The effect of statins and fibrates on interferon-γ and interleukin-2 release in patients with primary type II dyslipidemia

Simvastatin Reduces Protection and Intestinal T Cell Responses Induced by a Norovirus P Particle Vaccine in Gnotobiotic Pigs

Noroviruses (NoVs) are a leading cause of acute gastroenteritis worldwide. P particles are a potential vaccine candidate against NoV. Simvastatin is a cholesterol-reducing drug that is known to increase NoV infectivity. In this study, we examined simvastatin’s effects on P particle-induced protective efficacy and T-cell immunogenicity using the gnotobiotic pig model of human NoV infection and diarrhea. Pigs were intranasally inoculated with three doses (100 µg/dose) of GII.4/VA387-derived P particles together with monophosphoryl lipid A and chitosan adjuvants. Simvastatin-fed pigs received 8 mg/day orally for 11 days prior to challenge. A subset of pigs was orally challenged with 10 ID₅₀ of a NoV GII.4/2006b variant at post-inoculation day (PID) 28 and monitored for 7 days post-challenge. Intestinal and systemic T cell responses were determined pre- and postchallenge. Simvastatin abolished the P particle’s protection and significantly increased diarrhea severity after NoV infection. Simvastatin decreased proliferation of virus-specific and non-specific CD8 T cells in duodenum and virus-specific CD4 and CD8 T cells in spleen and significantly reduced numbers of intestinal mononuclear cells in vaccinated pigs. Furthermore, simvastatin significantly decreased numbers of duodenal CD4+IFN-γ+, CD8+IFN-γ+ and regulatory T cells and total duodenal activated CD4+ and CD8+ T cells in vaccinated pigs pre-challenge at PID 28. Following challenge, simvastatin prevented the IFN-γ+ T cell response in spleen of vaccinated pigs. These results indicate that simvastatin abolished P particle vaccine-induced partial protection through, at least in part, impairing T cell immunity. The findings have specific implications for the development of preventive and therapeutic strategies against NoV gastroenteritis, especially for the elderly population who takes statin-type drugs.

Inflammatory Activities in Type 2 Diabetes Patients With Co-morbid Angiopathies and Exploring Beneficial Interventions: A Systematic Review

Background: Diabetes is a long-term condition that can be treated and controlled but do not yet have a cure; it could be induced by inflammation and the goal of managing it is to prevent additional co-morbidities and reduce glycemic fluctuations. There is a need to examine inflammatory activities in diabetes-related angiopathies and explore interventions that could reduce the risk for future outcome or ameliorate its effects to provide insights for improved care and management strategies.

Method: The study was conducted in Embase (1946–2020), Ovid Medline (1950–2020), and PubMed databases (1960–2020) using the PICO framework. Primary studies (randomized controlled trials) on type 2 diabetes mellitus and inflammatory activities in diabetes-related angiopathies were included. Terms for the review were retrieved from the Cochrane library and from PROSPERO using its MeSH thesaurus qualifiers. Nine articles out of 454 total hits met the eligibility criteria. The quality assessment for the selected study was done using the Center for Evidence-Based Medicine Critical Appraisal Sheet.

Results: Data analysis showed that elevated CRP, TNF-α, and IL-6 were the most commonly found inflammatory indicator in diabetes-related angiopathies, while increased IL-10 and soluble RAGE was an indicator for better outcome. Use of drugs such as salsalate, pioglitazone, simvastatin, and fenofibrate but not glimepiride or benfotiamine reported a significant decrease in inflammatory events. Regular exercise and consumption of dietary supplements such as ginger, hesperidin which have anti-inflammatory properties, and those containing prebiotic fibers (e.g., raspberries) revealed a consistent significant (p < 0.05) reduction in inflammatory activities.

Conclusion: Inflammatory activities are implicated in diabetes-related angiopathies; regular exercise, the intake of healthy dietary supplements, and medications with anti-inflammatory properties could result in improved protective risk outcome for diabetes patients by suppressing inflammatory activities and elevating anti-inflammatory events.

Cell signaling and biological pathway in cardiovascular diseases

Currently, coronary artery disease accounts for a large proportion of deaths occurring worldwide. Damage to the heart muscle over a short period of time leads to myocardial infarction (MI). The biological mechanisms of atherosclerosis, one of the causes of MI, have been well studied. Resistin, a type of adipokine, is closely associated with intravascular level of low-density lipoprotein cholesterol and augmentation of the expression of adhesion molecules in endothelial cells. Therefore, resistin, which is highly associated with inflammation, can progress into coronary artery disease. Adenylyl cyclase associated protein 1, a binding partner of resistin, also plays an important role in inducing pro-inflammatory cytokines. The induction of these cytokines can aggravate atherosclerosis by promoting severe plaque rupture of the lesion site. Recently, drugs, such as statins that can inhibit inflammation have been extensively studied. The development of effective new drugs that can directly or indirectly block pro-inflammatory cytokines may have a great potential in the treatment of coronary artery disease in the future.

Fluvastatin for lowering lipids

BACKGROUND

Fluvastatin is thought to be the least potent statin on the market, however, the dose-related magnitude of effect of fluvastatin on blood lipids is not known.

