The risk of myocardial infarction in patients with reduced activity of cytochrome P450 2C9

Sex Differences in Clopidogrel Effects Among Young Patients With Acute Coronary Syndrome: A Role for Genetics?

Background

Poorer health outcomes experienced by young women with acute coronary syndrome may be related to sex differences in the safety and efficacy of antiplatelet agents, such as clopidogrel. Polymorphisms in drug metabolism enzyme (cytochrome P450 [CYP] family) genes are independent factors for the variability in response to clopidogrel. However, a sex-specific impact of genetics to explain worse clinical outcomes in women has not been explored extensively. Therefore, our objective was to determine whether an interaction of sex with CYP variants occurs among users of clopidogrel, and if so, its impact on 1-year adverse clinical outcomes.

Methods

We used data from a combined cohort of 2272 patients (median age 49 years; 56% female) hospitalized for acute coronary syndrome. We examined interactions between sex and CYP variants among clopidogrel users at admission and discharge to assess associations with 1-year readmission due to cardiac events.

Results

The case-only analysis of 177 participants on clopidogrel at the time of presentation showed that the risk of an atherothrombotic event was greater in female carriers of the CYP2C9∗3 loss-of-function allele (odds ratio = 3.77, 95% confidence interval = 1.54-9.24). The results of the multivariable logistic regression model for users of clopidogrel at discharge (n = 1733) indicated that women had significantly higher risk of atherothrombotic readmissions at 1 year (odds ratio = 1.55, 95% confidence interval = 1.16-2.07), compared to the risk for men, but the loss-of-function alleles, either individually or through a genetic risk score, were not associated with 1-year readmissions.

Conclusion

This study highlights the need for an improved understanding of the role of sex-by-gene interactions in causing sex differences in drug metabolism.

Gene- gene interaction between CYP2J2 and PPAR -γ gene on late-onset Alzheimer's disease in the eastern Chinese Han population

AIMS

To investigate the impact of PPAR -γ and CYP2J2 gene single nucleotide polymorphisms (SNPs) and gene- gene interactions on late-onset Alzheimer's disease (LOAD) risk in Chinese Han population.

METHODS

A total of 880 participants (514 males, 366 females), with a mean age of 81.7±15.9years old are selected, including 430 LOAD patients and 450 normal participants. Generalized multifactor dimensionality reduction (GMDR) is used to examine interaction among six SNPs, odds ratio (OR) and 95% confident interval (95%CI) are calculated by Logistic regression model.

RESULTS

Logistic regression analysis showed that increased LOAD risks are associated with T allele of the rs1155002 polymorphism, adjusted OR (95%CI)=1.46 (1.12-1.90), and T allele of the rs890293 polymorphism, adjusted OR (95%CI)=1.65 (1.30-2.06), and G allele of the rs1805192 polymorphism, adjusted OR (95%CI)=1.70 (1.25-2.27). We also found a potential gene-gene interaction between rs890293 and rs1805192. Participants with GT or TT of rs890293 and CG or GG of rs1805192 genotype have the highest LOAD risk, compared to participants with GG of rs890293 and CC of rs1805192 genotype, OR (95%CI)=2.22 (1.63 -2.85), after covariates adjustment.

CONCLUSIONS

rs1155002, rs890293 and rs1805192 polymorphism are associated with increased LOAD risk. Participants with GT or TT of rs890293 and CG or GG of rs1805192 genotype have the highest LOAD risk.

Sex differences in the impact of CYP2C19 polymorphisms and low-grade inflammation on coronary microvascular disorder

Categorization as a cytochrome P-450 (CYP) 2C19 poor metabolizer (PM) is reported to be an independent risk factor for cardiovascular disease. It is correlated with an increase in the circulating levels of high-sense C-reactive protein (hs-CRP) in women only, although its role in coronary microcirculation is unclear. We examined sex differences in the impact of the CYP2C19 genotype and low-grade inflammation on coronary microvascular disorder (CMVD). We examined CYP2C19 genotypes in patients with CMVD (n = 81) and in healthy subjects as control (n = 81). CMVD was defined as the absence of coronary artery stenosis and epicardial spasms, the presence of inverted lactic acid levels between the intracoronary and coronary sinuses, or an adenosine triphosphate-induced coronary flow reserve ratio < 2.5. CYP2C19 PMs have two loss-of-function (LOF) alleles (*2, *3). Extensive metabolizers have no LOF alleles, and intermediate metabolizers have one LOF allele. The ratio of CYP2C19 PM and hs-CRP levels in CMVD was significantly higher than that of controls, especially in women (40.9 vs. 13.8%, P = 0.013; 0.11 ± 0.06 vs. 0.07 ± 0.04 mg/dl, P = 0.001). Moreover, in each CYP2C19 genotype, hs-CRP levels in CMVD in CYP2C19 PMs were significantly higher than those of the controls, especially in women (0.15 ± 0.06 vs. 0.07 ± 0.03, P = 0.004). Multivariate analysis for CMVD indicated that the female sex, current smoking, and hypertension were predictive factors, and that high levels of hs-CRP and CYP2C19 PM were predictive factors in women only (odds ratio 3.5, 95% confidence interval 1.26-9.93, P = 0.033; odds ratio 4.1, 95% confidence interval 1.15-14.1, P = 0.038). CYP2C19 PM genotype may be a new candidate risk factor for CMVD via inflammation exclusively in the female population.

