No effect of combined coenzyme Q10 and selenium supplementation on atorvastatin-induced myopathy

Statin treatment reduces leucine turnover, but does not affect endogenous production of beta-hydroxy-beta-methylbutyrate (HMB)

BACKGROUND

Statins, or hydroxy-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitors, are one of the most commonly prescribed medications for lowering cholesterol. Myopathic side-effects ranging from pain and soreness to critical rhabdomyolysis are commonly reported and often lead to discontinuation. The pathophysiological mechanism is, in general, ascribed to a downstream reduction of Coenzyme Q10 synthesis, resulting in mitochondrial dysfunction. HMG-CoA is a metabolite of leucine and its corresponding keto acid α-ketoisocaproic acid (KIC) and beta-hydroxy-beta-methylbutyrate (HMB), however little is known about the changes in the metabolism of leucine and its metabolites in response to statins.

OBJECTIVE

We aimed to investigate if statin treatment has implications on the upstream metabolism of leucine to KIC and HMB, as well as on other branched chain amino acids (BCAA).

DESIGN

12 hyperlipidemic older adults under statin treatment were recruited. The study was conducted as a paired prospective study. Included participants discontinued their statin treatment for 4 weeks before they returned for baseline measurements (before). Statin treatment was then reintroduced, and the participants returned for a second study day 7 days after reintroduction (after statin). On study days, participants were injected with stable isotope pulses for measurement of the whole-body production (WBP) of all BCAA (leucine, isoleucine and valine) along with their respective keto acids and HMB.

RESULTS

We found a reduced leucine WBP (22 %, p = 0.0033), along with a reduction in valine WBP (13 %, p = 0.0224). All other WBP of BCAA and keto acids were unchanged. There were no changes in the WBP of HMB.

CONCLUSIONS

Our study shows that statin inhibition of HMG-CoA reductase has an upstream impact on the turnover of leucine and valine. Whether this impairment in WBP of leucine may contribute to the known pathophysiological side effects of statins on muscle remains to be further investigated.

Selenium Levels based on Various Menopause Complaints Assessed by Menopause-specific Quality of Life Questionnaire before and after Selenium Intervention

BACKGROUND: Menopausal symptoms can greatly affect a woman’s personal, social, and work life. Selenium functions as a cofactor for glutathione peroxidase and helps minimize oxidative damage through cellular metabolism in postmenopausal women when estradiol production decreases, antioxidant protection is lost and therefore oxidative stress is increased. AIM: The aim of the study was to evaluated effect of selenium supplementation on selenium levels based on menopausal complaints assessed by menopause-specific quality of life questionnaire (MENQOL). MATERIALS AND METHODS: This research is an analytical study with quasi-experimental pre-test and post-test one group only design. The research was conducted on all postmenopausal women in Medan who were aged >51-years-old and met inclusion and exclusion criteria. The research subjects underwent blood tests to assess serum selenium levels. If data were normally distributed, dependent T test will be used, while if data were not normally distributed, Wilcoxon test will be used. The analysis results were stated to be significant with p < 0.05. RESULTS: Mean selenium serum levels before selenium administration were 93.20 ± 17.253 μg/L which increased to 132.12 ± 19.866 μg/L after selenium administration. Comparison test results of selenium levels before and after administration found p = 0.000 (p < 0.05), which means there was a significant difference of selenium serum levels before and after selenium administration. Besides that, there were no significant scores difference in aspects of vasomotor disorders (p = 1.000 [p > 0.05]), psychosocial disorders (p = 0.090 [p > 0.05]), physical disorders (p = 0.323 [p > 0.05]), and sexual disorders (p = 0.959 [p > 0.05]) between before and after selenium administration. CONCLUSION: Total MENQOL scores and complaints based on aspects of vasomotor, psychosocial, physical, and sexual disturbances did not show statistically significant changes after administration selenium tablets 100 mcg/day for 7 days.

Combined Supplementation of Coenzyme Q10 and Other Nutrients in Specific Medical Conditions

Coenzyme Q₁₀ (CoQ₁₀) is a compound with a crucial role in mitochondrial bioenergetics and membrane antioxidant protection. Despite the ubiquitous endogenous biosynthesis, specific medical conditions are associated with low circulating CoQ₁₀ levels. However, previous studies of oral CoQ₁₀ supplementation yielded inconsistent outcomes. In this article, we reviewed previous CoQ₁₀ trials, either single or in combination with other nutrients, and stratified the study participants according to their metabolic statuses and medical conditions. The CoQ₁₀ supplementation trials in elders reported many favorable outcomes. However, the single intervention was less promising when the host metabolic statuses were worsening with the likelihood of multiple nutrient insufficiencies, as in patients with an established diagnosis of metabolic or immune-related disorders. On the contrary, the mixed CoQ₁₀ supplementation with other interacting nutrients created more promising impacts in hosts with compromised nutrient reserves. Furthermore, the results of either single or combined intervention will be less promising in far-advanced conditions with established damage, such as neurodegenerative disorders or cancers. With the limited high-level evidence studies on each host metabolic category, we could only conclude that the considerations of whether to take supplementation varied by the individuals' metabolic status and their nutrient reserves. Further studies are warranted.

