Publications by authors named "Julio D Duarte"

30 Publications

  • Page 1 of 1

Therapeutic Challenges and Emerging Treatment Targets for Pulmonary Hypertension in Left Heart Disease.

J Am Heart Assoc 2021 Jun 25;10(11):e020633. Epub 2021 May 25.

Department of Pharmacotherapy and Translational Research Center for Pharmacogenomics and Precision Medicine University of Florida College of Pharmacy Gainesville FL.

Pulmonary hypertension (PH) attributable to left heart disease (LHD) is believed to be the most common form of PH and is strongly associated with increased mortality and morbidity in this patient population. Specific therapies for PH-LHD have not yet been identified and the use of pulmonary artery hypertension-targeted therapies in PH-LHD are not recommended. Endothelin receptor antagonists, phosphodiesterase-5 inhibitors, guanylate cyclase stimulators, and prostacyclins have all been studied in PH-LHD with conflicting results. Understanding the mechanisms underlying PH-LHD could potentially provide novel therapeutic targets. Fibrosis, oxidative stress, and metabolic syndrome have been proposed as pathophysiological components of PH-LHD. Genetic associations have also been identified, offering additional mechanisms with biological plausibility. This review summarizes the evidence and challenges for treatment of PH-LHD and focuses on underlying mechanisms on the horizon that could develop into potential therapeutic targets for this disease.
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http://dx.doi.org/10.1161/JAHA.120.020633DOI Listing
June 2021

Patients with geographic barriers to health care access are prescribed a higher proportion of drugs with pharmacogenetic testing guidelines.

Clin Transl Sci 2021 May 5. Epub 2021 May 5.

Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Gainesville, Florida, USA.

Pharmacogenetic (PGx) testing may be particularly beneficial in medically underserved populations by reducing the number of appointments required to optimize drug therapy and increasing the effectiveness of less expensive off-patent drugs. The objective of this study was to identify patient populations with poor health care access and assess prescribing trends for drugs with published PGx testing guidelines. We used electronic health record data from 67,753 University of Florida Health patients, geographic access scores calculated via the 2-step floating catchment area method, and a composite measure of socioeconomic status. Comparing the poorest (Q4) and greatest (Q1) access score quartiles, poor geographic access was significantly associated with fewer prescriber encounters (incidence rate ratio [IRR] 0.88, 95% confidence interval [CI] 0.86-0.91), fewer total unique drugs (IRR 0.92, 95% CI 0.9-0.95), and fewer PGx guideline drugs (IRR 0.94, 95% CI 0.9-0.99). After correcting for number of unique drugs, patients in low-access areas were prescribed a greater proportion of PGx guideline drugs (IRR 1.08, 95% CI 1.04-1.13). We detected significant interactions between Black race and access score. Compared to Q1, Black patients with Q4 access scores were disproportionately affected and had fewer encounters (IRR 0.76, 95% CI 0.7-0.82) and a higher proportion of PGx drugs (IRR 1.26, 95% CI 1.13-1.41), creating further disparity. Overall, these results suggest that improved geographic access to PGx testing may allow prescribers to make more efficient use of limited opportunities to optimize therapy for drugs with PGx testing guidelines.
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http://dx.doi.org/10.1111/cts.13032DOI Listing
May 2021

Pharmacogenetics to guide cardiovascular drug therapy.

Nat Rev Cardiol 2021 May 5. Epub 2021 May 5.

Center for Pharmacogenomics and Precision Medicine and Department of Pharmacotherapy and Translational Research, University of Florida College of Pharmacy, Gainesville, FL, USA.

Over the past decade, pharmacogenetic testing has emerged in clinical practice to guide selected cardiovascular therapies. The most common implementation in practice is CYP2C19 genotyping to predict clopidogrel response and assist in selecting antiplatelet therapy after percutaneous coronary intervention. Additional examples include genotyping to guide warfarin dosing and statin prescribing. Increasing evidence exists on outcomes with genotype-guided cardiovascular therapies from multiple randomized controlled trials and observational studies. Pharmacogenetic evidence is accumulating for additional cardiovascular medications. However, data for many of these medications are not yet sufficient to support the use of genotyping for drug prescribing. Ultimately, pharmacogenetics might provide a means to individualize drug regimens for complex diseases such as heart failure, in which the treatment armamentarium includes a growing list of medications shown to reduce morbidity and mortality. However, sophisticated analytical approaches are likely to be necessary to dissect the genetic underpinnings of responses to drug combinations. In this Review, we examine the evidence supporting pharmacogenetic testing in cardiovascular medicine, including that available from several clinical trials. In addition, we describe guidelines that support the use of cardiovascular pharmacogenetics, provide examples of clinical implementation of genotype-guided cardiovascular therapies and discuss opportunities for future growth of the field.
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http://dx.doi.org/10.1038/s41569-021-00549-wDOI Listing
May 2021

County-level longitudinal clustering of COVID-19 mortality to incidence ratio in the United States.

