The myopathy of statins

Statins and New-Onset Diabetes in Cardiovascular and Kidney Disease Cohorts: A Meta-Analysis

BACKGROUND

Statins have long been prescribed for the primary and secondary prevention of cardiovascular disease (CVD) and kidney disease. Their benefits and efficacy are widely accepted in current clinical practice, but like any other therapeutic agents, they have adverse effects. One of the emerging concerns with statin therapy is the development of new-onset diabetes mellitus (NODM), a dreaded risk factor for CVD and kidney disease and widely viewed as CVD equivalent. Accumulating evidence indicates that NODM is a consequence of statin use.

METHODS

We conducted a meta-analysis of studies reporting on associations between NODM and statin use. Based on strict exclusion criteria, a total of 11 studies were selected. Their data were analyzed using Comprehensive Meta-Analysis® statistical software and reported as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

The cumulative fixed effect for use of statin therapy and incident NODM was an OR of 1.61 (95% CI 1.55-1.68, p < 0.001). Our results suggest that statin therapy is associated with NODM, such that there is a small but significant risk of NODM among patients receiving statin for CVD prevention therapy. However, this high-risk population also has other diabetes risk factors (such as obesity and hypertension) contributing to the development of NODM.

CONCLUSIONS

It is imperative that patients on statin therapy be monitored carefully for NODM. However, it can be argued that the risk of statin therapy is offset by the multitude of cardiovascular and kidney-protective effects provided by such an important and highly effective therapeutic agent.

Evaluation of sexual dimorphism in the efficacy and safety of simvastatin/atorvastatin therapy in a southern Brazilian cohort

BACKGROUND

Dyslipidemia is the primary risk factor for cardiovascular disease, and statins have been effective in controlling lipid levels. Sex differences in the pharmacokinetics and pharmacodynamics of statins contribute to interindividual variations in drug efficacy and toxicity.

OBJECTIVE

To evaluate the presence of sexual dimorphism in the efficacy and safety of simvastatin/atorvastatin treatment.

METHODS

Lipid levels of 495 patients (331 women and 164 men) were measured at baseline and after 6 ± 3 months of simvastatin/atorvastatin treatment to assess the efficacy and safety profiles of both drugs.

RESULTS

Women had higher baseline levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) compared with men (p < 0.0001). After treatment, women exhibited a greater decrease in plasma TC and LDL-C levels compared with men. After adjustment for covariates, baseline levels of TC and LDL-C influenced more than 30% of the efficacy of lipid-lowering therapy (p < 0.001), regardless of sex. Myalgia [with or without changes in creatine phosphokinase (CPK) levels] occurred more frequently in women (25.9%; p = 0.002), whereas an increase in CPK and/or abnormal liver function was more frequent in in men (17.9%; p = 0.017).

CONCLUSIONS

Our results show that baseline TC and LDL-C levels are the main predictors of simvastatin/atorvastatin therapy efficacy, regardless of sex. In addition, they suggest the presence of sexual dimorphism in the safety of simvastatin/atorvastatin. The effect of sex differences on receptors, transporter proteins, and gene expression pathways needs to be better evaluated and characterized to confirm these observations.

Extended release niacin-laropiprant in patients with hypercholesterolemia or mixed dyslipidemias improves clinical parameters

The progression of atherosclerosis remains a major cause of morbidity and mortality. Plaque formation is an immunological response driven by a number of risk factors, and reduction of risk is the primary goal of treatment. The role of LDL-C is well established and statins have proved effective drugs, although the relative risk reduction is only around 30%. The importance of other factors-notably low HDL-C and high TGs-has become increasingly clear and the search for alternative strategies continues. Niacin is particularly effective in achieving normalization of HDL-C but is clinically underutilized due to the side effect of cutaneous flushing. The discovery that flushing is mediated by mechanisms distinct from the lipid-lowering effects has led to the development of combination drugs with reduced side effects. This review considers the evidence regarding the clinical efficacy of extended-release niacin and the DP1 antagonist laropiprant in the treatment of hypercholesterolemia and mixed dyslipidemias.

Statin-induced myositis: a commonly encountered or rare side effect?

PURPOSE OF REVIEW

Statins are well established as first-line agents for cholesterol lowering in cardiovascular disease, with accumulating evidence supporting their initiation and guidelines recommending treatment to lower LDL levels. Although generally well tolerated with few side effects, including headaches and gastrointestinal symptoms, concerns are raised regarding myopathy, which may lead to fatal rhabdomyolysis. This review examines current evidence on statin interactions, mechanism of injury and toxicity.

RECENT FINDINGS

Significant myopathy is rare with an incidence of less than 0.5% of patients. Statin side effects may be dose-related, associated with other drug interactions that interfere with statin metabolic pathways through cytochrome p450 pathways or glucuronidation, or related to co-morbidities. Several theories have suggested that statin myotoxicity may be due to intracellular cholesterol depletion, or interference with oxidative phosphorylation pathways. Exact mechanisms are yet to be fully defined. Individuals with mixed dyslipidaemia may require combination therapy to achieve target lipid levels. No large-scale randomized trials have yet reported on the safety of combination therapy, although more recent studies may shed some light when they report.

CONCLUSION

As most individuals on statins are 'high-risk' patients, they tend to be on multiple agents for cardiovascular disease which may interact with their statin. Progression of myalgia or myositis to rhabdomyolysis is rare (one in 30-100,000 patient-years of exposure), but if progressive muscle symptoms are ignored then fatalities can occur. When prescribing statins, physicians should be alert to potential risks and educate patients to report any potentially significant symptoms.