Statin myalgia is not associated with reduced muscle strength, mass or protein turnover in older male volunteers, but is allied with a slowing of time to peak power output, insulin resistance and differential muscle mRNA expression

Association of lipid-lowering drugs with risk of sarcopenia: a drug target mendelian randomization study and meta-analysis

BACKGROUND

Lipid-lowering drugs are widely used among the elderly, with some studies suggesting links to muscle-related symptoms. However, the causality remains uncertain.

METHODS

Using the Mendelian randomization (MR) approach, we assessed the causal effects of genetically proxied reduced low-density lipoprotein cholesterol (LDL-C) through inhibitions of hydroxy-methyl-glutaryl-CoA reductase (HMGCR), proprotein convertase subtilisin/kexin type 9 (PCSK9), and Niemann-Pick C1-like 1 (NPC1L1) on sarcopenia-related traits, including low hand grip strength, appendicular lean mass, and usual walking pace. A meta-analysis was conducted to combine the causal estimates from different consortiums.

RESULTS

Using LDL-C pooled data predominantly from UK Biobank, genetically proxied inhibition of HMGCR was associated with higher appendicular lean mass (beta = 0.087, P = 7.56 × 10- 5) and slower walking pace (OR = 0.918, P = 6.06 × 10- 9). In contrast, inhibition of PCSK9 may reduce appendicular lean mass (beta = -0.050, P = 1.40 × 10- 3), while inhibition of NPC1L1 showed no causal impact on sarcopenia-related traits. These results were validated using LDL-C data from Global Lipids Genetics Consortium, indicating that HMGCR inhibition may increase appendicular lean mass (beta = 0.066, P = 2.17 × 10- 3) and decelerate walking pace (OR = 0.932, P = 1.43 × 10- 6), whereas PCSK9 inhibition could decrease appendicular lean mass (beta = -0.048, P = 1.69 × 10- 6). Meta-analysis further supported the robustness of these causal associations.

CONCLUSIONS

Genetically proxied HMGCR inhibition may increase muscle mass but compromise muscle function, PCSK9 inhibition could result in reduced muscle mass, while NPC1L1 inhibition is not associated with sarcopenia-related traits and this class of drugs may serve as viable alternatives to sarcopenia individuals or those at an elevated risk.

Feasibility of conducting a cohort randomized controlled trial assessing the effectiveness of a nurse-led package of care for knee pain

OBJECTIVE

To evaluate the feasibility of conducting a cohort randomized controlled trial (RCT) of a nurse-led package of care for knee pain and determining a treatment sequence for use in a future trial.

METHODS

This study was an open-label, three-arm, single-centre, mixed-methods, feasibility cohort RCT. Adults aged ≥40 years with moderate-to-severe knee pain for ≥3 months were eligible. Participants were randomized into group A (non-pharmacological treatment first), group B (pharmacological treatment first), or group C (usual care). The intervention was delivered over 26 weeks. Outcomes were dropout rate, recruitment rate, intervention fidelity, ability to collect outcome data, and treatment acceptability.

RESULTS

Seventeen participants were randomized and enrolled into each of groups A and B (5.2% recruitment rate), and 174 participants were randomized to group C. The participant characteristics at randomization were comparable across the three arms. Coronavirus disease (COVID-19) paused the study from March-November 2020. Participants enrolled in groups A and B before March 2020 were withdrawn at the restart. Of the 20 participants enrolled after the restart, 18 completed the study (10% dropout). The nurse reported delivering most aspects of the intervention with high fidelity. The participants viewed the package of care as structured, supportive and holistic, they learnt about self-managing knee pain, and they could engage with and follow the non-pharmacological treatment. Most found the non-pharmacological treatment more useful than the pharmacological treatment, preferring to receive it before or alongside analgesia. Many self-report questionnaires were not fully completed.

CONCLUSION

The nurse-led package of care for knee pain was acceptable, with low dropout, although the cohort RCT design may not be feasible for a definitive trial.

TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT03670706.

The effect of statins on falls and physical activity in people aged 65 and older: A systematic review

PURPOSE

Statins are commonly prescribed medications with recognised side effects including muscle weakness. Despite this, little is known about their effect on the physical activity and falls risk in the older population. This paper aims to explore the relationship between statin use and the physical activity and falls risk in adults aged 65 and older.

