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

Statins affect human iPSC-derived cardiomyocytes by interfering with mitochondrial function and intracellular acidification

Statins are effective drugs in reducing cardiovascular morbidity and mortality by inhibiting cholesterol synthesis. These effects are primarily beneficial for the patient's vascular system. A significant number of statin users suffer from muscle complaints probably due to mitochondrial dysfunction, a mechanism that has recently been elucidated. This has raised our interest in exploring the effects of statins on cardiac muscle cells in an era where the elderly and patients with poorer functioning hearts and less metabolic spare capacity start dominating our patient population. Here, we investigated the effects of statins on human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-derived CMs). hiPSC-derived CMs were exposed to simvastatin, atorvastatin, rosuvastatin, and cerivastatin at increasing concentrations. Metabolic assays and fluorescent microscopy were employed to evaluate cellular viability, metabolic capacity, respiration, intracellular acidity, and mitochondrial membrane potential and morphology. Over a concentration range of 0.3-100 µM, simvastatin lactone and atorvastatin acid showed a significant reduction in cellular viability by 42-64%. Simvastatin lactone was the most potent inhibitor of basal and maximal respiration by 56% and 73%, respectively, whereas simvastatin acid and cerivastatin acid only reduced maximal respiration by 50% and 42%, respectively. Simvastatin acid and lactone and atorvastatin acid significantly decreased mitochondrial membrane potential by 20%, 6% and 3%, respectively. The more hydrophilic atorvastatin acid did not seem to affect cardiomyocyte metabolism. This calls for further research on the translatability to the clinical setting, in which a more conscientious approach to statin prescribing might be considered, especially regarding the current shift in population toward older patients with poor cardiac function.

The atorvastatin metabolite pattern in muscle tissue and blood plasma is associated with statin muscle side effects in patients with coronary heart disease; An exploratory case-control study

Background and aims

Statin-associated muscle symptoms (SAMS) is a prevalent cause of statin discontinuation. It is challenging and time-consuming for clinicians to assess whether symptoms are caused by the statin or not, and diagnostic biomarkers are requested. Atorvastatin metabolites have been associated with SAMS. We aimed to compare atorvastatin pharmacokinetics between coronary heart disease (CHD) patients with and without clinically statin intolerance and statin-dependent histopathological alterations in muscle tissue. Secondarily we aimed to assess genetic variants relevant for the observed pharmacokinetic variables.

Methods

Twenty-eight patients with CHD and subjective SAMS were included in the exploratory MUSE biomarker study in 2020. Participants received atorvastatin 40 mg/day for seven weeks followed by no statins for eight weeks. Muscle biopsies and blood were collected at the end of each period. Four patients were categorized as clinically intolerant to ≥3 statins prior to study start whereas four patients had signs of muscle cell damage during treatment.

Results

We found significantly lower levels of atorvastatin acids, and higher lactone/acid ratios in the statin intolerant, both in muscle and plasma. With optimal cut-off, the combination of 2-OH-atorvastatin acid and the 2-OH-atorvastatin lactone/acid ratio provided sensitivity, specificity, and predictive values of 100 %. Patients with variants in UGT1A1 and UGT1A3 had higher lactone metabolite levels than those with wild type, both in muscle and plasma.

Conclusion

Atorvastatin metabolites appear promising as biomarkers for the identification of clinical statin intolerance in patients with self-perceived SAMS, but the findings have to be confirmed in larger studies.

High-dose atorvastatin therapy progressively decreases skeletal muscle mitochondrial respiratory capacity in humans

BACKGROUNDWhile the benefits of statin therapy on atherosclerotic cardiovascular disease are clear, patients often experience mild to moderate skeletal myopathic symptoms, the mechanism for which is unknown. This study investigated the potential effect of high-dose atorvastatin therapy on skeletal muscle mitochondrial function and whole-body aerobic capacity in humans.METHODSEight overweight (BMI, 31.9 ± 2.0) but otherwise healthy sedentary adults (4 females, 4 males) were studied before (day 0) and 14, 28, and 56 days after initiating atorvastatin (80 mg/d) therapy.RESULTSMaximal ADP-stimulated respiration, measured in permeabilized fiber bundles from muscle biopsies taken at each time point, declined gradually over the course of atorvastatin treatment, resulting in > 30% loss of skeletal muscle mitochondrial oxidative phosphorylation capacity by day 56. Indices of in vivo muscle oxidative capacity (via near-infrared spectroscopy) decreased by 23% to 45%. In whole muscle homogenates from day 0 biopsies, atorvastatin inhibited complex III activity at midmicromolar concentrations, whereas complex IV activity was inhibited at low nanomolar concentrations.CONCLUSIONThese findings demonstrate that high-dose atorvastatin treatment elicits a striking progressive decline in skeletal muscle mitochondrial respiratory capacity, highlighting the need for longer-term dose-response studies in different patient populations to thoroughly define the effect of statin therapy on skeletal muscle health.FUNDINGNIH R01 AR071263.