Coenzyme Q10 Supplementation in Statin Treated Patients: A Double-Blinded Randomized Placebo-Controlled Trial

Myalgia and new-onset of type 2 diabetes have been associated with statin treatment, which both could be linked to reduced coenzyme Q10 (CoQ10) in skeletal muscle and impaired mitochondrial function. Supplementation with CoQ10 focusing on levels of CoQ10 in skeletal muscle and mitochondrial function has not been investigated in patients treated with statins. To investigate whether concomitant administration of CoQ10 with statins increases the muscle CoQ10 levels and improves the mitochondrial function, and if changes in muscle CoQ10 levels correlate with changes in the intensity of myalgia. 37 men and women in simvastatin therapy with and without myalgia were randomized to receive 400 mg CoQ10 daily or matched placebo tablets for eight weeks. Muscle CoQ10 levels, mitochondrial respiratory capacity, mitochondrial content (using citrate synthase activity as a biomarker), and production of reactive oxygen species were measured before and after CoQ10 supplementation, and intensity of myalgia was determined using the 10 cm visual analogue scale. Muscle CoQ10 content and mitochondrial function were unaltered by CoQ10 supplementation. Individual changes in muscle CoQ10 levels were not correlated with changes in intensity of myalgia. CoQ10 supplementation had no effect on muscle CoQ10 levels or mitochondrial function and did not affect symptoms of myalgia.

Coenzyme Q10 supplementation for the treatment of statin-associated muscle symptoms

Aim: To determine the association of coenzyme Q10 (CoQ10) use with the resolution of statin-associated muscle symptoms (SAMS). Patients & methods: Retrospective analysis of a large, multicenter survey study of SAMS (total n = 511; n = 64 CoQ10 users). Univariate and multivariate logistic regression models assessed the association between CoQ10 use and the resolution of SAMS. Results: The frequency of SAMS resolution was similar between CoQ10 users and non-users (25% vs 31%, respectively; unadjusted odds ratio [OR]: 0.75 [95% CI: 0.41-1.38]; p = 0.357). Similarly, CoQ10 use was not significantly associated with the resolution of SAMS in multivariable models adjusted for SAMS risk factors (OR: 0.84 [95% CI: 0.45-1.55]; p = 0.568) or adjusted for significant differences among CoQ10 users and non-users (OR: 0.82 [95% CI: 0.45-1.51]; p = 0.522). Conclusion: CoQ10 was not significantly associated with the resolution of SAMS.

Statins: Neurobiological underpinnings and mechanisms in mood disorders

Statins (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors) treat dyslipidaemia and cardiovascular disease by inhibiting cholesterol biosynthesis. They also have immunomodulatory and anti-inflammatory properties. Beyond cardiovascular disease, cholesterol and inflammation appear to be components of the pathogenesis and pathophysiology of neuropsychiatric disorders. Statins may therefore afford some therapeutic benefit in mood disorders. In this paper, we review the pathophysiology of mood disorders with a focus on pharmacologically relevant pathways, using major depressive disorder and bipolar disorder as exemplars. Statins are discussed in the context of these disorders, with particular focus on the putative mechanisms involved in their anti-inflammatory and immunomodulatory effects. Recent clinical data suggest that statins may have antidepressant properties, however given their interactions with many known biological pathways, it has not been fully elucidated which of these are the major determinants of clinical outcomes in mood disorders. Moreover, it remains unclear what the appropriate dose, or appropriate patient phenotype for adjunctive treatment may be. High quality randomised control trials in concert with complementary biological investigations are needed if the potential clinical effects of statins on mood disorders, as well as their biological correlates, are to be better understood.

From Mitochondria to Atherosclerosis: The Inflammation Path

Inflammation is a key process in metazoan organisms due to its relevance for innate defense against infections and tissue damage. However, inflammation is also implicated in pathological processes such as atherosclerosis. Atherosclerosis is a chronic inflammatory disease of the arterial wall where unstable atherosclerotic plaque rupture causing platelet aggregation and thrombosis may compromise the arterial lumen, leading to acute or chronic ischemic syndromes. In this review, we will focus on the role of mitochondria in atherosclerosis while keeping inflammation as a link. Mitochondria are the main source of cellular energy. Under stress, mitochondria are also capable of controlling inflammation through the production of reactive oxygen species (ROS) and the release of mitochondrial components, such as mitochondrial DNA (mtDNA), into the cytoplasm or into the extracellular matrix, where they act as danger signals when recognized by innate immune receptors. Primary or secondary mitochondrial dysfunctions are associated with the initiation and progression of atherosclerosis by elevating the production of ROS, altering mitochondrial dynamics and energy supply, as well as promoting inflammation. Knowing and understanding the pathways behind mitochondrial-based inflammation in atheroma progression is essential to discovering alternative or complementary treatments.

