treatments induced a general tendency to a down-regulation of protein expression; in particular, atorvastatin affected the protein pattern more extensively with respect to the other treatments. Energy production systems, both oxidative and glycolytic enzymes and creatine kinase, were down-regulated following atorvastatin administration, whereas fenofibrate determined mostly alterations in glycolytic enzymes and creatine kinase, oxidative enzymes being relatively spared. Additionally, all treatments resulted in some modifications of proteins involved in cellular defenses against oxidative stress, such as heat shock proteins, and of myofibrillar proteins. These results were confirmed by immunoblot analysis. In conclusions, the proteomic analysis showed that either statin or fibrate administration can modify the expression of proteins essential for skeletal muscle function suggesting potential mechanisms for statin myopathy.     

Adverse effects of antiepileptic drugs on bone mineral density in children

Statins (hydroxy-methyl-glutaryl-coenzyme reductase inhibitors) remain the cornerstone of lipid-lowering therapy based on the evidence of clinical outcome trials. However, management of dyslipidemia in clinical practice may require the use of other hypolipidemic agents in combination with statins. Fibrate (agonist of peroxisome proliferator-activated receptor-α, PPR-α) monotherapy is effective for the treatment of hypertriglyceridemia, while the combination of a fibrate with a statin is an option in the management of patients with combined dyslipidemia and diabetes mellitus who present with atherogenic dyslipidemia (low high-density lipoprotein (HDL) cholesterol and elevated triglyceride levels). There is evidence that the combination treatment is efficacious towards a global improvement of the lipid abnormalities with a safety profile similar to that of fibrate monotherapy with regard to liver and muscle toxicity. Nevertheless, renal function may be more commonly affected in those treated with a ‘fibrate plus statin’. This concern has been raised with fibrate use either alone or in combination with a statin and should be taken into consideration when starting fibrate treatment while the pathophysiological basis and clinical implications of this drug-related effect need further investigation.     

Comparative effects of atorvastatin,simvastatin, and fenofibrate on serum homocysteine levels in patients with primary hyperlipidemia

Hyperhomocysteinemia is regarded as an independent risk factor for cardiovascular disease. Lipid-lowering agents, such as fibrates, can modify homocysteine levels. However, less is known about the effect of statin therapy on homocysteine. The authors compared the effects of atorvastatin (40 mg/day), simvastatin (40 mg/day), and micronized fenofibrate (200 mg/day) on the serum concentrations of total homocysteine, vitamin B12, and folic acid in patients with primary hyperlipidemia. A total of 128 patients with primary hyperlipidemia (total cholesterol > 240 mg/dL and triglycerides < 350 mg/dL) were assigned to atorvastatin, simvastatin, or fenofibrate. Serum lipid and metabolic parameters were measured at baseline and at 6 and 12 weeks of treatment. Homocysteine correlated positively with serum creatinine and uric acid levels and inversely with serum folic acid levels. All treatment modalities reduced total, low-density lipoprotein (LDL) cholesterol, and triglyceride concentrations. High-density lipoprotein (HDL) cholesterol levels significantly increased only in the fenofibrate-treated patients (47.9 +/- 12.5 vs. 50.7 +/- 12.6 vs. 51.2 +/- 12.8 mg/dL, p < 0.01). Atorvastatin and fenofibrate treatment resulted in a significant reduction of serum uric acid levels (5.3 +/- 1.6 vs. 4.9 +/- 1.4 vs. 4.8 +/- 1.4 mg/dL, p < 0.0001 for atorvastatin; 5.6 +/- 1.6 vs. 4.3 +/- 1.4 vs. 4.4 +/- 1.4 mg/dL, p < 0.0001 for fenofibrate). Homocysteine levels were significantly increased only by fenofibrate (10.3 +/- 3.3 vs. 14.1 +/- 3.8 vs. 14.2 +/- 3.6 microU/L, p < 0.001) but did not change from baseline following statin treatment. Neither statins nor fenofibrate had any effect on serum vitamin B12 and folic acid levels. In contrast to fenofibrate, therapeutic dosages of atorvastatin and simvastatin have a neutral effect on serum homocysteine levels, which is in favor of their "cardioprotective" properties.     

