Obesity status modifies the association between rs7556897T>C in the intergenic region SLC19A3-CCL20 and blood pressure in French children.

Background Growing evidence reports an association between inflammatory markers, obesity and blood pressure (BP). Specifically, the intergenic single nucleotide polymorphism (SNP) rs7556897T > C (MAF = 0.34) located between SLC19A3 and the CCL20 was shown to be associated with chronic inflammatory diseases. In addition, CCL20 expression was found increased in pancreatic islets of obese rodents and human pancreatic ß cells under the influence of inflammation. In this study, we hypothesized that SNP rs7556897 could affect BP levels, thus providing a link between inflammation, BP and obesity. Methods BP was measured under supine position with a manual sphygmomanometer; values reported were the means of three readings. We analyzed rs7556897 in 577 normal weight and 689 obese French children. Using real-time polymerase chain reaction (PCR), we quantified CCL20 and SLC19A3 expression in adipose tissue and peripheral blood mononuclear cells (PBMCs) of normal weight and overweight children. Results The rs7556897C allele was negatively associated with diastolic BP in normal weight children (ß = -0.012 ± 0.004, p = 0.006) but positively associated in obese children (ß = 2.178 ± 0.71, p = 0.002). A significant interaction between rs7556897T > C and the obesity status (obese or normal weight) was detected (ß = 3.49, p = 9.79 × 10-5) for BP in a combined population analysis. CCL20 mRNA was only expressed in the adipose tissue of overweight children, and its expression levels were 10.7× higher in PBMCs of overweight children than normal weight children. Finally, CCL20 mRNA levels were positively associated with rs7556897T > C in PBMCs of 58 normal weight children (ß = 0.43, p = 0.002). SLC19A3 was not expressed in PBMCs, and in adipose tissue, it showed same levels of expression in normal weight and overweight children. The gene expression results may highlight a specific involvement of CCL20 via communicating obesity/inflammation pathways that regulate BP. Conclusions Childhood obesity reverses the effect of rs7556897T > C on diastolic BP, possibly via the modulation of CCL20 expression levels.

Nuclear receptor gene polymorphisms and warfarin dose requirements in the Quebec Warfarin Cohort.

Warfarin is primarily metabolized by cytochrome 2C9, encoded by gene CYP2C9. Here, we investigated whether variants in nuclear receptor genes which regulate the expression of CYP2C9 are associated with warfarin response. We used data from 906 warfarin users from the Quebec Warfarin Cohort (QWC) and tested the association of warfarin dose requirement at 3 months following the initiation of therapy in nine nuclear receptor genes: NR1I3, NR1I2, NR3C1, ESR1, GATA4, RXRA, VDR, CEBPA, and HNF4A. Three correlated SNPs in the VDR gene (rs4760658, rs11168292, and rs11168293) were associated with dose requirements of warfarin (P = 2.68 × 10-5, P = 5.81 × 10-4, and P = 5.94 × 10-4, respectively). Required doses of warfarin were the highest for homozygotes of the minor allele at the VDR variants (P < 0.0026). Variants in the VDR gene were associated with the variability in response to warfarin, emphasizing the possible clinical relevance of nuclear receptor gene variants on the inter-individual variability in drug metabolism.

Rationale, design, and preliminary results of the Quebec Warfarin Cohort Study.