The impact of statins on physical activity and exercise capacity: an overview of the evidence, mechanisms, and recommendations

PURPOSE

Statins are among the most widely prescribed medications worldwide. Considered the 'gold-standard' treatment for cardiovascular disease (CVD), statins inhibit HMG-CoA reductase to ultimately reduce serum LDL-cholesterol levels. Unfortunately, the main adverse event of statin use is the development of muscle-associated problems, referred to as SAMS (statin-associated muscle symptoms). While regular moderate physical activity also decreases CVD risk, there is apprehension that physical activity may induce and/or exacerbate SAMS. While much work has gone into identifying the epidemiology of SAMS, only recent research has focused on the extent to which these muscle symptoms are accompanied by functional declines. The purpose of this review is to provide an overview of possible mechanisms underlying SAMS and summarize current evidence regarding the relationship between statin treatment, physical activity, exercise capacity, and SAMS development.

METHODS

PubMed and Google Scholar databases were used to search the most relevant and up-to-date peer-reviewed research on the topic.

RESULTS

The mechanism(s) behind SAMS, including altered mitochondrial metabolism, reduced coenzyme Q10 levels, reduced vitamin D levels, impaired calcium homeostasis, elevated extracellular glutamate, and genetic polymorphisms, still lack consensus and remain up for debate. Our summation of the evidence leads us to suggest that the etiology of SAMS development is likely multifactorial. Our review also demonstrates that there is limited evidence for statins impairing exercise adaptations or reducing exercise capacity for the majority of the investigated populations.

CONCLUSION

The available evidence indicates that the benefits of engaging in physical activity while on statin medication largely outweigh the risks.

Effect of Coenzyme Q10 on statin-associated myalgia and adherence to statin therapy: A systematic review and meta-analysis

BACKGROUND AND AIMS

Statin associated muscle symptoms are common and affect adherence to statin treatment. The objective of this study was to assess whether patients with statin-associated myalgia can be successfully treated with Coenzyme Q10 (CoQ10) to improve symptoms and maintain them on statin therapy.

METHODS

This systematic review was performed in line with the 2015 PRISMA statement. Relevant studies were identified via a search of MEDLINE, EMBASE and the Cochrane Library. Studies were screened to include randomised controlled trials of oral CoQ10 supplementation versus a placebo in adults with statin-associated myalgia. Continuation of statin therapy was a secondary outcome. Risk of bias was assessed using the Cochrane Risk of Bias tool. Pooled and sensitivity analyses were performed.

RESULTS

413 records were identified by the search strategy. Eight studies were selected for review, and 7 of them (with 321 patients) were included in the meta-analysis. Selected studies were published between 2007 and 2016 with the number of participants ranging from 37 to 76. Only two of these studies demonstrated a positive effect of CoQ10 therapy in relieving muscle pain. The meta-analysis did not demonstrate any benefit of CoQ10 supplementation in improving myalgia symptoms compared to placebo (weighted mean difference -0.42; 95% Confidence Interval [CI] -1.47 to 0.62). Similarly, CoQ10 did not improve the proportion of patients remaining on the statin treatment (RR 0.99; 95%CI, 0.81 to 1.20).

CONCLUSIONS

This systematic review and meta-analysis did not demonstrate that CoQ10 supplementation was beneficial for patients with statin-associated muscle pain or improved adherence to statin therapy.

Effects of Coenzyme Q10 on Statin-Induced Myopathy: An Updated Meta-Analysis of Randomized Controlled Trials

Background Previous studies have demonstrated a possible association between the induction of coenzyme Q10 (CoQ10) after statin treatment and statin-induced myopathy. However, whether CoQ10 supplementation ameliorates statin-induced myopathy remains unclear. Methods and Results PubMed, EMBASE , and Cochrane Library were searched to identify randomized controlled trials investigating the effect of CoQ10 on statin-induced myopathy. We calculated the pooled weighted mean difference ( WMD ) using a fixed-effect model and a random-effect model to assess the effects of CoQ10 supplementation on statin-associated muscle symptoms and plasma creatine kinase. The methodological quality of the studies was determined, according to the Cochrane Handbook. Publication bias was evaluated by a funnel plot, Egger regression test, and the Begg-Mazumdar correlation test. Twelve randomized controlled trials with a total of 575 patients were enrolled; of them, 294 patients were in the CoQ10 supplementation group and 281 were in the placebo group. Compared with placebo, CoQ10 supplementation ameliorated statin-associated muscle symptoms, such as muscle pain ( WMD , -1.60; 95% confidence interval [ CI ], -1.75 to -1.44; P<0.001), muscle weakness ( WMD , -2.28; 95% CI , -2.79 to -1.77; P=0.006), muscle cramp ( WMD , -1.78; 95% CI , -2.31 to -1.24; P<0.001), and muscle tiredness ( WMD , -1.75; 95% CI , -2.31 to -1.19; P<0.001), whereas no reduction in the plasma creatine kinase level was observed after CoQ10 supplementation ( WMD , 0.09; 95% CI , -0.06 to 0.24; P=0.23). Conclusions CoQ10 supplementation ameliorated statin-associated muscle symptoms, implying that CoQ10 supplementation may be a complementary approach to manage statin-induced myopathy.