Metabolic and monocyte-suppressing actions of fenofibrate in patients with mixed dyslipidemia and early glucose metabolism disturbances

The aim of this study was to compare the action of fenofibrate on monocyte cytokine release between patients with isolated mixed dyslipidemia and dyslipidemia coexisting with prediabetic states in relationship with its metabolic actions. We compared 96 primary mixed dyslipidemic patients and 29 age-, sex- and weight-matched control subjects with normal lipid profile. Depending on glucose metabolism, dyslipidemic patients were allocated into one of three treatment groups: isolated dyslipidemia, dyslipidemia coexisting with impaired fasting glucose (IFG) and dyslipidemia coexisting with impaired glucose tolerance (IGT). Lipid profile, fasting and 2-h post-glucose load plasma glucose levels, HOMA and monocyte release of interleukin-1β and MCP-1 were assessed at baseline and after 30 and 90 days of micronized fenofibrate treatment (267 mg/daily). Compared to monocytes from control subjects, monocytes of dyslipidemic patients released a greater amounts of interleukin-1β and MCP-1. MCP-1 release was higher in the IFG group than in the remaining groups of dyslipidemic patients. In all groups of dyslipidemic patients, micronized fenofibrate reduced monocyte release of interleukin-1β and MCP-1, and this effect was stronger in prediabetic subjects. Fenofibrate treatment also decreased HOMA in IFG and IGT patients, fasting plasma glucose in IFG subjects and 2-h post-glucose load plasma glucose in IGT patients. The observed differences between the studied groups regarding fenofibrate action on glucose homeostasis and cytokine release suggest that fibrate therapy may bring particular benefits to persons with metabolic syndrome.     

Comparison of inhibitory effects of irbesartan and atorvastatin treatment on the renin angiotensin system (RAS) in veins: a randomized double-blind crossover trial in healthy subjects

Experimental studies point to an interplay between hypercholesterolemia and hypertension, acting through the renin angiotensin system. In a crossover study design with 8 healthy subjects, the authors tested the hypothesis that statin treatment exerts renin angiotensin system-modulating effects in veins by down-regulation of AT1-receptors, resulting in reduced Angiotensin II (Ang II)-induced venoconstriction and by increasing the pleiotropic Ang II-metabolite Ang-(1-7). Irbesartan was used as positive control. Ang II-induced venoconstriction was 49% +/- 9% before and 64% +/- 10% after 30 days of atorvastatin treatment compared to 50% +/- 8% before and 15% +/- 9% after irbesartan (P = .004). Plasma angiotensin levels significantly increased only after irbesartan treatment (Ang II: 35 +/- 4 vs 329 +/- 101 pg/mL [P = .02]; Ang-(1-7): 10 +/- 3 vs 35 +/- 6 pg/mL [P = .01]) compared to atorvastatin treatment (Ang II: 26 +/- 5 vs 31 +/- 4 pg/mL [P = ns]; Ang-(1-7): 9 +/- 2 vs 11 +/- 3 pg/mL [P = ns]). The data indicate that atorvastatin does not inhibit Ang II-induced venoconstriction in vivo and point toward a supportive role of Ang-(1-7) in contributing to the antihypertensive and beneficial vascular effects of irbesartan.     

Monocyte release of tumor necrosis factor-alpha and interleukin-1beta in primary type IIa and IIb dyslipidemic patients treated with statins or fibrates