Pharmacogenomics and pharmacogenetics of thiazolidinediones: role in diabetes and cardiovascular risk factors

The most important goal in the treatment of patients with diabetes is to prevent the risk of cardiovascular disease (CVD), the first cause of mortality in these subjects. Thiazolidinediones (TZDs), a class of antidiabetic drugs, act as insulin sensitizers increasing insulin-dependent glucose disposal and reducing hepatic glucose output. TZDs including pioglitazone, rosiglitazone and troglitazone, by activating PPAR-γ have shown pleiotropic effects in reducing vascular risk factors and atherosclerosis. However, troglitazone was removed from the market due to its hepatoxicity, and rosiglitazone and pioglitazone both have particular warnings due to being associated with heart diseases. Specific genetic variations in genes involved in the pathways regulated by TDZs have demonstrated to modify the variability in treatment with these drugs, especially in their side effects. Therefore, pharmacogenomics and pharmacogenetics are an important tool in further understand intersubject variability per se but also to assess the therapeutic potential of such variability in drug individualization and therapeutic optimization.

Diplotypes of CYP2C9 gene is associated with coronary artery disease in the Xinjiang Han population for women in China

Background

Cytochrome P450 (CYP) 2C9 is expressed in the vascular endothelium and metabolizes arachidonic acid to biologically active epoxyeicosatrienoic acids (EETs), which have the crucial role in the modulation of cardiovascular homeostasis. We sought to assess the association between the human CYP2C9 gene and coronary artery disease (CAD) in Xinjiang Han Population of China.

Methods

301 CAD patients and 220 control subjects were genotyped for 4 single-nucleotide polymorphisms (SNPs) of the human CYP2C9 gene (rs4086116, rs2475376, rs1057910, and rs1934967) by a Real-Time PCR instrument. The datas were assessed for 3 groups: total, men, and women via diplotype-based case–control study.

Results

For women, the distribution of genotypes, dominant model and alleles of SNP2 (rs2475376) showed significant difference between the CAD patients and control participants (p = 0.033, P = 0.010 and p = 0.038, respectively). The significant difference of the dominant model (CC vs CT + TT) was retained after adjustment for covariates in women (OR: 2.427, 95% confidence interval [CI]: 1.305-4.510, p = 0.005). The haplotype (C-T-A-C) and the diplotypes (CTAC/CTAC) in CYP2C9 gene were lower in CAD patients than in control subjects (p* = 0.0016, and p* = 0.036 respectively). The haplotype (C-C-A-T) was higher in the CAD patients than in the control subjects in women (p* = 0.016).

Conclusions

CC genotype of rs2475376 and C-C-A-T haplotype in CYP2C9 may be a risk genetic marker of CAD in women. T allele of rs2475376, the haplotype (C-T-A-C) and the diplotype (CTAC/CTAC) could be protective genetic markers of CAD for women in Han population of China.

Cytochrome P450 and ischemic heart disease: current concepts and future directions

INTRODUCTION

The P450 enzymes (P450s) mediate the biotransformation of several drugs, steroid hormones, eicosanoids, cholesterol, vitamins, fatty acids and bile acids, many of which affect cardiovascular homeostasis. Experimental studies have demonstrated that several P450s modulate important steps in the pathogenesis of ischemic heart disease (IHD).

AREAS COVERED

This article discusses the current knowledge on i) the expression of P450s in cardiovascular and renal tissues; ii) the role of P450s in the pathophysiology of IHD, in particular the modulation of blood pressure and cardiac hypertrophy, coronary arterial tone, ischemia-reperfusion injury and the metabolism of cardiovascular drugs; iii) the available evidence from observational studies on the association between P450 gene polymorphisms and risk of myocardial infarction (MI); and iv) suggestions for further research in this area.