METHODS

MEDLINE, Embase, CINAHL and PsycINFO were searched on 21/11/2022 to obtain relevant articles. Data considered appropriate included that relating to muscle strength, grip strength, gait speed, balance and falls incidence. Reference and citation searches were performed to identify further relevant papers, and all eligible articles were subject to a Critical Appraisal Skills Programme (CASP) to assess potential bias. With the data being highly heterogeneous, no attempt to measure effect size was made and a narrative synthesis approach was used. The review proposal was registered with PROSPERO: CRD42022366159.

RESULTS

Twenty articles were included. Data were inconsistent throughout, with the overall trend suggesting no significant negative effects of statins on the parameters of physical activity, or on falls risk. This was especially true in matched and adjusted cohorts, where potential confounders had been accounted for.

CONCLUSION

This review did not identify a relationship between statin use and physical activity and falls risk in people aged 65 years and older. Ultimately, the risks and benefits of every medication should be considered in the context of each individual.

No benefit of vitamin D supplementation on muscle function and health-related quality of life in primary cardiovascular prevention patients with statin-associated muscle symptoms: A randomized controlled trial

BACKGROUND

Statins are the leading lipid-lowering drugs, reducing blood cholesterol by controlling its synthesis. Side effects are linked to the use of statins, in particular statin-associated muscle symptoms (SAMS). Some data suggest that vitamin D supplementation could reduce SAMS.

OBJECTIVE

The purpose of this study was to evaluate the potential benefits of vitamin D supplementation in a randomized controlled trial.

METHODS

Men (n = 23) and women (n = 15) (50.5 ± 7.7 years [mean ± SD]) in primary cardiovascular prevention, self-reporting or not SAMS, were recruited. Following 2 months of statin withdrawal, patients were randomized to supplementation (vitamin D or placebo). After 1 month of supplementation, statins were reintroduced. Before and 2 months after drug reintroduction, muscle damage (creatine kinase and myoglobin) was measured. Force (F), endurance (E) and power (P) of the leg extensors (ext) and flexors (fle) and handgrip strength (FHG) were also measured with isokinetic and handheld dynamometers, respectively. The Short Form 36 Health Survey (SF-36) questionnaire and a visual analog scale (VAS) were administrated to assess participants' self-reported health-related quality of life and SAMS intensity, respectively. Repeated-measures analysis was used to investigate the effects of time, supplementation, and their interaction, according to the presence of SAMS.

RESULTS

Despite no change for objective measures, subjective measures worsened after reintroduction of statins, independent of supplementation (VAS, SF-36 mental component score, all p < 0.05). However, no interaction between time and supplementation according to the presence of SAMS was observed for any variables.

CONCLUSIONS

Vitamin D supplementation does not appear to mitigate SAMS.

Mechanisms and effects of metformin on skeletal muscle disorders

Skeletal muscle disorders are mostly genetic and include several rare diseases. With disease progression, muscle fibrosis and adiposis occur, resulting in limited mobility. The long course of these diseases combined with limited treatment options affect patients both psychologically and economically, hence the development of novel treatments for neuromuscular diseases is crucial to obtain a better quality of life. As a widely used hypoglycemic drug in clinical practice, metformin not only has anti-inflammatory, autophagy-regulating, and mitochondrial biogenesis-regulating effects, but it has also been reported to improve the symptoms of neuromuscular diseases, delay hypokinesia, and regulate skeletal muscle mass. However, metformin's specific mechanism of action in neuromuscular diseases requires further elucidation. This review summarizes the evidence showing that metformin can regulate inflammation, autophagy, and mitochondrial biogenesis through different pathways, and further explores its mechanism of action in Duchenne muscular dystrophy, statin-associated muscle disorders, and age-related sarcopenia. This review clarifies the directions of future research on therapy for neuromuscular diseases.

Impact of statin withdrawal on perceived and objective muscle function

BACKGROUND AND AIMS

Statin-associated muscle symptoms (SAMS) are frequently reported. Nevertheless, few data on objective measures of muscle function are available. Recent data suggesting an important nocebo effect with statin use could confound such effects. The objective was to assess if subjective and objective measures of muscle function improve after drug withdrawal in SAMS reporters.

METHODS

Patients (59 men, 33 women, 50.3±9.6 yrs.) in primary cardiovascular prevention composed three cohorts: statin users with (SAMS, n = 61) or without symptoms (No SAMS, n = 15), and controls (n = 16) (registered at clinicaltrials.gov, NCT01493648). Force (F), endurance (E) and power (P) of the leg extensors (ext) and flexors (fle) and handgrip strength (Fhg) were measured using isokinetic and handheld dynamometers, respectively. A 10-point visual analogue scale (VAS) was used to self-assess SAMS intensity. Measures were taken before and after two months of withdrawal.