Both 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) as well as peroxisome proliferator-activated receptor (PPAR)alpha activators (fibrates) proved to be effective in the primary and secondary prevention of cardiovascular diseases. The benefits of hypolipemic therapy in cardiovascular diseases cannot be explained only by the lipid-lowering potential of these agents. The aim of this study was to clarify the effect of hypolipemic agents on proinflammatory cytokine release from human monocytes in relationship with their action on plasma levels of sensitive systemic marker of low-grade vascular inflammation. Plasma lipid and high-sensitivity C-reactive protein (hsCRP) levels, and the release of tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta from monocytes were assessed at baseline and 30 and 90 days following randomization of IIa dyslipidemic patients into fluvastatin or simvastatin groups and randomization of type IIb dyslipidemic patients to the micronized form of either ciprofibrate or fenofibrate. Lipopolysaccharide-stimulated monocytes from dyslipidemic patients released significantly more TNFalpha (types IIa and IIb dyslipidemias) and interleukin-1beta (type IIa dyslipidemia) in comparison with monocytes in 59 age-, sex-, and weight-matched control subjects. Their baseline hsCRP levels were also higher. Both statins and fibrates reduced the release of TNFalpha and interleukin-1beta, and lowered plasma hsCRP levels. The effects of hypolipemic agents on cytokine release and plasma hsCRP were unrelated to their lipid-lowering action. Our results have demonstrated that type IIa and IIb dyslipidemic patients exhibit the abnormal pattern of TNFalpha and interleukin-1beta production by activated monocytes. Both HMG-CoA reductase inhibitors and PPARalpha activators normalize monocytic secretion of these cytokines, and this action may partially contribute to the systemic antiinflammatory effect of hypolipemic agents. The statin- and fibrate-induced suppression of proinflammatory cytokine release from monocytes seems to play a role in their beneficial effect on the incidence of cardiovascular events.     

Angiogenic transcriptome of human microvascular endothelial cells: Effect of hypoxia, modulation by atorvastatin

Hypoxia changes expression of angiogenic genes. Statins were also reported to affect blood vessel formation. However, data on the effects of statins on endothelial cells in hypoxia are limited. Here, effect of hypoxia and atorvastatin was assessed in human microvascular endothelial cells (HMEC-1). Hypoxia (1% O2) up-regulated vascular endothelial growth factor-A (VEGF-A) but, unexpectedly, it decreased interleukin-8 (IL-8) and placenta growth factor (PlGF) expression. Atorvastatin (0.1-1 microM) attenuated PlGF in HMEC-1 in normoxia while it decreased VEGF-A and IL-8 production both in normoxia and hypoxia. Notably, the expression of VEGF-D, macrophage scavenger receptor-1 (MSR1), transforming growth factor beta receptor III (TGFbetaR3) and inhibitor of DNA binding 3 (ID3) was augmented by atorvastatin in cells cultured in normoxia, while in hypoxia the statin attenuated their expression. These data showed that hypoxia influenced in the opposite way the expression of major endothelial genes, augmenting VEGF-A and decreasing IL-8 and PlGF. The influence of atorvastatin on angiogenic gene expression is complex, and final pro- or anti-angiogenic outcome of statin therapy remains to be established for numerous angiogenesis-related diseases.     

Effect of monthly atorvastatin and fenofibrate treatment on monocyte chemoattractant protein-1 release in patients with primary mixed dyslipidemia

The aim of this study was to compare the effect of 30-day treatment with atorvastatin and fenofibrate on monocyte release and plasma levels of monocyte chemoattractant protein-1 (MCP-1). We studied 52 atherosclerotic patients with primary mixed dyslipidemia and 16 age-, sex-, and weight-matched control subjects with asymptomatic atherosclerosis. Dyslipidemic patients enrolled into the study were randomly divided into three groups, simultaneously treated with atorvastatin (20 mg/d, n = 18), fenofibrate (267 mg/d, n = 16), or placebo (n = 18). Plasma lipid-profile and content of MCP-1, and monocyte release of this chemokine were measured at baseline and after 30 days of therapy. Compared with the control subjects, dyslipidemic patients exhibited the increased plasma levels and monocyte MCP-1 release. Atorvastatin and fenofibrate not only improved lipid profile but also decreased monocyte secretion of this chemokine. Moreover, hypolipemic agents slightly reduced its plasma levels. MCP-1-lowering effect of atorvastatin and fenofibrate did not correlate with the lipid-lowering potential of these agents. Our results suggest that atorvastatin and fenofibrate produce their antiinflammatory effect partially via inhibiting monocyte release of MCP-1. The treatment-induced reduction in its secretion may contribute to the clinical effectiveness of statins and fibrates in the therapy for atherosclerosis and other chronic fibroproliferative diseases.     

