The Combination of Interferon‐Beta and HMG‐CoA Reductase Inhibition in Multiple Sclerosis: Enthusiasm Lost too Soon?

Recent studies support the notion that statins, widely prescribed cholesterol‐lowering agents, may target key elements in the immunological cascade leading to inflammation and tissue damage in the pathogenesis of multiple sclerosis (MS). Compelling experimental and observational clinical studies highlighted the possibility that statins may also exert immunomodulatory synergy with approved MS drugs, resulting in several randomized clinical trials testing statins in combination with interferon‐beta (IFN‐β). Some data, however, suggest that this particular combination may not be clinically beneficial, and might actually have a negative effect on the disease course in some patients with MS. In this regard, a small North American trial indicated that atorvastatin administered in combination with IFN‐β may increase disease activity in relapsing‐remitting MS. Although other trials did not confirm this finding, the enthusiasm for studies with statins dwindled. This review aims to provide a comprehensive overview of the completed clinical trials and reports of the interim analyses evaluating the combination of IFN‐β and statins in MS. Moreover, we try to address the evident question whether usage of this combination routinely requires caution, since the number of IFN‐β‐treated MS patients receiving statins for lowering of cholesterol is expected to grow.     

Effects of statins on all-cause mortality at different low-density-lipoprotein cholesterol levels in Asian patients with type 2 diabetes

Objective: To investigate the effects of statins on all-cause mortality risk at different low-density lipoprotein cholesterol (LDL-C) levels, and to compare the mortality risk between statin users and non-users with identical LDL-C levels in a type 2 diabetes cohort.

Methods: In total, 10,582 outpatients aged ≥18 years with type 2 diabetes mellitus (T2DM) between 2009 and 2012 were enrolled in this retrospective cohort study in central Taiwan. All-cause mortality events were followed up until the end of 2014. According to the medical records during the follow-up period, the patients were classified into statin (+) and statin (?) groups. Patients were categorized into different LDL-C segments based on their mean LDL-C levels during the 2.8-year follow-up.

Results: Non-cardiovascular mortality accounted for more than half the deaths. Overall, statin therapy significantly reduced the all-cause mortality risk in both univariable and multivariable models (hazard ratios?=?0.39 and 0.38, respectively). Sub-group analyses showed that the lowest mortality risk occurred in the 80–89?mg/dL segment in the statin (?) group and in the 90–99?mg/dL segment in the statin (+) group. Statin therapy significantly reduced the mortality risk at all LDL-C levels except for low LDL-C (<60?mg/dL).

Conclusions: In addition to reducing LDL-C levels, statin therapy reduced all-cause mortality risk in Taiwanese patients with T2DM. Statins further reduced the mortality risk at most LDL levels. However, at low LDL-C levels, the positive effects of statins may have been nullified.     

Hypertriglyceridemia: A Review of Clinical Relevance and Treatment Options: Focus on Cerivastatin

SUMMARY

The triglyceride (TG) level is one of several lipid parameters that can aid prediction of coronary heart disease (CHD) risk. An elevated plasma TG level is strongly associated with an increased risk of CHD.

Hypertriglyceridemia, the second most common dyslipidemic abnormality in hypertensive subjects after increased low-density lipoprotein cholesterol (LDL-C), is defined by the National Cholesterol Education Programme (NCEP) as a fasting TG level of >2.26?mmol/l (>200?mg/dl) and is recognised as a primary indicator for treatment in type IIb dyslipidemia. Raised TG levels can be present in individuals at risk for CHD when the total cholesterol is normal. However, not all individuals with raised TG levels have increased risk of CHD. Factors such as: diet, age, lifestyle, and a range of medical conditions, drug therapy and metabolic disorders, can all affect the TG level. In some of these circumstances, other factors protect against the risk of CHD, and can minimise or negate the effect of the risk factors present.

Although TG reducing therapy has been shown to be associated with an improved clinical outcome, more research is needed to determine whether this is an independent effect of TG reduction or an effect of normalising the overall lipid profile in hypertriglyceridemic patients. Further trials are required to quantify the clinical benefits of lowering TG to ‘target’ levels and to confirm targets defined by NCEP-II (shown in Table 1).

The role of TG in CHD pathogenesis is thought to involve several direct and indirect mechanisms, such as effects on the metabolism of other lipoproteins, transport proteins, enzymes, and on coagulation and endothelial dysfunction. More research is required to fully elucidate the role of TG, the ways in which it can influence other risk factors and the mechanism of its own more direct role in the atherogenic process.

