Association Between SLCO1B1 Gene T521C Polymorphism and Statin-Related Myopathy Risk: A Meta-Analysis of Case-Control Studies

Pharmacogenomics of lipid-lowering agents: the impact on efficacy and safety

Hyperlipidemia is a significant risk factor for cardiovascular disease morbidity and mortality. The lipid-lowering drugs are considered the cornerstone of primary and secondary prevention of atherosclerotic cardiovascular disease. Unfortunately, the lack of efficacy and associated adverse effects, ranging from mild-to-moderate to potentially life-threatening, lead to therapy discontinuation. Numerous reports support the role of gene polymorphisms in drugs' pharmacokinetic parameters and their associated adverse reactions. Therefore, this study aims to understand the pharmacogenomics of lipid-lowering drugs and the impact of genetic variants of key genes on the drugs' efficacy and toxicity. Indeed, genetically guided lipid-lowering therapy enhances overall safety, improves drug adherence and achieves long-term therapy.

Association between single nucleotide polymorphism SLCO1B1 gene and simvastatin pleiotropic effects measured through flow-mediated dilation endothelial function parameters

BACKGROUND

Atherosclerosis is a condition in which the medium to large arteries become inflamed over time. The cornerstone to the atherosclerosis process is endothelial dysfunction. Simvastatin is a cholesterol-lowering drug known for its endothelial cell pleiotropic properties. The role of genetic polymorphisms in simvastatin-resistance difficulties has recently piqued people's interest. This problem is thought to be linked to the pleiotropic action of simvastatin, particularly in terms of restoring endothelial function. The goal of this study is to see if there is a link between the single nucleotide polymorphism (SNP) c.521T>C and the pleiotropic effect of simvastatin as determined by the endothelial function parameter, flow-mediated dilation (FMD).

METHODS

This research was a multicentre cross-sectional study including 71 hypercholesterolemia patients who have been on simvastatin for at least 3 months. The real-time polymerase chain reaction identified SNP c.521T>C. The right brachial artery ultrasonography was used to measure FMD.

RESULTS

In 71 hypercholesterolemia patients, the SNP c.521T>C was found in 9.9% of them. On χ² analysis, there was no significant association between SNP c.521T>C (TC genotype) and FMD (p = 0.973). On logistic regression analysis, the duration of simvastatin medication was linked with an increased incidence (Adj. OR (adjusted odds ratio) = 2.424; confidence interval (CI) = 1.117-5.260, p = 0.025) and a reduction in systolic blood pressure (Adj. OR = 0.92; CI = 0.025-0.333, p = 0.001).

CONCLUSION

There was no association between FMD and the SNP c.521T>C (TC genotype). The duration of simvastatin medication and systolic blood pressure were both associated to FMD.

Analysis of the difference in SLCO1B1 and APOE gene polymorphisms between Mongolian and Han populations

Objective: To analyze SLCO1B1 and APOE polymorphisms and their clinical significance in the Mongolian and Han populations in Ordos, Inner Mongolia. Methods: Mongolian patients (n = 200) with cardiovascular disease admitted to our hospital from January 2018 to December 2020 were selected as the Mongolian population group. Han patients (n = 200) with cardiovascular diseases admitted during the same period were selected as the Han population group. Mutations in SLCO1B1 and APOE were detected by real-time fluorescence qPCR, and the differences between the two groups were analyzed. Results: The nucleotide polymorphisms of SLCO1B1 and APOE in the Mongolian and Han populations were consistent with the Hardy-Weinberg law. There were significant differences in gender, age, BMI, hypertension, alcohol consumption, dyslipidemia and low-density lipoprotein cholesterol levels between the two groups. APOE genotypes were classified according to those related to the efficacy of statins and the risk of atherosclerosis, and there was a significant difference between the two groups. Conclusion: There were differences in SLCO1B1 and APOE polymorphisms between the Mongolian and Han populations in Ordos. These may explain the differences in the incidence of cardiovascular diseases and the lipid-lowering efficacy of statins between the two populations.

Pharmacogenomic Study of Statin-Associated Muscle Symptoms in the ODYSSEY OUTCOMES Trial

Statin-associated muscle symptoms (SAMS) are the most frequently reported adverse events for statin therapies. Previous studies have reported an association between the p.Val174Ala missense variant in SLCO1B1 and SAMS in simvastatin-treated subjects; however, evidence for genetic predictors of SAMS in atorvastatin- or rosuvastatin-treated subjects is currently lacking.

