Increases in creatine kinase with atorvastatin treatment are not associated with decreases in muscular performance

Pitavastatin Is Well-Tolerated With no Detrimental Effects on Physical Function

BACKGROUND

Little is known about the potential benefits or harms of statins on physical function among people with human immunodeficiency virus (PWH).

METHODS

REPRIEVE was a double-blind randomized controlled trial evaluating pitavastatin for primary prevention of major adverse cardiovascular events in PWH. Time to complete 10 chair rises, 4-m gait speed, grip strength, and a modified short physical performance test were assessed annually for up to 5 years in the ancillary study PREPARE and analyzed using linear mixed models.

FINDINGS

Of 602 PWH, 52% were randomized to pitavastatin and 48% to placebo. Median age was 51 years; 18% were female at birth; 2% transgender; and 40% Black, and 18% Hispanic. Median PREPARE follow-up was 4.7 (4.3-5.0) years. Muscle symptoms (grade ≥3 or treatment-limiting) occurred in 5% of both groups. There was no evidence of decline in chair rise rate in either treatment group and no difference in the pitavastatin group compared to placebo (estimated difference -0.10 [95% confidence interval, -.30 to 0.10] rises/min/year; P = .31). Small declines over time were observed in other physical function tests in both treatment groups, with no apparent differences between groups.

INTERPRETATION

We observed minimal declines in physical function over 5 years of follow-up among middle-aged PWH, with no differences among PWH randomized to pitavastatin compared to placebo. This finding, combined with low prevalence of myalgias, supports the long-term safety of statin therapy on physical function, when used for primary prevention of major adverse cardiovascular events among PWH.

CYP3A4*1B and CYP3A5*3 SNPs significantly impact the response of Egyptian candidates to high-intensity statin therapy to atorvastatin

BACKGROUND

A single nucleotide polymorphism (SNP) is a variation in the DNA sequence that results from the alteration of a single nucleotide in the genome. Atorvastatin is used to treat hypercholesterolemia. It belongs to a class of drugs called statins, which lower elevated levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). Research findings on the associations between the response to atorvastatin and genetic polymorphisms in CYP3A4 and CYP3A5 are inconclusive. The effects of CYP3A4*1B (rs2740574 C/T) and CYP3A5*3 (rs776746 T/C) on atorvastatin therapy have not been previously studied among Egyptians.

OBJECTIVE

This research aimed to investigate the effects of the genetic polymorphisms CYP3A4*1B and CYP3A5*3 on atorvastatin treatment in Egyptians.

METHODS

In this prospective cohort study, 100 subjects were genotyped for these SNPs. All participants were screened for serum lipid profiles, liver enzymes, total bilirubin (TB), and creatine kinase (CK) before and after 40 mg postatorvastatin therapy. Atorvastatin plasma levels were assessed posttreatment; atorvastatin pharmacokinetics were evaluated in five carriers of the CYP3A4*1B (T/T) and CYP3A5*3 (C/C) genotypes.

RESULTS

The allele frequencies of the CYP3A4*1B and CYP3A5*3 SNPs were 86% and 83%, respectively. The CYP3A4*1B (T/T) and CYP3A5*3 (C/C) genotypes significantly improved the serum triglyceride (TG) level (P < 0.05) and elevated the TB level (P < 0.001). Atorvastatin plasma levels were greater in CYP3A4*1B (T/T) (P < 0.05) and CYP3A5*3 (C/C) (P < 0.001) genotype carriers. Both SNPs significantly affected the pharmacokinetics of atorvastatin compared with those of Egyptian volunteers and various ethnic populations.

CONCLUSIONS

The CYP3A4*1B and CYP3A5*3 variants were prevalent in the study participants and could impact the effectiveness and safety of atorvastatin therapy. The mutant genotype of the CYP3A4*1B SNP and the CYP3A5*3 SNP led to high atorvastatin levels. Both variants had a notable effect on the pharmacokinetics of atorvastatin among Egyptians compared with healthy Egyptians and volunteers from other ethnic populations. Overall, clinicians can learn more about the impact of both variants in response to atorvastatin.