Differential effects of OATP2B1 on statin accumulation and toxicity in a beta cell model

An increased risk of new-onset diabetes mellitus has been recently reported for statin therapy, and experimental studies have shown reduced glucose-stimulated insulin secretion (GSIS) and mitochondrial dysfunction in beta cells with effects differing among agents. Organic anion transporting polypeptide (OATP) 2B1 contributes to hepatic uptake of rosuvastatin, atorvastatin and pravastatin, three known substrates. Since OATP2B1 is present in beta cells of the human pancreas, we investigated if OATP2B1 facilitates the local accumulation of statins in a rat beta cell model INS-1 832/13 (INS-1) thereby amplifying statin-induced toxicity. OATP2B1 overexpression in INS-1 cells via adenoviral transduction showed 2.5-, 1.8- and 1.4-fold higher cellular retention of rosuvastatin, atorvastatin and pravastatin, respectively, relative to LacZ control, while absolute intracellular concentration was about twice as high for the lipophilic atorvastatin compared to the more hydrophilic rosuvastatin and pravastatin. After 24 h statin treatment at high concentrations, OATP2B1 enhanced statin toxicity involving activation of intrinsic apoptosis (caspase 3/7 activation) and mitochondrial dysfunction (NADH dehydrogenase activity) following rosuvastatin and atorvastatin, which was partly reversed by isoprenoids. OATP2B1 had no effect on statin-induced reduction in GSIS, mitochondrial electron transport chain complex expression or caspase 9 activation. We confirmed a dose-dependent reduction in insulin secretion by rosuvastatin and atorvastatin in native INS-1 with a modest change in cellular ATP. Collectively, our results indicate a role of OATP2B1, which is abundant in human beta cells, in statin accumulation and statin-induced toxicity but not insulin secretion of rosuvastatin and atorvastatin in INS-1 cells.

Potential mechanisms underlying the effect of walking exercise on cancer-related fatigue in cancer survivors

PURPOSE

Cancer-related fatigue (CRF) is a common and debilitating long-term side effect of cancer and its treatment. While exercise has been shown to effectively reduce CRF, the underlying mechanisms are not fully clear. Therefore, the aim of this study was to explore the effects of a 4-month walking exercise program on fatigue severity and to explore potential underlying physiological, behavioral, and psychological mechanisms of action.

METHODS

We included 27 cancer survivors (59 ± 15 years, 37% female) with variable cancer diagnoses who were at least moderately fatigued and finished treatment between 6 and 36 months ago. This study with a quasi-experimental interrupted time-series design compared a 4-month walking intervention period with a 4-month control period. Measurements of fatigue and physiological, behavioral, and psychological factors were performed, supplemented with participants' perceptions on how exercise influenced their fatigue.

RESULTS

A significant and clinically relevant decrease in fatigue severity was found over time (β =  - 8.1, 95% CI =  - 12.1; - 4.2), but could not be attributed directly to the walking exercise intervention. Increases in muscle strength (β =  - 0.07, 95% CI =  - 0.12; - 0.02), physical activity (β =  - 0.1, 95% CI =  - 0.2; - 0.04), and sleep quality (β = 1.1, 95% CI = 0.3; 1.9), as well as decreases in muscle relaxation times (β = 0.09, 95% CI = 0.02; 0.16) and psychological distress (β = 1.1, 95% CI = 0.8; 1.3) were associated with reductions in fatigue severity. Resilience and physical well-being were perceived as most important constructs explaining the walking exercise effects on fatigue.

CONCLUSION

Our findings reveal potential physiological, behavioral, and psychological mechanisms underlying the multidimensional effects of exercise on fatigue severity.

IMPLICATIONS FOR CANCER SURVIVORS

Incorporating resistance exercise and addressing resilience and physical well-being might improve the efficacy of exercise interventions for cancer survivors.

