Diagnosis, prevention, and management of statin adverse effects and intolerance: Canadian Working Group Consensus update

Niacin as antidyslipidemic drug

Niacin is an important vitamin (B3) that can be used in gram doses to positively modify pathogenetically relevant lipid disorders: elevated LDL cholesterol, elevated non-HDL cholesterol, elevated triglycerides, elevated lipoprotein(a), and reduced HDL cholesterol. This review reports the latest published findings with respect to niacin's mechanisms of action on these lipids and its anti-inflammatory and anti-atherosclerotic effects. In the pre-statin era, niacin was shown to have beneficial effects on cardiovascular end-points; but in recent years, two major studies performed in patients whose LDL cholesterol levels had been optimized by a statin therapy did not demonstrate an additional significant effect on these end-points in the groups where niacin was administered. Both studies have several drawbacks that suggest that they are not representative for other patients. Thus, niacin still plays a role either as an additive to a statin or as a substitute for a statin in statin-intolerant patients. Moreover, patients with elevated triglyceride and low HDL cholesterol levels and patients with elevated lipoprotein(a) concentrations will possibly benefit from niacin, although currently the study evidence for these indications is rather poor. Niacin may be useful for compliant patients, however possible side effects (flushing, liver damage) and contraindications should be taken into consideration.

Genetic and immunologic susceptibility to statin-related myopathy

Statin-related myopathy (SRM) undermines drug adherence that is critical for achieving the benefits of lipid-lowering therapy. While the exact mechanism of SRM remains largely unknown, recent evidence supports specific genetic and immunologic influence on the development of intolerance. Genes of interest include those involved in the pharmacokinetics of statin response (i.e. drug metabolism, uptake transporters, and efflux transporters), pharmacodynamics (i.e. drug toxicity and immune-mediated myopathy), and gene expression. We examine the influence of genetic and immunologic variation on the pharmacokinetics, pharmacodynamics, and gene expression of SRM.

Statin intolerance - an attempt at a unified definition. Position paper from an International Lipid Expert Panel

Statins are one of the most commonly prescribed drugs in clinical practice. They are usually well tolerated and effectively prevent cardiovascular events. Most adverse effects associated with statin therapy are muscle-related. The recent statement of the European Atherosclerosis Society (EAS) has focused on statin associated muscle symptoms (SAMS), and avoided the use of the term 'statin intolerance'. Although muscle syndromes are the most common adverse effects observed after statin therapy, excluding other side effects might underestimate the number of patients with statin intolerance, which might be observed in 10-15% of patients. In clinical practice, statin intolerance limits effective treatment of patients at risk of, or with, cardiovascular disease. Knowledge of the most common adverse effects of statin therapy that might cause statin intolerance and the clear definition of this phenomenon is crucial to effectively treat patients with lipid disorders. Therefore, the aim of this position paper was to suggest a unified definition of statin intolerance, and to complement the recent EAS statement on SAMS, where the pathophysiology, diagnosis and the management were comprehensively presented.

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.

The effect of infrequent low-dose rosuvastatin on the lipid profile

We retrospectively studied 21 patients who had difficulty tolerating daily or alternating-day statins. Patients received rosuvastatin at a mean frequency of 1.7 doses per week, and a mean dose of 11.7 mg per week. We assessed lipid profiles at baseline and after at least 3 months of therapy. We found that total and low-density lipoprotein cholesterol were reduced by 2.03 ± 2.04 and 1.31 ± 0.83 mmol/L (27.9% and 31.5%), respectively, from baseline (both P < 0.001). Thus, in patients with statin intolerance, infrequent low-dose rosuvastatin significantly improved low-density lipoprotein cholesterol and was well tolerated over the long term.

Coenzyme Q10 supplementation decreases statin-related mild-to-moderate muscle symptoms: a randomized clinical study

Background

Statin use is frequently associated with muscle-related symptoms. Coenzyme Q10 supplementation has yielded conflicting results in decreasing statin myopathy. Herein, we tested whether coenzyme Q10 supplementation could decrease statin-associated muscular pain in a specific group of patients with mild-to-moderate muscle symptoms.

Material/Methods

Fifty patients treated with statins and reporting muscle pain were recruited. The Q10 group (n=25) received coenzyme Q10 supplementation over a period of 30 days (50 mg twice daily), and the control group (n=25) received placebo. The Brief Pain Inventory (BPI) questionnaire was used and blood testing was performed at inclusion in the study and after 30 days of supplementation.