EXPERT OPINION

P450s exert important modulatory effects in experimental models of IHD and MI. However, observational studies have provided conflicting results on the association between P450 genetic polymorphisms and MI. Further, adequately powered studies are required to ascertain the biological and clinical impact of P450s on clinical IHD end-points, that is, fatal and nonfatal MI, revascularization and long-term outcomes post MI. Pharmacogenetic substudies of recently completed cardiovascular clinical trials might represent an alternative strategy in this context.

Myocardial infarction in a patient with left ventricular noncompaction: a case report

We describe a 73-year-old male patient with left ventricular noncompaction (LVNC) who was diagnosed with acute myocardial infarction (MI), three-vessel coronary artery disease, a fresh intraventricular thrombus, and mitral regurgitation. He was treated with full anticoagulant therapy, coronary artery bypass grafting, and mitral valve repair. This case adds to a small but growing literature showing association between LVNC and MI and/or coronary artery disease. We suggest that patients with LVNC could be considered at heightened risk for MI, and the two conditions might have a common genetic underpinning in some cases.

The Rotterdam Study: 2012 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, oncological, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over a 1,000 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Impact of CYP2C8 and 2C9 polymorphisms on coronary artery disease and myocardial infarction in the LURIC cohort

Aims: As data on the cardiovascular risk associated with CYP2C8 and CYP2C9 polymorphisms is controversial, we performed a cross-sectional analysis of subjects enrolled in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study. Materials & methods: CYP2C8 and CYP2C9 genetic polymorphisms were determined with real-time PCR in 2827 patients. Based on angiography, 1052 of these patients had coronary artery disease (CAD) and 615 did not; 1160 patients had signs or a history of myocardial infarction (MI) in addition to CAD. The association of genotypes with CAD and MI was determined by logistic regression analysis, adjusted for age, sex, dyslipidemia, hypertension, diabetes mellitus and smoking status. Results: Frequencies of CYP2C8 and 2C9 variants were neither significantly different between CAD and control patients, nor between MI and control patients. Men carrying the CYP2C9*3 allele had an increased risk of MI (odds ratio [OR]: 1.67; 95% CI: 1.06–2.63; p = 0.03) and women carrying the CYP2C9*3 allele had a decreased risk of CAD (OR: 0.65; 95%CI: 0.42–0.9; p = 0.05). Conclusion: Overall, LURIC data confirmed that there is no major cardiovascular risk associated with CYP2C8 and CYP2C9 variants in a cardiovascular risk population of patients having undergone coronary angiography.

Genetic variance in CYP2C8 and increased risk of myocardial infarction

BACKGROUND

Epoxyeicosatrienoic acids (EETs) are important mediators in vasodilatation, acting as endothelium-derived hyperpolarizing factors. CYP2C enzymes catalyze the metabolism of arachidonic acid to EETs. Genetic variation within the genes encoding for these enzymes may result in differences in vascular response, among others in myocardial tissue, and may therefore increase the risk of myocardial infarction (MI). CYP2C8 and CYP2C9 are encoded by the genes of the same name. CYP2C9 polymorphisms have been associated with an increased risk of MI. As CYP2C8 is genetically linked to CYP2C9 and on account of its role in EET production, we hypothesized that CYP2C8 polymorphisms are associated with the risk of MI.

METHODS

This study was embedded within the Rotterdam study, a prospective population-based cohort study. The study population included all participants with successful genotyping and without prevalent MI (n=5199). Twenty-five tagging single nucleotide polymorphisms within and around the gene-coding areas of CYP2C8 and CYP2C9 were tested for an association with incident MI using survival analysis techniques with multivariable adjustment for potential confounders.

RESULTS

During follow-up, 290 persons developed an incident MI. One tag-SNP in the CYP2C8 gene was associated with incident MI after Bonferroni correction, rs1058932C>T (variant genotype hazard ratio 1.54; 95% CI: 1.22-1.95). There was a significant gene-sex interaction with a relative excess risk of 1.40 (95% CI: 0.33-2.47) for men.

CONCLUSION

SNP rs1058932C>T within the CYP2C8 gene is associated with an increased risk of MI, which is, possibly because of a vascular effect of sex steroids, highest in males.