Chinese Expert Consensus on the Clinical Diagnosis and Management of Statin Intolerance

The clinical benefits of statins have well-established and recognized worldwide. Although statins are well-tolerated generally, however, the report of statin-related adverse event and statin intolerance are common in China, which results in insufficient use of statins and poor adherence. The main reason may be attributed to confusions or misconceptions in the clinical diagnosis and management in China, including the lack of unified definitions and diagnostic standards, broad grasp of diagnosis, and unscientific management strategies. Based on that, this consensus carefully summarized the statin-related gene polymorphism and statin usage issue among Chinese population, and comprehensively reviewed global research data on statin intolerance, referenced guidelines, and consensus literature on statin intolerance in foreign and different regions, proposes an appropriate and easy to implement statin intolerance definition as well as corresponding diagnostic criteria and management strategies for Chinese clinicians, in order to improve the clinical application of statin drugs and enhance the prevention and treatment level of atherosclerotic cardiovascular disease in China.

TOMM40 and TOMM22 of the Translocase Outer Mitochondrial Membrane Complex rescue statin-impaired mitochondrial dynamics, morphology, and mitophagy in skeletal myotubes

Background

Statins are the drugs most commonly used for lowering plasma low-density lipoprotein (LDL) cholesterol levels and reducing cardiovascular disease risk. Although generally well tolerated, statins can induce myopathy, a major cause of non-adherence to treatment. Impaired mitochondrial function has been implicated as a cause of statin-induced myopathy, but the underlying mechanism remains unclear. We have shown that simvastatin downregulates transcription of TOMM40 and TOMM22 , genes that encode major subunits of the translocase of outer mitochondrial membrane (TOM) complex which is responsible for importing nuclear-encoded proteins and maintaining mitochondrial function. We therefore investigated the role of TOMM40 and TOMM22 in mediating statin effects on mitochondrial function, dynamics, and mitophagy.

Methods

Cellular and biochemical assays and transmission electron microscopy were used to investigate effects of simvastatin and TOMM40 and TOMM22 expression on measures of mitochondrial function and dynamics in C2C12 and primary human skeletal cell myotubes.

Results

Knockdown of TOMM40 and TOMM22 in skeletal cell myotubes impaired mitochondrial oxidative function, increased production of mitochondrial superoxide, reduced mitochondrial cholesterol and CoQ levels, disrupted mitochondrial dynamics and morphology, and increased mitophagy, with similar effects resulting from simvastatin treatment. Overexpression of TOMM40 and TOMM22 in simvastatin-treated muscle cells rescued statin effects on mitochondrial dynamics, but not on mitochondrial function or cholesterol and CoQ levels. Moreover, overexpression of these genes resulted in an increase in number and density of cellular mitochondria.

Conclusion

These results confirm that TOMM40 and TOMM22 are central in regulating mitochondrial homeostasis and demonstrate that downregulation of these genes by statin treatment mediates disruption of mitochondrial dynamics, morphology, and mitophagy, effects that may contribute to statin-induced myopathy.

GRAPHICAL ABSTRACT

Statin-Associated Myalgias and Muscle Injury-Recognizing and Managing Both While Still Lowering the Low-Density Lipoprotein

Although statins are generally safe and well tolerated, some patients experience muscle complaints that can be attributed to their use. Those with muscle discomfort but no demonstrable muscle weakness or creatine kinase (CK) elevations may have statin-associated muscle symptoms. Individuals with elevated CK levels, with or without muscle discomfort or weakness, may have statin-associated myotoxicity. Rare patients have statin-associated autoimmune myopathy, a disease characterized by proximal muscle weakness, elevated CK levels, and autoantibodies recognizing hydroxy-methyl-glutaryl coenzyme A reductase. In this review, the author provides the clinician with a practical approach to diagnosing and managing patients with each of these statin side effects.

Statin-Associated Myalgias and Muscle Injury-Recognizing and Managing Both While Still Lowering the Low-Density Lipoprotein

Although statins are generally safe and well tolerated, some patients experience muscle complaints that can be attributed to their use. Those with muscle discomfort but no demonstrable muscle weakness or creatine kinase (CK) elevations may have statin-associated muscle symptoms. Individuals with elevated CK levels, with or without muscle discomfort or weakness, may have statin-associated myotoxicity. Rare patients have statin-associated autoimmune myopathy, a disease characterized by proximal muscle weakness, elevated CK levels, and autoantibodies recognizing hydroxy-methyl-glutaryl coenzyme A reductase. In this review, the author provides the clinician with a practical approach to diagnosing and managing patients with each of these statin side effects.