Over- and undercoagulation with warfarin are associated with hemorrhagic and thromboembolic events, respectively. Genetic and clinical factors affect warfarin response, and the causes of this variability remain unclear. We present descriptive statistics and test for predictors of poor anticoagulation control. The Quebec Warfarin Cohort (QWC) comprises 1059 new warfarin users, with prospective follow-up using telephone questionnaires every 3 months for 1 year, and using healthcare administrative databases (RAMQ and Med-Echo) for 5 years prior to cohort entry and up to 10 years following active patient participation. Genetic material was collected, and genotyping of CYP2C9 and VKORC1 genes was conducted. Measured outcomes included the percentage of time patients spent within therapeutic range, anticoagulation control, warfarin dose, bleeding, and thromboembolic events. We report baseline characteristics and outcomes after 1 year of follow-up. Poor anticoagulation control was defined as time in therapeutic range <60% in the 3- to 12-month interval. Participants had a mean age of 71 years, and 62% were men. The most common indication for warfarin was atrial fibrillation (87%). Mean time in therapeutic range was 56% (±25%) in the 3 months following warfarin initiation, and 70% (±21%) in the 3- to 12-month interval. During follow-up, the rate of stroke or systemic embolism was 1.8 events per 100 person-years; for major bleeding events, 3.3 events per 100 person-years. Independent predictors of poor anticoagulation control were chronic kidney disease, heart failure, dyslipidemia, and age. The QWC represents a good research cohort to investigate clinical and genetic factors in a warfarin-anticoagulated population.

An expanded pharmacogenomics warfarin dosing table with utility in generalised dosing guidance.

Pharmacogenomics (PGx) guided warfarin dosing, using a comprehensive dosing algorithm, is expected to improve dose optimisation and lower the risk of adverse drug reactions. As a complementary tool, a simple genotype-dosing table, such as in the US Food and Drug Administration (FDA) Coumadin drug label, may be utilised for general risk assessment of likely over- or under-anticoagulation on a standard dose of warfarin. This tool may be used as part of the clinical decision support for the interpretation of genetic data, serving as a first step in the anticoagulation therapy decision making process. Here we used a publicly available warfarin dosing calculator (www.warfarindosing.org) to create an expanded gene-based warfarin dosing table, the CPMC-WD table that includes nine genetic variants in CYP2C9, VKORC1, and CYP4F2. Using two datasets, a European American cohort (EUA, n=73) and the Quebec Warfarin Cohort (QWC, n=769), we show that the CPMC-WD table more accurately predicts therapeutic dose than the FDA table (51 % vs 33 %, respectively, in the EUA, McNemar's two-sided p=0.02; 52 % vs 37 % in the QWC, p<1×10(-6)). It also outperforms both the standard of care 5 mg/day dosing (51 % vs 34 % in the EUA, p=0.04; 52 % vs 31 % in the QWC, p<1×10(-6)) as well as a clinical-only algorithm (51 % vs 38 % in the EUA, trend p=0.11; 52 % vs 45 % in the QWC, p=0.003). This table offers a valuable update to the PGx dosing guideline in the drug label.

Smoking and wound complications after coronary artery bypass grafting.

BACKGROUND: The harmful effects of smoking on the postsurgical wound healing disturbances have been widely investigated across various surgical procedures. These effects after coronary artery bypass graft (CABG) surgery have been less explored. We aimed to investigate the association of smoking and the wound healing problems in post-CABG patients. MATERIALS AND METHODS: We compared the incidence of wound complications in 405 smokers and 405 nonsmokers who underwent an elective CABG surgery. The incidence of leg and sternal wound complications was evaluated during the first 7 d as well as at a 6-wk postoperative visit. RESULTS: One hundred fifty-six leg wound complications were noted in 132 patients (16.3%). The overall rate of leg wound healing disturbances was significantly higher in smokers than those in nonsmokers (odds ratio, 1.47; 95% confidence interval, 1.109-4.019; P = 0.010). The incidence rates of leg wound edge necrosis and dehiscence were significantly higher in smokers compared with those in nonsmokers (3.7% versus 0.7%, P = 0.004 and 6.6% versus 0.7%, P < 0.0001, respectively). We found no significant differences between the incidence of postoperative leg wound infection, hematoma, wound edema, and seroma in active smokers and those who never smoked. Thirty-seven postsurgical sternal wound complications (4.6%) were developed in 33 patients (4.1%). The overall rate of sternal wound healing disturbances was similar between smokers and nonsmokers. There was a trend between the sternal wound dehiscence and smoking (P = 0.03); however, the other sternal wound complications were not associated with smoking. CONCLUSIONS: Smoking may contribute to the disturbances of wound healing, especially wound dehiscence, in post-CABG patients.