The angiotensin-converting enzyme I/D polymorphism does not impact training-induced adaptations in exercise capacity in patients with stable coronary artery disease

Systematic exercise training effectively improves exercise capacity in patients with coronary artery disease (CAD), but the magnitude of improvements is highly heterogeneous. We investigated whether this heterogeneity in exercise capacity gains is influenced by the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene. Patients with CAD (n = 169) were randomly assigned to 12 weeks of exercise training or standard care, and 142 patients completed the study. The ACE polymorphism was determined for 128 patients (82% males, 67 ± 9 years). Peak oxygen uptake was measured before and after the 12-week intervention. The ACE I/D polymorphism frequency was n = 48 for D/D homozygotes, n = 61 for I/D heterozygotes and n = 19 for I/I homozygotes. Baseline peak oxygen uptake was 23.3 ± 5.0 ml/kg/min in D/D homozygotes, 22.1 ± 5.3 ml/kg/min in I/D heterozygotes and 23.1 ± 6.0 ml/kg/min in I/I homozygotes, with no statistical differences between genotype groups (P = 0.50). The ACE I/D polymorphism frequency in the exercise group was n = 26 for D/D, n = 21 for I/D and n = 12 for I/I. After exercise training, peak oxygen uptake was increased (P < 0.001) in D/D homozygotes by 2.6 ± 1.7 ml/kg/min, in I/D heterozygotes by 2.7 ± 1.9 ml/kg/min, and in I/I homozygotes by 2.1 ± 1.3 ml/kg/min. However, the improvements were similar between genotype groups (time × genotype, P = 0.55). In conclusion, the ACE I/D polymorphism does not affect baseline exercise capacity or exercise capacity gains in response to 12 weeks of high-intensity exercise training in patients with stable CAD.Clinical trial registration: www.clinicaltrials.gov (NCT04268992).

Statins and Cardiomyocyte Metabolism, Friend or Foe?

Statins inhibit HMG-CoA reductase, the rate-limiting enzyme in cholesterol synthesis, and are the cornerstone of lipid-lowering treatment. They significantly reduce cardiovascular morbidity and mortality. However, musculoskeletal symptoms are observed in 7 to 29 percent of all users. The mechanism underlying these complaints has become increasingly clear, but less is known about the effect on cardiac muscle function. Here we discuss both adverse and beneficial effects of statins on the heart. Statins exert pleiotropic protective effects in the diseased heart that are independent of their cholesterol-lowering activity, including reduction in hypertrophy, fibrosis and infarct size. Adverse effects of statins seem to be associated with altered cardiomyocyte metabolism. In this review we explore the differences in the mechanism of action and potential side effects of statins in cardiac and skeletal muscle and how they present clinically. These insights may contribute to a more personalized treatment strategy.

Mitochondrial complex III activity: from invasive muscle biopsies to patient-friendly buccal swab analysis

Drug-induced mitochondrial dysfunction is a common adverse effect, particularly in case of statins-the most prescribed drugs worldwide. These drugs have been shown to inhibit complex III (CIII) of the mitochondrial oxidative phosphorylation process, which is related to muscle pain. As muscle pain is the most common complaint of statin users, it is crucial to distinguish it from other causes of myalgia to prevent unnecessary cessation of drug therapy. However, diagnosing CIII inhibition currently requires muscle biopsies, which are invasive and not practical for routine testing. Less invasive alternatives for measurement of mitochondrial complex activities are only available yet for complex I and IV. Here, we describe a non-invasive spectrophotometric method to determine CIII catalytic activities using buccal swabs, which we validated in a cohort of statin and non-statin users. Our data indicate that CIII can be reliably measured in buccal swabs, as evidenced by reproducible results above the detection limit. Further validation on a large-scale clinical setting is recommended.

Developing In Vitro Models to Define the Role of Direct Mitochondrial Toxicity in Frequently Reported Drug-Induced Rhabdomyolysis

The United States Food and Drug Administration Adverse Event Reporting System (FAERS) logged 27,140 rhabdomyolysis cases from 2004 to 31 March 2020. We used FAERS to identify 14 drugs frequently reported in 6583 rhabdomyolysis cases and to investigate whether mitochondrial toxicity is a common pathway of drug-induced rhabdomyolysis by these drugs. Preliminary screening for mitochondrial toxicity was performed using the acute metabolic switch assay, which is adapted here for use in murine L6 cells. Fenofibrate, risperidone, pregabalin, propofol, and simvastatin lactone drugs were identified as mitotoxic and underwent further investigation, using real-time respirometry (Seahorse Technology) to provide more detail on the mechanism of mitochondrial-induced toxicity. To confirm the human relevance of the findings, fenofibrate and risperidone were evaluated in primary human skeletal muscle-derived cells (HSKMDC), using the acute metabolic switch assay and real-time respirometry, which confirmed this designation, although the toxic effects on the mitochondria were more pronounced in HSKMDC. Overall, these studies demonstrate that the L6 model of acute modification may find utility as an initial, cost-effective screen for identifying potential myotoxicants with relevance to humans and, importantly, that drug-induced mitochondrial dysfunction may be a common mechanism shared by some drugs that induce myotoxicity.