Sci Rep 2021 02 4;11(1):3088. Epub 2021 Feb 4.

Informatics Institute, University of Florida, Gainesville, FL, USA.

As of November 12, 2020, the mortality to incidence ratio (MIR) of COVID-19 was 5.8% in the US. A longitudinal model-based clustering system on the disease trajectories over time was used to identify "vulnerable" clusters of counties that would benefit from allocating additional resources by federal, state and county policymakers. County-level COVID-19 cases and deaths, together with a set of potential risk factors were collected for 3050 U.S. counties during the 1st wave of COVID-19 (Mar25-Jun3, 2020), followed by similar data for 1344 counties (in the "sunbelt" region of the country) during the 2nd wave (Jun4-Sep2, 2020), and finally for 1055 counties located broadly in the great plains region of the country during the 3rd wave (Sep3-Nov12, 2020). We used growth mixture models to identify clusters of counties exhibiting similar COVID-19 MIR growth trajectories and risk-factors over time. The analysis identifies "more vulnerable" clusters during the 1st, 2nd and 3rd waves of COVID-19. Further, tuberculosis (OR 1.3-2.1-3.2), drug use disorder (OR 1.1), hepatitis (OR 13.1), HIV/AIDS (OR 2.3), cardiomyopathy and myocarditis (OR 1.3), diabetes (OR 1.2), mesothelioma (OR 9.3) were significantly associated with increased odds of being in a more vulnerable cluster. Heart complications and cancer were the main risk factors increasing the COVID-19 MIR (range 0.08-0.52% MIR↑). We identified "more vulnerable" county-clusters exhibiting the highest COVID-19 MIR trajectories, indicating that enhancing the capacity and access to healthcare resources would be key to successfully manage COVID-19 in these clusters. These findings provide insights for public health policymakers on the groups of people and locations they need to pay particular attention while managing the COVID-19 epidemic.
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http://dx.doi.org/10.1038/s41598-021-82384-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7862666PMC
February 2021

IL-18 mediates sickle cell cardiomyopathy and ventricular arrhythmias.

Blood 2021 Mar;137(9):1208-1218

Department of Medicine, Indiana University, Indianapolis, IN.

Previous reports indicate that IL18 is a novel candidate gene for diastolic dysfunction in sickle cell disease (SCD)-related cardiomyopathy. We hypothesize that interleukin-18 (IL-18) mediates the development of cardiomyopathy and ventricular tachycardia (VT) in SCD. Compared with control mice, a humanized mouse model of SCD exhibited increased cardiac fibrosis, prolonged duration of action potential, higher VT inducibility in vivo, higher cardiac NF-κB phosphorylation, and higher circulating IL-18 levels, as well as reduced voltage-gated potassium channel expression, which translates to reduced transient outward potassium current (Ito) in isolated cardiomyocytes. Administering IL-18 to isolated mouse hearts resulted in VT originating from the right ventricle and further reduced Ito in SCD mouse cardiomyocytes. Sustained IL-18 inhibition via IL-18-binding protein resulted in decreased cardiac fibrosis and NF-κB phosphorylation, improved diastolic function, normalized electrical remodeling, and attenuated IL-18-mediated VT in SCD mice. Patients with SCD and either myocardial fibrosis or increased QTc displayed greater IL18 gene expression in peripheral blood mononuclear cells (PBMCs), and QTc was strongly correlated with plasma IL-18 levels. PBMC-derived IL18 gene expression was increased in patients who did not survive compared with those who did. IL-18 is a mediator of sickle cell cardiomyopathy and VT in mice and a novel therapeutic target in patients at risk for sudden death.
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http://dx.doi.org/10.1182/blood.2020005944DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7933768PMC
March 2021

Impact of the CYP2C19*17 Allele on Outcomes in Patients Receiving Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention.

Clin Pharmacol Ther 2021 Mar 2;109(3):705-715. Epub 2020 Oct 2.

Department of Pharmacotherapy and Translational Research, Center for Pharmacogenomics and Precision Medicine, University of Florida, Gainesville, Florida, USA.