Mechanisms of statin-associated skeletal muscle-associated symptoms

Statins lower the serum low-density lipoprotein cholesterol and prevent cardiovascular events by inhibiting 3-hydroxy-3-methyl-glutaryl-CoA reductase. Although the safety of statins is documented, many patients ingesting statins may suffer from skeletal muscle-associated symptoms (SAMS). Importantly, SAMS are a common reason for stopping the treatment with statins. Statin-associated muscular symptoms include fatigue, weakness and pain, possibly accompanied by elevated serum creatine kinase activity. The most severe muscular adverse reaction is the potentially fatal rhabdomyolysis. The frequency of SAMS is variable but in up to 30% of the patients ingesting statins, depending on the population treated and the statin used. The mechanisms leading to SAMS are currently not completely clarified. Over the last 15 years, several research articles focused on statin-induced mitochondrial dysfunction as a reason for SAMS. Statins can impair the function of the mitochondrial respiratory chain, thereby reducing ATP and increasing ROS production. This can induce mitochondrial membrane permeability transition, release of cytochrome c into the cytosol and induce apoptosis. In parallel, statins inhibit activation of Akt, mainly due to reduced function of mTORC2, which may be related to mitochondrial dysfunction. Mitochondrial dysfunction by statins is also responsible for activation of AMPK, which is associated with impaired activation of mTORC1. Reduced activation of mTORC1 leads to increased skeletal muscle protein degradation, impaired protein synthesis and stimulation of apoptosis. In this paper, we discuss some of the different hypotheses how statins affect skeletal muscle in more detail, focusing particularly on those related to mitochondrial dysfunction and the impairment of the Akt/mTOR pathway.

Important drug-micronutrient interactions: A selection for clinical practice

Interactions between drugs and micronutrients have received only little or no attention in the medical and pharmaceutical world in the past. Since more and more pharmaceutics are used for the treatment of patients, this topic is increasingly relevant. As such interactions - depending on the duration of treatment and the status of micronutrients - impact the health of the patient and the action of the drugs, physicians and pharmacists should pay more attention to such interactions in the future. This review aims to sensitize physicians and pharmacists on drug micronutrient interactions with selected examples of widely pescribed drugs that can precipitate micronutrient deficiencies. In this context, the pharmacist, as a drug expert, assumes a particular role. Like no other professional in the health care sector, he is particularly predestined and called up to respond to this task. The following article intends to point out the relevance of mutual interactions between micronutrients and various examples of widely used drugs, without claiming to be exhaustive.

Statin-Associated Muscle Disease: Advances in Diagnosis and Management

Since the first approval of lovastatin in 1987, hydroxy-methyl-glutaryl CoA (HMG CoA) reductase inhibitors, or statins, have been effective and widely popular cholesterol-lowering agents with substantial benefits for the prevention and treatment of cardiovascular disease. Not all patients can tolerate these drugs, however, and statin intolerance is most frequently associated with a range of side effects directed toward skeletal muscle, termed statin-associated muscle symptoms or SAMS. SAMS are particularly difficult to treat because there are no validated biomarkers or tests that can be used to confirm patient self-reports of SAMS, and a number of patients who report SAMS have non-specific muscle pain not attributable to statin therapy. This review summarizes the most recent evidence related to diagnosis and management of SAMS. First, the range of skeletal muscle side effects associated with statin therapy is described. Second, data regarding the incidence and prevalence of SAMS, the most frequently experienced muscle side effect, are presented. Third, the most promising new techniques to confirm diagnosis of SAMS are explored. Finally, the most effective strategies for the clinical management of SAMS are summarized. Better diagnostic and treatment strategies for SAMS will increase the number of patients using these life-saving statins, thereby increasing statin adherence and reducing the costs of avoidable cardiovascular events.

Does Coenzyme Q10 Supplementation Mitigate Statin-Associated Muscle Symptoms? Pharmacological and Methodological Considerations

Statin drugs markedly reduce low-density lipoprotein cholesterol and consequently the incidence of cardiac events. In approximately 5-10% of adults, these drugs are associated with a range of muscle side effects such as muscle pain, cramping and weakness. Reduction in mitochondrial coenzyme Q10 (CoQ10), or ubiquinone, has been proposed as a mechanism for these statin-associated muscle symptoms (SAMS), and thus various formulations of CoQ10 are marketed and consumed for the prevention and treatment of SAMS. However, data supporting the efficacy of CoQ10 are equivocal, with some studies showing that CoQ10 supplementation reduces the incidence and severity of SAMS and others finding no beneficial effects of supplementation. Methodological and pharmacological issues may confound interpretation of data on this topic. For example, many patients who report SAMS, such as those who have been enrolled in previous CoQ10 studies, may be experiencing non-specific (non-statin-associated) muscle pain. In addition, the effectiveness of oral CoQ10 supplementation to increase mitochondrial CoQ10 in human skeletal muscle is not well established. This manuscript will critically evaluate the published data on the efficacy of CoQ10 supplements in the prevention and treatment of SAMS.