A novel machine learning-based screening identifies statins as inhibitors of the calcium pump SERCA

We report a novel small-molecule screening approach that combines data augmentation and machine learning to identify Food and Drug Administration (FDA)-approved drugs interacting with the calcium pump (Sarcoplasmic reticulum Ca2+-ATPase, SERCA) from skeletal (SERCA1a) and cardiac (SERCA2a) muscle. This approach uses information about small-molecule effectors to map and probe the chemical space of pharmacological targets, thus allowing to screen with high precision large databases of small molecules, including approved and investigational drugs. We chose SERCA because it plays a major role in the excitation-contraction-relaxation cycle in muscle and it represents a major target in both skeletal and cardiac muscle. The machine learning model predicted that SERCA1a and SERCA2a are pharmacological targets for seven statins, a group of FDA-approved 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors used in the clinic as lipid-lowering medications. We validated the machine learning predictions by using in vitro ATPase assays to show that several FDA-approved statins are partial inhibitors of SERCA1a and SERCA2a. Complementary atomistic simulations predict that these drugs bind to two different allosteric sites of the pump. Our findings suggest that SERCA-mediated Ca2+ transport may be targeted by some statins (e.g., atorvastatin), thus providing a molecular pathway to explain statin-associated toxicity reported in the literature. These studies show the applicability of data augmentation and machine learning-based screening as a general platform for the identification of off-target interactions and the applicability of this approach extends to drug discovery.

Prolonged Moderate-Intensity Exercise Does Not Increase Muscle Injury Markers in Symptomatic or Asymptomatic Statin Users

BACKGROUND

Statin use may exacerbate exercise-induced skeletal muscle injury caused by reduced coenzyme Q10 (CoQ10) levels, which are postulated to produce mitochondrial dysfunction.

OBJECTIVES

We determined the effect of prolonged moderate-intensity exercise on markers of muscle injury in statin users with and without statin-associated muscle symptoms. We also examined the association between leukocyte CoQ10 levels and muscle markers, muscle performance, and reported muscle symptoms.

METHODS

Symptomatic (n = 35; age 62 ± 7 years) and asymptomatic statin users (n = 34; age 66 ± 7 years) and control subjects (n = 31; age 66 ± 5 years) walked 30, 40, or 50 km/d for 4 consecutive days. Muscle injury markers (lactate dehydrogenase, creatine kinase, myoglobin, cardiac troponin I, and N-terminal pro-brain natriuretic peptide), muscle performance, and reported muscle symptoms were assessed at baseline and after exercise. Leukocyte CoQ10 was measured at baseline.

RESULTS

All muscle injury markers were comparable at baseline (P > 0.05) and increased following exercise (P < 0.001), with no differences in the magnitude of exercise-induced elevations among groups (P > 0.05). Muscle pain scores were higher at baseline in symptomatic statin users (P < 0.001) and increased similarly in all groups following exercise (P < 0.001). Muscle relaxation time increased more in symptomatic statin users than in control subjects following exercise (P = 0.035). CoQ10 levels did not differ among symptomatic (2.3 nmol/U; IQR: 1.8-2.9 nmol/U), asymptomatic statin users (2.1 nmol/U; IQR: 1.8-2.5 nmol/U), and control subjects (2.1 nmol/U; IQR: 1.8-2.3 nmol/U; P = 0.20), and did not relate to muscle injury markers, fatigue resistance, or reported muscle symptoms.

CONCLUSIONS

Statin use and the presence of statin-associated muscle symptoms does not exacerbate exercise-induced muscle injury after moderate exercise. Muscle injury markers were not related to leukocyte CoQ10 levels. (Exercise-induced Muscle Damage in Statin Users; NCT05011643).

Side effects of statins: from pathophysiology and epidemiology to diagnostic and therapeutic implications

Treatment with statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, has proven beneficial preventive effects on cardiovascular events. However, discontinuation due to intolerance and non-adherence remain two of the major gaps in both primary and secondary prevention. This leads many patients with high-risk of atherosclerotic cardiovascular disease (ASCVD) to be inadequately treated or not to achieve target lipid level goals, and as consequence they undergo an increased risk of cardiovascular events. The aim of this review is thus to give an overview of the reasons for discontinuation and on the possible mechanisms behind them. Although statins, as a class, are generally safe, they are associated with an increased risk of diabetes mellitus and hepatic transaminase elevations. Incidence of cataracts or cognitive dysfunction and others presented in the literature (e.g. proteinuria and haematuria) have been never confirmed to have a causal link. Conversely, debated remains the effect on myalgia. Muscle side effects are the most commonly reported, although myalgia is still believed by some to be the result of a nocebo/drucebo effect. Concerning mechanisms behind muscular side effects, no clear conclusions have been reached. Thus, if on one side it is important to identify individuals either at higher risk to develop a side effect, or with confirmed risk factors and conditions of statin intolerance, on the other side alternative strategies should be identified to avoid an increased ASCVD risk.