OBJECTIVES

Primary objectiveTo quantify the effects of various doses of fluvastatin on blood total cholesterol, low-density lipoprotein (LDL cholesterol), high-density lipoprotein (HDL cholesterol), and triglycerides in participants with and without evidence of cardiovascular disease.Secondary objectivesTo quantify the variability of the effect of various doses of fluvastatin.To quantify withdrawals due to adverse effects (WDAEs) in randomised placebo-controlled trials.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to February 2017: the Cochrane Central Register of Controlled Trials (CENTRAL) (2017, Issue 1), MEDLINE (1946 to February Week 2 2017), MEDLINE In-Process, MEDLINE Epub Ahead of Print, Embase (1974 to February Week 2 2017), the World Health Organization International Clinical Trials Registry Platform, CDSR, DARE, Epistemonikos and ClinicalTrials.gov. We also contacted authors of relevant papers regarding further published and unpublished work. No language restrictions were applied.

SELECTION CRITERIA

Randomised placebo-controlled and uncontrolled before and after trials evaluating the dose response of different fixed doses of fluvastatin on blood lipids over a duration of three to 12 weeks in participants of any age with and without evidence of cardiovascular disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included, and extracted data. We entered data from placebo-controlled and uncontrolled before and after trials into Review Manager 5 as continuous and generic inverse variance data, respectively. WDAEs information was collected from the placebo-controlled trials. We assessed all trials using the 'Risk of bias' tool under the categories of sequence generation, allocation concealment, blinding, incomplete outcome data, selective reporting, and other potential biases.

MAIN RESULTS

One-hundred and forty-five trials (36 placebo controlled and 109 before and after) evaluated the dose-related efficacy of fluvastatin in 18,846 participants. The participants were of any age with and without evidence of cardiovascular disease, and fluvastatin effects were studied within a treatment period of three to 12 weeks. Log dose-response data over doses of 2.5 mg to 80 mg revealed strong linear dose-related effects on blood total cholesterol and LDL cholesterol and a weak linear dose-related effect on blood triglycerides. There was no dose-related effect of fluvastatin on blood HDL cholesterol. Fluvastatin 10 mg/day to 80 mg/day reduced LDL cholesterol by 15% to 33%, total cholesterol by 11% to 25% and triglycerides by 3% to 17.5%. For every two-fold dose increase there was a 6.0% (95% CI 5.4 to 6.6) decrease in blood LDL cholesterol, a 4.2% (95% CI 3.7 to 4.8) decrease in blood total cholesterol and a 4.2% (95% CI 2.0 to 6.3) decrease in blood triglycerides. The quality of evidence for these effects was judged to be high. When compared to atorvastatin and rosuvastatin, fluvastatin was about 12-fold less potent than atorvastatin and 46-fold less potent than rosuvastatin at reducing LDL cholesterol. Very low quality of evidence showed no difference in WDAEs between fluvastatin and placebo in 16 of 36 of these short-term trials (risk ratio 1.52 (95% CI 0.94 to 2.45).

AUTHORS' CONCLUSIONS

Fluvastatin lowers blood total cholesterol, LDL cholesterol and triglyceride in a dose-dependent linear fashion. Based on the effect on LDL cholesterol, fluvastatin is 12-fold less potent than atorvastatin and 46-fold less potent than rosuvastatin. This review did not provide a good estimate of the incidence of harms associated with fluvastatin because of the short duration of the trials and the lack of reporting of adverse effects in 56% of the placebo-controlled trials.

Dyslipidemia rather than Type 2 Diabetes Mellitus or Chronic Periodontitis Affects the Systemic Expression of Pro- and Anti-Inflammatory Genes

A high percentage of type 2 diabetes mellitus (T2D) patients are also affected by dyslipidemia and chronic periodontitis (CP), but no studies have determined the gene expression in patients that are simultaneously affected by all three diseases. We investigated the systemic expression of immune-related genes in T2D, dyslipidemia, and CP patients. One hundred and fifty patients were separated into five groups containing 30 individuals each: (G1) poorly controlled T2D with dyslipidemia and CP; (G2) well-controlled T2D with dyslipidemia and CP; (G3) normoglycemic individuals with dyslipidemia and CP; (G4) healthy individuals with CP; (G5) systemic and periodontally healthy individuals. Blood analyses of lipid and glycemic profiles were carried out. The expression of genes, including IL10, JAK1, STAT3, SOCS3, IP10, ICAM1, IFNA, IFNG, STAT1, and IRF1, was investigated by RT-qPCR. Patients with dyslipidemia demonstrated statistically higher expression of the IL10 and IFNA genes, while IFNG, IP10, IRF1, JAK1, and STAT3 were lower in comparison with nondyslipidemic patients. Anti-inflammatory genes, such as IL10, positively correlated with parameters of glucose, lipid, and periodontal profiles, while proinflammatory genes, such as IFNG, were negatively correlated with these parameters. We conclude that dyslipidemia appears to be the primary disease that is associated with gene expression of immune-related genes, while parameters of T2D and CP were correlated with the expression of these important immune genes.

Lymphocyte-suppressing action of simvastatin in patients with isolated hypertriglyceridemia

BACKGROUND

No previous study examined whether statins affect lymphocyte cytokine release in patients with isolated hypertriglyceridemia.

METHODS

The study included 46 patients with elevated triglyceride levels and peripheral artery stenosis, randomly assigned to receive simvastatin or placebo. Plasma lipids, glucose homeostasis markers, plasma C-reactive protein and lymphocyte cytokine release were measured at baseline and at the end of the treatment.

RESULTS

Ninety-day simvastatin treatment reduced lymphocyte release of TNF-α, interleukin-2 and interferon-γ, which was accompanied by a decrease in plasma C-reactive protein.