RESULTS

Following withdrawal, repeated-measures analyses show improvements for the entire cohort in Eext, Efle, Ffle, Pext and Pfle (range +7.2 to +13.3%, all p≤0.02). Post-hoc analyses show these changes to occur notably in SAMS (+8.8 to +16.6%), concurrent with a decrease in subjective perception of effects in SAMS (VAS, from 5.09 to 1.85). Fhg was also improved in SAMS (+4.0 to +6.2%) when compared to No SAMS (-1.7 to -4.2%) (all p = 0.02).

CONCLUSIONS

Whether suffering from "true" SAMS or nocebo, those who reported SAMS had modest but relevant improvements in muscle function concurrent with a decrease in subjective symptoms intensity after drug withdrawal. Greater attention by clinicians to muscle function in frail statin users appears warranted.

TRIAL REGISTRATION

This study is registered in clinicaltrials.gov (NCT01493648).

The effect of 8 weeks of physical training on muscle performance and maximal fat oxidation rates in patients treated with simvastatin and coenzyme Q10 supplementation

Statins are prescribed for the treatment of elevated cholesterol, but they may negatively affect metabolism, muscle performance, and the response to training. Coenzyme Q10 (CoQ10) supplementation may alleviate these effects. Combined simvastatin and CoQ10 treatment during physical training has never been tested. We studied the response to 8 weeks training (maximal oxygen uptake ( V ̇ O 2 max ), fat oxidation (MFO), the workload at which MFO occurred, and muscle strength) in statin naive dyslipidaemic patients who received simvastatin (40 mg/day) with (S + Q, n = 9) or without (S + Pl, n = 10) CoQ10 supplementation (2 × 200 mg/day) or placebo (Pl + Pl, n = 7) in a randomized, double-blind placebo-controlled study. V ̇ O 2 max and maximal workload increased with training (main effect of time, P < 0.05). MFO increased from 0.29 ± 0.10, 0.26 ± 0.10, and 0.38 ± 0.09 to 0.42 ± 0.09, 0.38 ± 0.10 and 0.48 ± 0.16 g/min in S + Q, S + Pl, and Pl + Pl, respectively (main effect of time, P = 0.0013). The workload at MFO increased from 75 ± 25, 56 ± 23, and 72 ± 17 to 106 ± 25, 84 ± 13 and 102 ± 31 W in S + Q, S + Pl, and Pl + Pl, respectively (main effect of time, P < 0.0001). Maximal voluntary contraction and rate of force development were unchanged. Exercise improved aerobic physical capacity and simvastatin with or without CoQ10 supplementation did not inhibit this adaptation. The similar increases in MFO and in the workload at which MFO occurred in response to training shows that the ability to adapt substrate selection and oxidation rates is preserved with simvastatin treatment, despite the potential negative impact of simvastatin at the mitochondrial level. CoQ10 supplementation does not augment this adaptation. KEY POINTS: Simvastatins are prescribed for treatment of elevated cholesterol, but they may negatively affect metabolism, muscle performance and the response to training. Coenzyme Q10 (CoQ10) supplementation may alleviate some of these effects. We found that simvastatin treatment does not negatively affect training-induced adaptations of substrate oxidation during exercise. Likewise, maximal oxygen uptake increases with physical training also in patients in treatment with simvastatin. CoQ10 supplementation in simvastatin-treated patients presents no advantage in the adaptations to physical training Simvastatin treatment decreases plasma concentrations of total CoQ10, but this can be alleviated by simultaneous supplementation with CoQ10.

Statin use, development of sarcopenia, and long-term survival after endovascular aortic repair

OBJECTIVE

Statin therapy, associated with improved short-term survival after treatment of abdominal aortic aneurysms, may also predispose to muscle side effects. Evidence on statin-related sarcopenia is limited mainly to muscle function, and it is subject to several sources of bias. In the long term, postoperative development of sarcopenia is linked to mortality after endovascular repair (EVAR). We investigated statin use and long-term postoperative mortality after EVAR in relation to objective measurable markers of sarcopenia (psoas muscle surface area and density).

