Influence of Baseline Psychological Health on Muscle Pain During Atorvastatin Treatment

Assessment and management of statin-associated muscle symptoms (SAMS): A clinical perspective from the National Lipid Association

Statin-associated muscle symptoms (SAMS) are the most common form of statin intolerance and are associated with increased risk of cardiovascular events that manifest from statin underutilization and discontinuation. The reported frequencies of SAMS are divergent in the literature. The writing group estimates the prevalence of SAMS, namely all muscle symptoms temporally related to statin use but without regard to causality, to be about 10% (range 5% to 25%), and the prevalence of pharmacological SAMS, specifically muscle symptoms resulting from pharmacological properties of the statin, to be about 1-2% (range 0.5% to 4%). In clinical practice, SAMS are likely to result from a combination of pharmacological and nonpharmacological effects, however this does not make the symptoms any less clinically relevant. Regardless of the etiology, SAMS need to be addressed in accordance with patients' preferences and experiences. This clinical perspective reviews the epidemiology and underlying pathophysiology of SAMS, and the cardiovascular consequences resulting from statin discontinuation. We present patient-centered clinical and communication strategies to mitigate SAMS and improve medication adherence and outcomes among statin users. Treatment strategies include 1) optimizing lifestyle interventions, 2) modulating risk factors that may contribute to muscle symptoms, 3) optimizing statin tolerability by dose reduction, decreased dosing frequency, or use of an alternate statin with more favorable pharmacokinetic properties, and 4) use of non-statins, emphasizing those with evidence for atherosclerotic risk reduction, either in combination with or in place of statin therapy depending on the patient's circumstances. The focus of this clinical perspective is sustainable lipoprotein goal achievement, which is important for cardiovascular risk reduction.

Clinical and psychological factors in coronary heart disease patients with statin associated muscle side-effects

Background

To compare clinical and psychological factors among patients with self-perceived statin-associated muscle symptoms (SAMS), confirmed SAMS, and refuted SAMS in coronary heart disease patients (CHD).

Methods

Data were obtained from a cross-sectional study of 1100 CHD outpatients and a study of 71 CHD outpatients attending a randomized, double-blinded, placebo-controlled, crossover study to test effects of atorvastatin 40 mg/day on muscle symptom intensity. Clinical and psychosocial factors were compared between patients with and without SAMS in the cross-sectional study, and between patients with confirmed SAMS and refuted SAMS in the randomized study.

Results

Bilateral, symmetric muscle symptoms in the lower extremities during statin treatment were more prevalent in patients with confirmed SAMS compared to patients with refuted SAMS (75% vs. 41%, p = 0.01) in the randomized study. No significant differences in psychological factors (anxiety, depression, worry, insomnia, type D personality characteristics) were detected between patients with and without self-perceived SAMS in the cross-sectional study, or between patients with confirmed SAMS and refuted SAMS, in the randomized study.

Conclusions

Patients with confirmed SAMS more often present with bilateral lower muscle symptoms compared to those with refuted SAMS. Psychological factors were not associated with self-perceived SAMS or confirmed SAMS. A careful pain history and a search for alternative causes of muscle symptoms are likely to promote communication in patients with SAMS, and may reduce the risk for statin discontinuation.

The comparative effects of high dose atorvastatin and proprotein convertase subtilisin/kexin type 9 inhibitor on the mitochondria of oxidative muscle fibers in obese-insulin resistant female rats

The present study aimed to compare the effects of high dose atorvastatin and a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor on the mitochondrial function in oxidative muscle fibers in obese female rats. Female Wistar rats were fed with either a normal diet (ND: n = 12) or a high-fat diet (HFD: n = 36) for a total of 15 weeks. At week 13, ND-fed rats received a vehicle, and HFD-fed rats were divided to three groups to receive either a vehicle, 40 mg/kg/day of atorvastatin, or 4 mg/kg/day of PCSK9 inhibitor (SBC-115076) for 3 weeks. Soleus muscles were investigated to assess mitochondrial ROS, membrane potential, swelling, mitochondrial-related protein expression, and level of malondialdehyde (MDA). The results showed that HFD-fed rats with vehicle developed obese-insulin resistance and dyslipidemia. Both atorvastatin and PCSK9 inhibitor reduced obesity and dyslipidemia, as well as improved insulin sensitivity in HFD-fed rats. However, the efficacy of PCSK9 inhibitor to increase weight loss and reduce dyslipidemia in HFD-fed rats was greater than those of atorvastatin. An increase in MDA level, ratio of p-Drp1^ser616/total Drp1 protein, CPT1 protein, mitochondrial ROS, and membrane depolarization in the soleus muscle were observed in HFD-fed rats with vehicle. PCSK9 inhibitor enabled the restoration of all these parameters to normal levels. However, atorvastatin facilitated restoration of some parameters, including MDA level, p-Drp1^ser616/total Drp1 ratio, and CPT1 protein expression. These findings suggest that PCSK9 inhibitor is superior to atorvastatin in instigating weight loss, cholesterol reduction, and attenuation of mitochondrial oxidative stress in oxidative muscle fibers of obese female rats.