Impact of Atorvastatin on Skeletal Muscle Mitochondrial Activity, Locomotion and Axonal Excitability-Evidence from ApoE-/- Mice

The cardiovascular benefit of statins is well established. However, only 20% of high-risk patients remain adequately adherent after 5 years of treatment. Among reasons for discontinuation, statin associated-muscle pain symptoms are the most prevalent. Aim of the present study was to evaluate the impact of high dose atorvastatin on skeletal muscle mitochondrial activity, aerobic and anaerobic exercise, and axonal excitability in a murine model of atherosclerosis. ApoE^-/- mice were fed 12 weeks a high-fat high-cholesterol diet alone or containing atorvastatin (40 mg/Kg/day). Outcomes were the evaluation of muscle mitochondrial functionality, locomotion, grip test, and axonal excitability (compound action potential recording analysis of Aα motor propioceptive, Aβ mechanoceptive and C nociceptive fibres). Atorvastatin led to a reduction in muscle mitochondrial biogenesis and mitochondrial ATP production. It did not affect muscular strength but led to a time-dependent motor impairment. Atorvastatin altered the responsiveness of mechanoceptive and nociceptive fibres, respectively, the Aβ and C fibres. These findings point out to a mild sensitization on mechanical, tactile and pain sensitivity. In conclusion, although the prevalence of muscular side effects from statins may be overestimated, understanding of the underlying mechanisms can help improve the therapeutic approach and reassure adherence in patients needing-to-be-treated.

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.

Moderate Intensity Exercise Training Improves Skeletal Muscle Performance in Symptomatic and Asymptomatic Statin Users

BACKGROUND

The combination of statin therapy and physical activity reduces cardiovascular disease risk in patients with hyperlipidemia more than either treatment alone. However, mitochondrial dysfunction associated with statin treatment could attenuate training adaptations.

OBJECTIVES

This study determined whether moderate intensity exercise training improved muscle and exercise performance, muscle mitochondrial function, and fiber capillarization in symptomatic and asymptomatic statin users.

METHODS

Symptomatic (n = 16; age 64 ± 4 years) and asymptomatic statin users (n = 16; age 64 ± 4 years) and nonstatin using control subjects (n = 20; age 63 ± 5 years) completed a 12-week endurance and resistance exercise training program. Maximal exercise performance (peak oxygen consumption), muscle performance and muscle symptoms were determined before and after training. Muscle biopsies were collected to assess citrate synthase activity, adenosine triphosphate (ATP) production capacity, muscle fiber type distribution, fiber size, and capillarization.

RESULTS

Type I muscle fibers were less prevalent in symptomatic statin users than control subjects at baseline (P = 0.06). Exercise training improved muscle strength (P < 0.001), resistance to fatigue (P = 0.01), and muscle fiber capillarization (P < 0.01), with no differences between groups. Exercise training improved citrate synthase activity in the total group (P < 0.01), with asymptomatic statin users showing less improvement than control subjects (P = 0.02). Peak oxygen consumption, ATP production capacity, fiber size, and muscle symptoms remained unchanged in all groups following training. Quality-of-life scores improved only in symptomatic statin users following exercise training (P < 0.01).

CONCLUSIONS

A moderate intensity endurance and resistance exercise training program improves muscle performance, capillarization, and mitochondrial content in both asymptomatic and symptomatic statin users without exacerbating muscle complaints. Exercise training may even increase quality of life in symptomatic statin users. (The Effects of Cholesterol-Lowering Medication on Exercise Performance [STATEX]; NL5972/NTR6346).

The impact of statin therapy and aerobic exercise training on skeletal muscle and whole-body aerobic capacity

Background

Statin use is widely recognized for improving cardiovascular health, but questions remain on how statin use influences skeletal muscle, particularly mitochondrial function.

Study objective design and participants

The influence of statin therapy and exercise (EX) on aerobic capacity was determined. In Study1, skeletal muscle aerobic capacity was measured before and after 80 mg atorvastatin therapy. In Study2, aerobic capacity (skeletal muscle and whole body) was measured before and after a 12-week exercise randomized control trial in older adults (age = 67 ± 5 yrs.), a subset of which were on chronic low-moderate intensity statin therapy.

Main outcome measures

Muscle oxidative capacity was determined from the phosphocreatine recovery rate constant (kPCr) using ³¹P Magnetic Resonance Spectroscopy. Whole body peak oxygen uptake (VO₂ peak) was measured during a graded exercise test with indirect calorimetry.