METHODS

Altogether 216 abdominal aortic aneurysm patients treated with EVAR between 2006 and 2014 at Tampere University Hospital (Finland) were retrospectively studied. Psoas muscle parameters at the L3 level were evaluated from baseline and mainly 1- to 3-year follow-up computed tomography studies. Cox regression was used to study the association between statin medication, psoas muscle changes, and all-cause mortality.

RESULTS

The majority of patients were male (87%), and the mean age was 77.7 years (standard deviation, 7.4). The median duration of follow-up was 6.3 years (interquartile range, 3.5) with a total mortality of 54.2% (n = 117). Regardless of a higher burden of comorbidities, statin users (n = 119) had lower mortality when compared with nonusers (multivariable hazard ratio [HR]: 0.69, 95% confidence interval: 0.48-0.99, P = .048). Furthermore, statin use was not associated with inferior muscle parameter values, and the relative change in psoas muscle area was actually lower in statin users compared with nonusers (-15.7% and -21.1%, P < .046).

CONCLUSIONS

Statin use is associated with lower long-term mortality among patients undergoing EVAR without predisposing to increased sarcopenia.

Statins induce skeletal muscle atrophy via GGPP depletion-dependent myostatin overexpression in skeletal muscle and brown adipose tissue

Myopathy is the major adverse effect of statins. However, the underlying mechanism of statin-induced skeletal muscle atrophy, one of statin-induced myopathy, remains to be elucidated. Myostatin is a negative regulator of skeletal muscle mass and functions. Whether myostatin is involved in statin-induced skeletal muscle atrophy remains unknown. In this study, we uncovered that simvastatin administration increased serum myostatin levels in mice. Inhibition of myostatin with follistatin, an antagonist of myostatin, improved simvastatin-induced skeletal muscle atrophy. Simvastatin induced myostatin expression not only in skeletal muscle but also in brown adipose tissue (BAT). Mechanistically, simvastatin inhibited the phosphorylation of forkhead box protein O1 (FOXO1) in C2C12 myotubes, promoting the nuclear translocation of FOXO1 and thereby stimulating the transcription of myostatin. In differentiated brown adipocytes, simvastatin promoted myostatin expression mainly by inhibiting the expression of interferon regulatory factor 4 (IRF4). Moreover, the stimulative effect of simvastatin on myostatin expression was blunted by geranylgeranyl diphosphate (GGPP) supplementation in both myotubes and brown adipocytes, suggesting that GGPP depletion was attributed to simvastatin-induced myostatin expression. Besides, the capacities of statins on stimulating myostatin expression were positively correlated with the lipophilicity of statins. Our findings provide new insights into statin-induced skeletal muscle atrophy. Graphical headlights 1. Simvastatin induces skeletal muscle atrophy via increasing serum myostatin levels in mice; 2. Simvastatin promotes myostatin expression in both skeletal muscle and brown adipose tissue through inhibiting GGPP production; 3. The stimulating effect of statins on myostatin expression is positively correlated with the lipophilicity of statins.

Plant Extracts as Possible Agents for Sequela of Cancer Therapies and Cachexia

Cancer is a leading cause of the death worldwide. Since the National Cancer Act in 1971, various cancer treatments were developed including chemotherapy, surgery, radiation therapy and so forth. However, sequela of such cancer therapies and cachexia are problem to the patients. The primary mechanism of cancer sequela and cachexia is closely related to reactive oxygen species (ROS) and inflammation. As antioxidant properties of numerous plant extracts have been widely reported, plant-derived drugs may have efficacy on managing the sequela and cachexia. In this study, recent seventy-four studies regarding plant extracts showing ability to manage the sequela and cachexia were reviewed. Some plant-derived antioxidants inhibited cancer proliferation and inflammation after surgery and others prevented chemotherapy-induced normal cell apoptosis. Also, there are plant extracts that suppressed radiation-induced oxidative stress and cell damage by elevation of glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and regulation of B-cell lymphoma 2 (BcL-2) and Bcl-2-associated X protein (Bax). Cachexia was also alleviated by inhibition of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) by plant extracts. This review focuses on the potential of plant extracts as great therapeutic agents by controlling oxidative stress and inflammation.

Physical Function Impairment and Frailty in Middle-Aged People Living With Human Immunodeficiency Virus in the REPRIEVE Trial Ancillary Study PREPARE

BACKGROUND

People with human immunodeficiency virus (PWH) are at risk for accelerated development of physical function impairment and frailty; both associated with increased risk of falls, hospitalizations, and death. Identifying factors associated with physical function impairment and frailty can help target interventions.