Histopathologic and Biochemical Evidence for Mitochondrial Disease Among 279 Patients with Severe Statin Myopathy

BACKGROUND

Statins have well-known benefits in the prevention of cardiovascular disease, however, 7-29% of patients develop muscle side effects and up to 0.5% develop severe symptoms. Mitochondrial dysfunction has been associated with severe statin-induced myopathy (SM); however, there is a paucity of systematic studies in affected individuals.

OBJECTIVES

The goal of this study was to combine clinical and laboratory features with quantitative biochemical and histopathologic studies of skeletal muscle biopsies from SM cases to determine what proportion could be attributed to mitochondrial dysfunction and how many of these had primary respiratory chain defects.

METHODS

A retrospective analysis was performed on patient records derived from 279 SM patients whose muscle biopsies were referred to our clinical diagnostic laboratory for analysis. Clinical, histopathologic and biochemical features were compared with two myopathic control groups unexposed to statins: individuals with idiopathic mitochondrial myopathy (MMP; n = 94) and with unknown metabolic myopathy (UMP; n = 86); normal controls were unavailable for this record review study.

RESULTS

More SM patients had significantly elevated plasma CK than in the other two groups (p < 0.01). A subset of SM patients (67 of 279; 24%) had histopathologic and/or electron microscopic (EM) evidence for mitochondrial dysfunction in skeletal muscle; more cases were identified by EM than by histochemical analysis. Of 279 cases, 29 (10%) were confirmed to have respiratory chain defects by biochemical analysis; 4 of these had mitochondrial abnormalities by EM. An additional 20 cases had mitochondrial abnormalities by EM without a biochemical diagnosis.

CONCLUSIONS

Both primary and secondary mitochondrial dysfunction was found in subsets of SM patients. The fact that respiratory chain defects were not found in most cases with histopathologic mitochondrial abnormalities does not rule out primary mitochondrial disease in these cases, however, it is more likely that secondary effects on mitochondrial structure and function have occurred; molecular analysis may be helpful only in a small number of cases.

A Peculiar Formula of Essential Amino Acids Prevents Rosuvastatin Myopathy in Mice

AIMS

Myopathy, characterized by mitochondrial oxidative stress, occurs in ∼10% of statin-treated patients, and a major risk exists with potent statins such as rosuvastatin (Rvs). We sought to determine whether a peculiar branched-chain amino acid-enriched mixture (BCAAem), found to improve mitochondrial function and reduce oxidative stress in muscle of middle-aged mice, was able to prevent Rvs myopathy.

RESULTS

Dietary supplementation of BCAAem was able to prevent the structural and functional alterations of muscle induced by Rvs in young mice. Rvs-increased plasma 3-methylhistidine (a marker of muscular protein degradation) was prevented by BCAAem. This was obtained without changes of Rvs ability to reduce cholesterol and triglyceride levels in blood. Rather, BCAAem promotes de novo protein synthesis and reduces proteolysis in cultured myotubes. Morphological alterations of C2C12 cells induced by statin were counteracted by amino acids, as were the Rvs-increased atrogin-1 mRNA and protein levels. Moreover, BCAAem maintained mitochondrial mass and density and citrate synthase activity in skeletal muscle of Rvs-treated mice beside oxygen consumption and ATP levels in C2C12 cells exposed to statin. Notably, BCAAem assisted Rvs to reduce oxidative stress and to increase the anti-reactive oxygen species (ROS) defense system in skeletal muscle. Innovation and Conclusions: The complex interplay between proteostasis and antioxidant properties may underlie the mechanism by which a specific amino acid formula preserves mitochondrial efficiency and muscle health in Rvs-treated mice. Strategies aimed at promoting protein balance and controlling mitochondrial ROS level may be used as therapeutics for the treatment of muscular diseases involving mitochondrial dysfunction, such as statin myopathy. Antioxid. Redox Signal. 25, 595-608.

The role of mitochondria in statin-induced myopathy

BACKGROUND

Statins inhibit hydroxymethylglutaryl-coenzyme A reductase, decrease plasma low-density lipoprotein cholesterol and reduce cardiovascular morbidity and mortality. They can also exert adverse effects, mostly affecting skeletal muscle, ranging from mild myalgia to rhabdomyolysis.

MATERIALS AND METHODS

Based on a PubMed search until December 2014, this review summarizes studies on statin effects on muscle mitochondrial morphology and function in the context of myopathy.

RESULTS

Possible mechanisms of statin-induced myopathy include lower cholesterol synthesis and production of prenylated proteins, reduced dolichols and increased atrogin-1 expression. Statin-treated patients frequently feature decreased muscle coenzyme Q10 (CoQ10) contents, suggesting that statins might impair mitochondrial function. In cell cultures, statins diminish muscle oxygen consumption, promote mitochondrial permeability transient pore opening and generate apoptotic proteins. Animal models confirm the statin-induced decrease in muscle CoQ10, but reveal no changes in mitochondrial enzyme activities. Human studies yield contradictory results, with decreased CoQ10, elevated lipids, decreased enzyme activities in muscle and impaired maximal oxygen uptake in several but not all studies. Some patients are susceptible to statin-induced myopathy due to variations in genes encoding proteins involved in statin uptake and biotransformation such as the solute carrier organic anion transporter family member 1B1 (SLCO1B1) or cytochrome P450 (CYP2D6, CYP3A4, CYP3A5). Carriers for carnitine palmitoyltransferase II deficiency and McArdle disease also present with higher prevalence of statin-induced myopathy.