Impact of regular physical activity on weekly warfarin dose requirement.

Warfarin is an oral anticoagulant agent with a narrow therapeutic index. There is a marked inter- and intra-patient variability in warfarin dose requirement. All factors influencing warfarin response are not known and this study aims to evaluate if regular physical activity (RPA) is a determining factor. RPA level was collected with the Stanford Brief Activity Survey in 1064 incident warfarin users, as part of the Quebec Warfarin Cohort (QWC), and with the Global Physical Activity Questionnaire in 618 patients from the Montreal Heart Institute (MHI) Biobank. Linear regression was performed to model relationship of warfarin dose after 3 months of therapy in the QWC with RPA, while controlling for height, weight, age, CYP2C9 (*2 and *3 alleles) and VKORC1 (*2 allele) genotype. Warfarin dose of prevalent users was modeled in the MHI Biobank for replication. A higher level of physical activity was associated with higher doses of warfarin in both cohorts. In the QWC, physical activity could explain 5.4 % (P < 0.001) and 0.9 % (P = 3.23 × 10(-5)) of variance in dose, in univariate and multivariable models, respectively. Similarly, RPA was found to be associated with 1.7 % (P = 0.0012) and 0.5 % (P = 0.0391) of inter-individual variability in warfarin dose requirement before and after adjustment for other covariables, respectively. RPA is associated with higher warfarin dose requirement. The relevance of clinical recommendations on RPA to maintain a steady response to warfarin should be assessed in further studies.

Genetic determined low response to thienopyridines is associated with higher systemic inflammation in smokers.

AIM: To investigate whether the interactions of CYP2C19*2 and CYP2C19*17 with smoking are associated with the levels of P2Y12 receptor inhibition and CRP, in on-thienopyridine post-stenting patients. METHODS & RESULTS: At 1-month follow-up, the interactions of smoking and CYP2C19 polymorphisms on the vasodilator-stimulated phosphoprotein - platelet reactivity index (VASP PRI), and CRP were explored in three metabolizing groups (1128 patients) as follow: poor metabolizers (*2 carriers/*17 noncarriers); intermediate metabolizers (*2 carriers/*17 carriers or *2 noncarriers/*17 noncarriers); and ultrarapidmetabolizers (*2 allele noncarriers/*17 carriers). The interactions of metabolizing status and smoking was significant for CRP (p = 0.001) but not for VASP PRI (p = 0.734). CONCLUSION: Interaction between CYP2C19 polymorphisms and smoking modifies on-treatment CRP level of post-stenting, on-thienopyridine patients. This effect seems to be independent to the level of P2Y12 receptor inhibition.

Cardiovascular pharmacogenomics; state of current knowledge and implementation in practice.

Pharmacogenomics (PGx) is the science that examines how an individual's genetic make-up affects the safety and efficacy of therapeutic drugs. PGx of response to cardiovascular (CV) medications is of the most successfully translated branches of PGx into the clinical workout. However, the clinical implementation of PGx of CV drugs is yet far beyond the growth of our understanding of the role of genetics in drug therapy. A considerable amount of efforts have been devoted by the regulatory agents like the food and drug administration (FDA) as well as the expert-based networks such as the Clinical Pharmacogenetics Implementation Consortium (CPIC) to overcome the existing barriers. This has been done, at least in part, for some of the most widely prescribed CV drugs, including clopidogrel, warfarin and simvastatin for which the PGx knowledge have been satisfactorily robust to provoke the CPIC to issue the guidelines for these drugs and the FDA to update the drugs' labeling, both strongly recommended the use of genotype-guided dosing for these medications, provided that the genetic data are available. For other drugs, however, studies have produced contradictory results and further large and well-designed clinical trials are required to expand and confirm the clinical utility of their PGx data. This review paper presents the current state of knowledge in the field of PGx of CV medications and describes the facilities assisting to the translation of PGx data into the clinical practice. Afterward, the existing body of PGx literature of the most-commonly used CV medications is comprehensively discussed.