Genetic Variant ABCC1 rs45511401 Is Associated with Increased Response to Statins in Patients with Familial Hypercholesterolemia

Statins are the first-line treatment for familial hypercholesterolemia (FH), but response is highly variable due to genetic and nongenetic factors. Here, we explored the association between response and genetic variability in 114 Brazilian adult FH patients. Specifically, a panel of 84 genes was analyzed by exon-targeted gene sequencing (ETGS), and the functional impact of variants in pharmacokinetic (PK) genes was assessed using an array of functionality prediction methods. Low-density lipoprotein cholesterol (LDL-c) response to statins (reduction ≥ 50%) and statin-related adverse event (SRAE) risk were assessed in carriers of deleterious variants in PK-related genes using multivariate linear regression analyses. Fifty-eight (50.8%) FH patients responded to statins, and 24 (21.0%) had SRAE. Results of the multivariate regression analysis revealed that ABCC1 rs45511401 significantly increased LDL-c reduction after statin treatment (p < 0.05). In silico analysis of the amino-acid change using molecular docking showed that ABCC1 rs45511401 possibly impairs statin efflux. Deleterious variants in PK genes were not associated with an increased risk of SRAE. In conclusion, the deleterious variant ABCC1 rs45511401 enhanced LDL-c response in Brazilian FH patients. As such, this variant might be a promising candidate for the individualization of statin therapy.

Relationship between genetic polymorphism of drug transporters and the efficacy of Rosuvastatin, atorvastatin and simvastatin in patients with hyperlipidemia

Background

To determine the effect of genetic polymorphism of drug transporters on the efficacy of treatment with Rosuvastatin, Atorvastatin and Simvastatin in patients with hyperlipidemia.

Methods

The study consists of 180 patients, aged 40–75 years, with hyperlipidemia. All patients were divided into two equal groups: patients with different SLCO1B1 (521CC, 521CT and 521TT) and MDR1 (3435CC, 3435TC and 3435TT) genotypes. Each group was divided into rosuvastatin-treated, atorvastatin-treated and simvastatin-treated subgroups. The lipid-lowering effect of statins was assessed by tracing changes in total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels.

Results

The use of statins over a 4-month period led to substantial reductions in TC and LDL-C levels. The hypolipidemic effect of studied agents was seen in both groups. However, it was less pronounced in patients with 521CC genotype. No statistically significantly differences were found between carriers of 3435TT, 3435CT and 3435CC genotypes.

Conclusions

The lipid-lowering efficacy of rosuvastatin was higher compared to other two statins. Patients with SLCO1B1 521CC genotype are more likely to encounter a decrease in the hypolipidemic effect of statins. Such a risk should be considered when treating this category of patients. MDR1 polymorphism had no significant effect on statin efficacy.

Pharmacogenomics of statins: lipid response and other outcomes in Brazilian cohorts

Statins are inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase, a key enzyme in cholesterol biosynthesis, that are highly effective in reducing plasma low-density lipoprotein (LDL) cholesterol and decreasing the risk of cardiovascular events. In recent years, a multitude of variants in genes involved in pharmacokinetics (PK) and pharmacodynamics (PD) have been suggested to influence the cholesterol-lowering response. However, the vast majority of studies have analyzed the pharmacogenetic associations in populations in Europe and the USA, whereas data in other populations, including Brazil, are mostly lacking. This narrative review provides an update of clinical studies on statin pharmacogenomics in Brazilian cohorts exploring lipid-lowering response, adverse events and pleiotropic effects. We find that variants in drug transporter genes (SLCO1B1 and ABCB1) positively impacted atorvastatin and simvastatin response, whereas variants in genes of drug metabolizing enzymes (CYP3A5) decreased response. Furthermore, multiple associations of variants in PD genes (HMGCR, LDLR and APOB) with statin response were identified. Few studies have explored statin-related adverse events, and only ABCB1 but not SLCO1B1 variants were robustly associated with increased risk in Brazil. Statin-related pleiotropic effects were shown to be influenced by variants in PD (LDLR, NR1H2) and antioxidant enzyme (NOS3, SOD2, MTHFR, SELENOP) genes. The findings of these studies indicate that statin pharmacogenomic associations are distinctly different in Brazil compared to other populations. This review also discusses the clinical implications of pharmacogenetic studies and the rising importance of investigating rare variants to explore their association with statin response.

Association of SLCO1B1 c.521T>C (rs4149056) with discontinuation of atorvastatin due to statin-associated muscle symptoms

The most common adverse drug reaction from statins are statin-associated muscle symptoms (SAMS), characterized by myopathy (weakness), myalgia (muscle pain), and commonly elevation in serum creatine kinase. All statins are substrates of the organic anion transporter 1B1 (OATP1B1; gene: SLCO1B1), albeit to different degrees. A genetic polymorphism in SLCO1B1, c.521T>C (rs4149056), markedly decreases OATP1B1 function. The literature is currently unclear as to whether SLCO1B1 c.521T>C is significantly associated with discontinuation of atorvastatin specifically due to SAMS. Our hypothesis was that individuals carrying the SLCO1B1 decreased function 521C allele are more likely to discontinue atorvastatin due to SAMS. This was a retrospective analysis of survey data from 379 Caucasians genotyped for rs4149056 and treated with atorvastatin for at least 12 months. Crude and multivariable logistic regression, adjusted for established risk factors for SAMS, determined the association of SLCO1B1 c.521T>C with discontinuation of atorvastatin due to SAMS (SLCO1B1 521T-homozygotes vs. 521C-carriers). The sample was 51% male, with a mean age of 57 years (SD = 11). Sixty-one percent of participants reported discontinuing atorvastatin due to SAMS, and 32% overall carried the 521C allele. SLCO1B1 521C-carrier status was not a significant predictor of atorvastatin discontinuation in any model: crude OR = 1.07; 95% CI, 0.68-1.66; P = 0.78 and adjusted OR = 1.07; 95% CI, 0.68-1.69; P = 0.76. The results were similar in a sub-group of participants treated with higher doses of atorvastatin (>20 mg). In summary, SLCO1B1 c.521T>C was not significantly associated with discontinuation of atorvastatin therapy due to SAMS.