Statin intolerance: an updated, narrative review mainly focusing on muscle adverse effects

INTRODUCTION

Statins have been established as the standard of care for dyslipidemia and preventing cardiovascular diseases while posing few safety concerns. However, misconceptions about statin intolerance lead to their underuse, indicating a need to improve the understanding of the safety of this treatment.

AREAS COVERED

We searched PubMed and reviewed literatures related to statin intolerance published between February 2015 and February 2020. Important large-scale or landmark studies published before 2015 were also cited as key evidence.

EXPERT OPINION

Optimal lowering of low-density lipoprotein cholesterol with statins substantially reduces the risk of cardiovascular events. Muscle adverse events (AEs) were the most frequently reported AEs by statin users in clinical practice, but they usually occurred at a similar rate with statins and placebo in randomized controlled trials and had a spurious causal relationship with statin treatment. We proposed a rigorous definition for identifying true statin intolerance and present the criteria for defining different forms of muscle AEs and an algorithm for their management. True statin intolerance is uncommon, and every effort should be made to exclude false statin intolerance and ensure optimal use of statins. For the management of statin intolerance, statin-based approaches should be prioritized over non-statin approaches.

Statins and muscle pain

Introduction: Statins remain among the most frequently prescribed drugs and constitute a cornerstone in the prevention of cardiovascular disease. However, muscle symptoms are often reported from patients on statins. Muscle symptoms are frequently reported as adverse events associated with statin therapy.Areas covered: In the present narrative review, statin-associated muscle pain is discussed. It elucidates potential mechanisms and possible targets for management.Expert opinion: In general, the evidence in support of muscle pain caused by statins is in some cases equivocal and not particularly strong. Reported symptoms are difficult to quantify. Rarely is it possible to establish a causal link between statins and muscle pain. In randomized controlled trials, statins are well tolerated, and muscle-pain related side-effects is similar to placebo. There are also nocebo effects of statins. Exchange of statin may be beneficial although all statins have been associated with muscle pain. In some patients reduction of dose is worth trying, especially in primary prevention Although the benefits of statins outweigh potential risks in the vast majority of cases, careful clinical judgment may be necessary in certain cases to manage potential side effects on an individual basis.

Statin Toxicity

There is now overwhelming evidence to support lowering LDL-c (low-density lipoprotein cholesterol) to reduce cardiovascular morbidity and mortality. Statins are a class of drugs frequently prescribed to lower cholesterol. However, in spite of their wide-spread use, discontinuation and nonadherence remains a major gap in both the primary and secondary prevention of atherosclerotic cardiovascular disease. The major reason for statin discontinuation is because of the development of statin-associated muscle symptoms, but a range of other statin-induced side effects also exist. Although the mechanisms behind these side effects have not been fully elucidated, there is an urgent need to identify those at increased risk of developing side effects as well as provide alternative treatment strategies. In this article, we review the mechanisms and clinical importance of statin toxicity and focus on the evaluation and management of statin-associated muscle symptoms.

Fast skeletal troponin I, but not the slow isoform, is increased in patients under statin therapy: a pilot study

Introduction

Statin therapy is often associated with muscle complaints and increased serum creatine kinase (CK). However, although essential in determining muscle damage, this marker is not specific for skeletal muscle. Recent studies on animal models have shown that slow and fast isoforms of skeletal troponin I (ssTnI and fsTnI, respectively) can be useful markers of skeletal muscle injury. The aim of this study was to evaluate the utility of ssTnI and fsTnI as markers to monitor the statin-induced skeletal muscle damage.

Materials and methods

A total of 51 patients (14 using and 37 not using statins) admitted to the intensive care unit of the University of Ferrara Academic Hospital were included in this observational study. Serum activities of CK, aldolase, alanine aminotransferase and myoglobin were determined by spectrophotometric assays or routine laboratory analysis. Isoforms ssTnI and fsTnI were determined by commercially available ELISAs. The creatine kinase MB isoform (CK-MB) and cardiac troponin I (cTnI) were evaluated as biomarkers of cardiac muscle damage by automatic analysers.

Results

Among the non-specific markers, only CK was significantly higher in statin users (P = 0.027). Isoform fsTnI, but not ssTnI, was specifically increased in those patients using statins (P = 0.009) evidencing the major susceptibility of fast-twitch fibres towards statins. Sub-clinical increase in fsTnI, but not CK, was more frequent in statin users (P = 0.007). Cardiac markers were not significantly altered by statins confirming the selectivity of the effect on skeletal muscle.