CONCLUSION

The obtained results suggest that statins produce lymphocyte-suppressing and systemic anti-inflammatory effects in patients with isolated hypertriglyceridemia.

Genome-wide association study indicates variants associated with insulin signaling and inflammation mediate lipoprotein responses to fenofibrate

OBJECTIVE

A shift towards overall larger very low-density lipoprotein (VLDL), and smaller low-density lipoprotein and high-density lipoprotein (HDL) diameters occurs in insulin resistance (IR), which reflects shifts in the distribution of the subfraction concentrations. Fenofibrate, indicated for hypertriglyceridemia, simultaneously reduces IR and shifts in lipoprotein diameter. Individual responses to fenofibrate vary, and we conducted a genome-wide association study to identify genetic differences that could contribute to such differences.

METHODS

Association analysis was conducted between single nucleotide polymorphisms (SNPs) on the Affymetrix 6.0 array and fasting particle diameter responses to a 12-week fenofibrate trial, in 817 related Caucasian participants of the Genetics of Lipid Lowering Drugs and Diet Network. Linear models were conducted, which adjusted for age, sex and study center as fixed effects, and pedigree as a random effect. The top three SNPs associated with each fraction were examined subsequently for associations with changes in subfraction concentrations.

RESULTS

SNPs in AHCYL2 and CD36 genes reached, or closely approached, genome-wide levels of significance with VLDL and HDL diameter responses to fenofibrate, respectively (P=4×10(-9) and 8×10(-8)). SNPs in AHCYL2 were associated with a decrease in the concentration of the large VLDL subfraction only (P=0.002). SNPs associated with HDL diameter change were not associated with a single subfraction concentration change (P>0.05) indicating small shifts across all subfractions.

CONCLUSION

We report novel associations between lipoprotein diameter responses to fenofibrate and the AHCYL2 and CD36 genes. Previous associations of these genes with IR emphasize the role of IR in mediating lipoprotein response to fenofibrate.

The PPAR alpha gene is associated with triglyceride, low-density cholesterol and inflammation marker response to fenofibrate intervention: the GOLDN study

As a peroxisome proliferator-activated receptor alpha (PPARα) agonist, fenofibrate favorably modulates dyslipidemia and inflammation markers, which are associated with cardiovascular risk. To determine whether variation in the PPARα receptor gene was associated with lipid and inflammatory marker response, we conducted a three week trial of fenofibrate in 861 men and women. Mixed linear models which controlled for age and sex, as well as family pedigree and study-center, were constructed using SNPs in the PPARα gene as predictors and changes in fasting triglycerides (TGs), cholesterol and inflammatory markers as outcomes. Significant associations with low-density cholesterol (LDL-C) and interleukin-2 (IL-2; P<.001) responses to fenofibrate were found. Although there were suggestive associations with tumour necrosis factor-alpha (TNF-α) and TG responses (P<.05), these did not survive the correction for multiple testing. We conclude that variants in the PPARα gene may contribute to future pharmacogenomic paradigms seeking to predict fenofibrate responders from both an anti-dyslipidemic and anti-inflammatory perspective.

The effect of ezetimibe, administered alone or in combination with simvastatin, on lymphocyte cytokine release in patients with elevated cholesterol levels

OBJECTIVE

Studies assessing the extra-lipid effects of ezetimibe have provided contrasting results. In the present study, we compared the effects of ezetimibe and simvastatin, administered alone or in combination, on the secretory function of human lymphocytes, systemic inflammation and endothelial function in subjects with elevated cholesterol levels.

METHODS

A prospective study involving a group of 178 ambulatory patients with isolated hypercholesterolaemia who were randomly assigned in a double-blind fashion to 90days of treatment with ezetimibe (10mg), simvastatin (40mg), ezetimibe (10mg) plus simvastatin (4mg) or placebo. A total of 170 patients completed the study.

MAIN OUTCOME MEASURES

Lymphocyte cytokine release and plasma levels of high-sensitivity C-reactive protein (hsCRP) and intercellular adhesion molecule 1 (ICAM-1).

RESULTS

Although both drugs reduced lymphocyte release of tumour necrosis factor-α, interferon-γ and interleukin-2 in a lipid-independent manner, only the effect of simvastatin was statistically significant (P<0.001). This lymphocyte-suppressing effect, which was accompanied by a decrease in plasma levels of hsCRP and ICAM-1 (P<0.001), was strongest in patients receiving both simvastatin and ezetimibe. There were no differences in lymphocyte-suppressing, systemic anti-inflammatory and endothelial protective effects of simvastatin between insulin-resistant and insulin-sensitive subjects, whereas the effects of ezetimibe and the combined treatment were greater in the former group of patients (P<0.01 and P<0.001, respectively).

CONCLUSIONS

The results of this study indicate that simvastatin is superior to ezetimibe in producing lymphocyte-suppressing, systemic anti-inflammatory and endothelial protective effects in patients with elevated cholesterol levels. Hypercholesterolaemic patients with high cardiovascular risk may receive the greatest benefits from concomitant treatment with a statin and ezetimibe.

Coexistence of primary aldosteronism and Hashimoto's thyroiditis

In light of research carried out in recent years, it seems that aldosterone may produce a complex proinflammatory effect. Theoretically, excessive aldosterone release may stimulate the development and/or progression of autoimmune disorders. In this article, we report a case of a female in whom primary aldosteronism coexisted with Hashimoto’s thyroiditis. Surgical removal of an aldosterone-producing tumor improved thyroid function and decreased thyroid autoimmunity. We describe in details diagnostic and treatment strategies applied in our patient and their impact on the course and outcome of thyroiditis. We also present monocyte and lymphocyte cytokine release in the index subjects before and after surgical treatment. We conclude that primary aldosteronism may exacerbate the clinical course of autoimmune thyroiditis and probably also of other autoimmune disorders.