Efficacy and safety of statins in ethnic differences: a lesson for application in Indigenous Australian patient care

Although statins are effective in treating high cholesterol, adverse effects do occur with their use. Efficacy and tolerability vary among statins in different ethnic groups. Indigenous Australians have a high risk for cardiovascular and kidney diseases. Prescribing statins to Indigenous Australians with multi-morbidity requires different strategies to increase efficacy and reduce their toxicity. Previous studies have reported that Indigenous Australians are more susceptible to severe statin-induced myopathies. However, there is a lack of evidence in the underlying genetic factors in this population. This review aims to identify: inter-ethnic differences in the efficacy and safety of statins; major contributing factors accounting for any identified differences; and provide an overview of statin-induced adverse effects in Indigenous Australians.

A systematic review and meta-analysis of genotype-based and individualized data analysis of SLCO1B1 gene and statin-induced myopathy

This meta-analysis was conducted to determine the genotypic effects of rs4149056 and rs2306283 polymorphism in SLCO1B1 gene on myopathy in patients with statin. Studies were searched using multiple databases and selected following inclusion criteria. Two reviewers independently performed data extraction and assessments for risk of bias. Fixed-or-random-effect was applied to pool allele frequency/effects. Mixed-effect logit model was used to pool genotypic effects using individual patient data. Heterogeneity and publication bias were explored. Fourteen studies were pooled for rs4149056; the minor C allele frequency were 15% in Caucasians and 14% in Asians. Six studies were pooled for rs2306283; the minor G allele frequency was 34% in Caucasian and 75% in Asians. Genotypic effects of rs4149056 polymorphism in Caucasians indicated that statin users who carried CC and TC genotypes had a significantly higher risk of myopathy than those who carried TT genotype, with a pooled odds ratio (OR) of 2.9 (95% confidence interval, 1.59, 5.34) and 1.6 (1.20, 2.16), respectively. For subgroup analysis, CC and TC genotypes also suggested a higher risk of myopathy in simvastatin users [OR = 2.8 (1.17, 6.77) and OR = 1.8 (1.15, 2.77), respectively] and in atorvastatin users [OR = 4.0 (1.23, 12.63) and OR = 2.0 (1.11, 3.52), respectively] than those who carried TT genotype. There was no significant association between rs2306283 polymorphism and myopathy in Caucasians and Asians. There was no evidence of publication bias for both polymorphisms.

Correlation between single-nucleotide polymorphisms and statin-induced myopathy: a mixed-effects model meta-analysis

PURPOSE

A meta-analysis was performed to evaluate the correlation between single-nucleotide polymorphisms (SNPs) and risk of statin-induced myopathy (SIM).

METHODS

We retrieved the studies published on SIM until April 2019 from the PubMed, Embase, and Cochrane Library databases. We collected data from 32 studies that analyzed 10 SNPs in five genes and included 21,692 individuals and nine statins.

RESULTS

The analysis of the heterozygous (p = 0.017), homozygous (p = 0.002), dominant (p = 0.005), and recessive models (p = 0.009) of SLCO1B1 rs4149056 showed that this SNP increases the risk of SIM. Conversely, heterozygous (p = 0.048) and dominant models (p = 0.030) of SLCO1B1 rs4363657 demonstrated that this SNP is associated with a reduced risk of SIM. Moreover, an increased risk of SIM was predicted for carriers of the rs4149056 C allele among simvastatin-treated patients, whereas carriers of the GATM rs9806699 A allele among rosuvastatin-treated patients had a lower risk of SIM.

CONCLUSION

The meta-analysis revealed that the rs4149056 and rs4363657 SNPs in SLCO1B1 and the rs9806699 SNP in GATM are correlated with the risk of SIM.

Pharmacogenetics of Statin-Induced Myotoxicity

Statins, a class of lipid-lowering medications, have been a keystone treatment in cardiovascular health. However, adverse effects associated with statin use impact patient adherence, leading to statin discontinuation. Statin-induced myotoxicity (SIM) is one of the most common adverse effects, prevalent across all ages, genders, and ethnicities. Although certain demographic cohorts carry a higher risk, the impaired quality of life attributed to SIM is significant. The pathogenesis of SIM remains to be fully elucidated, but it is clear that SIM is multifactorial. These factors include drug-drug interactions, renal or liver dysfunction, and genetics. Genetic-inferred risk for SIM was first reported by a landmark genome-wide association study, which reported a higher risk of SIM with a polymorphism in the SLCO1B1 gene. Since then, research associating genetic factors with SIM has expanded widely and has become one of the foci in the field of pharmacogenomics. This review provides an update on the genetic risk factors associated with SIM.