Genotyping for CYP2C19 no function alleles to guide antiplatelet therapy after percutaneous coronary intervention (PCI) improves clinical outcomes. Although results for the increased function CYP2C19*17 allele are also reported, its clinical relevance in this setting remains unclear. A collaboration across nine sites examined antiplatelet therapy prescribing and clinical outcomes in 3,342 patients after implementation of CYP2C19-guided antiplatelet therapy. Risk of major atherothrombotic and bleeding events over 12 months after PCI were compared across cytochrome P450 2C19 isozyme (CYP2C19) metabolizer phenotype and antiplatelet therapy groups by proportional hazards regression. Clopidogrel was prescribed to a similar proportion of CYP2C19 normal (84.5%), rapid (82.9%), and ultrarapid metabolizers (80.6%) (P = 0.360). Clopidogrel-treated normal metabolizers (20.4 events/100 patient-years; adjusted hazard ratio (HR) 1.00, 95% confidence interval (CI), 0.75-1.33, P = 0.993) and clopidogrel-treated rapid or ultrarapid metabolizers (19.1 events/100 patient-years; adjusted HR 0.95, 95% CI, 0.69-1.30, P = 0.734) exhibited no difference in major atherothrombotic events compared with patients treated with prasugrel or ticagrelor (17.6 events/100 patient-years). In contrast, clopidogrel-treated intermediate and poor metabolizers exhibited significantly higher atherothrombotic event risk compared with prasugrel/ticagrelor-treated patients (adjusted HR 1.56, 95% CI, 1.12-2.16, P = 0.008). When comparing clopidogrel-treated rapid or ultrarapid metabolizers to normal metabolizers, no difference in atherothrombotic (adjusted HR 0.97, 95% CI, 0.73-1.29, P = 0.808) or bleeding events (adjusted HR 1.34, 95% CI, 0.83-2.17, P = 0.224) were observed. In a real-world setting of genotype-guided antiplatelet therapy, the CYP2C19*17 allele did not significantly impact post-PCI prescribing decisions or clinical outcomes. These results suggest the CYP2C19 *1/*17 and *17/*17 genotypes have limited clinical utility to guide antiplatelet therapy after PCI.
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http://dx.doi.org/10.1002/cpt.2039DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7902344PMC
March 2021

Cost-effectiveness of CYP2C19-guided antiplatelet therapy in patients with acute coronary syndrome and percutaneous coronary intervention informed by real-world data.

Pharmacogenomics J 2020 10 11;20(5):724-735. Epub 2020 Feb 11.

Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, USA.

Current guidelines recommend dual antiplatelet therapy (DAPT) consisting of aspirin and a P2Y12 inhibitors following percutaneous coronary intervention (PCI). CYP2C19 genotype can guide DAPT selection, prescribing ticagrelor or prasugrel for loss-of-function (LOF) allele carriers (genotype-guided escalation). Cost-effectiveness analyses (CEA) are traditionally grounded in clinical trial data. We conduct a CEA using real-world data using a 1-year decision-analytic model comparing primary strategies: universal empiric clopidogrel (base case), universal ticagrelor, and genotype-guided escalation. We also explore secondary strategies commonly implemented in practice, wherein all patients are prescribed ticagrelor for 30 days post PCI. After 30 days, all patients are switched to clopidogrel irrespective of genotype (nonguided de-escalation) or to clopidogrel only if patients do not harbor an LOF allele (genotype-guided de-escalation). Compared with universal clopidogrel, both universal ticagrelor and genotype-guided escalation were superior with improvement in quality-adjusted life years (QALY's). Only genotype-guided escalation was cost-effective ($42,365/QALY) and demonstrated the highest probability of being cost-effective across conventional willingness-to-pay thresholds. In the secondary analysis, compared with the nonguided de-escalation strategy, although genotype-guided de-escalation and universal ticagrelor were more effective, with ICER of $188,680/QALY and $678,215/QALY, respectively, they were not cost-effective. CYP2C19 genotype-guided antiplatelet prescribing is cost-effective compared with either universal clopidogrel or universal ticagrelor using real-world implementation data. The secondary analysis suggests genotype-guided and nonguided de-escalation may be viable strategies, needing further evaluation.
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http://dx.doi.org/10.1038/s41397-020-0162-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7417282PMC
October 2020

Beta-Blocker Dose Stratifies Mortality Risk in a Racially Diverse Heart Failure Population.

J Cardiovasc Pharmacol 2020 03;75(3):250-258

Department of Pharmacotherapy and Translational Research, Center for Pharmacogenomics and Precision Medicine, University of Florida College of Pharmacy, Gainesville, FL.