The effect of bezafibrate and omega-3 fatty acids on lymphocyte cytokine release and systemic inflammation in patients with isolated hypertriglyceridemia

PURPOSE

The aim of this study was to compare the effects of fibrates and omega-3 fatty acids on lymphocyte secretory function and systemic inflammation in patients with isolated hypertriglyceridemia.

METHODS

The study included 107 patients with isolated hypertriglyceridemia who received bezafibrate (200 mg twice daily), omega-3 fatty acids (1 g twice daily) or placebo for 12 weeks. The lipid profile, fasting and 2-h post-glucose load plasma glucose levels, homeostasis model assessment index (HOMA), plasma high-sensitivity C-reactive protein (hsCRP) levels and lymphocyte release of interleukin-2, interferon-γ and tumor necrosis factor-α were assessed at baseline, on the day of randomization, and after 4 and 12 weeks of treatment.

RESULTS

Both bezafibrate and omega-3 fatty acids reduced plasma triglyceride levels. Bezafibrate additionally decreased total and low-density lipoprotein-cholesterol levels and the HOMA and insignificantly decreased post-glucose load plasma glucose, as well as increased high-density lipoprotein-cholesterol. Bezafibrate treatment was associated with a reduction in lymphocyte release of interleukin-2, interferon-γ and tumor necrosis factor-α, which was accompanied by a reduction in plasma hsCRP levels. Omega-3 fatty acid did not significantly reduce lymphocyte cytokine release and plasma hsCRP. The anti-inflammatory effects of both drugs did not correlate with their action on plasma lipids, but in the case of the former the effect was related to the improvement in insulin sensitivity.

CONCLUSION

Our results indicate that bezafibrate is superior to omega-3 fatty acid in inhibiting systemic inflammation and lymphocyte secretory function.

Cytokines, macrophage lipid metabolism and foam cells: implications for cardiovascular disease therapy

Cardiovascular disease is the biggest killer globally and the principal contributing factor to the pathology is atherosclerosis; a chronic, inflammatory disorder characterized by lipid and cholesterol accumulation and the development of fibrotic plaques within the walls of large and medium arteries. Macrophages are fundamental to the immune response directed to the site of inflammation and their normal, protective function is harnessed, detrimentally, in atherosclerosis. Macrophages contribute to plaque development by internalizing native and modified lipoproteins to convert them into cholesterol-rich foam cells. Foam cells not only help to bridge the innate and adaptive immune response to atherosclerosis but also accumulate to create fatty streaks, which help shape the architecture of advanced plaques. Foam cell formation involves the disruption of normal macrophage cholesterol metabolism, which is governed by a homeostatic mechanism that controls the uptake, intracellular metabolism, and efflux of cholesterol. It has emerged over the last 20 years that an array of cytokines, including interferon-γ, transforming growth factor-β1, interleukin-1β, and interleukin-10, are able to manipulate these processes. Foam cell targeting, anti-inflammatory therapies, such as agonists of nuclear receptors and statins, are known to regulate the actions of pro- and anti-atherogenic cytokines indirectly of their primary pharmacological function. A clear understanding of macrophage foam cell biology will hopefully enable novel foam cell targeting therapies to be developed for use in the clinical intervention of atherosclerosis.

Effect of simvastatin and fenofibrate on cytokine release and systemic inflammation in type 2 diabetes mellitus with mixed dyslipidemia

The aim of our study was to compare the effect of simvastatin and fenofibrate treatment on the secretory function of human monocytes and lymphocytes and on systemic inflammation in type 2 diabetes and to assess whether their coadministration is superior to treatment with only 1 of these drugs. One hundred ninety-six adult patients with recently diagnosed and previously untreated type 2 diabetes and mixed dyslipidemia, complying throughout the study with lifestyle intervention and treated with metformin, were randomized in a double-blind fashion to receive simvastatin (40 mg), fenofibrate (200 mg), simvastatin plus fenofibrate, or placebo for 90 days. Main outcome measurements were monocyte and lymphocyte release of proinflammatory cytokines and plasma levels of C-reactive protein. One hundred ninety patients completed the study. Simvastatin and fenofibrate decreased monocyte release of tumor necrosis factor-α, interleukin-1β, interleukin-6, and monocyte chemoattractant protein-1 and lymphocyte release of interleukin-2, interferon-γ, and tumor necrosis factor-α, which was accompanied by a decrease in plasma C-reactive protein levels. Anti-inflammatory effects of fenofibrate partly correlated with the improvement in insulin sensitivity. Lymphocyte-suppressing, but not monocyte-suppressing, effect was stronger if these 2 agents were administered together. In conclusion, simvastatin and fenofibrate exhibit a similar effect on the secretory function of human monocytes and lymphocytes and on systemic inflammation in type 2 diabetic subjects with mixed dyslipidemia. This effect may be clinically relevant in the prevention of vascular complications in metformin- and diet-treated subjects with newly diagnosed diabetic dyslipidemia.