METHODS

The REPRIEVE trial enrolled participants 40-75 years of age, receiving stable antiretroviral therapy with CD4+ T-cell count >100 cells/mm3, and with low to moderate cardiovascular disease risk. We conducted a cross-sectional analysis of those concurrently enrolled in the ancillary study PREPARE at enrollment.

RESULTS

Among the 266 participants, the median age was 51 years; 81% were male, and 45% were black, and 28% had hypertension. Body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) was 25 to <30 in 38% and ≥30 in 30%, 33% had a high waist circumference, 89% were physically inactive, 37% (95% confidence interval, 31%, 43%) had physical function impairment (Short Physical Performance Battery score ≤10), and 6% (4%, 9%) were frail and 42% prefrail. In the adjusted analyses, older age, black race, greater BMI, and physical inactivity were associated with physical function impairment; depression and hypertension were associated with frailty or prefrailty.

CONCLUSIONS

Physical function impairment was common among middle-aged PWH; greater BMI and physical inactivity are important modifiable factors that may prevent further decline in physical function with aging.

CLINICAL TRIALS REGISTRATION

NCT02344290.

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.

Muscle Toxicity of Drugs: When Drugs Turn Physiology into Pathophysiology

Drugs are prescribed to manage or prevent symptoms and diseases, but may sometimes cause unexpected toxicity to muscles. The symptomatology and clinical manifestations of the myotoxic reaction can vary significantly between drugs and between patients on the same drug. This poses a challenge on how to recognize and prevent the occurrence of drug-induced muscle toxicity. The key to appropriate management of myotoxicity is prompt recognition that symptoms of patients may be drug related and to be aware that inter-individual differences in susceptibility to drug-induced toxicity exist. The most prevalent and well-documented drug class with unintended myotoxicity are the statins, but even today new classes of drugs with unintended myotoxicity are being discovered. This review will start off by explaining the principles of drug-induced myotoxicity and the different terminologies used to distinguish between grades of toxicity. The main part of the review will focus on the most important pathogenic mechanisms by which drugs can cause muscle toxicity, which will be exemplified by drugs with high risk of muscle toxicity. This will be done by providing information on key clinical and laboratory aspects, muscle electromyography patterns and biopsy results, and pathological mechanism and management for a specific drug from each pathogenic classification. In addition, rather new classes of drugs with unintended myotoxicity will be highlighted. Furthermore, we will explain why it is so difficult to diagnose drug-induced myotoxicity, and which tests can be used as a diagnostic aid. Lastly, a brief description will be given of how to manage and treat drug-induced myotoxicity.

Glucose homeostasis in statin users-The LIFESTAT study

BACKGROUND

Statins are widely used to lower cholesterol concentrations in both primary and secondary prevention of cardiovascular disease. The treatment increases the risk of muscle pain (myalgia) and of type 2 diabetes. However, the underlying mechanisms remain disputed.

METHODS

We investigated whether statin induced myalgia is coupled to impaired glucose homeostasis using oral glucose tolerance test (OGTT), intravenous glucose tolerance test (IVGTT), and the hyperinsulinemic euglycemic clamp. We performed a cross-sectional study of statin users without CVD (primary prevention) stratified into a statin myalgic (M; n = 25) and a non-myalgic (NM; n = 39) group as well as a control group (C; n = 20) consisting of non-statin users.

RESULTS

A reduction in the insulin secretion rate during the OGTT was observed in the myalgic group compared with the non-myalgic group (AUC ISR_OGTT , C: 1032 (683 - 1500); M: 922 (678 - 1091); NM: 1089 (933 - 1391) pmol·L^-1 ·min (median with 25%-75% percentiles), but no other measurements indicated impaired β-cell function. We found no other differences between the three groups for other measurements in the OGTT, IVGTT, and euglycemic clamp. Muscle protein content of GLUT4 and hexokinase II was similar between the three groups.

CONCLUSIONS

We conclude that statin users in primary prevention experiencing myalgia do not have impaired glucose homeostasis compared with other statin users or non-users. We consider this an important aspect in the dialogue between physician and patient regarding statin treatment and adverse effects.

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.