Epoxyeicosanoid signaling in CNS function and disease

Epoxyeicosatrienoic acids (EETs) are arachidonic acid metabolites of cytochrome P450 epoxygenase enzymes recognized as key players in vascular function and disease, primarily attributed to their potent vasodilator, anti-inflammatory and pro-angiogenic effects. Although EETs' actions in the central nervous system (CNS) appear to parallel those in peripheral tissue, accumulating evidence suggests that epoxyeicosanoid signaling plays different roles in neural tissue compared to peripheral tissue; roles that reflect distinct CNS functions, cellular makeup and intercellular relationships. This is exhibited at many levels including the expression of EETs-synthetic and -metabolic enzymes in central neurons and glial cells, EETs' role in neuro-glio-vascular coupling during cortical functional activation, the capacity for interaction between epoxyeicosanoid and neuroactive endocannabinoid signaling pathways, and the regulation of neurohormone and neuropeptide release by endogenous EETs. The ability of several CNS cell types to produce and respond to EETs suggests that epoxyeicosanoid signaling is a key integrator of cell-cell communication in the CNS, coordinating cellular responses across different cell types. Under pathophysiological conditions, such as cerebral ischemia, EETs protect neurons, astroglia and vascular endothelium, thus preserving the integrity of cellular networks unique to and essential for proper CNS function. Recognition of EETs' intimate involvement in CNS function in addition to their multi-cellular protective profile has inspired the development of therapeutic strategies against CNS diseases such as cerebral ischemia, tumors, and neural pain and inflammation that are based on targeting the cellular actions of EETs or their biosynthetic and metabolizing enzymes. Based upon the emerging importance of epoxyeicosanoids in cellular function and disease unique to neural systems, we propose that the actions of "neuroactive EETs" are best considered separately, and not in aggregate with all other peripheral EETs functions.

The Rotterdam Study: 2010 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in close to a 1,000 research articles and reports (see www.epib.nl/rotterdamstudy). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Impact of genetic polymorphisms in CYP2C8 and rosiglitazone intake on the urinary excretion of dihydroxyeicosatrienoic acids

The cytochrome P450 enzymes CYP2C8, CYP2C9 and CYP2J2 generate 8,9-, 11,12-, and 14,15-epoxyeicosatrienic acid (EET) from arachidonic acid, and these EETs are then hydrolyzed to dihydroxyeicosatrienoic acids (DHET) before excretion into the urine. It is unknown how genetic polymorphisms affect formation of these diuretic, vasodilatory and anti-inflammatory eicosanoids, and whether the CYP2C8 substrate rosiglitazone inhibits their formation. Methods: A panel of 14, 13 and four carriers of the CYP2C8 genotypes *1/*1, *1/*3 and *3/*3, respectively was preselected for this study. Daily morning oral doses of 8 mg rosiglitazone were administered for 15 days. Urine was collected prior to rosiglitazone, and for 24 h after the first and last administration of rosiglitazone. Urinary EETs and DHETs were analyzed by tandem mass spectrometry. Results:Carriers of the high-activity CYP2C8*3 allele had higher excretion of all three DHETs (p < 0.01 for 11,12-DHET, p < 0.05 for 14,15-DHET), whereas carriers of the low-activity CYP2C8 haplotype C (genotypes GCGA at positions rs2275622, rs7909236, rs1113129 and rs11572080) had lower DHET excretion in urine before and during rosiglitazone. Rosiglitazone intake leads to a decrease in DHET excretion by approximately 10% (p < 0.02). Urinary excretion of unhydrolyzed EETs was below the limit of quantification of 50 pg/ml in all samples. Conclusion: The data consistently indicate that genetic variation in CYP2C8 moderately modulates-EET formation as reflected in urinary DHET excretion. This might impact cardiovascular functions, and may be one mechanism explaining the influence of CYP polymorphisms on myocardial infarction and hypertension.

Genetic variation in the cytochrome P450 epoxygenase pathway and cardiovascular disease risk

The cytochrome (CYP) P450 epoxygenase pathway catalyzes the epoxidation of arachidonic acids to epoxyeicosatrienoic acids, which are subsequently hydrolyzed to less active dihydroxyeicosatrienoic acids by soluble epoxide hydrolase. Numerous preclinical studies have demonstrated that CYP-derived epoxyeicosatrienoic acids possess potent vasodilatory and anti-inflammatory properties in the cardiovascular system. In humans, functionally relevant polymorphisms, which may significantly modulate epoxyeicosatrienoic acid levels in vivo, have been identified in the genes encoding CYP2J2, CYP2C8, CYP2C9 and soluble epoxide hydrolase. Initial epidemiologic studies have demonstrated that genetic variation in the CYP epoxygenase pathway significantly modifies cardiovascular disease risk at the population level in humans, providing support for the hypothesis that modulation of this pathway may represent a novel approach to the prevention and treatment of cardiovascular disease. Future studies in humans validating these relationships and characterizing the underlying mechanisms will be necessary to fully understand the functional role of the CYP epoxygenase pathway in cardiovascular disease.