Human cytochrome P450 epoxygenases: variability in expression and role in inflammation-related disorders.

Beyond their contribution to the metabolism of xenobiotics, cytochrome P450 (CYP) epoxygenases are actively involved in the metabolism of endogenous substances, like arachidonic acid (AA). The main human CYP epoxygenases, i.e. CYP2C8, CYP2C9, CYP2C19 and CYP2J2, convert AA to four regioisomer epoxyeicosatrienoic acids (EETs). EETs possess a wide range of established protective effects on the human cardiovascular system of which anti-inflammatory actions have gained great recent interest. The expression of CYP epoxygenases is regulated through an extremely complex network of nuclear receptors, microRNAs and genetic/epigenetic factors. Accordingly, a large number of biological variables as well as xenobiotics and environmental factors can influence the expression of CYP epoxygenases, resulting in a significant intra- and inter-individual variability in the expression and activity of these enzymes and subsequently in EET biosynthesis. Moreover, human CYP epoxygenases are mainly expressed in the liver; however, these enzymes are also expressed, at various extents, in most extrahepatic tissues, resulting in a marked inter-tissue variability in the expression of CYP epoxygenases. The inter-tissue, inter- and intra-individual variability in the expression of epoxygenases may lead to differences in the relative abundance of EETs among tissues, among individuals of a population and/or different ethnicities and in a given individual under various conditions. The variation in the abundance of EETs may explain, at least in part, the inter-tissue and inter-individual differences observed in the prevalence of inflammation-related disorders including cardiovascular disease, and why in a given individual, various conditions can contribute to the development of diseases with an important inflammatory component.

Influence of inflammation on cardiovascular protective effects of cytochrome P450 epoxygenase-derived epoxyeicosatrienoic acids.

In addition to their role as xenobiotic metabolizing enzymes, cytochrome P450 (CYP) epoxygenases actively contribute to the metabolism of endogenous substances such as arachidonic acid. Epoxyeicosatrienoic acids (EETs) are epoxide derivative of arachidonic acid. CYP2C8/9 and CYP2J2 are the main epoxygenases expressed in human tissues including endothelial cells which are the chief sources of EET formation in human body. Once formed, EETs are primarily metabolized to their less biologically active metabolites, dihydroxyeicosatrienoic acids, by soluble epoxy hydrolase (sEH) enzyme. EETs possess a wide range of established protective effects on human cardiovascular system of which vasodilatory, angiogenic and anti-inflammatory actions have been more extensively described. On the other hand, inflammation has shown to decrease the expression and activity of CYP enzyme, including epoxygenases. Given the fact that CYP epoxygenase-derive EETs exhibit potent cardiovascular protective effects, including anti-inflammation, and that inflammation suppress CYP activation and EET formation, it would make sense to speculate that under inflammatory conditions there exists an inflammation-epoxygenase-EET-inflammation vicious cycle in which the inflammation-induced downregulation of CYP epoxygenases causes a decrease in the EET production. Insufficient EET synthesis would, in turn, lead to an ineffective EET-mediated anti-inflammatory effect, leading to an augmentation of systemic and regional inflammatory responses and further downregulation of CYP epoxygenase activity/EET production. This cycle, if any, might help to better understanding of pathophysiology of chronic cardiovascular diseases and also could be an emerging target for further pharmacological therapy of disorders in which increased inflammatory responses are known to occur.

Conference Scene: Systems biology and personalized health science and translation.