Results

The intensity of muscle pain, measured as the Pain Severity Score (PSS), in the Q10 group was reduced from 3.9±0.4 to 2.9±0.4 (P<0.001). The Pain Interference Score (PIS) after Q10 supplementation was reduced from 4.0±0.4 to 2.6±0.4 (P<0.001). In the placebo group, PSS and PIS did not change. Coenzyme Q10 supplementation decreased statin-related muscle symptoms in 75% of patients. The relative values of PSS and PIS significantly decreased (−33.1% and −40.3%, respectively) in the Q10 group compared to placebo group (both P<0.05). From baseline, no differences in liver and muscle enzymes or cholesterol values were found.

Conclusions

The present results show that coenzyme Q10 supplementation (50 mg twice daily) effectively reduced statin-related mild-to-moderate muscular symptoms, causing lower interference of statin-related muscular symptoms with daily activities.

Dietary supplementation with essential amino acids boosts the beneficial effects of rosuvastatin on mouse kidney

The effects of high-potency statins on renal function are controversial. To address the impact of statins on renal morpho-functional aspects, normotensive young mice were treated with rosuvastatin (Rvs). Moreover, because statins may impair mitochondrial function, mice received either dietary supplementation with an amino acid mixture enriched in essential amino acids (EAAm), which we previously demonstrated to increase mitochondrial biogenesis in muscle or an unsupplemented control diet for 1 month. Mitochondrial biogenesis and function, apoptosis, and insulin signaling pathway events were studied, primarily in cortical proximal tubules. By electron microscopy analysis, mitochondria were more abundant and more heterogeneous in size, with dense granules in the inner matrix, in Rvs- and Rvs plus EAAm-treated animals. Rvs administration increased protein kinase B and endothelial nitric oxide synthase phosphorylation, but the mammalian target of rapamycin signaling pathway was not affected. Rvs increased the expression of sirtuin 1, peroxisome proliferator-activated receptor γ coactivator-1α, cytochrome oxidase type IV, cytochrome c, and mitochondrial biogenesis markers. Levels of glucose-regulated protein 75 (Grp75), B-cell lymphoma 2, and cyclin-dependent kinase inhibitor 1 were increased in cortical proximal tubules, and expression of the endoplasmic reticulum-mitochondrial chaperone Grp78 was decreased. EAAm supplementation maintained or enhanced these changes. Rvs promotes mitochondrial biogenesis, with a probable anti-apoptotic effect. EAAm boosts these processes and may contribute to the efficient control of cellular energetics and survival in the mouse kidney. This suggests that appropriate nutritional interventions may enhance the beneficial actions of Rvs, and could potentially prevent chronic renal side effects.

Improving lipid control following myocardial infarction

PURPOSE OF REVIEW

Following a myocardial infarction, lipid-lowering therapy is an established intervention to reduce the risk of recurrent cardiovascular events. Prior studies show a need to improve clinical practice in this area. Here, we review the latest research and perspectives on improving postmyocardial infarction lipid control.

RECENT FINDINGS

Dyslipidemia and myocardial infarction remain leading causes of global disability and premature mortality throughout the world. The processes of care in lipid control involve multiple patient-level, provider-level, and healthcare system-level factors. They can be challenging to coordinate. Recent studies show suboptimal use of early high-intensity statin therapy and overall lipid control following myocardial infarction. Encouragingly, lipid control has improved over the last decade. Implementation science has identified checklists as an effective tool. At the top of the checklist for reducing atherogenic lipids and recurrent event risk postmyocardial infarction is early high-intensity statin therapy. Smoking cessation and participation in cardiac rehabilitation are also priorities, as are lifestyle counseling, promotion of medication adherence, ongoing lipid surveillance, and medication management.

SUMMARY

Optimizing lipid control could further enhance clinical outcomes after myocardial infarction.