Farmacogenômica e Doença Cardiovascular: Onde Estamos e Para Onde Vamos

A farmacogenômica (FGx) investiga a interação entre genes e medicamentos. Através da análise de regiões específicas do DNA, informações sobre o perfil de metabolização do paciente para um determinado fármaco podem ser descritas, assim como o perfil esperado de resposta ao tratamento. Objetivamente, esse tipo de teste pode ter impacto no tratamento de pacientes que não estão respondendo adequadamente a um determinado medicamento, seja pela ausência dos efeitos esperados ou em virtude do aparecimento de efeitos adversos. Neste cenário, o objetivo desta revisão é o de informar o cardiologista clínico sobre esta importante área do conhecimento e atualizá-lo sobre o tema, procurando preencher as lacunas no que diz respeito à relação custo-benefício da aplicação da FGx nas doenças cardiovasculares, além de fornecer informações para a implementação da terapia guiada pela FGx na prática clínica.

A population approach of rifampicin pharmacogenetics and pharmacokinetics in Mexican patients with tuberculosis

The aim of this study was to develop a population pharmacokinetic model of rifampicin (RMP) in Mexican patients with tuberculosis (TB) to evaluate the influence of anthropometric and clinical covariates, as well as genotypic variants associated with MDR1 and OATP1B1 transporters. A prospective study approved by Research Ethics Committee was performed at Hospital Central in San Luis Potosí, Mexico. TB patients under DOTS scheme and who signed informed consent were consecutively included. Anthropometric and clinical information was retrieved from medical records. Single nucleotide polymorphisms in MDR1 (C3435T) and SLCO1B1 (A388G and T521C) genes were evaluated. RMP plasma concentrations and time data were assessed with NONMEM software. A total of 71 Mexican TB patients from 18 to 72 years old were included for RMP quantification from 0.3 to 12 h after dose; 329 and 97 plasma concentrations were available for model development and validation, respectively. Sequential process includes a typical lag time of 0.25 h prior to absorption start with a Ka of 1.24 h^-1 and a zero-order absorption of 0.62 h to characterize the gradual increase in RMP plasma concentrations. Final model includes total body weight in volume of distribution (0.7 L/kg, CV = 26.8%) and a total clearance of 5.96 L/h (CV = 38.5%). Bioavailability was modified according to time under treatment and generic formulation administration. In conclusion, a population pharmacokinetic model was developed to describe the variability in RMP plasma concentrations in Mexican TB patients. Genetic variants evaluated did not showed significant influence on pharmacokinetic parameters. Final model will allow therapeutic drug monitoring at early stages.

The atorvastatin metabolic phenotype shift is influenced by interaction of drug-transporter polymorphisms in Mexican population: results of a randomized trial

Atorvastatin (ATV) is a blood cholesterol-lowering drug used to prevent cardiovascular events, the leading cause of death worldwide. As pharmacokinetics, metabolism and response vary among individuals, we wanted to determine the most reliable metabolic ATV phenotypes and identify novel and preponderant genetic markers that affect ATV plasma levels. A controlled, randomized, crossover, single-blind, three-treatment, three-period, and six-sequence clinical study of ATV (single 80-mg oral dose) was conducted among 60 healthy Mexican men. ATV plasma levels were measured using high-performance liquid chromatography mass spectrometry. Genotyping was performed by real-time PCR with TaqMan probes. Four ATV metabolizer phenotypes were found: slow, intermediate, normal and fast. Six gene polymorphisms, SLCO1B1-rs4149056, ABCB1-rs1045642, CYP2D6-rs1135840, CYP2B6-rs3745274, NAT2-rs1208, and COMT- rs4680, had a significant effect on ATV pharmacokinetics (P < 0.05). The polymorphisms in SLCO1B1 and ABCB1 seemed to have a greater effect and were especially important for the shift from an intermediate to a normal metabolizer. This is the first study that demonstrates how the interaction of genetic variants affect metabolic phenotyping and improves understanding of how SLCO1B1 and ABCB1 variants that affect statin metabolism may partially explain the variability in drug response. Notwithstanding, the influence of other genetic and non-genetic factors is not ruled out.

Cirrhosis as new indication for statins

In the recent years, there have been an increasing number of reports on favourable effects of statins in patients with advanced chronic liver disease. These include reduction in portal pressure, improved liver sinusoidal endothelial and hepatic microvascular dysfunction, decreased fibrogenesis, protection against ischaemia/reperfusion injury, safe prolongation of ex vivo liver graft preservation, reduced sensitivity to endotoxin-mediated liver damage, protection from acute-on-chronic liver failure, prevention of liver injury following hypovolaemic shock and preventing/delaying progression of cirrhosis of any aetiology. Moreover, statins have been shown to have potential beneficial effects in the progression of other liver diseases, such as chronic sclerosing cholangitis and in preventing hepatocellular carcinoma. Because of these many theoretically favourable effects, statins have evolved from being considered a risk to kind of wonder drugs for patients with chronic liver diseases. The present article reviews the current knowledge on the potential applications of statins in chronic liver diseases, from its mechanistic background to objective evidence from clinical studies.