Design of cohort studies in chronic diseases using routinely collected databases when a prescription is used as surrogate outcome

Background

There has been little research on design of studies based on routinely collected data when the clinical endpoint of interest is not recorded, but can be inferred from a prescription. This often happens when exploring the effect of a drug on chronic diseases. Using the LifeLink claims database in studying the possible anti-inflammatory effects of statins in rheumatoid arthritis (RA), oral steroids (OS) were treated as surrogate of inflammatory flare-ups. We compared two cohort study designs, the first using time to event outcomes and the second using quantitative amount of the surrogate.

Methods

RA patients were extracted from the LifeLink database. In the first study, patients were split into two sub-cohorts based on whether they were using OS within a specified time window of the RA index date (first record of RA). Using Cox models we evaluated the association between time-varying exposure to statins and (i) initiation of OS therapy in the non-users of OS at RA index date and (ii) cessation of OS therapy in the users of OS at RA index date. In the second study, we matched new statin users to non users on age and sex. Zero inflated negative binomial models were used to contrast the number of days' prescriptions of OS in the year following date of statin initiation for the two exposure groups.

Results

In the unmatched study, the statin exposure hazard ratio (HR) of initiating OS in the 31451 non-users of OS at RA index date was 0.96(95% CI 0.9,1.1) and the statin exposure HR of cessation of OS therapy in the 6026 users of OS therapy at RA index date was 0.95 (0.87,1.05). In the matched cohort of 6288 RA patients the statin exposure rate ratio for duration on OS therapy was 0.88(0.76,1.02). There was digit preference for outcomes in multiples of 7 and 30 days.

Conclusions

The 'time to event' study design was preferable because it better exploits information on all available patients and provides a degree of robustness toward confounding. We found no convincing evidence that statins reduce inflammation in RA patients.

Effect of bezafibrate on monocyte cytokine release and systemic inflammation in patients with impaired fasting glucose

This study assessed the effect of bezafibrate on monocyte secretory function and systemic inflammation in patients with impaired fasting glucose (IFG), comparing this effect with that produced by bezafibrate in mixed dyslipidemic subjects. The study included 28 patients with IFG, 29 individuals with mixed dyslipidemia, and 24 age-, sex- and weight-matched control subjects without lipid and glucose metabolism abnormalities. Compared with the control group, in both IFG and mixed dyslipidemic subjects, monocyte release of monocyte chemoattractant protein-1 (MCP-1), interleukin-6, tumor necrosis factor-α (TNF-α), and interleukin-1β was increased, which was accompanied by higher plasma levels of high-sensitivity C-reactive protein (hsCRP). Despite affecting plasma lipids in both treatment groups, bezafibrate administration (200 mg twice daily for 90 days) reduced fasting plasma glucose levels, the homeostasis model assessment index, and glycated hemoglobin only in IFG subjects. Bezafibrate treatment normalized monocyte release of MCP-1, interleukin-6, TNF-α, and interleukin-1β and also normalized plasma hsCRP levels in mixed dyslipidemic subjects, whereas in IFG individuals the drug reduced only MCP-1 and interleukin-6 release. This study shows that IFG is associated with the presence of systemic inflammation and abnormal monocyte secretory function. Compared with patients with mixed dyslipidemia, IFG patients who are administered bezafibrate experience a stronger effect on glucose metabolism and weaker anti-inflammatory and monocyte-suppressing actions.

The effect of fenofibrate on lymphocyte cytokine release in patients with impaired fasting glucose and impaired glucose tolerance: a preliminary report

OBJECTIVE

The aim of our study was to investigate the effect of fenofibrate on lymphocyte secretory function in patients with isolated early glucose metabolism abnormalities.

METHODS

Fifty-eight patients with impaired fasting glucose (IFG), fifty-six subjects with impaired glucose tolerance (IGT) and fifty-five normolipidemic control subjects with asymptomatic atherosclerosis, were treated for 90 days with either micronized fenofibrate (200 mg/day) or placebo.

RESULTS

Compared to control subjects, lymphocytes of both IGF and IGT patients released more amounts of interleukin-2, interferon-γ and TNF-α, and exhibited higher plasma levels of hsCRP. Despite improving glucose metabolism markers in both IFG and IGT subjects, fenofibrate reduced lymphocyte cytokine release only in the latter group of patients.

CONCLUSIONS

Our results show for the first time that lymphocyte secretory function is disturbed at early stages of glucose metabolism disturbances and that IGT- but not IFG-induced abnormal function of T cells is corrected by fenofibrate administration.

Peroxisome proliferator-activated receptor agonists: do they increase cardiovascular risk?

Cardiovascular disease is a major cause of morbidity and mortality among people with type 2 diabetes mellitus. The peroxisome proliferator-activated receptor (PPAR) agonists have a significant role on glucose and fat metabolism. Thiazolidinediones (TZDs) are predominantly PPARγ agonists, and their primary benefit appears to be the prevention of diabetic complications by improving glycemic control and lipid profile. Recently, the cardiovascular safety of rosiglitazone was brought to center stage following meta analyses and the interim analysis of the RECORD trial. Current evidence points to rosiglitazone having a greater risk of myocardial ischemic events than placebo, metformin, or sulfonylureas. This review article discusses the mechanism of action of PPAR agonists and correlates it with clinical and laboratory outcomes in the published literature. In addition, this review article attempts to discuss some of the molecular mechanisms regarding the association between TZDs therapy and the nontraditional cardiovascular risks.

The therapeutic modulation of atherogenic dyslipidemia and inflammatory markers in the metabolic syndrome: what is the clinical relevance?