Interleukin-1 in Alzheimer's disease and multi-infarct dementia: neuropsychological correlations.

It has been reported that patients with Alzheimer's disease (AD) exhibit an overproduction of interleukin-1 (IL-1) in the cerebrospinal fluid and brain tissue. Since IL-1 appears to promote the expression of the beta-amyloid precursor protein (APP) gene, we have investigated the concentrations of serum IL-1 alpha and IL-1 beta and AD and multi-infarct dementia (MID) in order to evaluate whether IL-1 acts as a peripheral activating factor on cerebrovascular endothelial cells stimulating APP production. Serum IL-1 alpha levels did not differ significantly between healthy elderly subjects (110.7 +/- 23.3 pg/ml), early-onset AD (EOAD; 112.5 +/- 23.3 pg/ml), late-onset AD (LOAD; 89.2 +/- 17.6 pg/ml) or MID (116.8 +/- 50.4 pg/ml) patients. Serum IL-1 beta levels were also similar in controls (223.7 +/- 55.7 pg/ml), EOAD (223.1 +/- 79.5 pg/ml), LOAD (212.5 +/- 58.9 pg/ml) and MID (199.4 +/- 29.0 pg/ml). In LOAD a negative correlation between mental performance (MMS score), IL-1 alpha (r = -0.7728; p less than 0.0715) and IL-1 beta (r = -0.9214; p less than 0.0011) was observed. These results indicate that serum IL-1 levels are not altered in AD and MID; therefore, it is unlikely that blood-borne IL-1 influences APP production in the central nervous system (CNS). In conclusion, the neuroimmune dysfunction present in AD seems to be mainly concentrated in the CNS, with only minor immune alterations at the peripheral level.     

Atorvastatin reduces the expression of prostaglandin E2 receptors in human carotid atherosclerotic plaques and monocytic cells: potential implications for plaque stabilization

Prostaglandin E2 (PGE2), the product of cyclooxygenase-2 (COX-2) and prostaglandin E synthase-1 (mPGES-1), acts through its receptors (EPs) and induces matrix metalloproteinase (MMP) expression, which may favor the instability of atherosclerotic plaques. The effect of statins on EPs expression has not been previously studied. The aim of this study was to investigate the effect of atorvastatin (ATV, 80 mg/d, for one month) on EP expression in plaques and peripheral blood mononuclear cells (PBMC) of patients with carotid atherosclerosis. In addition, we studied the mechanisms by which statins could modulate EPs expression on cultured monocytic cells (THP-1) stimulated with proinflammatory cytokines (IL-1beta and TNF-alpha). Patients treated with atorvastatin showed reduced EP-1 (14 +/- 1.8% versus 26 +/- 2%; P < 0.01), EP-3 (10 +/- 1.5% versus 26 +/- 1.5%; P < 0.05), and EP-4 expression (10 +/- 4.1% versus 26.6 +/- 4.9%; P < 0.05) in atherosclerotic plaques (immunohistochemistry), and EP-3 and EP-4 mRNA expression in PBMC (real time PCR) in relation to non-treated patients. In cultured monocytic cells, atorvastatin (10 micromol/L) reduced EP-1/-3/-4 expression, along with COX-2, mPGES-1, MMP-9, and PGE2 levels elicited by IL-1beta and TNF-alpha. Similar results were noted with aspirin (100 micromol/L), dexamethasone (1 micromol/L), and the Rho kinase inhibitors Y-27632 and fasudil (10 micromol/L both). The effect of atorvastatin was reversed by mevalonate, farnesyl pyrophosphate, and geranylgeranyl pyrophosphate. On the whole, we have shown that atorvastatin reduces EPs expression in atherosclerotic plaques and blood mononuclear cells of patients with carotid stenosis and in cultured monocytic cells. The inhibition of EP receptors could explain, at least in part, some of the mechanisms by which statins could modulate the COX-2/mPGES-1 proinflammatory pathway and favor plaque stabilization in humans.     