Results

High dose statin therapy resulted in a 12% reduction in muscle oxidative capacity (pre = 1.34 ± 0.34 min^-1, post = 1.17 ± 0.25 min^-1, p = 0.004). Similarly, chronic low-moderate dose statin therapy was associated with lower muscle oxidative capacity at baseline (1.50 ± 0.35 min^-1) compared to non-statin users (1.88 ± 0.047 min^-1, p = 0.019). Following EX, muscle oxidative capacity increased by 35-40% (statin: Pre: 1.39 ± 0.44 vs. Post: 1.88 ± 0.47 min^-1, no statin Pre: 1.86 ± 0.58 vs. Post: 2.58 ± 0.85 min^-1) compared to control groups (Pre: 1.74 ± 0.27 vs Post: 1.75 ± 0.49 min^-1, p = 0.001). VO₂ peak increased by 11% for EX groups (Pre: 18.8 ± 2.8 vs. Post: 20.8 ± 3.0 ml·kg^-1·min^-1) following training compared to a small decline in controls (Pre: 21.8 ± 3.7 vs. Post: 20.8 ± 3.04 ml·kg^-1·min^-1, p = 0.001).

Conclusions

Statin therapy resulted in reduced muscle oxidative capacity. Aerobic exercise improved skeletal muscle oxidative capacity and whole-body aerobic capacity during statin therapy.

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.

Rationale for the use of metformin and exercise to counteract statin-associated side effects

INTRODUCTION

Statins are the most widely prescribed drugs for lowering low-density lipoprotein cholesterol (LDL-C) and reducing cardiovascular morbidity and mortality. They are usually well-tolerated, but have two main safety concerns: statin-associated muscle symptoms (SAMS) and new-onset type 2 diabetes (NOD).

METHODS

A PubMed search was carried out using the following key words were used: statins, statin-associated muscle symptoms, statin myalgia, statin-associated diabetes, metformin and statins, exercise and statins.

RESULTS

Mitochondrial damage and muscle atrophy are likely the central mechanisms producing SAMS, whereas decreased glucose transport, fatty acid oxidation and insulin secretion are likely involved in the development of NOD. Metformin and exercise training share many pathways that could potentially contrast SAMS and NOD. Clinical evidence also supports the combination of statins with metformin and exercise.

CONCLUSION

This combination appears attractive both from a clinical and an economical viewpoint, since all three therapies are highly cost-effective and their combination could result in diabetes and cardiovascular disease prevention.

Improvement of Platelet Respiration by Cell-Permeable Succinate in Diabetic Patients Treated with Statins

Diabetes mellitus (DM) is the most severe metabolic disease that reached the level of a global pandemic and is associated with high cardiovascular morbidity. Statins are the first-line lipid-lowering therapy in diabetic patients with or without a history of atherosclerotic disease. Although well tolerated, chronic treatment may result in side effects that lead to treatment interruption. Mitochondrial dysfunction has emerged as a central pathomechanism in DM- and statin-induced side effects. Assessment of mitochondrial respiration in peripheral platelets has been increasingly used as a mirror of organ mitochondrial dysfunction. The present study aimed to assess the: (i) changes in mitochondrial respiration elicited by statins in patients with type 2 DM and (ii) the effects of cell-permeable succinate (NV118) on respiratory parameters in platelets harvested from these patients. No significant changes were found in global mitochondrial respiration of intact platelets isolated from diabetic patients treated with either atorvastatin or rosuvastatin. Similarly, no significant changes in mitochondrial respiration of permeabilized platelets were found between diabetic patients treated with atorvastatin and healthy controls. Acute ex vivo administration of NV118 significantly improved respiration in isolated platelets. These results prompt further research on the role of permeable succinate as a therapeutic alternative for improving mitochondrial function in metabolic pathologies and point to the role of peripheral platelets as a potential biomarker of treatment response.

Exhaled Breath Reflects Prolonged Exercise and Statin Use during a Field Campaign

Volatile organic compounds (VOCs) in exhaled breath provide insights into various metabolic processes and can be used to monitor physiological response to exercise and medication. We integrated and validated in situ a sampling and analysis protocol using proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) for exhaled breath research. The approach was demonstrated on a participant cohort comprising users of the cholesterol-lowering drug statins and non-statin users during a field campaign of three days of prolonged and repeated exercise, with no restrictions on food or drink consumption. The effect of prolonged exercise was reflected in the exhaled breath of participants, and relevant VOCs were identified. Most of the VOCs, such as acetone, showed an increase in concentration after the first day of walking and subsequent decrease towards baseline levels prior to walking on the second day. A cluster of short-chain fatty acids including acetic acid, butanoic acid, and propionic acid were identified in exhaled breath as potential indicators of gut microbiota activity relating to exercise and drug use. We have provided novel information regarding the use of breathomics for non-invasive monitoring of changes in human metabolism and especially for the gut microbiome activity in relation to exercise and the use of medication, such as statins.