Conclusions

Serum fsTnI could be a good marker for monitoring statin-associated muscular damage outperforming traditional markers.

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.

Practical aspects in the management of statin-associated muscle symptoms (SAMS)

BACKGROUND AND AIMS

Statin-associated muscle symptoms (SAMS) frequently cause statin non-adherence, switching and discontinuation, contributing to adverse cardiovascular (CV) outcomes. Therefore, the management of SAMS is key in the effective treatment of patients with cardiovascular disease (CVD), through achievement of maximum-tolerated statin dosing and other practical aspects. The aim of this article is to provide practical, focused advice for healthcare professionals on the management of patients with SAMS.

METHODS

An expert working group combined current evidence, published guidelines and experiences surrounding a number of topics concerning SAMS to provide recommendations on how to best assess and manage this condition and reach the highest tolerated dose of statin for each individual patient.

RESULTS

The group collaborated to provide guidance on definitions in the SAMS field, psychological issues, re-challenging and switching treatments, as well as interpretation of current guidelines and optimal treatment of SAMS in different patient populations. An algorithm was developed to guide the management of patients with SAMS. In addition, the expert working group considered some of the more complex scenarios in a series of frequently asked questions and suggested answers.

CONCLUSIONS

The expert working group gave recommendations for healthcare professionals on the management of SAMS but highlighted the importance of tailoring the treatment approach to each individual patient. Evidence supporting the role of nutraceuticals and complementary therapies, such as vitamin D, was lacking, however the majority of the group favoured combination therapy with ezetimibe and the addition of PCSK9 inhibitors in high-risk patients.

The effects of statins on exercise and physical activity

OBJECTIVE

We sought to review studies examining the effect of statins on symptoms of exercise tolerance, markers of muscle injury and activity levels in physical active individuals.

BACKGROUND

Statin therapy reduces atherosclerotic cardiovascular disease (CVD) events. Regular physical activity is also associated with reduced CVD events, but statin therapy can produce muscle complaints, which may be more frequent in physically active individuals. We reviewed the literature to determine the effects of statins on symptoms, exercise performance and activity levels in physically active individuals.

METHODS

We performed a PubMed search to identify English language articles reporting on statins and their effect on athletic/exercise performance, and symptoms in active individuals.

RESULTS

We identified 65 articles, 32 of which provided sufficient information to be included in this review. Seventeen of the 32 studies examined the incidence of myalgia while exercising on statins, and showed that myalgia was increased in 8 of the 17 (47%) of these studies. Of the 17 studies examining the effects of statin therapy on muscle injury, 6 (35%) studies reported that statins augment the increase in creatine kinase (CK) produced by exercise. There were 10 studies that examined statin effects on aerobic exercise performance, only 3 of which (33%) concluded that statins decreased performance. Two (25%) of the 8 studies examined the effects of statins on muscular strength and suggested that statins decreased muscular strength, whereas 2 (25%) reported increased strength. Statins did not consistently affect physical activity levels since statins were associated with an increase in activity in 3 of the 5 studies examining habitual exercise. None of the studies showed a relationship between statins use and exercise and an increase in myalgia or a decrease in exercise performance. There was also no correlation between intensity of statin therapy and an effect on these variables.

CONCLUSION

Statins may increase the incidence of exercise-related muscle complaints and in some studies augment the exercise-induced rise in muscle enzymes, but statins do not consistently reduce muscle strength, endurance, overall exercise performance or physical activity.

Plasma 2-hydroxyglutarate and hexanoylcarnitine levels are potential biomarkers for skeletal muscle toxicity in male Fischer 344 rats

To identify new candidate biomarkers for skeletal muscle toxicity, an unbiased metabolomic analysis was performed in rats treated with two distinct myotoxicants, cerivastatin (CER) and tetramethyl-p-phenylenediamine (TMPD). Skeletal muscle toxicity was induced in male Fischer 344 rats by administering CER or TMPD and monitored using established endpoints, such as increased plasma creatine kinase (CK) activity and histopathology, and a metabolomic analysis of skeletal muscle and plasma samples. Plasma CK levels in CER-treated rats were markedly elevated at Day 11; however, those in TMPD-treated rats showed a statistically significant decrease at 24 hr after dosing. Light microscopy revealed that vacuolated or necrotic fibers were evident in all CER-treated rats on Day 11, and slightly vacuolated fibers were observed in TMPD-treated rats at 6 and 24 hr after dosing. Metabolomic analysis of the rectus femoris indicated increases in 2-hydroxyglutarate (2HG) in CER-treated rats and hexanoylcarnitine in CER- and TMPD-treated rats. There were also increases in plasma 2HG in CER-treated rats on Days 8 and 11 and in TMPD-treated rats at 24 hr after dosing and increases in plasma hexanoylcarnitine in CER-treated rats on Day 11 and in TMPD-treated rats at 6 and 24 hr after dosing. These experiments demonstrated the potential of plasma 2HG and hexanoylcarnitine as specific and easily detectable biomarkers for skeletal muscle toxicity in rats and demonstrated the value of metabolomics for biomarker detection and identification in toxicological studies.