Heart failure (HF) is highly prevalent and a major cause of death in the United States. The effect of HF medications on survival has been predicted by validated models studied in populations predominantly of European descent. This study aimed to identify medications associated with survival in a racially diverse HF population. Patients with HF were recruited and followed from 2001 to 2015. Data were collected from electronic health records and the Social Security Death Index. The primary analysis tested the association between medication dose and all-cause mortality, with a secondary analysis assessing the composite outcome of death or cardiac-related hospitalization. Circulating concentration of the fibrotic marker procollagen type III N-terminal peptide (PIIINP) was also compared with medication doses in patients with concentrations available. The study population consisted of 337 patients, of which 25.2% died and 46% were hospitalized. Increased beta-blocker (BB) dose was significantly associated with survival in the base model [hazard ratio (HR) = 0.71, P = 0.017] and marginally associated in the comprehensive model (HR = 0.75, P = 0.068). BB dose was also associated with decreased risk of the composite end point in the base model (HR = 0.80, P = 0.029) and to a lesser extent in the comprehensive model (HR = 0.83, P = 0.085). Furthermore, increased BB dose was inversely associated with circulating PIIINP concentration (P = 0.041). In conclusion, our study highlights the importance of BB dose escalation for survival and decreased hospitalization in patients with HF, regardless of race or HF type. It also suggests that benefits observed with high-dose BBs could be mediated, at least in part, by decreased cardiac fibrosis.
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http://dx.doi.org/10.1097/FJC.0000000000000779DOI Listing
March 2020

Transcriptome-wide analysis associates ID2 expression with combined pre- and post-capillary pulmonary hypertension.

Sci Rep 2019 12 20;9(1):19572. Epub 2019 Dec 20.

Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Gainesville, FL, USA.

Heart failure with preserved ejection fraction (HFpEF) patients who develop pulmonary hypertension (PH) have an increased risk of death, with combined pre- and post-capillary PH (CpcPH) having the highest risk. However, the mechanism behind PH development in HFpEF is poorly understood. We aimed to identify transcriptomic associations with PH development in HFpEF. Blood was collected from 30 HFpEF patients: 10 without PH, 10 with isolated post-capillary PH, and 10 with CpcPH. Gene expression measurements were completed using transcriptome-wide RNA sequencing. Gene expression differences were compared using a quasi-likelihood method adjusting for age, sex, race, and smoking-status. Biological pathways were compared using global gene expression differences. A replication in 34 additional heart failure patients and a validation in lung tissue from a representative mouse model were completed using quantitative PCR. Six differentially expressed genes were identified when comparing transcriptomics between subjects with CpcPH and those without PH. When tested in additional subjects, only the association with ID2 replicated. Consistent with clinical findings, Id2 expression was also upregulated in mice with HFpEF and PH. Pathway analysis identified proliferative and mitochondrial pathways associated with CpcPH. Thus, these patients may possess systemic pathophysiological differences similar to those observed in pulmonary arterial hypertension patients.
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http://dx.doi.org/10.1038/s41598-019-55700-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6925238PMC
December 2019

Determinants of Cytochrome P450 2D6 mRNA Levels in Healthy Human Liver Tissue.

Clin Transl Sci 2019 07 3;12(4):416-423. Epub 2019 Apr 3.

Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, USA.

Cytochrome P450 2D6 (CYP2D6) is a major drug-metabolizing enzyme that exhibits large interindividual variability. Recent studies suggest that differential transcriptional regulation of CYP2D6 in part may be responsible for the variability. In this study, we characterized potential determinants of CYP 2D6  transcript levels in healthy human liver tissue samples (n = 115), including genetic polymorphisms in CYP2D6 and the genes encoding transcription regulators for CYP2D6 expression; mRNA expression of the transcription factors and their known target genes; and hepatic levels of bile acids and retinoids, agents that modulate the expression/activity of the transcription factors. Their associations with CYP2D6 mRNA levels in the tissues were examined. Results from multivariable linear regression analysis revealed CYP8B1 mRNA level and rs3892097, the single- nucleotide polymorphism defining the nonfunctional CYP2D6*4 allele, as the two most significant predictors of CYP2D6 mRNA levels in the liver tissue samples, explaining 30% of the variability.
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http://dx.doi.org/10.1111/cts.12632DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6618095PMC
July 2019

Association of Genetic Variants With Warfarin-Associated Bleeding Among Patients of African Descent.

JAMA 2018 10;320(16):1670-1677

Northwestern University, Department of Pharmacology, Chicago, Illinois.

Importance: Major warfarin-related bleeding occurs more frequently in African Americans than in other populations. Identification of potential genetic factors related to this adverse event may help identify at-risk patients.

Objective: To identify genetic factors associated with warfarin-related bleeding in patients of African descent at an international normalized ratio (INR) of less than 4.