Association between rs4149056 variant in SLCO1B1 and early discontinuation of statin after acute myocardial infarction

Data from two French surveys were used to analyze the association between in-hospital statin discontinuation and SLCO1B1 polymorphism (rs4149056) in patients with acute myocardial infarction. Using TaqMan allelic discrimination assay, 1674 and 1708 patients were genotyped for SLCO1B1 in 2005 and 2010, respectively. The association with in-hospital statin discontinuation was assessed after adjusting for confounding factors. In 2005, homozygosity for the reduced-function allele was associated with an increased risk of in-hospital statin discontinuation (OR: 3.68; p = 0.004) compared with the wild-type allele but this association disappeared in 2010. However, statin type and intensity-dose differed significantly between the surveys. SLCO1B1 polymorphism (rs4149056) does not seem to be a major determinant of early ‘in-hospital’ statin discontinuation after acute myocardial infarction.

Comparative and quantitative assessment on statin efficacy and safety: insights into inter-statin and inter-individual variability via dose- and exposure-response relationships

Introduction: Statins are prescribed widely for cholesterol-lowering therapy, but it is known that their efficacy and safety profiles vary, despite the shared pharmacophore and pharmacological target. The immense body of related clinical and preclinical data offers a unique opportunity to explore the possible factors underlying inter-statin and inter-individual variabilities.Area covered: Clinical and preclinical data from various statins were compiled with regard to the efficacy (cholesterol-lowering effect) and safety (muscle toxicity). Based on the compiled data, dose- and exposure-response relationships were explored to obtain mechanistic and quantitative insights into the variations in the efficacy and safety profiles of statins.Expert opinion: Our analyses indicated that the inter-statin variability in the cholesterol-lowering effect may be mainly attributable to variations in potency of inhibition of the pharmacological target, rather than variations in drug exposure at the site of drug action. However, the drug exposure at the sites of drug action (i.e., the liver for efficacy and the muscle for safety) may contribute to the differences in the efficacy and safety observed in individual patients.

Evidence to Support Inclusion of Pharmacogenetic Biomarkers in Randomised Controlled Trials

Pharmacogenetics and biomarkers are becoming normalised as important technologies to improve drug efficacy rates, reduce the incidence of adverse drug reactions, and make informed choices for targeted therapies. However, their wider clinical implementation has been limited by a lack of robust evidence. Suitable evidence is required before a biomarker's clinical use, and also before its use in a clinical trial. We have undertaken a review of five pharmacogenetic biomarker-guided randomised controlled trials (RCTs) and evaluated the evidence used by these trials to justify biomarker inclusion. We assessed and quantified the evidence cited in published rationale papers, or where these were not available, obtained protocols from trial authors. Very different levels of evidence were provided by the trials. We used these observations to write recommendations for future justifications of biomarker use in RCTs and encourage regulatory authorities to write clear guidelines.

Role of genetics in the prediction of statin-associated muscle symptoms and optimization of statin use and adherence

Statin therapy reduces cardiovascular events in patients with, or at risk of, atherosclerotic cardiovascular disease. However, statins are underutilized in patients for whom they are indicated and are frequently discontinued. Discontinuation may be the result of statin-associated muscle symptoms (SAMS), which encompass a broad spectrum of clinical phenotypes from myalgia to severe myopathy. As with many adverse drug reactions (ADRs), inter-individual variability in susceptibility to SAMS is due, at least in part, to differences in host genetics. The genetic basis for SAMS has been investigated in candidate gene studies, genome-wide association studies, and, more recently, studies of multi-omic networks, including at the transcriptome level. In this article, we provide a systematic review of the pharmacogenetic basis of SAMS, focusing on how an understanding of the genetic and molecular determinants of SAMS can be considered in a personalized approach to reduce the incidence of this ADR, optimize statin adherence, and reduce the risk for cardiovascular events.

Latest Updates on Lipid Management

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death worldwide. Despite the clinical long-term and near-term benefits of lowering cholesterol in, respectively, primary and secondary prevention of ASCVD, cholesterol levels remain under-treated, with many patients not achieving their recommended targets. The present article will review the latest updates on lipid management with emphases on the different classes of cholesterol-lowering agents and their clinical uses.

Impact of pharmacogenetics on statin-induced myopathy in South-Indian subjects

OBJECTIVES

Statins are the most commonly prescribed medications for the treatment of atherosclerotic cardiovascular disease. Statin-associated adverse effects occur in ∼10% of patients and are associated with polymorphisms in several key genes coding for transporters and metabolizing enzymes that affect statin pharmacokinetics. In the present study, we examine the association between cytochrome P450 3A5*3 (CYP3A5*3) T>C (rs776746), COQ G>C (rs4693075), and SLCO1B1 T>C (rs4149056) genetic variants with the risk of myopathy in South Indian patients on statin therapy.

METHODS

A total of 202 patients on atorvastatin or rosuvastatin therapy for 12 years were recruited in the study. Genotyping of drug metabolic CYP3A5*3 gene variant and drug transporter genes COQ G>C (rs4693075) and SLCO1B1 T>C (rs4149056) was analyzed by Sanger's sequencing.