Skeletal muscle metabolic adaptations to endurance exercise training are attainable in mice with simvastatin treatment

We tested the hypothesis that a 6-week regimen of simvastatin would attenuate skeletal muscle adaptation to low-intensity exercise. Male C57BL/6J wildtype mice were subjected to 6-weeks of voluntary wheel running or normal cage activities with or without simvastatin treatment (20 mg/kg/d, n = 7-8 per group). Adaptations in in vivo fatigue resistance were determined by a treadmill running test, and by ankle plantarflexor contractile assessment. The tibialis anterior, gastrocnemius, and plantaris muscles were evaluated for exercised-induced mitochondrial adaptations (i.e., biogenesis, function, autophagy). There was no difference in weekly wheel running distance between control and simvastatin-treated mice (P = 0.51). Trained mice had greater treadmill running distance (296%, P<0.001), and ankle plantarflexor contractile fatigue resistance (9%, P<0.05) compared to sedentary mice, independent of simvastatin treatment. At the cellular level, trained mice had greater mitochondrial biogenesis (e.g., ~2-fold greater PGC1α expression, P<0.05) and mitochondrial content (e.g., 25% greater citrate synthase activity, P<0.05), independent of simvastatin treatment. Mitochondrial autophagy-related protein contents were greater in trained mice (e.g., 40% greater Bnip3, P<0.05), independent of simvastatin treatment. However, Drp1, a marker of mitochondrial fission, was less in simvastatin treated mice, independent of exercise training, and there was a significant interaction between training and statin treatment (P<0.022) for LC3-II protein content, a marker of autophagy flux. These data indicate that whole body and skeletal muscle adaptations to endurance exercise training are attainable with simvastatin treatment, but simvastatin may have side effects on muscle mitochondrial maintenance via autophagy, which could have long-term implications on muscle health.

The Impact of Exercise on Statin-Associated Skeletal Muscle Myopathy

HMG-CoA reductase inhibitors (statins) are the most effective pharmacological means of reducing cardiovascular disease risk. The most common side effect of statin use is skeletal muscle myopathy, which may be exacerbated by exercise. Hypercholesterolemia and training status are factors that are rarely considered in the progression of myopathy. The purpose of this study was to determine the extent to which acute and chronic exercise can influence statin-induced myopathy in hypercholesterolemic (ApoE^-/-) mice. Mice either received daily injections of saline or simvastatin (20 mg/kg) while: 1) remaining sedentary (Sed), 2) engaging in daily exercise for two weeks (novel, Nov), or 3) engaging in daily exercise for two weeks after a brief period of training (accustomed, Acct) (2x3 design, n = 60). Cholesterol, activity, strength, and indices of myofiber damage and atrophy were assessed. Running wheel activity declined in both exercise groups receiving statins (statin x time interaction, p<0.05). Cholesterol, grip strength, and maximal isometric force were significantly lower in all groups following statin treatment (statin main effect, p<0.05). Mitochondrial content and myofiber size were increased and 4-HNE was decreased by exercise (statin x exercise interaction, p<0.05), and these beneficial effects were abrogated by statin treatment. Exercise (Acct and Nov) increased atrogin-1 mRNA in combination with statin treatment, yet enhanced fiber damage or atrophy was not observed. The results from this study suggest that exercise (Nov, Acct) does not exacerbate statin-induced myopathy in ApoE^-/- mice, yet statin treatment reduces activity in a manner that prevents muscle from mounting a beneficial adaptive response to training.

Statin-associated myopathy and the quest for biomarkers: can we effectively predict statin-associated muscle symptoms?