Patients with hypertriglyceridemia have been shown to respond well to dietary control and to the use of lipid lowering drugs such as 3-hydroxy-3-methylglutaryl-Coenzyme A (HMG CoA) reductase inhibitors (known as statins), fibrates and nicotinic acids. However, recent retrospective real-life clinical studies show that only 38% of patients receiving some form of lipid-lowering therapy achieved NCEP-defined LDL-C target levels, demonstrating the need for the use of more aggressive treatment.

In hypertriglyceridemic patients, the newer statins, cerivastatin and atorvastatin, have shown comparable efficacy in reducing TG compared with the older statins. Achieving NCEP target lipid levels has been shown to reduce the risk of cardiovascular disease in dyslipidemic individuals, including high-risk patient groups such as those with additional risk factors, existing heart disease, diabetes mellitus and metabolic syndrome.

Although the latest clinical studies investigating combination therapies, i.e. dual therapy with both a statin and a fibrate, have demonstrated them to be effective for overall control of lipid parameters and reducing coronary events, it is not yet clear whether this offers any significant advantage over monotherapy. Results from ongoing longer-term end-point clinical studies may provide further information in this area and consequent reviews of primary care management policies for dyslipidemia. Statin monotherapy may be a reliable option for primary care treatment of dyslipidemia (including hypertriglyceridemia).     

Impact of statin dosing intensity on transaminase and creatine kinase

Purpose

Higher intensity statin therapy reduces cardiovascular events more than lower intensity therapy, but the safety impact of higher intensity therapy is unknown. We performed a meta-analysis of randomized controlled trials comparing higher versus lower intensity therapy on liver and muscle safety.

Methods

A systematic literature search through January 2006 was conducted to identify randomized trials comparing higher versus lower intensity statin therapy meeting our criteria. Weighted averages were reported as relative risks (RRs) with 95% confidence intervals (random-effects model). Statistical heterogeneity scores were assessed with the Q statistic and L’Abbe plots. Publication bias was assessed with the Egger weighted regression and funnel plots.

Results

Higher intensity statin therapy increased the incidence of transaminase elevations (RR 3.10 [95% Confidence Interval [CI], 0.88-7.85]) versus lower intensity statin therapy. When studies of hydrophilic and lipophilic statins were evaluated separately, higher intensity hydrophilic statin therapy increased the risk for transaminase elevations (RR 3.54 [95% CI, 1.83-6.85]), but higher intensity lipophilic therapy did not (RR 1.58 [95% CI, 0.81-3.08]). The risk of creatine kinase (CK) elevations showed a trend toward an increase (RR 2.63 [95% CI, 0.88-7.85]) with higher intensity therapy. No occurrences of CK elevations occurred in studies evaluating hydrophilic statins, whereas lipophilic statins showed an increased risk with higher intensity therapy (RR 6.09 [95% CI, 1.36-27.35]).

Conclusions

More aggressive statin therapy increases the incidence of transaminase elevations in clinical trials versus lower intensity therapy. Increases in transaminases may be more problematic when hydrophilic statins are used aggressively, whereas CK elevations are more problematic with higher intensity lipophilic statin therapy.     

HMG-CoA reductase inhibitors deplete circulating classical and non-classical monocytes following human heart transplantation

BACKGROUND: Monocytes mediate immune responses following solid organ transplantation via cytokine secretion and differentiation to macrophage/dendritic cell lineages. To date, the pleiotropic immunomodulatory effect of statins on human monocytes following human heart transplantation has yet to be elucidated. This study was designed to assess the effects of statin administration on the monocyte repertoire. METHODS: 108 patients were recruited into the study. Clinical data were collected from patients' notes. Peripheral blood immunophenotype was determined via flow cytometry (using CD11c, CD14, CD16, CD49d, CD64, CD80 and CD195). RESULTS: There were fewer circulating classical (p=0.0001) and non-classical (p=0.0013) monocytes in patients treated with a statin. CD64 expression was down-regulated (p=0.011 and p=0.049) whereas CD49d expression was up-regulated (p=0.004 and p=0.022) on classical and non-classical monocytes in this group. Patients receiving Atorvastatin had fewer circulating classical monocytes (p=0.001) compared to patients administered Pravastatin. Patients receiving Pravastatin had fewer circulating non-classical monocytes (p=0.029) compared to patients administered Atorvastatin. DISCUSSION: Statin administration alters the circulating monocyte repertoire following heart transplantation, including population size, FcgammaRI and VLA-4 adhesion molecule expression. Furthermore, different statin treatments are associated with a selective depletion of macrophage or DC (re)generating monocytes.     