The metabolic syndrome consists of a constellation of clinical and biochemical risk factors that cluster together and heighten the risk for atherogenesis, cardiovascular diseases, and diabetes. Established risk cardiovascular factors like hypertension, atherogenic dyslipidaemia, and glucose intolerance occur in the setting of insulin resistance and central adiposity, with genetic and environmental influences modulating the ultimate risk. Chronic insults to the endothelium take its toll in the form of silent as well as clinically evident cardiovascular events. The cellular and vascular accompaniments have shed some light into the underlying pathophysiology. Heightened, low-grade inflammatory processes as well as a continuum of vascular insults ranging from early endothelial derangements to advanced atherosclerosis have been examined. In recent years there has been an explosion of basic and clinical knowledge related to the metabolic syndrome. Although dyslipidaemia is considered a traditional risk component for the syndrome, its qualitative aspects, genetically determined subfractions, and variation in proatherogenic tendency have generated renewed interest and debate. New targets within the dyslipidaemic spectrum that have differing clinical relevance are being evaluated. The effect of heredity, lifestyle changes, pharmacotherapeutic agents, and supplements is being investigated. Further research into the impact of dyslipidemia and inflammation as both pathophysiologic risk factors and objects for targeted therapy in the metabolic syndrome should deepen our understanding and unravel answers to the underlying dynamics in this global epidemic.

Treatment of hyperlipidaemia with fenofibrate and related fibrates

BACKGROUND

Fenofibrate is the most widely used fibrate. Its efficacy and tolerability in the treatment of hypertriglyceridaemia and combined hyperlipidaemia have been demonstrated in several clinical trials.

OBJECTIVE

To review the pharmacology, lipid-lowering and extra-lipid effects of fenofibrate and to preview ABT-335, an investigational new fenofibric acid molecule.

RESULTS

The effects of fenofibrate are mediated through the active metabolite fenofibric acid, and are described in detail in the paper. ABT-335 is a salt of fenofibric acid and, unlike fenofibrate, does not require first pass metabolism to the active moiety. ABT-335 is being developed for combination use with statins, and has recently completed three large Phase III randomised controlled trials in which the efficacy and safety of ABT-335 in combination with the three most commonly prescribed statins, atorvastatin, simvastatin and rosuvastatin, was evaluated in patients with mixed dyslipidaemia.

CONCLUSION

ABT-335 in combination with statins may provide a safe and efficacious treatment modality that enables achievement of several therapeutic goals in patients with mixed dyslipidaemia who have high cardiovascular risk.

Conjugated linoleic acid supplementation reduces peripheral blood mononuclear cell interleukin-2 production in healthy middle-aged males

Conjugated linoleic acid (CLA) refers to geometric and positional isomers of linoleic acid. Animal studies have shown that CLA modulates the immune system and suggest that it may have a therapeutic role in inflammatory disorders. This double-blind placebo-controlled intervention trial investigated the effects of CLA supplementation on indices of immunity relating to cardiovascular disease (CVD) in a cohort of healthy middle-aged male volunteers. Subjects were randomly assigned to supplement their diet with 2.2 g 50:50 isomeric blend of cis 9, trans 11 (c9, t11)-CLA and trans 10, cis 12 (t10, c12)-CLA or placebo daily for 8 weeks. Interleukin (IL) 2, IL-10 and tumour necrosis factor (TNF) alpha were measured in the supernatant of cultured unstimulated and concanavalin A (Con A)-stimulated peripheral blood mononuclear cells (PBMC) by ELISA. Serum IL-6 and plasma CRP were measured by ELISA and plasma fibrinogen by automated clotting assay. Gene expression was investigated by real-time RT-PCR. CLA supplementation significantly reduced Con A-stimulated PBMC IL-2 secretion (37.1%; P=.02). CLA supplementation had no significant effect on transcription of IL-2. CLA supplementation had no direct significant effects on PBMC TNFalpha or IL-10 secretion. Other inflammatory markers associated with CVD, including IL-6, CRP and fibrinogen, were not affected by CLA supplementation. This study showed that CLA supplementation reduced PBMC IL-2 secretion from Con A-stimulated PBMC but lacked effect on other markers of the human inflammatory response.

Inflammation in diabetes mellitus: role of peroxisome proliferator-activated receptor-alpha and peroxisome proliferator-activated receptor-gamma agonists

Patients with type 2 diabetes mellitus and/or the metabolic syndrome have considerable cardiovascular risk. Treatment with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) and with antihypertensive and some antihyperglycemic agents reduces this risk, but residual macrovascular morbidity and mortality persist, even in patients assigned to intensive multifactorial intervention programs. Therapeutic strategies that target inflammation and lipid abnormalities not well addressed by statins may offer additional opportunities for improving the prognosis of these patients. Inflammation, a key mechanism of atherogenesis, appears to have particular relevance to diabetic vascular complications, as well as in the development of diabetes itself. Oxidative stress and hyperglycemia also figure among the pathogenic factors that promote cardiovascular complications in patients with the metabolic syndrome and/or diabetes and may augment the ongoing inflammation. Peroxisome proliferator-activated receptor (PPAR)-alpha and PPAR-gamma, members of the nuclear receptor family, form ligand-activated transcription factors that regulate key important metabolic pathways. PPARs have become therapeutic targets through the use of the fibrate class of antidyslipidemic drugs (PPAR-alpha) and the insulin-sensitizing thiazolidinediones (PPAR-gamma). The activation of these PPARs may also suppress inflammation and atherosclerosis. Recent clinical trials (Fenofibrate Intervention and Event Lowering in Diabetes [FIELD], Prospective Pioglitazone Clinical Trial in Macrovascular Events [PROactive]) have considered the impact of these PPAR agonists on cardiovascular disease, with mixed effects that require careful analysis, especially given ongoing trials and additional PPAR agonists in development.