Over the past three decades, statins have become the cornerstone of prevention and treatment of atherosclerotic cardiovascular and metabolic diseases. Albeit generally well tolerated, these drugs can elicit a variety of muscle-associated symptoms that represent the most important reason for treatment discontinuation. Statin-associated myopathy has been systematically underestimated by randomized controlled trials as compared with the incidence observed in clinical practice and obtained from patient registries. There are several reasons for this discrepancy, among which the lack of reliable diagnostic tests and a validated questionnaire to assess muscle symptoms are recognized as unmet needs. Here, we review the cellular and molecular mechanisms underlying statin-associated myopathy and discuss the experimental and clinical data on various biomarkers to diagnose and predict muscle-related complaints.

A Nutraceutical Composition Decreases CPK Levels in Saos-2 Cells and in Patients with Elevated Serum Levels of This Enzyme

OBJECTIVES

This study aimed to investigate the effects of a nutraceutical composition on the expression of some genes involved in muscle cells and functioning in osteoblast cells. The effects of nutraceutical composition have been compared to the effects of atorvastatin, which induces muscle pain and elevated creatine phosphokinase (CPK) serum level when administered to patients. In particular, we analyzed the MyoD-1 gene, which is responsible for modulation of the CPK gene, which is a marker of muscle pain and damage.

METHODS

The effects of nutraceutical composition on Saos-2 cells were compared with the effects of atorvastatin. The mRNAs were extracted and the expression levels of mitochondrial and cytoplasmic CPK genes and MyoD-1 were analyzed by real-time polymerase chain reaction (RT-PCR). Moreover, the effects on lactate dehydrogenase (LDH) activity and adenosine triphosphate (ATP) synthesis were measured in the osteoblast cell line. Furthermore, 11 patients with muscle pain or elevated CPK serum levels received a supplementation of the nutraceutical composition to test whether CPK levels could be downregulated.

RESULTS

The analysis in Saos-2 cells showed that the nutraceutical composition upregulates the gene expression of MyoD-1 and downregulates the expression of the cytoplasmic isoform of CPK gene expression (p ≤ 0.05); moreover, it slightly increases ATP amount and decreases LDH activity. Conversely, atorvastatin represses the expression of MyoD-1 gene without significant changing into the expression levels of both cytoplasmic and mitochondrial CPK genes. Moreover, atorvastatin does not increase the ATP amount or increase LDH activity. Remarkable, the nutraceutical composition is able to decrease CPK levels in serum of patients and in some cases improve myalgia symptoms.

CONCLUSION

The nutraceutical composition decreases CPK levels both in vitro and in vivo, suggesting that it might be useful to management of nonneurological myalgia symptoms.

Pharmacological research on natural substances in Latvia: Focus on lunasin, betulin, polyprenol and phlorizin

In this concise review the current research in plant bioactive compound studies in Latvia is described. The paper summarizes recent studies on substances from edible plants (e.g., cereals and apples) or their synthetic analogues, such as peptide lunasin, as well as substances isolated from inedible plants (e.g., birch and conifer), such as pentacyclic triterpenes (e.g., betulin, betulinic acid, and lupeol) and polyprenols. Latvian researchers have been first to demonstrate the presence of lunasin in triticale and oats. Additionally, the impact of genotype on the levels of lunasin in cereals was shown. Pharmacological studies have revealed effects of lunasin and synthetic triterpenes on the central nervous system in rodents. We were first to show that synthetic lunasin causes a marked neuroleptic/cataleptic effect and that betulin antagonizes bicuculline-induced seizures (a GABA A receptor antagonist). Studies on the mechanisms of action showed that lunasin binds to dopamine D1 receptors and betulin binds to melanocortin and gamma-aminobutyric acid A receptors therefore we suggest that these receptors play an essential role in lunasin's and betulin's central effects. Recent studies on conifer polyprenols demonstrated the ability of polyprenols to prevent statin-induced muscle weakness in a rat model. Another study on plant compounds has demonstrated the anti-hyperglycemic activity of phlorizin-containing unripe apple pomace in healthy volunteers. In summary, research into plant-derived compounds in Latvia has been focused on fractionating, isolating and characterizing of lunasin, triterpenes, polyprenols and phlorizin using in vitro, and in vivo assays, and human observational studies.