Protective effects of a squalene synthase inhibitor, lapaquistat acetate (TAK-475), on statin-induced myotoxicity in guinea pigs

High-dose statin treatment has been recommended as a primary strategy for aggressive reduction of LDL cholesterol levels and protection against coronary artery disease. The effectiveness of high-dose statins may be limited by their potential for myotoxic side effects. There is currently little known about the molecular mechanisms of statin-induced myotoxicity. Previously we showed that T-91485, an active metabolite of the squalene synthase inhibitor lapaquistat acetate (lapaquistat: a previous name is TAK-475), attenuated statin-induced cytotoxicity in human skeletal muscle cells [Nishimoto, T., Tozawa, R., Amano, Y., Wada, T., Imura, Y., Sugiyama, Y., 2003a. Comparing myotoxic effects of squalene synthase inhibitor, T-91485, and 3-hydroxy-3-methylglutaryl coenzyme A. Biochem. Pharmacol. 66, 2133-2139]. In the current study, we investigated the effects of lapaquistat administration on statin-induced myotoxicity in vivo. Guinea pigs were treated with either high-dose cerivastatin (1 mg/kg) or cerivastatin together with lapaquistat (30 mg/kg) for 14 days. Treatment with cerivastatin alone decreased plasma cholesterol levels by 45% and increased creatine kinase (CK) levels by more than 10-fold (a marker of myotoxicity). The plasma CK levels positively correlated with the severity of skeletal muscle lesions as assessed by histopathology. Co-administration of lapaquistat almost completely prevented the cerivastatin-induced myotoxicity. Administration of mevalonolactone (100 mg/kg b.i.d.) prevented the cerivastatin-induced myotoxicity, confirming that this effect is directly related to HMG-CoA reductase inhibition. These results strongly suggest that cerivastatin-induced myotoxicity is due to depletion of mevalonate derived isoprenoids. In addition, squalene synthase inhibition could potentially be used clinically to prevent statin-induced myopathy.     

Synthesis and characterization of a fluvastatin-releasing hydrogel delivery system to modulate hMSC differentiation and function for bone regeneration

Increases in bone formation have been demonstrated in mice and rats treated with statins, a group of molecules that increase the production of bone morphogenetic proteins-2 (BMP2) by stimulating its promoter. However, clinical use of statins (e.g., fluvastatin) is limited by the lack of a suitable delivery system to localize and sustain release. To harness the therapeutic effect of statins in orthopedic applications, a fluvastatin-releasing macromer was synthesized. When copolymerized with a dimethacrylated poly(ethylene glycol) solution, this fluvastatin-containing molecule was covalently incorporated into hydrogel networks, and hydrolysis of lactic acid ester bonds resulted in the release of the pendantly tethered fluvastatin from the hydrogel into the surrounding solution. The rate of fluvastatin release was controlled by the length of lactic acid spacer (2–6 repeats), and the dose was controlled by the initial comonomer composition (5–500 μg fluvastatin/gel). Released fluvastatin increased human mesenchymal stem cell (hMSC) gene expression of CBFA1, ALP, and COL I by 34-fold, 2.6-fold, and 1.8-fold, respectively, after 14 days of in vitro culture. In addition, treating hMSCs with the released fluvastatin resulted in an average of 2.0- and 1.5-fold greater BMP2 production whereas mineralization increased an average of 3.0-fold and 2.5-fold for 0.01 and 0.1 μM fluvastatin, respectively, over the 2 week culture period. Therefore, fluvastatin-releasing hydrogels may be useful in bone tissue engineering applications, not only for triggering osteogenic differentiation of hMSCs, but also by modulating their function.     