After a 1-day advanced course on systems biology, the main themes of this 3-day colloquium were developed: from systems biology to systems medicine with special applications to cancer; pharmacogenomics in drug discovery and clinical application; and epigenomics and genome-wide association studies in cardiovascular diseases. In two roundtable discussions on pharmacogenomics and genome-wide association studies, the progress and the difficulties in the implementation of omics technologies in clinical practice were discussed. Three workshops were also organized on technical tools linked to the meeting themes.

Influence of genetic variations on levels of inflammatory markers of healthy subjects at baseline and one week after clopidogrel therapy; results of a preliminary study.

We aimed to assess the association between the most common polymorphisms of cytochrome P450 (CYP) epoxygenases on the plasma levels of inflammatory markers in a population of healthy subjects. We also sought to determine whether CYP2C19 2 polymorphism is associated with the anti-inflammatory response to clopidogrel. In a population of 49 healthy young males, the baseline plasma levels of inflammatory markers including C-reactive protein, haptoglobin, orosomucoid acid, CD-40 were compared in carriers vs. non-carriers of the most frequent CYP epoxygenase polymorphisms: CYP2C9 2, CYP2C9 3, CYP2C19 2, CYP2C8 2 and CYP2J2 7. Also, the variation of inflammatory markers from baseline to 7 days after administration of 75 mg per day of clopidogrel were compared in carriers vs. non-carriers of CYP2C19 allele and also in responders vs. hypo-responders to clopidogrel, determined by platelet reactivity tests. There was no significant association between epoxygenase polymorphisms and the baseline levels of inflammatory markers. Likewise, CYP2C19 allele was not associated with anti-inflammatory response to clopidogrel. Our findings did not support the notion that the genetic variations of CYP epoxygenases are associated with the level of inflammatory markers. Moreover, our results did not support the hypothesis that CYP2C19 2 polymorphism is associated with the variability in response to the anti-inflammatory properties of clopidogrel.

Comparison of three risk assessment methods for venous thromboembolism prophylaxis.

Venous thromboembolism (VTE) is a major problem for hospitalized patients. Nevertheless, adherence to VTE prophylaxis guidelines is suboptimal, partly because of physicians' neglect due to excessive workload. Simplified risk assessment methods (RAMs) facilitate timely risk stratification and thromboprophylaxis. However, the accuracy of such RAMs has not been extensively studied. Using the prospectively collected data from hospitalized patients of Masih-Daneshvari Hospital, we tested the accuracy of the Goldhaber RAM and the Harinath and St. John RAM for VTE prophylaxis, compared with the eighth edition of the American College of Chest Physicians (ACCP) recommendations. We evaluated 1091 patients. With reference to the ACCP recommendations, both RAMs had high specificities for detection of patients at risk of VTE (97.33 and 99.11%, respectively); however, we found significant interdepartment differences. The Goldhaber RAM had superior accuracy in medical oncology patients (P = 0.03), whereas the Harinath and St. John method was superior among surgical patients (P < 0.001). Overall accuracies of Goldhaber RAM for appropriate VTE risk assessment and for proper detection of at-risk patients were close to 60%. Corresponding figures were close to 70% for the Harinath and St. John method. Simplified VTE prophylaxis RAMs are valuable, especially for transmitting electronic alerts and for timely risk assessment and thromboprophylaxis. Both of the studied RAMs had high specificities and positive-predictive values, minimizing the risk of overprophylaxis. Improving the sensitivity of such RAMs can help for timely risk assessment for a greater array of real-world patients.

Clinical necessity of partitioning of human plasma haptoglobin reference intervals by recently-discovered rs2000999.