Effects of 96 Weeks of Rosuvastatin on Bone, Muscle, and Fat in HIV-Infected Adults on Effective Antiretroviral Therapy

Heightened inflammation and immune activation are associated with lower bone mineral density (BMD) and lean body mass (LBM) among HIV-infected persons. We hypothesized that a reduction in inflammation with rosuvastatin would be associated with improvements in BMD and LBM. HIV-infected participants on stable antiretroviral therapy without statin indication and with heightened immune activation (≥19% CD8(+)CD38(+)HLA-DR(+) T cells) or inflammation (hsCRP ≥2 mg/liter) were randomized to rosuvastatin 10 mg daily or placebo for 96 weeks. Among 72 participants randomized to rosuvastatin and 75 to placebo, there were no significant differences in the relative changes in BMD (p > 0.29) or in fat (p ≥ 0.19). A trend toward increased LBM (p = 0.059) was seen in the rosuvastatin arm without differences in creatinine kinase or self-reported physical activity (p ≥ 0.10). In a multivariable regression model, rosuvastatin was associated with a significant positive effect on LBM after adjusting for age, sex, race, smoking status, and detectable HIV-1 viral load. Higher baseline sCD163 correlated with increases in LBM from weeks 0 to 96 (p = 0.023); greater changes in total and leg lean mass were seen among statin users with higher compared to lower baseline IP-10 levels (LBM 1.8 vs. -0.3%; p = 0.028 and leg lean mass 2.9 vs. -1.7%; p = 0.012). Rosuvastatin is associated with an absence of toxicity on BMD and a potential benefit on LBM over 96 weeks of therapy. The preservation of LBM in the rosuvastatin arm over the 2 years of the study is of major clinical relevance in delaying loss of muscle mass with aging.

Statin intolerance: diagnosis and remedies

Despite the efficacy of statins in reducing cardiovascular events in both primary and secondary prevention, the adherence to statin therapy is not optimal, mainly due to the occurrence of muscular adverse effects. Several risk factors may concur to the development of statin-induced myotoxicity, including patient-related factors (age, sex, and race), statin properties (dose, lipophilicity, and type of metabolism), and the concomitant administration of other drugs. Thus, the management of patients intolerant to statins, particularly those at high or very high cardiovascular risk, involves alternative therapies, including the switch to another statin or the use of intermittent dosage statin regimens, as well as nonstatin lipid lowering drugs (ezetimibe and fibrates) or new hypolipidemic drugs such as PCSK9 monoclonal antibodies, the antisense oligonucleotide against the coding region of human apolipoprotein B mRNA (mipomersen), and microsomal triglyceride transfer protein inhibitor lomitapide. Ongoing clinical trials will reveal whether the lipid-lowering effects of alternative therapies to statins can also translate into a cardiovascular benefit.

Effects of Statin Therapy on Exercise Levels in Participants in the National Runners' and Walkers' Health Study

OBJECTIVES

To determine whether decreases in exercise 1) were greater in individuals who were diagnosed as having hypercholesterolemia than in those without the diagnosis during follow-up and 2) were greater in incident hypercholesterolemic participants starting statins than in those not treated with cholesterol-lowering medications.

PARTICIPANTS AND METHODS

Regression analyses of changes since baseline (Δ) in exercise vs diagnosis of hypercholesterolemia and its treatment in 66,377 runners and 12,031 walkers not using cholesterol medications at baseline who were resurveyed during the National Runners' and Walkers' Health Study follow-up (January 1, 1991, through December 31, 2006).

RESULTS

A total of 3510 runners began statin treatment, 1779 began other or unspecified cholesterol-lowering drug treatment, and 2583 had untreated hypercholesterolemia; 58,505 runners remained nonhypercholesterolemic controls during the mean 7.2-year follow-up. Usual distance run decreased significantly more in hypercholesterolemic runners who began taking statins (mean ± SE: -0.47±0.06 km/d) than in runners who remained nonhypercholesterolemic during follow-up (-0.08±0.02 km/d) (P<.001). However, running distance also decreased significantly more in hypercholesterolemic runners who began unspecified/other (-0.52±0.08 km/d) or no (-0.47±0.07 km/d) cholesterol drugs than in nonhypercholesterolemic runners during follow-up. Moreover, Δrunning distance did not differ significantly between hypercholesterolemic runners who were statin treated vs those treated with other/unspecified (P=.64) or no (P=.94) cholesterol drugs. Initiating statin therapy was not associated with Δrunning pace in hypercholesterolemic runners or Δwalking distances in hypercholesterolemic walkers.

CONCLUSION

These results are consistent with the premise that a decrease in running distance is associated with hypercholesterolemia and do not suggest that statins reduce exercise level or intensity.