RESULTS

In our study subjects, the percentage of patients diagnosed to have statin-induced myopathy was 18%. The majority of the patients were on 10 mg/day dose of either atorvastatin or rosuvastatin. The homozygous nonexpressors genotype CYP3A5*3/3 frequency of the CYP3A5 polymorphism was higher in patients with myopathy. But we could not find association of CYP3A5, COQ, and SLCO1B1 gene polymorphisms with either rosuvastatin or atorvastatin.

CONCLUSION

Our results clearly demonstrate that the frequency of CYP3A5*3 splicing variant is higher in myopathy group than in the tolerant group. We did not find significant association of genetic polymorphisms in CYP3A5, COQ, and SLCO1B1 with atorvastatin- or rosuvastatin-induced myopathy.

A comprehensive review and meta-analysis of risk factors for statin-induced myopathy

PURPOSE

To aid prescribers in assessing a patient's risk for statin-induced myopathy (SIM), we performed a comprehensive review of currently known risk factors and calculated aggregated odds ratios for each risk factor through a meta-analysis.

METHODS

This meta-analysis was done through four phases: (1) Identification of the relevant primary literature; (2) abstract screening using inclusion and exclusion criteria; (3) detailed review and data extraction; and (4) synthesis and statistical analysis.

RESULTS

Out of 44 papers analyzed from 836 papers searched from MEDLINE, 18 different potential risk factors were collected, divided into three categories: three demographics (11 papers), ten clinical factors (31 papers), and five pharmacogenetics/biomarkers (12 papers). Risk factors significant for myopathy and/or rhabdomyolysis included age, gender, diabetes, renal impairment, cardiovascular disease, certain interacting drugs, and mutations of the SLCO1B1 gene, which encodes a transporter protein in the liver. Several factors, such as gender, race, cardiovascular disease, and the GATM gene, which encodes a protein for creatine synthesis, appeared to be protective in terms of the outcomes of interest.

CONCLUSIONS

This comprehensive assessment of risk factors can help support clinicians in reducing the incidence of SIM in their patient population on statins.

Statin-related myopathies

Statins are the Marmite ('You either love it or hate it!') of the drug world, both in terms of therapeutic benefit and risk of side effects. Proponents think that they are potential life-savers, opponents that their main benefit is lining the pockets of pharma. Some consider side effects to be a major issue, outweighing any therapeutic benefit, others that they are rare and essentially innocuous. Statin-induced myalgia is relatively common but often mild and for most people does not limit treatment. In others, reducing the dose or changing the preparation may help. In all, withdrawal of the statin leads to resolution. Statin-induced rhabdomyolysis, most often precipitated by drug-drug interaction, affects only a tiny proportion of statin users, but because of the widespread prescribing of statins is an important clinical problem. Statin-induced immune-mediated necrotising myopathy represents a novel disease mechanism and clinically mimics forms of myositis. Resolution often requires immunosuppressant drug treatment, as well as statin withdrawal.

Role of Preemptive Genotyping in Preventing Serious Adverse Drug Events in South Korean Patients

INTRODUCTION

Preemptive and multi-variant genotyping is suggested to improve the safety of patient drug therapy. The number of South Koreans who would benefit from this approach is unknown.

OBJECTIVE

We aimed to quantify the number of patients who may experience serious adverse drug events (ADEs) due to high-risk pharmacogenetic variants and who may benefit from preemptive genotyping.

METHODS

The health claims dataset of the Korean Health Insurance Review and Assessment service for 3 % of the South Korean population for year 2011 was used to calculate the number of patients exposed to 84 drugs covered by National Health Insurance with pharmacogenomic biomarkers. The product of ADE risk-conferring genotype prevalence, ADE prevalence rates, and genotype effect sizes in South Koreans or East Asians derived from published literature and the 1000 Genomes Project, and the drug exposure data were solved to estimate the number of South Koreans in whom preemptive genotyping may prevent serious ADEs.

RESULTS

Among 1,341,077 patients in the dataset with prescriptions, 47.4 % were prescribed a drug whose response was affected by genetic variants and 31.9 % were prescribed at least one drug with serious ADEs modulated by these variants. Without genetic testing, the number of South Korean patients predicted to experience serious ADEs due to their higher ADE risk genotypes was estimated at 729. Extrapolating this to the total South Korean population indicated that approximately 24,300 patients in 2011 might have benefitted from preemptive genotyping.

CONCLUSIONS

This study quantified the number of South Korean patients predicted to have serious ADEs and demonstrated the need for preemptive genotyping to assist safer drug therapy in South Korea.

Genetic and Clinical Factors Are Associated With Statin-Related Myotoxicity of Moderate Severity: A Case-Control Study

We evaluated the contribution of patient-specific clinical and genetic factors to statin-related muscle toxicity (SRM) without a significant creatine kinase elevation (125 cases related to simvastatin or atorvastatin and 481 controls). The association between 12 single nucleotide polymorphisms (SNPs) in nine candidate genes and clinical factors with SRM was evaluated. Of the 12 SNPs genotyped, only rs4149056 in SLCO1B1 was associated with SRM in univariate analysis (with any statin, odd ratio (OR) = 1.73, 95% confidence interval (CI) = 1.14-2.62, P = 0.010) and this association was influenced by sex (P = 0.006) and BMI (P = 0.02). In multivariate and binary logistic regression analyses, SLCO1B1 rs4149056 genotype (OR = 1.66, 95% CI: 1.08-2.54, P = 0.014) and sex (OR = 1.72, 95% CI = 1.15-2.59, P = 0.006) were independently associated with muscle toxicity related to statin treatment. Patient-specific genetic and clinical factors associated with increased systemic exposure to statins are implicated in the full spectrum of SRM, including myalgia in addition to severe myopathy.