Effects of simvastatin on human T cells in vivo

OBJECTIVE

The use of statins has shown several anti-inflammatory actions, including modulatory effects on T cells in vitro. Since the effects on human T cells in vivo are less clarified, our aim was to investigate the effects of simvastatin on human T cells in vivo and ex vivo.

METHODS AND RESULTS

A randomized, double-blind, placebo-controlled study design was applied. Eighty volunteers with mild to moderate hypercholesterolemia received either simvastatin 40 mg or placebo for 6 weeks. The serum levels of C-reactive protein (CRP) were significantly reduced by simvastatin. The proportions of CD4+ and CD8+ T cell subsets expressing early (CD25) or late (HLA-DR) activation markers, as assessed by flow cytometry, were not changed by simvastatin. However, simvastatin tended to increase the density of HLA-DR and L-selectin per CD8+ T cell. The T helper(h)1/Th2 response was evaluated by stimulatory assays followed by intra-cellular staining of interferon-gamma and interleukin-4. Simvastatin treatment did not affect the Th1 response but the results indicated a potential to suppress Th2.

CONCLUSION

Simvastatin treatment resulted in a few discrete changes as regards peripheral T cells. However, the findings do not provide evidence that simvastatin-induced anti-inflammatory actions are related to any significant modulatory effects on human T cells in clinically healthy men with hypercholesterolemia.

Serum markers of vascular inflammation in dyslipemia

Atherosclerosis is widely recognized as an inflammatory disease because systemic and local inflammatory events mediate all phases of plaque development and progression. Basic and clinical studies have focused on identifying potentially useful markers of inflammation. In this article, we review the inflammatory pathogenesis of atherosclerosis, and highlight recent results of several of the more promising markers of inflammation for cardiovascular risk assessment. Of these markers, the most reliable and accessible for clinical use is currently high-sensitivity C-reactive protein (CRP). At present, most clinical guidelines do not recommend routine measurement of these inflammatory markers. However, these serum markers of vascular inflammation may be useful as an adjunct to lipid screening, especially for patients whose lipid values may not be severely elevated, but who are at intermediate risk according to scoring systems that take into account multiple established risk factors. In addition, since the pleiotropic effects of statins include the inhibition of inflammatory response, serum inflammatory markers could also be useful for monitoring this action. Nevertheless, several issues have to be evaluated before the measurements of inflammatory markers can be used for cardiovascular risk prediction in either clinical practice or in clinical trials evaluating anti-atherosclerotic drugs.

Pleiotropic effects of fibrates

Fibrates are a widely used class of hypolipidemic drugs. The effects of fibrates are mediated through the activation of the transcription factor peroxisome proliferator-activated receptor a (PPARa). Fibrates act to modulate the transcription of genes that encode proteins controlling lipid transport and metabolism. Fibrates also exert pleiotropic anti-inflammatory effects by down regulating expression of genes encoding inflammatory cytokines and acute phase response proteins. These combined actions translate into clinical benefit as demonstrated by the reduction in cardiovascular morbidity and mortality in primary and secondary intervention trials.

Fenofibrate: a novel formulation (Triglide) in the treatment of lipid disorders: a review

Cardiovascular disease is the major cause of mortality worldwide and accounts for approximately 40% of all deaths. Dyslipidemia is one of the primary causes of atherosclerosis and effective interventions to correct dyslipidemia should form an integral component of any strategy aimed at preventing cardiovascular disease. Fibrates have played a major role in the treatment of hyperlipidemia for more than two decades. Fenofibrate is one of the most commonly used fibrates worldwide. Since fenofibrate was first introduced in clinical practice, a major drawback has been its low bioavailability when taken under fasting conditions. Insoluble Drug Delivery-Microparticle fenofibrate is a new formulation that has an equivalent extent of absorption under fed or fasting conditions. In this review, we will discuss the clinical pharmacology of fenofibrate, with particular emphasis on this novel formulation, as well as its lipid-modulating and pleiotropic actions. We will also analyze the major trial that evaluated fibrates for primary and secondary prevention of cardiovascular disease, the safety and efficacy profile of fibrate-statin combination treatment, and the current recommendations regarding the use of fibrates in clinical practice.

The PPAR-alpha activator fenofibrate fails to provide myocardial protection in ischemia and reperfusion in pigs

Rodent studies suggest that peroxisome proliferator-activated receptor-alpha (PPAR-alpha) activation reduces myocardial ischemia-reperfusion (I/R) injury and infarct size; however, effects of PPAR-alpha activation in large animal models of myocardial I/R are unknown. We determined whether chronic treatment with the PPAR-alpha activator fenofibrate affects myocardial I/R injury in pigs. Domestic farm pigs were assigned to treatment with fenofibrate 50 mg.kg(-1).day(-1) orally or no drug treatment, and either a low-fat (4% by weight) or a high-fat (20% by weight) diet. After 4 wk, 66 pigs underwent 90 min low-flow regional myocardial ischemia and 120 min reperfusion under anesthetized open-chest conditions, resulting in myocardial stunning. The high-fat group received an infusion of triglyceride emulsion and heparin during this terminal experiment to maintain elevated arterial free fatty acid (FFA) levels. An additional 21 pigs underwent 60 min no-flow ischemia and 180 min reperfusion, resulting in myocardial infarction. Plasma concentration of fenofibric acid was similar to the EC50 for activation of PPAR-alpha in vitro and to maximal concentrations achieved in clinical use. Myocardial expression of PPAR-alpha mRNA was prominent but unaffected by fenofibrate treatment. Fenofibrate increased expression of carnitine palmitoyltransferase (CPT)-I mRNA in liver and decreased arterial FFA and lactate concentrations (each P < 0.01). However, fenofibrate did not affect myocardial CPT-I expression, substrate uptake, lipid accumulation, or contractile function during low-flow I/R in either the low- or high-fat group, nor did it affect myocardial infarct size. Despite expression of PPAR-alpha in porcine myocardium and effects of fenofibrate on systemic metabolism, treatment with this PPAR-alpha activator does not alter myocardial metabolic or contractile responses to I/R in pigs.