Skeletal muscle disease in rheumatoid arthritis: the center of cardiometabolic comorbidities?

PURPOSE OF REVIEW

Despite its critical roles in body movement, structure, and metabolism, skeletal muscle remains underappreciated in the context of rheumatoid arthritis. In rheumatoid arthritis, chronic inflammation, physical inactivity, and medication toxicities impair skeletal muscle. These skeletal muscle alterations contribute to continued rheumatoid arthritis disparities in physical function and cardiometabolic health.

RECENT FINDINGS

In the prebiologic disease-modifying antirheumatic drug era, rheumatoid arthritis skeletal muscle atrophy was the central feature of 'rheumatoid cachexia,' a hypermetabolic state driven by chronic systemic inflammation and muscle protein degradation. In the current era, rheumatoid arthritis muscle deficits are less visible, yet persist as a key component of 'sarcopenic obesity.' In rheumatoid arthritis sarcopenic obesity, chronic inflammation, physical inactivity, and medication toxicities contribute to muscle contractile deficits, inflammation, altered metabolism, and intramuscular adiposity, a key predictor of rheumatoid arthritis disability and insulin resistance.

SUMMARY

Rheumatoid arthritis skeletal muscle disease in the current era is defined by impaired contractile function (poor strength and endurance) and sarcopenic obesity (decreased muscle mass, increased fat mass, and intramuscular adiposity). These muscle impairments contribute to disability and cardiometabolic disease in rheumatoid arthritis. Management should focus on monitoring of rheumatoid arthritis muscle function and body composition, limiting potentially myotoxic drugs, and prescription of exercise training.

Cell-Permeable Succinate Rescues Mitochondrial Respiration in Cellular Models of Statin Toxicity

Statins are the cornerstone of lipid-lowering therapy. Although generally well tolerated, statin-associated muscle symptoms (SAMS) represent the main reason for treatment discontinuation. Mitochondrial dysfunction of complex I has been implicated in the pathophysiology of SAMS. The present study proposed to assess the concentration-dependent ex vivo effects of three statins on mitochondrial respiration in viable human platelets and to investigate whether a cell-permeable prodrug of succinate (complex II substrate) can compensate for statin-induced mitochondrial dysfunction. Mitochondrial respiration was assessed by high-resolution respirometry in human platelets, acutely exposed to statins in the presence/absence of the prodrug NV118. Statins concentration-dependently inhibited mitochondrial respiration in both intact and permeabilized cells. Further, statins caused an increase in non-ATP generating oxygen consumption (uncoupling), severely limiting the OXPHOS coupling efficiency, a measure of the ATP generating capacity. Cerivastatin (commercially withdrawn due to muscle toxicity) displayed a similar inhibitory capacity compared with the widely prescribed and tolerable atorvastatin, but did not elicit direct complex I inhibition. NV118 increased succinate-supported mitochondrial oxygen consumption in atorvastatin/cerivastatin-exposed platelets leading to normalization of coupled (ATP generating) respiration. The results acquired in isolated human platelets were validated in a limited set of experiments using atorvastatin in HepG2 cells, reinforcing the generalizability of the findings.

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.

Home-based inspiratory muscle training for management of older patients with heart failure with preserved ejection fraction: does baseline inspiratory muscle pressure matter?

BACKGROUND

Heart failure with preserved ejection fraction is a clinical syndrome characterised by reduced exercise capacity. Some evidence has shown that a simple and home-based programme of inspiratory muscle training offers promising results in terms of aerobic capacity improvement in patients with heart failure with preserved ejection fraction. This study aimed to investigate whether the baseline inspiratory muscle function predicts the changes in aerobic capacity (measured as peak oxygen uptake; peak VO₂) after a 12-week home-based programme of inspiratory muscle training in patients with heart failure with preserved ejection fraction.

METHODS

A total of 45 stable symptomatic patients with heart failure with preserved ejection fraction and New York Heart Association II-III received a 12-week home-based programme of inspiratory muscle training between June 2015 and December 2016. They underwent cardiopulmonary exercise testing and measurements of maximum inspiratory pressure pre and post-inspiratory muscle training. Maximum inspiratory pressure and peak VO₂ were registered in both visits. Multivariate linear regression analysis was used to assess the association between changes in peak VO₂ (Δ-peakVO₂) and baseline predicted maximum inspiratory pressure (pp-MIP).