BACKGROUND: Very recently, we identified a novel polymorphism, rs2000999, located in haptoglobin gene (HP) as a strong genetic determinant of the haptoglobin levels (Hp). We aim to determine the reference values of Hp on the basis of its main sources of biological variation including the rs2000999 in a large French origin population, the STANISLAS Family Study (SFS). METHODS: Through a stepwise regression analysis, the main biological variables of Hp levels were identified in 3129 "apparently" disease-free individuals of the SFS. Hp reference ranges were subsequently established in a subgroup of 2923 selected healthy subjects, as the reference population. RESULTS: The plasma reference values of Hp ranged 0.08-1.97 g/L in males and 0.08-2.19 g/L in females. Gender, age, smoking, plasma levels of hemoglobin and the newly-discovered HP polymorphism, rs2000999, were found to be the strongest biological predictors of the Hp concentrations in human plasma. Hp levels, in both genders and in all age groups, were negatively associated with the presence and number of rs2000999 minor allele. CONCLUSION: To be reliably interpretable in daily medical practice, the HP polymorphism, rs2000999, should be considered for partitioning its reference values. This polymorphism may also help for setting decision limits for medical interpretation of Hp concentrations.

AssessMent of ProphylAxis for VenouS ThromboembolIsm in hospitalized patients: the MASIH study.

BACKGROUND: Venous thromboembolism (VTE) accounts for several cases of in-hospital mortality (over 100 000 deaths annually in the West). Despite the existence of effective prophylaxis guidelines for at-risk patients, the guidelines adherence is missing. METHODS: We evaluated the thromboprophylaxis reception and appropriateness based on the eighth edition of the American College of Chest Physicians (ACCP) guidelines on VTE prophylaxis, among hospitalized patients of a World Health Organization (WHO)-collaborating teaching hospital in a 3-month period. RESULTS: From the 904 evaluated cases, 481 entered the study. Appropriate decision on whether to prophylaxe or not, was made in 305 (63.40%), however, complete appropriateness (considering correct regimen type, dosing, and duration) was seen only in 229 patients (47.60%). The ACCP risk for VTE was the strongest predictor of thromboprophylaxis prescription (odds ratio [OR]: 2.62, 95% confidence interval [CI]: 1.35-5.05). CONCLUSIONS: Our thromboprophylaxis results were comparable to that of Western countries. Improved thromboprophylaxis appropriateness, which requires improving the physicians' thromboprophylaxis awareness and knowledge, could reduce the rate of in-hospital VTE and translate into better patient care.

Biological and genetic factors associated with ABCB1 and pregnane-X-receptor expressions in peripheral blood mononuclear cells in the STANISLAS cohort.

BACKGROUND: ABCB1 is a membrane transporter ubiquitously expressed particularly in peripheral blood mononuclear cells (PBMCs). Resistance to drugs is associated with genetic variations of its gene and with modulation of its expression through the pregnane-X-receptor (PXR) transcription factor. We have previously shown that ABCB1 polymorphisms were associated with blood lipid concentrations. METHODS: We wanted to investigate the variation factors and the genetic determinants of ABCB1 and PXR expressions in PBMCs, and their interrelationships with plasma lipid levels. ABCB1 and PXR mRNA were quantified by real-time quantitative RT-PCR in PBMCs of 42 men and 39 women. RESULTS: ABCB1 and PXR were both expressed in PBMCs of all individuals, but their expressions were not significantly correlated. ABCB1 mRNA was correlated with body mass index (BMI; p=0.01) and age (p=0.03). In women, lymphocyte count also correlated with ABCB1 transcripts (p<0.01). After adjustment for BMI, correlation with age disappears. PXR mRNA expression depends on gender with men expressing higher PXR levels (p=0.01). PXR expression also correlates with γ-glutamyltransferase (GGT; p=0.02), but this disappeared after adjustment. CONCLUSIONS: Neither ABCB1 nor PXR expressions correlate with ABCB1 gene variants. Finally, association between ABCB1 or PXR expression in PBMCs and lipid or apolipoprotein plasma concentrations were not significant in this subset of healthy subjects. These results should be confirmed in a larger population sample and extended to patients with various cardiovascular risk profiles.