Relationships between physical activity and muscular strength among healthy adults across the lifespan

The purpose of this study was to examine relationships between objective and self-report measures of physical activity and muscle strength among healthy adults ranging in age from 20 to 91 years. Participants (n = 412) were mostly Caucasian men (48 %) and women (52 %) 43.9 ± 16.1 year of age with a body mass index (BMI) of 26.4 ± 4.8 kg/m(2). Physical activity was measured objectively with an accelerometer and by self-report with the Paffenbarger Physical Activity Questionnaire. Upper and lower body muscle strength were measured with an isokinetic dynamometer and handgrip strength with a static dynamometer. Multivariate regression assessed relationships between physical activity and muscle strength. The strongest correlates of upper body strength including handgrip strength were gender (r = -0.861 to -0.716), age (r = -0.445 to -0.241), BMI (r = 0.134-0.397), and physical activity (r = 0.093-0.186). The strongest correlates of lower body strength were gender (r = -0.772 to -0.634), age (r = -0.663 to -0.445), BMI (r = 0.160-0.266), and physical activity (r = -0.139 to 0.151). The strongest correlates of muscle strength were gender (explaining 40-74 % of the variance), age (6-44 %), and BMI (2-16 %), while physical activity correlations were weaker (1-3 %). Conflict surrounding the influence of a physically active lifestyle on muscle strength with age may be due to the stronger influences of other factors that supersede those of physical activity whether measured objectively or by self-report methods.

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.

Treatment of dyslipidemia with statins and physical exercises: recent findings of skeletal muscle responses

Statin treatment in association with physical exercise practice can substantially reduce cardiovascular mortality risk of dyslipidemic individuals, but this practice is associated with myopathic event exacerbation. This study aimed to present the most recent results of specific literature about the effects of statins and its association with physical exercise on skeletal musculature. Thus, a literature review was performed using PubMed and SciELO databases, through the combination of the keywords "statin" AND "exercise" AND "muscle", restricting the selection to original studies published between January 1990 and November 2013. Sixteen studies evaluating the effects of statins in association with acute or chronic exercises on skeletal muscle were analyzed. Study results indicate that athletes using statins can experience deleterious effects on skeletal muscle, as the exacerbation of skeletal muscle injuries are more frequent with intense training or acute eccentric and strenuous exercises. Moderate physical training, in turn, when associated to statins does not increase creatine kinase levels or pain reports, but improves muscle and metabolic functions as a consequence of training. Therefore, it is suggested that dyslipidemic patients undergoing statin treatment should be exposed to moderate aerobic training in combination to resistance exercises three times a week, and the provision of physical training prior to drug administration is desirable, whenever possible.

Effects of randomized rosuvastatin compared with placebo on bone and body composition among HIV-infected adults

BACKGROUND

Statins have a beneficial effect on bone mineral density (BMD) and lean mass in some studies of HIV-uninfected adults; however, this has never been investigated in the setting of HIV infection.

DESIGN

HIV-infected individuals on stable antiretroviral therapy with a low-density lipoprotein cholesterol level of 130 mg/dl or less and evidence of heightened immune activation or inflammation were randomized to rosuvastatin 10 mg daily or placebo for 96 weeks.

METHODS

This was a prespecified interim analysis at 48 weeks. Between-group and within-group differences were compared; multivariable regression models were constructed.

RESULTS

Seventy-two individuals were randomized to statin therapy and 75 to placebo. Modest 48-week relative increases in trochanter BMD [0.9%; 95% confidence interval (95% CI) -0.9 to 0.6] and total hip BMD (0.6%; 95% CI 0.0-1.1) in the statin arm were significantly greater than placebo (P < 0.05). The relationship between statin use and total hip BMD change was robust to adjustment of age, sex, race and smoking status (P = 0.02) and strengthened by inclusion of baseline (P = 0.01) and week 48 change in soluble tumour necrosis factor-α receptor (sTNFR)-1 (P = 0.009). Relative increases in total body, trunk and limb fat were similar between statin and placebo arms (P ≥ 0.58). Although a significant gain in leg lean mass was seen in the statin arm, this was not significantly different compared with placebo (P = 0.36).

CONCLUSION

The improvements seen in total hip BMD after 48 weeks of rosuvastatin therapy support further potential benefits of statin therapy in HIV, beyond a reduction of cardiovascular risk.