Pharmacogenomics, lipid disorders, and treatment options

Statins form the backbone of lipid-lowering therapy in the prevention of cardiovascular disease. Numerous studies have evaluated the effect of genomics on the clinical efficacy and adverse effects of statins. Several gene variants that can be linked to either the pharmacokinetics or pharmacodynamics of statins have been identified as potentially important, although there are some discrepant findings among studies. Effect sizes are modest for lipid-lowering efficacy and perhaps somewhat larger for risk of myopathy, although results are inconsistent. Pharmacogenomics of nonstatin lipid-lowering agents have not been evaluated to the same extent, given their relatively limited use, although there are some promising candidate genes for further study. Finally, with several new classes of lipid-lowering therapies soon becoming available, there may be a potential application for pharmacogenomics to identify patients ideally suited to receive-or those who should avoid-specific medications.

Simvastatin dose and risk of rhabdomyolysis: nested case-control study based on national health and drug dispensing data

BACKGROUND

Two randomised controlled trials have found a higher risk of rhabdomyolysis in users of 80 mg versus 20 mg simvastatin, but there is very limited information about the risk associated with other doses. We undertook a nested case-control study, using routinely collected national health and drug dispensing data, to estimate the relative and absolute risks of rhabdomyolysis resulting in hospital admission or death according to simvastatin dose.

METHODS AND RESULTS

The underlying study cohort comprised all patients (n=313,552) who initiated a new episode of simvastatin use in New Zealand between 1 May 2005 and 31 December 2009. Cases (n=29) were patients with a diagnosis of rhabdomyolysis after cohort entry, confirmed by hospital discharge letter or death records. Ten controls, matched by year of birth and sex, were randomly selected from the study cohort using risk set sampling. Current users of 40 mg simvastatin daily were about five times as likely to develop rhabdomyolysis as those taking 20mg; the adjusted odds ratio was 5.3 (95% CI 1.9-15.0). The absolute excess risk of rhabdomyolysis associated with the use of 40 mg versus 20mg was about 10 per 100,000 person-years; the crude incidence rates were 11.5 (95% CI 7.1-17.5) and 2.1 (95% CI 0.7-4.8) per 100,000 person-years respectively.

CONCLUSIONS

These findings provide reassurance that the absolute risk of rhabdomyolysis in a general population of simvastatin users is very low. Nonetheless, they also raise questions about the optimal simvastatin regimen to maximise cardiovascular benefits and minimise the risk of serious muscle injury.

Effects of Campomanesia xanthocarpa on inflammatory processes, oxidative stress, endothelial dysfunction and lipid biomarkers in hypercholesterolemic individuals

In Brazil, the edible plant Campomanesia xanthocarpa Berg. (Myrtaceae), popularly known as "guavirova," has been studied in hypercholesterolemic individuals. The present work investigated the effects of C. xanthocarpa on inflammatory processes, oxidative stress, endothelial dysfunction and lipid biomarkers in hypercholesterolemic individuals. A total of 156 individuals were selected in a double-blind fashion and randomly divided into two groups in accordance with the intervals used in the criteria for hypercholesterolemia: individuals with total cholesterol (TC) levels between 200 and 240 mg/dL (undesirable level individuals - UL) and individuals with TC levels >240 mg/dL (hypercholesterolemic individuals - HL). Both groups had a control group (CG), which received placebo treatment, an encapsulated excipient group (lactose) and an experimental group that received 500 mg (EG 500), 750 mg (EG 750) or 1000 mg (EG 1000) of encapsulated C. xanthocarpa. The inflammatory processes (high-sensitivity C-reactive protein - hs-CRP), oxidative stress (advanced oxidation protein products-AOPPs; ischemia-modified albumin-IMA), endothelial dysfunction (nitric oxide - NOx) and biochemical (TC, triglycerides, high-density lipoprotein - HDL, low-density lipoproteins - LDL, and very low-density lipoprotein - VLDL) parameters were measured before and 90 days after the initiation of treatment. A significant decrease in TC and LDL levels was observed in HL individuals from the EG 500 group (reduction of 29 ± 3% and 41 ± 5% to levels before treatment) compared to the CG group individuals. A significant reduction in oxidative stress and inflammatory process components (reduction of 52 ± 11% in AOPPs, 32 ± 10% in IMA and 57 ± 7% in hs-CRP) and a significant increase in NOx (increase of 84 ± 27%) was observed in HL individuals in the EG 1000 group when compared to the CG group individuals. Treatment with encapsulated C. xanthocarpa reduced blood TC and LDL levels in hypercholesterolemic individuals. In addition to its effect on cholesterol levels, this plant reduced oxidative stress in hypercholesterolemic individuals and improved the levels of NOx.