CONCLUSIONS

Despite the widespread use of statins, the pathogenesis of statin-induced myopathy remains unclear, requiring prospective randomized controlled trials with intensive phenotyping also for identifying strategies for its risk assessment, prevention and treatment.

Muscle-related side-effects of statins: from mechanisms to evidence-based solutions

PURPOSE OF REVIEW

This article highlights the recent findings regarding statin-associated muscle side effects, including mechanisms and treatment as well as the need for more comprehensive clinical trials in statin myalgia.

RECENT FINDINGS

Statin myalgia is difficult to diagnose and treat, as major clinical trials have not routinely assessed muscle side-effects, there are few clinically relevant biomarkers and assessment tools for the symptoms, many apparent statin-related muscle symptoms may be nonspecific and related to other drugs or health conditions, and prevalence estimates vary widely. Data thus suggest that only 30-50% of patients with self-reported statin myalgia actually experience muscle pain on statins during blinded, placebo-controlled trials. In addition, evidence to date involving mechanisms underlying statin myalgia and its range of symptoms and presentations supports the hypothesis that there are multiple, interactive and potentially additive mechanisms underlying statin-associated muscle side-effects.

SUMMARY

There are likely multiple and interactive mechanisms underlying statin myalgia, and recent studies have produced equivocal data regarding prevalence of statin-associated muscle side-effects, contributing factors and effectiveness of common interventions. Therefore, more clinical trials on statin myalgia are critical to the field, as are systematic resources for quantifying, predicting and reporting statin-associated muscle side-effects.

Coenzyme Q10 and statin-related myopathy

Statins inhibit the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, which is involved in the production of mevalonic acid in the cholesterol biosynthesis pathway. This pathway also results in the production of other bioactive molecules including coenzyme Q10 (also known as ubiquinone or ubidecarenone). Coenzyme Q10 is a naturally-occurring coenzyme with antioxidant effects that is involved in electron transport in mitochondria and is thought to play a role in energy transfer in skeletal muscle. Muscle-related problems are a frequently reported adverse effect of statins, and it has been hypothesised that a reduced endogenous coenzyme Q10 concentration is a cause of statin-induced myopathy. Coenzyme Q10 supplementation has therefore been proposed to reduce the adverse muscular effects sometimes seen with statins. Here, we consider whether coenzyme Q10 has a place in the management of statin-induced myopathy.

Lipid-lowering efficacy of atorvastatin

BACKGROUND

This represents the first update of this review, which was published in 2012. Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

Primary objective To quantify the effects of various doses of atorvastatin on serum total cholesterol, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol and triglycerides in individuals with and without evidence of cardiovascular disease. The primary focus of this review was determination of the mean per cent change from baseline of LDL-cholesterol. Secondary objectives • To quantify the variability of effects of various doses of atorvastatin.• To quantify withdrawals due to adverse effects (WDAEs) in placebo-controlled randomised controlled trials (RCTs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 11, 2013), MEDLINE (1966 to December Week 2 2013), EMBASE (1980 to December Week 2 2013), Web of Science (1899 to December Week 2 2013) and BIOSIS Previews (1969 to December Week 2 2013). We applied no language restrictions.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of three to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included and extracted data. We collected information on withdrawals due to adverse effects from placebo-controlled trials.

MAIN RESULTS

In this update, we found an additional 42 trials and added them to the original 254 studies. The update consists of 296 trials that evaluated dose-related efficacy of atorvastatin in 38,817 participants. Included are 242 before-and-after trials and 54 placebo-controlled RCTs. Log dose-response data from both trial designs revealed linear dose-related effects on blood total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides. The Summary of findings table 1 documents the effect of atorvastatin on LDL-cholesterol over the dose range of 10 to 80 mg/d, which is the range for which this systematic review acquired the greatest quantity of data. Over this range, blood LDL-cholesterol is decreased by 37.1% to 51.7% (Summary of findings table 1). The slope of dose-related effects on cholesterol and LDL-cholesterol was similar for atorvastatin and rosuvastatin, but rosuvastatin is about three-fold more potent. Subgroup analyses suggested that the atorvastatin effect was greater in females than in males and was greater in non-familial than in familial hypercholesterolaemia. Risk of bias for the outcome of withdrawals due to adverse effects (WDAEs) was high, but the mostly unclear risk of bias was judged unlikely to affect lipid measurements. Withdrawals due to adverse effects were not statistically significantly different between atorvastatin and placebo groups in these short-term trials (risk ratio 0.98, 95% confidence interval 0.68 to 1.40).