Validation of a clinically-relevant rodent model of statin-associated muscle symptoms for use in pharmacological studies

Various rodent models of statin-associated muscle symptoms (SAMS) have been used to investigate the aetiology of statin myotoxicity. Variability between these models, however, may be contributing to the ambiguity currently surrounding the pathogenesis of SAMS. Furthermore, few studies have assessed the reproducibility of these models. The aim of this study was to compare two established rodent models of statin myotoxicity, differing in treatment duration and dose, to determine which reproducibly caused changes characteristic of SAMS. Isolated skeletal muscle organ bath experiments, biochemical analyses, real-time quantitative-PCR and biometric assessments were used to compare changes in skeletal muscle and renal integrity in statin-treated animals and time-matched control groups. The SIM80 model (80 mg kg^-1 day^-1 simvastatin for 14 days) produced fibre-selective skeletal muscle damage characteristic of SAMS. Indeed, fast-twitch gastrocnemius muscles showed increased Atrogin-1 expression, reduced peak force of contraction and decreased Myh2 expression while slow-twitch soleus muscles were unaffected. Contrastingly, the SIM50 model (50 mg kg^-1 day^-1 simvastatin for 30 days) produced little evidence of significant skeletal muscle damage. Neither statin treatment protocol caused significant pathological changes to the kidney. The results of this study indicate that the SIM80 model induces a type of SAMS in rodents that resembles the presentation of statin-induced myalgia in humans. The findings support that the SIM80 model is reproducible and can thus be reliably used as a platform to assess the aetiology and treatment of this condition.

Creatine supplementation does not alter the creatine kinase response to eccentric exercise in healthy adults on atorvastatin

BACKGROUND

Serum creatine kinase (CK) levels are higher after eccentric, muscle-damaging exercise in statin-treated patients. This could contribute to the increased statin-associated muscle symptoms reported in physically active individuals.

OBJECTIVE

We tested the hypothesis in this pilot study that creatine (Cr) monohydrate supplementation would reduce the CK response to eccentric exercise in patients using statins to determine if Cr supplementation could be a strategy to mitigate statin-associated muscle symptoms in physically active individuals.

METHODS

Healthy, nonsmoking men (n = 5) and women (n = 14) were randomized to Cr monohydrate = atorvastatin 80 mg + 10 g Cr monohydrate (n = 10, age = 60 ± 7 years) or to placebo (PL) = atorvastatin 80 mg + PL (n = 9, age = 52 ± 6 years). After 4 weeks of treatment, subjects performed 45 minutes of eccentric exercise (downhill walking at a -15% grade). Serum CK levels, muscle soreness (visual analog scale after two squats), and muscle pain severity and interference (using the brief pain inventory) were measured before and after 4 weeks of treatment, and then for 4 consecutive days after downhill walking. Vitamin D, or serum 25(OH)D, was also measured at baseline.

RESULTS

The PL group was younger (P = .01) but not otherwise different in blood lipids, vitamin D, CK, muscle visual analog scale, and pain scores before (all P > .21) or after (all P > .12) treatment. CK increased in all subjects after downhill walking (P < .01), but neither the relative peak change (expressed as group mean difference with 95% confidence intervals: 43.52% [-196.41, 283.45]) nor the absolute peak change (67.38 U/L [-121.55, 256.31]) relative to baseline was different between groups (P = .46 and .71, respectively). A similar lack of treatment effect was observed for muscle soreness (11.03 mm [-9.49, 31.55]), pain severity (0.77 pts [-0.95, 2.50]), and pain interference (1.02 pts [-1.25, 3.29]) with P-values for group comparisons = 0.27, 0.36, and 0.35, respectively. However, subjects with "insufficient" Vitamin D < 30 ng/mL (n = 10) had an ∼2-fold greater CK increase with eccentric exercise (nominal P-value = .04) than subjects with higher vitamin D levels.

CONCLUSION

Cr monohydrate did not reduce CK increases after exercise in statin-treated subjects. We did observe that low vitamin D levels are associated with a greater CK response to eccentric exercise in statin-treated subjects.

An update on the relationship between statins and physical activity

PURPOSE OF REVIEW

This review examined studies published within the last 16 months that investigated the relationship between statins and physical activity.

RECENT FINDINGS

These recent studies suggest that statins do not adversely affect cardiorespiratory fitness, muscle strength, athletic performance, or physical activity adherence. One recent study comparing patients with statin-associated myalgia and nonstatin-using controls did report that statins are associated with a slowing of time to peak power output, increased abdominal adiposity, and insulin resistance. Statin users also had different muscle gene expression than controls, but conclusions are limited by the design of that study.