Statin drug interactions and related adverse reactions: an update

INTRODUCTION

Statins reduce the risk of cardiovascular morbidity and mortality in patients with or at risk for cardiovascular disease and their use is expanding, especially in elderly. Statins are prescribed on a long-term basis and may undergo drug-drug interactions (DDIs) with other drugs. Statins have different safety and tolerability, and this might affect the possibility of DDIs with other cardiovascular drugs, increasing the risk of statin-associated myopathy and hepatotoxicity. Polypharmacy and pharmacogenetic variability are potential causes of statin DDIs. Thus, the safety and adverse effects of statins, particularly in patients receiving multiple medications at risk of DDIs, are a matter of special concern.

AREAS COVERED

The purpose of this manuscript is to give an update on the potential statin DDIs and related adverse drug reactions (myopathy and hepatotoxicity), with special considerations on polypharmacy in elderly population, HIV patients, cardiovascular drugs and liver toxicities. The potential DDIs among statins and monoclonal antibodies including the recently approved PCSK9 inhibitors are also extensively discussed in the present review.

EXPERT OPINION

A better understanding of the incidence and clinical significance of statin DDIs will help physicians in fine-tuning the lipid-lowering therapeutic interventions thus providing their patients with an evidence-based, safe and cost-effective clinical support.

En route to precision medicine through the integration of biological sex into pharmacogenomics

Frequently, pharmacomechanisms are not fully elucidated. Therefore, drug use is linked to an elevated interindividual diversity of effects, whether therapeutic or adverse, and the role of biological sex has as yet unrecognized and underestimated consequences. A pharmacogenomic approach could contribute towards the development of an adapted therapy for each male and female patient, considering also other fundamental features, such as age and ethnicity. This would represent a crucial step towards precision medicine and could be translated into clinical routine. In the present review, we consider recent results from pharmacogenomics and the role of sex in studies that are relevant to cardiovascular therapy. We focus on genome-wide analyses, because they have obvious advantages compared with targeted single-candidate gene studies. For instance, genome-wide approaches do not necessarily depend on prior knowledge of precise molecular mechanisms of drug action. Such studies can lead to findings that can be classified into three categories: first, effects occurring in the pharmacokinetic properties of the drug, e.g. through metabolic and transporter differences; second, a pharmacodynamic or drug target-related effect; and last diverse adverse effects. We conclude that the interaction of sex with genetic determinants of drug response has barely been tested in large, unbiased, pharmacogenomic studies. We put forward the theory that, to contribute towards the realization of precision medicine, it will be necessary to incorporate sex into pharmacogenomics.

[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.

Pharmacogenetic Foundations of Therapeutic Efficacy and Adverse Events of Statins

Background: In the era of precision medicine, more attention is paid to the search for predictive markers of treatment efficacy and tolerability. Statins are one of the classes of drugs that could benefit from this approach because of their wide use and their incidence of adverse events. Methods: Literature from PubMed databases and bibliography from retrieved publications have been analyzed according to terms such as statins, pharmacogenetics, epigenetics, toxicity and drug–drug interaction, among others. The search was performed until 1 October 2016 for articles published in English language. Results: Several technical and methodological approaches have been adopted, including candidate gene and next generation sequencing (NGS) analyses, the latter being more robust and reliable. Among genes identified as possible predictive factors associated with statins toxicity, cytochrome P450 isoforms, transmembrane transporters and mitochondrial enzymes are the best characterized. Finally, the solute carrier organic anion transporter family member 1B1 (SLCO1B1) transporter seems to be the best target for future studies. Moreover, drug–drug interactions need to be considered for the best approach to personalized treatment. Conclusions: Pharmacogenetics of statins includes several possible genes and their polymorphisms, but muscular toxicities seem better related to SLCO1B1 variant alleles. Their analysis in the general population of patients taking statins could improve treatment adherence and efficacy; however, the cost–efficacy ratio should be carefully evaluated.

Pharmacogenetics of Lipid-Lowering Agents: Precision or Indecision Medicine?

Lipid-lowering medications, particularly statins, have been a popular target for pharmacogenetic studies. A handful of genes have shown promise for predicting response to therapy from the perspective of lipid lowering, as well as myopathy. A number of genes have been implicated and have biological plausibility based on their involvement with the pharmacokinetics or pharmacodynamics of statins or other lipid-lowering medications. The level of confidence and replication of these findings varies, although several associations are likely true. Novel classes of lipid-lowering therapy have opened up new possibilities in the treatment of severe inherited forms of dyslipidemia, making the identification of such mutations an important pharmacogenetic predictor of failure of standard therapy, with potential response to novel therapy. Advances in next-generation sequencing technology bring the application of pharmacogenetics even closer to routine clinical practice.