RESULTS

The median (interquartile range) age was 73 (68-77) years, 47% were women and 35.6% displayed New York Heart Association III. The mean peak VO₂ at baseline and Δ-peakVO₂ post-training were 10.4±2.8 ml/min/kg and +2.2±1.3 ml/min/kg (+21.3%), respectively. The median (interquartile range) of pp-MIP and Δ-MIP were 71% (64-92) and 39.2 (26.7-80.4) cmH₂O, respectively. After a multivariate analysis, baseline pp-MIP was not associated with Δ-peakVO₂ (β coefficient 0.005, 95% confidence interval -0.009-0.019, P=0.452).

CONCLUSIONS

In symptomatic and deconditioned older patients with heart failure with preserved ejection fraction, a home-based inspiratory muscle training programme improves aerobic capacity regardless of the baseline maximum inspiratory pressure.

Mechanisms of statin-associated skeletal muscle-associated symptoms

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

Plasma 2-hydroxyglutarate, a promising prognostic biomarker candidate for skeletal muscle injury in Fischer 344 rats

Previously, we have demonstrated the potential of plasma 2-hydroxyglutarate (2HG) as an easily detectable biomarker for skeletal muscle injury in rats. Here, we examined whether plasma 2HG was superior to conventional skeletal muscle damage biomarkers, including aspartate aminotransferase (AST), creatine kinase (CK), and skeletal muscle-type CK isoenzyme (CK-MM) levels, in rats. Skeletal muscle injury was induced in 4- or 9-week-old male Fischer 344 rats by cerivastatin (CER) or tetramethyl-p-phenylenediamine (TMPD) administration. Plasma 2HG levels were measured on days 4, 8, and 11 (CER group) and at 6 and 24 hr post-administration (TMPD group). Plasma AST, CK, and CK-MM activities and histopathological changes in the rectus femoris muscle were evaluated at the study endpoints. In the CER group, AST, CK, and CK-MM increased in 4- and 9-week-old rats, whereas increases in CK (4- and 9-week-old rats) and CK-MM (4-week-old rats) were not obvious in the TMPD group. In both 4- and 9-week-old rats, plasma 2HG increased on day 8 and at 24 hr post-administration in the CER and TMPD groups, respectively. Histopathological analysis revealed myofiber vacuolation and necrosis in both groups. The histopathological damage to the rectus femoris muscle was more severe in the CER than in the TMPD group. Increased plasma 2HG was associated with CER- and TMPD-induced skeletal muscle injuries in rats and was not affected by age differences or repeated blood collection. The results suggest that plasma 2HG is superior to CK and CK-MM as a biomarker for mild skeletal muscle injury.

Atorvastatin, but not pravastatin, inhibits cardiac Akt/mTOR signaling and disturbs mitochondrial ultrastructure in cardiac myocytes

Statins, which reduce LDL-cholesterol by inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, are among the most widely prescribed drugs. Skeletal myopathy is a known statin-induced adverse effect associated with mitochondrial changes. We hypothesized that similar effects would occur in cardiac myocytes in a lipophilicity-dependent manner between 2 common statins: atorvastatin (lipophilic) and pravastatin (hydrophilic). Neonatal cardiac ventricular myocytes were treated with atorvastatin and pravastatin for 48 h. Both statins induced endoplasmic reticular (ER) stress, but only atorvastatin inhibited ERK1/2^T202/Y204, Akt^Ser473, and mammalian target of rapamycin signaling; reduced protein abundance of caveolin-1, dystrophin, epidermal growth factor receptor, and insulin receptor-β; decreased Ras homolog gene family member A activation; and induced apoptosis. In cardiomyocyte-equivalent HL-1 cells, atorvastatin, but not pravastatin, reduced mitochondrial oxygen consumption. When male mice underwent atorvastatin and pravastatin administration per os for up to 7 mo, only long-term atorvastatin, but not pravastatin, induced elevated serum creatine kinase; swollen, misaligned, size-variable, and disconnected cardiac mitochondria; alteration of ER structure; repression of mitochondria- and endoplasmic reticulum-related genes; and a 21% increase in mortality in cardiac-specific vinculin-knockout mice during the first 2 months of administration. To our knowledge, we are the first to demonstrate in vivo that long-term atorvastatin administration alters cardiac ultrastructure, a finding with important clinical implications.-Godoy, J. C., Niesman, I. R., Busija, A. R., Kassan, A., Schilling, J. M., Schwarz, A., Alvarez, E. A., Dalton, N. D., Drummond, J. C., Roth, D. M., Kararigas, G., Patel, H. H., Zemljic-Harpf, A. E. Atorvastatin, but not pravastatin, inhibits cardiac Akt/mTOR signaling and disturbs mitochondrial ultrastructure in cardiac myocytes.