Atorvastatin glucuronidation is minimally and nonselectively inhibited by the fibrates gemfibrozil, fenofibrate, and fenofibric acid.

Gemfibrozil coadministration generally results in plasma statin area under the curve (AUC) increases, ranging from moderate (2- to 3-fold) with simvastatin, lovastatin, and pravastatin to most significant with cerivastatin (5.6-fold). Inhibition of statin glucuronidation has been postulated as a potential mechanism of interaction (Drug Metab Dispos 30:1280-1287, 2002). This study was conducted to determine the in vitro inhibitory potential of fibrates toward atorvastatin glucuronidation. [(3)H]Atorvastatin, atorvastatin, and atorvastatin lactone were incubated with human liver microsomes or human recombinant UDP-glucuronosyltransferases (UGTs) and characterized using liquid chromatography (LC)/tandem mass spectrometry and LC/UV/beta-radioactivity monitor/mass spectrometry. [(3)H]Atorvastatin yields a minor ether glucuronide (G1) and a major acyl glucuronide (G2) with subsequent pH-dependent lactonization of G2 to yield atorvastatin lactone. Atorvastatin lactonization best fit substrate inhibition kinetics (K(m) = 12 microM, V(max) = 74 pmol/min/mg, K(i) = 75 microM). Atorvastatin lactone yields a single ether glucuronide (G3). G3 formation best fit Michaelis-Menten kinetics (K(m) = 2.6 microM, V(max) = 10.6 pmol/min/mg). Six UGT enzymes contribute to atorvastatin glucuronidation with G2 and G3 formation catalyzed by UGTs 1A1, 1A3, 1A4, 1A8, and 2B7, whereas G1 formation was catalyzed by UGTs 1A3, 1A4, and 1A9. Gemfibrozil, fenofibrate, and fenofibric acid inhibited atorvastatin lactonization with IC(50) values of 346, 320, and 291 microM, respectively. Based on unbound fibrate concentrations at the inlet to the liver, these data predict a small increase in atorvastatin AUC (approximately 1.2-fold) after gemfibrozil coadministration and no interaction with fenofibrate. This result is consistent with recent clinical reports indicating minimal atorvastatin AUC increases ( approximately 1.2- to 1.4-fold) with gemfibrozil.     

Combination therapy with statin and fibrate in patients with dyslipidemia associated with insulin resistance,metabolic syndrome and type 2 diabetes mellitus

Introduction: People with insulin resistance/metabolic syndrome (IR/MS) and/or type 2 diabetes mellitus (T2DM) have increased rates of cardiovascular disease (CVD) even when low-density lipoprotein cholesterol levels are at or near target levels. Contributors to this problem are the high triglyceride (TG) levels and low levels of high-density lipoprotein cholesterol (HDLC) that are commonly present in this population, even with statin therapy.

Areas covered: This review focuses on the use of a combination of statins with fibrates, which lower TG and raise HDLC concentrations and, therefore, have the potential to further lower rates of CVD more in people with IR/MS and/or T2DM. Treatment with this combination is uncommon because doctors and patients are fearful of muscle, liver and renal complications and because the evidence that the combination will actually reduce risk has been lacking. In this review, the authors examine the efficacy and safety of the statin–fibrate combination, particularly fenofibrate and simvastatin, the combination used in the ACCORD trial.

Expert opinion: The authors' opinion is that this combination of fenofibrate and statin is as safe as either drug alone and, in patients with significant dyslipidemia, is likely to reduce CVD. Concerns remain concerning fenofibrate-associated increases in serum creatinine levels and the significant heterogeneity in the reduction in CVD by the combination in women. A trial of statin + fenofibrate in people with IR/MS and/or T2DM who also have significant dyslipidemia is needed.     