The frequency of SLCO1B1*5 polymorphism genotypes among Russian and Sakha (Yakutia) patients with hypercholesterolemia

Introduction

Statins are the most commonly prescribed medicines for treatment of hypercholesterolemia. At the same time, up to 25% of patients cannot tolerate or have to discontinue the statin therapy due to statin-induced myopathy. In a majority of cases, statin-induced myopathy is attributed to SLCO1B1 gene polymorphism. The strongest association between statin-induced myopathy and SLCO1B1 gene polymorphism was described for simvastatin. Our research was focused on the frequency of SLCO1B1*5 genetic variant in the Russian population and in the native population of Sakha (Yakutia).

Materials and methods

A total of 1,071 hyperlipidemic Russian and 76 hyperlipidemic Sakha (Yakutian) patients were included in the study. Genotypes of SLCO1B1*5 (c.521T>C, rs4149056) were determined with polymerase chain reaction amplification. The results of our study were compared with data about hyperlipidemic patients in available publications.

Results

In the Russian population 665 (62%) patients had TT genotype of SLCO1B1*5, 346 (32%) patients had TC genotype, and in 60 patients (6%) CC variant was found (Hardy–Weinberg’s chi-square test was 3.1 P=0.21). In comparison with Brazil, France, the People’s Republic of China, Japan, and the native population of Sakha (Yakutia), C-allele, which causes an increased risk of statin-induced myopathy, was found significantly more often in the Russian population. In the native population of Sakha (Yakutia) SLCO1B1 polymorphism was TT – 62 (82%), TC – 11 (14%), CC – 3 (4%) (Hardy–Weinberg’s chi-square test was 5.13 P=0.077). In comparison with data from Brazil, France, the People’s Republic of China, and Japan, C-allele frequency in the Sakha (Yakutian) population was not significantly different.

Conclusion

Thus, we have studied the incidence of pathologic SLCO1B1 c.521C-allele in Russian and Sakha hyperlipidemic patients. The presence of SLCO1B1 C-allele in patients with hyperlipidemia forces us to be more careful in hypolipidemic drug prescription, especially statins, according to a higher risk of statin-induced myopathy development. The fact that SLCO1B1 C-allele is rarer among Sakha patients, could be interesting from the point of studying adverse drug effects frequency and statins’ effectiveness.

Addition of Simvastatin to Standard Therapy for the Prevention of Variceal Rebleeding Does Not Reduce Rebleeding but Increases Survival in Patients With Cirrhosis

BACKGROUND & AIMS

The combination of β-blockers and band ligation is the standard approach to prevent variceal rebleeding, but bleeding recurs and mortality is high. The lipid-lowering drug simvastatin decreases portal pressure, improves hepatocellular function, and might reduce liver fibrosis. We assessed whether adding simvastatin to standard therapy could reduce rebleeding and death after variceal bleeding in patients with cirrhosis.

METHODS

We performed a multicenter, double-blind, parallel trial of 158 patients with cirrhosis receiving standard prophylaxis to prevent rebleeding (a β-blocker and band ligation) in Spain from October 2010 through October 2013. Within 10 days of bleeding, subjects were randomly assigned, but stratified by Child-Pugh class of A or B vs C, to groups given simvastatin (20 mg/d the first 15 days, 40 mg/d thereafter; n = 69) or placebo (n = 78). Patients were followed for as long as 24 months. The primary end point was a composite of rebleeding and death, and main secondary end points were the individual components of the composite (death and rebleeding).

RESULTS

The primary end point was met by 30 of 78 patients in the placebo group and 22 of 69 in the simvastatin group (P = .423). Seventeen patients in the placebo group died (22%) vs 6 patients in the simvastatin group (9%) (hazard ratio for adding simvastatin to therapy = 0.39; 95% confidence interval: 0.15-0.99; P = .030). Simvastatin did not increase survival of patients with Child-Pugh class C cirrhosis. Rebleeding occurred in 28% of patients in the placebo group and 25% in the simvastatin group (P = .583). Serious adverse events occurred in 53% of patients in the placebo group and 49% in the simvastatin group (P = .752); the percentages of serious adverse events related to therapy were 11% in the placebo group vs 8% in the in the simvastatin group (P = .599). Two patients in the simvastatin group, each with advanced liver disease, developed rhabdomyolysis.

CONCLUSIONS

In a randomized controlled trial, addition of simvastatin to standard therapy did not reduce rebleeding, but was associated with a survival benefit for patients with Child-Pugh class A or B cirrhosis. Survival was not the primary end point of the study, so these results require validation. The incidence of rhabdomyolysis in patients receiving 40 mg/d simvastatin was higher than expected. European Clinical Trial Database ID: EUDRACT 2009-016500-24; ClinicalTrials.gov ID: NCT01095185.

Insights into solute carriers: physiological functions and implications in disease and pharmacokinetics

SLCs transport many endogenous and exogenous compounds including drugs; SLCs dysfunction has implications in pharmacokinetics, drug toxicity or lack of efficacy.