AUTHORS' CONCLUSIONS

This update resulted in no change to the main conclusions of the review but significantly increases the strength of the evidence. Studies show that atorvastatin decreases blood total cholesterol and LDL-cholesterol in a linear dose-related manner over the commonly prescribed dose range. New findings include that atorvastatin is more than three-fold less potent than rosuvastatin, and that the cholesterol-lowering effects of atorvastatin are greater in females than in males and greater in non-familial than in familial hypercholesterolaemia. This review update does not provide a good estimate of the incidence of harms associated with atorvastatin because included trials were of short duration and adverse effects were not reported in 37% of placebo-controlled trials.

Selenium and coenzyme Q10 interrelationship in cardiovascular diseases--A clinician's point of view

A short review is given of the potential role of selenium deficiency and selenium intervention trials in atherosclerotic heart disease. Selenium is an essential constituent of several proteins, including the glutathione peroxidases and selenoprotein P. The selenium intake in Europe is generally in the lower margin of recommendations from authorities. Segments of populations in Europe may thus have a deficient intake that may be presented by a deficient anti-oxidative capacity in various illnesses, in particular atherosclerotic disease, and this may influence the prognosis of the disease. Ischemic heart disease and heart failure are two conditions where increased oxidative stress has been convincingly demonstrated. Some of the intervention studies of anti-oxidative substances that have focused on selenium are discussed in this review. The interrelationship between selenium and coenzyme Q10, another anti-oxidant, is presented, pointing to a theoretical advantage in using both substances in an intervention if there are deficiencies within the population. Clinical results from an intervention study using both selenium and coenzyme Q10 in an elderly population are discussed, where reduction in cardiovascular mortality, a better cardiac function according to echocardiography, and finally a lower concentration of the biomarker NT-proBNP as a sign of lower myocardial wall tension could be seen in those on active treatment, compared to placebo.

Effects of coenzyme Q10 on statin-induced myopathy: a meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the efficacy of coenzyme Q10 (CoQ10) supplementation on statin-induced myopathy.

PARTICIPANTS AND METHODS

We searched the MEDLINE, Cochrane Library, Scopus, and EMBASE databases (November 1, 1987, to May 1, 2014) to identify randomized controlled trials investigating the impact of CoQ10 on muscle pain and plasma creatine kinase (CK) activity as 2 measures of statin-induced myalgia. Two independent reviewers extracted data on study characteristics, methods, and outcomes.

RESULTS

We included 6 studies with 302 patients receiving statin therapy: 5 studies with 226 participants evaluated the effect of CoQ10 supplementation on plasma CK activity, and 5 studies (4 used in the CK analysis and 1 other study) with 253 participants were included to assess the effect of CoQ10 supplementation on muscle pain. Compared with the control group, plasma CK activity was increased after CoQ10 supplementation, but this change was not significant (mean difference, 11.69 U/L [to convert to μkat/L, multiply by 0.0167]; 95% CI, -14.25 to 37.63 U/L; P=.38). Likewise, CoQ10 supplementation had no significant effect on muscle pain despite a trend toward a decrease (standardized mean difference, -0.53; 95% CI, -1.33 to 0.28; P=.20). No dose-effect association between changes in plasma CK activity (slope, -0.001; 95% CI, -0.004 to 0.001; P=.33) or in the indices of muscle pain (slope, 0.002; 95% CI, -0.005 to 0.010; P=.67) and administered doses of CoQ10 were observed.

CONCLUSION

The results of this meta-analysis of available randomized controlled trials do not suggest any significant benefit of CoQ10 supplementation in improving statin-induced myopathy. Larger, well-designed trials are necessary to confirm the findings from this meta-analysis.

A randomized trial of coenzyme Q10 in patients with confirmed statin myopathy

BACKGROUND

Coenzyme Q10 (CoQ10) supplementation is the most popular therapy for statin myalgia among both physicians and patients despite limited and conflicting evidence of its efficacy.

OBJECTIVE

This study examined the effect of coenzyme Q10 (CoQ10) supplementation on simvastatin-associated muscle pain, muscle strength and aerobic performance in patients with confirmed statin myalgia.

METHODS

Statin myalgia was confirmed in 120 patients with prior symptoms of statin myalgia using an 8-week randomized, double-blind crossover trial of simvastatin 20 mg/d and placebo. Forty-one subjects developed muscle pain with simvastatin but not with placebo and were randomized to simvastatin 20 mg/d combined with CoQ10 (600 mg/d ubiquinol) or placebo for 8 weeks. Muscle pain (Brief Pain Inventory [BPI]), time to pain onset, arm and leg muscle strength, and maximal oxygen uptake (VO2max) were measured before and after each treatment.

RESULTS

Serum CoQ10 increased from 1.3 ± 0.4 to 5.2 ± 2.3 mcg/mL with simvastatin and CoQ10, but did not increase with simvastatin and placebo (1.3 ± 0.3 to 0.8 ± 0.2) (p < 0.05). BPI pain severity and interference scores increased with simvastatin therapy (both p < 0.01), irrespective of CoQ10 assignment (p = 0.53 and 0.56). There were no changes in muscle strength or VO2max with simvastatin with or without CoQ10 (all p > 0.10). Marginally more subjects reported pain with CoQ10 (14 of 20 vs 7 of 18; p = 0.05). There was no difference in time to pain onset in the CoQ10 (3.0 ± 2.0 weeks) vs. placebo (2.4 ± 2.1 wks) groups (p = 0.55). A similar lack of CoQ10 effect was observed in 24 subjects who were then crossed over to the alternative treatment.