Comparison of micronized fenofibrate and pravastatin in patients with primary hyperlipidemia

Micronized fenofibrate lowers total cholesterol and low-density lipoprotein cholesterol to a similar extent as statins but raises high-density lipoprotein cholesterol and lowers triglycerides to a greater extent. The comparative lipid-modifying efficacy of micronized fenofibrate and pravastatin has not been evaluated in dyslipidemic patients. This prospective, multicenter, randomized trial compared the efficacy of 3 months' treatment with micronized fenofibrate (200 mg once daily) or pravastatin (20 mg once daily) in hypercholesterolemic type IIa and mixed dyslipidemic type IIb patients. Two hundred sixty-five male and female patients (18-75 years) were recruited from 28 European centers, and 151 were analyzed. Micronized fenofibrate was at least as effective as pravastatin in reducing levels of low-density lipoprotein cholesterol and total cholesterol in primary dyslipidemia but was significantly more effective than pravastatin in raising high-density lipoprotein cholesterol (respectively, 13.2% vs. 5.6%; p = 0.0084) and lowering triglycerides (-38.7% vs. -11.8%; p = 0.0001). In type IIa dyslipidemia, micronized fenofibrate was as effective as pravastatin in raising high-density lipoprotein cholesterol (+8.6% vs. +8.0%) but was fivefold more effective in lowering triglycerides (-34.3% vs. -7.2%; p = 0.0001). In type IIb dyslipidemic patients with low baseline high-density lipoprotein cholesterol levels, micronized fenofibrate was 10-fold and nearly 3-fold superior to pravastatin in raising high-density lipoprotein cholesterol and lowering triglycerides, respectively. Micronized fenofibrate may be considered an effective first-line therapy for patients with primary hyperlipidemia, particularly those with type IIb mixed dyslipidemia or type 2 diabetes.     

Effects of fenofibrate and simvastatin on plasma sICAM-1 and MCP-1 concentrations in patients with hyperlipoproteinemia

OBJECTIVE: The most important mechanism through which high plasma lipid levels trigger the formation of atherosclerotic lesions involves a change in the expression of adhesion molecules on endothelial and smooth muscle cells. The aim of this study was to evaluate an extralipid effect of fenofibrate and simvastatin by examination of MCP-1 and ICAM-1 plasma concentration after 1-month hypolipemic therapy as well as MCP-1 and ICAM-1 plasma concentration after 1-month therapy with low-fat diet alone. METHODS: Twenty patients with HLPIIb or HLPIIa, who did not respond to a low-fat diet, were treated with micronized fenofibrate or simvastatin, respectively, for 1 month. The control group included 18 normo-lipidemic, healthy age-matched participants; 10 patients with HLPIIa were effectively treated with a low-fat diet for 1 month. This group was compared to a control group of 10 healthy subjects. The plasma adhesion molecule levels were measured by an ELISA method before and after the treatment. To accurately evaluate the adhesion molecule levels, we excluded hyperlipidemic patients and control subjects with any inflammatory disease. RESULTS: sICAM-1 levels were significantly higher in HLPIIa and HLPIIb patients (331 +/- 19 ng/ml and 423 +/- 23 ng/ml, respectively) compared with the control group (236 +/- 12 mg/ml). MCP-1 levels were also significantly higher in HLPIIa and HLPIIb patients (170 +/- 9 pg/ml and 183 +/- 15 pg/ml, respectively) compared with the control group (100 +/- 4 pg/ml). Fenofibrate (200 mg daily) significantly decreased sICAM-1 (by 17%) and MCP-1 levels (by 12.5%). Simvastatin (20 mg daily) caused a significant decrease (by 10.5%) in sICAM-1 levels only. Restriction in dietary lipids resulted in a significant decrease in the levels of cholesterol (8%), LDL cholesterol (14.9%) and ApoB (12.7%), which was accompanied by a significant decrease in the levels of sICAM-1 (8.7%) and MCP-1 (16.1%). CONCLUSION: The results of this study suggest that high lipid levels are accompanied by increased levels of sICAM-1 and MCP-1 and that hypolipidemic therapy only slightly decreases the levels of these molecules compared with plasma lipids. The hypolipidemic diet-related decrease in the levels of lipids, ICAM-1 and MCP-1 suggests that it is a drug-induced decrease in lipid levels but not a direct action of the drugs on endothelial cells, smooth muscle cells or macrophages that leads to a decrease in the levels of adhesion molecules.