Fluvastatin enhancement of trastuzumab and classical cytotoxic agents in defined breast cancer cell lines in vitro

The combination of anticancer drugs used in the clinic has been based upon empiricism, and the potential permutations of currently available drugs overwhelm the clinical trials system. Recently, investigators have suggested that the combination of a blockade of vital signal transduction pathways in combination with more standard therapy might enhance anticancer effect. Using a panel of breast cancer cell lines and isobologram median effect analysis, a method of determining synergism or antagonism of drugs, we have investigated in vitro potentially clinically useful combinations of agents with the human cell lines MCF7/wt, MCF7/adr, BT474, and SK-BR-3 grown in log phase. Results were confirmed by curve shift analysis. Cells were exposed to the agent(s) for 72 h and then analyzed for cytotoxicity using a MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyl-tetrazolium bromide) assay. Fluvastatin, an inhibitor of prenylation with excellent tolerability in man, was chosen to disrupt signal transduction pathways and thus potentially enhance the effect of more traditional anticancer agents. Anticancer agents tested were cytotoxics used in the treatment of breast cancer, trastuzumab, and rapamycin as an inhibitor of the AKT pathway. Fluvastatin combined with trastuzumab demonstrates global synergy of cytotoxic effect that is confirmed by apoptosis assay. These effects could only be partially reversed by adding farnesol or geranylgeraniol to restore prenylation. Epirubicin is also synergistic with fluvastatin in three of the four cell lines. Rapamycin, an inhibitor of MTOR, was synergistic with fluvastatin in two of the four cell lines and antagonistic in two other cell lines. The combination of fluvastatin or another inhibitor of prenylation and trastuzumab may be attractive for clinical development as the effect of trastuzumab in Her2/neu positive breast tumors is incomplete as a single agent.     

Lipid-Altering Therapies and the Progression of Atherosclerotic Disease

Lipids play a key role in the progression of atherosclerosis, and lipid-lowering therapies have been studied for 30 years in coronary disease. Measurement of the progression of atherosclerosis through carotid intima-media thickness, coronary mean lumen diameter, and, mostly recently, intravascular ultrasound is generally accepted. This article reviews the role of lipid-lowering therapies in changing the rate of atherosclerosis progression in the coronary and carotid circulations. Statins are the primary therapy used to reduce atherosclerosis and cardiovascular events, including strokes and transient ischemic attacks, and have benefits in reducing events in patients undergoing carotid endarterectomy. In contrast, data for other agents, including fibrates and nicotinic acid, in reducing the progression of atherosclerosis are less extensive and not as well known. There is increasing interest in optimizing the whole lipid profile, as this might deliver extra benefits over and above statin therapy alone. Initial proof of this concept has recently come from studies that measured the progression of atherosclerosis and showed that adding nicotinic acid to statin therapy and, more directly, infusion of high-density lipoprotein-like particles reduced progression and indeed might induce regression of the disease. It is likely that the management of significant carotid stenosis will become ever more drug focused and will be customized to the lipid profile of each patient with intervention reserved only for late-stage symptomatic disease.     

Association of statin therapy and increased survival in patients with multiple organ dysfunction syndrome

Objective The multiple organ dysfunction syndrome (MODS) is the sequential failure of several organ systems after a trigger event, such as sepsis, pneumonia or cardiogenic shock. Even today, mortality is high. Statin therapy is associated with reduction of inflammation and subsequent rates of severe sepsis and ICU admission of patients admitted to hospital with presumed or documented acute bacterial infection. Our study aimed to characterize a potential survival benefit by statin therapy in MODS patients.Design Retrospective cohort study.Setting Twelve-bed medical intensive care unit in a university center.Patients Forty score-defined MODS patients under statin treatment and 80 age- and sex-matched score-defined MODS patients without statin treatment. Inclusion criterion was an APACHE II score ≥ 20 at admission to ICU.Interventions Assessment of statin treatment and calculation of disease severity by scoring. The patients were followed up for 28-day mortality as well as for hospital mortality.Measurements and results The MODS severity was equally pronounced in both groups. There were 42/80 deaths in the group without statin treatment and 13/40 deaths in the statin group (28-day mortality 53% vs. 33%, p = 0.03). Cox proportional hazard analysis revealed a hazard ratio of 0.53 (95% CI 0.29–0.99, p = 0.04). Hospital mortality was calculated at 72% (non-statin group) vs. 35% (statin group; chi-square  = 15.6, p < 0.0001). The overall hospital mortality was 60%.Conclusions Patients under statin treatment developing MODS might have a better outcome than patients without statin therapy, probably by reduction of inflammatory responses and increase of vagal activity in MODS.H.S. and U.M.-W. are supported by a grant of the Deutsche Forschungsgemeinschaft (SCHM 1398/3-1,-2). M.B. is supported by a grant of the Deutsche Forschungsgemeinschaft (BU 859/3-1,-2,3). There was no involvement of the founding source in study design, analysis and interpretation of the data, in writing the report and in the decision to submit the paper for publication. There is no conflict of interest inherent in the paper's content.