SUMMARY

Previous reports suggest that statin-associated muscle symptoms such as myalgia, cramps, and weakness occur more frequently in physically active individuals, but the recent studies we reviewed do not provide additional support for this possibility. Well-designed clinical trials are needed to determine whether different statins or statin doses evoke statin-associated muscle symptoms or muscle damage that may reduce cardiorespiratory fitness and adherence to physical activity.

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.

Statins Affect Skeletal Muscle Performance: Evidence for Disturbances in Energy Metabolism

CONTEXT

Statin myopathy is linked to disturbances in mitochondrial function and exercise intolerance.

OBJECTIVES

To determine whether differences exist in exercise performance, muscle function, and muscle mitochondrial oxidative capacity and content between symptomatic and asymptomatic statin users, and control subjects.

DESIGN

Cross-sectional study.

SETTING

Department of Physiology, Radboud University Medical Center.

PARTICIPANTS

Long-term symptomatic and asymptomatic statin users, and control subjects (n = 10 per group).

INTERVENTIONS

Maximal incremental cycling tests, involuntary electrically stimulated isometric quadriceps-muscle contractions, and biopsy of vastus lateralis muscle.

MAIN OUTCOMES MEASURED

Maximal exercise capacity, substrate use during exercise, muscle function, and mitochondrial energy metabolism.

RESULTS

Peak oxygen uptake, maximal work load, and ventilatory efficiency were comparable between groups, but both statin groups had a depressed anaerobic threshold compared with the control group (P = 0.01). Muscle relaxation time was prolonged in both statin groups compared with the control group and rate of maximal force rise was decreased (Ptime×group < 0.001 for both measures). Mitochondrial activity of complexes II and IV was lower in symptomatic statin users than control subjects and tended to be lower for complex (C) III (CII: P = 0.03; CIII: P = 0.05; CIV: P = 0.04). Mitochondrial content tended to be lower in both statin groups than in control subjects.

CONCLUSION

Statin use attenuated substrate use during maximal exercise performance, induced muscle fatigue during repeated muscle contractions, and decreased muscle mitochondrial oxidative capacity. This suggests disturbances in mitochondrial oxidative capacity occur with statin use even in patients without statin-induced muscle complaints.

[Use of pharmacogenetic testing to prevent adverse drug reactions during statin therapy]

The number of patients receiving statins increases every year and due to the fact that they should take statins during their lives, the problem of their safety use comes to the forefront. The paper analyzes the safety of using the medications of this group and discusses the diagnosis of myopathies induced by statins and the occurrence of immune-mediated statin myopathies. It considers a personalized approach to prescribing statins, analyzes Russian and foreign experience in using pharmacogenetics to reduce the risk of myopathies, publishes the results of the authors' experience in clinically introducing pharmacogenetic testing at hospitals, and analyzes the long-term results of determining the polymorphism of the SLCO1B1 gene for the prediction of the risk of adverse events when using statins and estimating patient compliance to prescribed treatment.

Statin-Associated Side Effects

Hydroxy-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors or statins are well tolerated, but associated with various statin-associated symptoms (SAS), including statin-associated muscle symptoms (SAMS), diabetes mellitus (DM), and central nervous system complaints. These are "statin-associated symptoms" because they are rare in clinical trials, making their causative relationship to statins unclear. SAS are, nevertheless, important because they prompt dose reduction or discontinuation of these life-saving mediations. SAMS is the most frequent SAS, and mild myalgia may affect 5% to 10% of statin users. Clinically important muscle symptoms, including rhabdomyolysis and statin-induced necrotizing autoimmune myopathy (SINAM), are rare. Antibodies against HMG-CoA reductase apparently provoke SINAM. Good evidence links statins to DM, but evidence linking statins to other SAS is largely anecdotal. Management of SAS requires making the possible diagnosis, altering or discontinuing the statin treatment, and using alternative lipid-lowering therapy.