In vitro effect of statins on cytokine production and mitogen response of human peripheral blood mononuclear cells

The in vitro effect of the hydrophilic statin - pravastatin - and three hydrophobic statins - atorvastatin, lovastatin and simvastatin - on the production of IL-1beta, IL-1ra, IL-2, IL-6 and IFN-gamma by human peripheral blood mononuclear cells (PBMC) and their response to mitogens was examined. Lovastatin and simvastatin increased the production of IL-1beta in a dose dependent manner and reduced secretion of IL-1ra at high concentration. These two statins exerted a dose dependent inhibitory effect on IL-2 production and reduced the secretion of IFNgamma at high dose. Atorvastatin did not affect IL-1beta, but suppressed IL-1ra, IL-2 and IFNgamma production. Atorvastatin, lovastatin and simvastatin caused a dose dependent inhibition of mitogen-induced proliferation of PBMC. IL-6 production was not affected by any one of the statins. While pravastatin caused a slight reduction in the proliferative response of PBMC to PHA, it did not affect either their response to Con A and PWM, or the secretion of cytokines tested.

Peroxisome proliferator-activated receptors and inflammation

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptors family. PPARs are a family of 3 ligand-activated transcription factors: PPARalpha (NR1C1), PPARbeta/delta (NUC1; NR1C2), and PPARgamma (NR1C3). PPARalpha, -beta/delta, and -gamma are encoded by different genes but show substantial amino acid similarity, especially within the DNA and ligand binding domains. All PPARs act as heterodimers with the 9-cis-retinoic acid receptors (retinoid X receptor; RXRs) and play important roles in the regulation of metabolic pathways, including those of lipid of biosynthesis and glucose metabolism, as well as in a variety of cell differentiation, proliferation, and apoptosis pathways. Recently, there has been a great deal of interest in the involvement of PPARs in inflammatory processes. PPAR ligands, in particular those of PPARalpha and PPARgamma, inhibit the activation of inflammatory gene expression and can negatively interfere with pro-inflammatory transcription factor signaling pathways in vascular and inflammatory cells. Furthermore, PPAR levels are differentially regulated in a variety of inflammatory disorders in man, where ligands appear to be promising new therapies.

Monocyte Release of Tumor Necrosis Factor-α and Interleukin-1β 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.

Hypolipidemic Drugs Affect Monocyte IL-1β Gene Expression and Release in Patients with IIa and IIb Dyslipidemia

Because atherosclerosis has been proven to be an inflammatory disease, it became obvious that the proper treatment of dyslipidemic patients should not only correct lipid parameters but also inhibit the inflammatory state. One of the crucial proinflammatory and procoagulant cytokines participating in the pathogenesis of atherosclerosis is interleukin-1beta (IL-1beta). Therefore, the aim of the study was to asses the effect of statin and fibrate therapy (for dyslipidemia IIa and IIb, respectively) on IL-1beta gene expression and monocyte release evaluated in each patient. Additionally, the effect of hypolipidemic therapy on fibrinolysis was evaluated. The study was carried out in 37 patients: 12 with biochemically confirmed type IIa dyslipidemia (treated with atorvastatin), 12 with type IIb dyslipidemia (treated with fenofibrate), and 13 age- and sex-matched normolipidemic persons (control). IL-1beta concentrations in cultured monocytes and PAI-1 (Plasminogen Activator Inhibitor) plasma levels were measured using the ELISA method. To evaluate the expression of IL-1beta gene in monocytes, a semiquantitive RT-PCR procedure was performed. The results were normalized with the expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a housekeeping gene. Although IL-1beta monocyte release was markedly elevated in patients with atherogenic dyslipidemias, IL-1beta gene expression was only slightly and nonsignificantly higher in the studied groups versus control. We have observed significant reduction of IL-1beta mRNA expression after 30-day treatment with the examined drugs (atorvastatin, 2.10 +/- 0.50 versus 1.05 +/- 0.15; P < 0.001, fenofibrate; 2.27 +/- 0.48 versus 1.23 +/- 0.27; P < 0.01). There was no significant difference between statin and fibrate effect on IL-1beta mRNA expression. Similarly, we have noticed significant reduction of IL-1beta release by cultured monocytes after 30-day statin therapy (133.0 +/- 5.7 pg/mL versus 77.0 +/- 3.6 pg/mL; P < 0.01) and fibrate therapy (143.9 +/- 6.5 pg/mL versus 86.2 +/- 5.9 pg/mL; P < 0.01). Besides this antiinflammatory effect, we have observed a 30% reduction of PAI-1 plasma levels in both treated groups. In conclusion, effective 1-month hypolipidemic therapy with atorvastatin or fenofibrate diminished plasma levels of proinflammatory and procoagulatory state markers.