CONCLUSIONS

Only 36% of patients complaining of statin myalgia develop symptoms during a randomized, double-blind crossover of statin vs placebo. CoQ10 supplementation does not reduce muscle pain in patients with statin myalgia. Trial RegistrationNCT01140308; www.clinicaltrials.gov.

An assessment by the Statin Muscle Safety Task Force: 2014 update

The National Lipid Association's Muscle Safety Expert Panel was charged with the duty of examining the definitions for statin-associated muscle adverse events, development of a clinical index to assess myalgia, and the use of diagnostic neuromuscular studies to investigate muscle adverse events. We provide guidance as to when a patient should be considered for referral to neuromuscular specialists and indications for the performance of a skeletal muscle biopsy. Based on this review of evidence, we developed an algorithm for the evaluation and treatment of patients who may be intolerant to statins as the result of adverse muscle events. The panel was composed of clinical cardiologists, clinical lipidologists, an exercise physiologist, and a neuromuscular specialist.

Overcoming toxicity and side-effects of lipid-lowering therapies

Lowering serum lipid levels is part of the foundation of treating and preventing clinically significant cardiovascular disease. Recently, the American Heart Association/American College of Cardiology released cholesterol guidelines which advocate for high efficacy statins rather than LDL-c goals for five patient subgroups at high risk for cardiovascular disease. Therefore, it is critical that clinicians have an approach for managing side-effects of statin therapy. Statins are associated with myopathy, transaminase elevations, and an increased risk of incident diabetes mellitus among some patients; connections between statins and other processes, such as renal and neurologic function, have also been studied with mixed results. Statin-related adverse effects might be minimized by careful assessment of patient risk factors. Strategies to continue statin therapy despite adverse effects include switching to another statin at a lower dose and titrating up, giving intermittent doses of statins, and adding non-statin agents. Non-statin lipid-lowering drugs have their own unique limitations. Management strategies and algorithms for statin-associated toxicities are available to help guide clinicians. Clinical practice should emphasize tailoring therapy to address each individual's cholesterol goals and risk of developing adverse effects on lipid-lowering drugs.

Toxic myopathies

PURPOSE

This article reviews the most important muscle toxins, many of which are widely prescribed medications. Particular emphasis is placed on statins, which cause muscle symptoms in a relatively large proportion of the patients who take them.

RECENT FINDINGS

As with other toxic myopathies, most cases of statin-associated myotoxicity are self-limited and subside with discontinuation of the offending agent. Importantly, about 2% of the population is homozygous for a single nucleotide polymorphism, and these individuals have a dramatically increased risk of self-limited statin myopathy. Much more rarely, statins trigger a progressive autoimmune myopathy characterized by a necrotizing muscle biopsy and autoantibodies recognizing hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase, the pharmacologic target of statins.

SUMMARY

In most cases, toxic myopathies resolve after the toxic agent is stopped. Recognizing that statins can cause an autoimmune necrotizing myopathy is important because patients with this form of statin-triggered muscle disease usually require immunosuppressive therapy.

Lipid lowering efficacy of atorvastatin

BACKGROUND

Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

To quantify the dose-related effects of atorvastatin on blood lipids and withdrawals due to adverse effects (WDAE).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library Issue 4, 2011, MEDLINE (1966 to November 2011), EMBASE (1980 to November 2011), ISI Web of Science (1899 to November 2011) and BIOSIS Previews (1969 to November 2011). No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of 3 to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. WDAE information was collected from the placebo-controlled trials.

MAIN RESULTS

Two hundred fifty-four trials evaluated the dose-related efficacy of atorvastatin in 33,505 participants. Log dose-response data revealed linear dose-related effects on blood total cholesterol, low-density lipoprotein (LDL)-cholesterol and triglycerides. Combining all the trials using the generic inverse variance fixed-effect model for doses of 10 to 80 mg/day resulted in decreases of 36% to 53% for LDL-cholesterol. There was no significant dose-related effects of atorvastatin on blood high-density lipoprotein (HDL)-cholesterol. WDAE were not statistically different between atorvastatin and placebo for these short-term trials (risk ratio 0.99; 95% confidence interval 0.68 to 1.45).

AUTHORS' CONCLUSIONS

Blood total cholesterol, LDL-cholesterol and triglyceride lowering effect of atorvastatin was dependent on dose. Log dose-response data was linear over the commonly prescribed dose range. Manufacturer-recommended atorvastatin doses of 10 to 80 mg/day resulted in 36% to 53% decreases of LDL-cholesterol. The review did not provide a good estimate of the incidence of harms associated with atorvastatin because of the short duration of the trials and the lack of reporting of adverse effects in 37% of the placebo-controlled trials.