Current Treatment of Dyslipidemia: A New Paradigm for Statin Drug Use and the Need for Additional Therapies

Coronary heart disease (CHD) is the leading cause of death in most countries, with the high prevalence currently driven by dual epidemics of obesity and diabetes. Statin drugs, the most effective, evidence-based agents to prevent and treat this disease, have a central role in management and are advised in all published guidelines. The 2013 American College of Cardiology/American Heart Association (ACC/AHA) cholesterol and assessment guidelines ('new ACC/AHA guidelines') emphasized global cardiovascular (CV) risk reduction as opposed to targeting low-density lipoprotein-cholesterol (LDL-C) levels, stressed the use of statins in two dose intensities, utilized a new risk calculator using pooled cohort equations, and lowered the risk cutoff for initiation of statin therapy. Although there were major strengths of the new ACC/AHA guidelines, substantial controversy followed their release, particulars of which are discussed in this review. They were generally regarded as improvements in an ongoing transition using evidenced-based data for maximum patient benefit. Several guidelines, other than the ACC/AHA guidelines, currently provide practitioners with choices, some depending on practice locations. Cholesterol control with statin drugs is used in all paradigms. However, some patients respond inadequately, approximately 15% are intolerant, and other factors prevent attaining cholesterol goals in as many as 40% of patients. Even after treatment, substantial residual risk for ongoing major events remains. Another readily available modality that can rival statin drugs in effectiveness is vast improvement in diet and lifestyle within the general population; however, despite great effort, existing programs to implement such changes have failed. Hence, despite unrivaled success, there is great need for additional drugs to prevent and treat CHD, whether as monotherapy or in combination with statin drugs. New American guidelines do not discuss or recommend any nonstatin drugs for CHD, and the US FDA has moved away from approving drugs based solely on changes in surrogates in the absence of clinical outcomes trials. Both have significantly altered the realities of developing pharmacotherapies and cardiology practice.

Obesity Appears to Be Associated With Altered Muscle Protein Synthetic and Breakdown Responses to Increased Nutrient Delivery in Older Men, but Not Reduced Muscle Mass or Contractile Function

Obesity is increasing, yet despite the necessity of maintaining muscle mass and function with age, the effect of obesity on muscle protein turnover in older adults remains unknown. Eleven obese (BMI 31.9 ± 1.1 kg · m(-2)) and 15 healthy-weight (BMI 23.4 ± 0.3 kg · m(-2)) older men (55-75 years old) participated in a study that determined muscle protein synthesis (MPS) and leg protein breakdown (LPB) under postabsorptive (hypoinsulinemic-euglycemic clamp) and postprandial (hyperinsulinemic hyperaminoacidemic-euglycemic clamp) conditions. Obesity was associated with systemic inflammation, greater leg fat mass, and patterns of mRNA expression consistent with muscle deconditioning, whereas leg lean mass, strength, and work done during maximal exercise were no different. Under postabsorptive conditions, MPS and LPB were equivalent between groups, whereas insulin and amino acid administration increased MPS in only healthy-weight subjects and was associated with lower leg glucose disposal (LGD) (63%) in obese men. Blunting of MPS in the obese men was offset by an apparent decline in LPB, which was absent in healthy-weight subjects. Lower postprandial LGD in obese subjects and blunting of MPS responses to amino acids suggest that obesity in older adults is associated with diminished muscle metabolic quality. This does not, however, appear to be associated with lower leg lean mass or strength.

Effect of hyperinsulinaemia-hyperaminoacidaemia on leg muscle protein synthesis and breakdown: reassessment of the two-pool arterio-venous balance model

Accurate measurement of muscle protein turnover is critical for understanding the physiological processes underlying muscle atrophy and hypertrophy. Several mathematical approaches, used in conjunction with a tracer amino acid infusion, have been described to derive protein synthesis and breakdown rates from a two-pool (artery-vein) model. Despite apparently common underlying principles, these approaches differ significantly (some seem to not take into account arterio-venous shunting of amino acids, which comprises ∼80-90% of amino acids appearing in the vein) and most do not specify how tracer enrichment (i.e. mole percent excess (MPE) or tracer-to-tracee ratio (TTR)) and amino acid concentration (i.e. unlabelled only or total labelled plus unlabelled) should be expressed, which could have a significant impact on the outcome when using stable isotope labelled tracers. We developed equations that avoid these uncertainties and used them to calculate leg phenylalanine (Phe) kinetics in subjects who received a [(2) H5 ]Phe tracer infusion during postabsorptive conditions and during a hyperinsulinaemic-euglycaemic clamp with concomitant protein ingestion. These results were compared with those obtained by analysing the same data with previously reported equations. Only some of them computed the results correctly when used with MPE as the enrichment measure and total (tracer+tracee) Phe concentrations; errors up to several-fold in magnitude were noted when the same approaches were used in conjunction with TTR and/or unlabelled concentration only, or when using the other approaches (irrespective of how concentration and enrichment are expressed). Our newly developed equations should facilitate accurate calculation of protein synthesis and breakdown rates.