Design, Setting, And Participants: A case-control genome-wide association study involving patients of African descent taking warfarin was conducted in a discovery cohort (University of Chicago [2009-2011] and the University of Illinois at Chicago [2002-2011]), and associations were confirmed in a replication cohort (University of Chicago [2015-2016]). Potential population stratification was examined in the discovery cohort by principal component analysis. Odds ratios (ORs) and 95% CIs were computed for bleeding risk by logistic regression analysis. Summary statistics from the discovery and the replication cohorts were analyzed with a fixed effects meta-analysis. The potential influence of single-nucleotide polymorphisms (SNPs) on gene expression was studied by luciferase expression assays.

Exposures: Single-nucleotide polymorphisms associated with warfarin-related bleeding.

Main Outcomes And Measures: Major bleeding-defined as bleeding requiring hospitalization, causing a decrease in hemoglobin level of more than 2 g/dL, requiring blood transfusion, or any combination of the 3-while taking warfarin at an INR of less than 4.

Results: The discovery cohort consisted of 31 cases (mean age, 60.1 years [SD, 14.9 years], 26 women [83.9%]) and 184 warfarin-treated controls (mean age, 57.1 years [SD, 15.7 years]) with no documented bleeding. The replication cohort consisted of 40 cases (mean age, 55.6 years [SD, 17.3 years], 27 women [67.5%]), and 148 warfarin-treated controls (mean age, 55.4 years [SD, 17.1 years]; 98 women [66.2%]) with no documented bleeding. In the discovery cohort, 4 SNPs in linkage disequilibrium on chromosome 6 (rs115112393, rs16871327, rs78132896, and rs114504854) were associated with warfarin-related bleeding but did not reach genome-wide significance. The SNP rs78132896 occurred in 11 cases (35.5%) and 9 controls (4.9%) in the discovery cohort (OR, 8.31; 95% CI, 3.2-21.5; P < 6.21 × 10-8), and the association was confirmed in the replication cohort (the SNP was present in 14 cases [35.0%] and 7 controls [4.8%]; OR, 8.24; 95% CI, 3.1-25.3, P = 5.64 × 10-5). Genome-wide significance of this SNP was achieved when the cohorts were combined via meta-analysis (OR, 8.27; 95% CI, 4.18-16.38; P = 2.05 × 10-11). These SNPs are found only in people of African descent. In vitro luciferase expression assays demonstrated that rs16871327 (enhancer SNP) and rs78132896 (promoter SNP) risk alleles together increased EPHA7 gene (Entrez Gene 2045) transcription by a mean of 14.95 (SD, 1.7) compared with wild-type alleles (mean, 9.56 [SD, 0.84]; difference, 5.39; 95% CI, 4.1-6.6; P < .001).

Conclusions And Relevance: In this preliminary study involving patients of African descent taking warfarin, 4 single-nucleotide polymorphisms in linkage disequilibrium on chromosome 6 were associated with an increased risk of major bleeding at INR of less than 4. Validation of these findings in an independent prospective cohort is required.
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http://dx.doi.org/10.1001/jama.2018.14955DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6233811PMC
October 2018

Endothelial nitric oxide synthase genotype is associated with pulmonary hypertension severity in left heart failure patients.

Pulm Circ 2018 Apr-Jun;8(2):2045894018773049

6 Division of Pulmonary, Critical Care, Sleep, and Occupational Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.

The biological mechanisms behind the development of pulmonary hypertension in the setting of left heart failure (HF-PH), including combined pre- and post-capillary pulmonary hypertension (Cpc-PH), remains unclear. This study aimed to use candidate polymorphisms in nitric oxide synthase (NOS) genes to explore the role of NOS in HF-PH. DNA samples from 118 patients with HF-PH were genotyped for the NOS3 rs1799983 and NOS2 rs3730017 polymorphisms. A multiple regression model was used to compare hemodynamic measurements between genotype groups. Patients with the T/T genotype at rs1799983 possessed a nearly 10 mmHg increased transpulmonary gradient (TPG) compared to those with other genotypes ( P = 0.006). This finding was replicated in an independent cohort of 94 HF-PH patients ( P = 0.005). However, when tested in a cohort of 162 pre-capillary pulmonary arterial hypertension patients, no association was observed. In a combined analysis of both HF-PH cohorts, mean pulmonary artery pressure (mPAP), diastolic pulmonary gradient (DPG), and CpcPH status were also associated with rs1799983 genotype ( P = 0.005, P = 0.03, and P = 0.02, respectively). In patients with HF-PH, the NOS3 rs1799983 polymorphism is associated with TPG, and potentially mPAP and DPG as well. These findings suggest that endothelial NOS (encoded by NOS3) may be involved in the pulmonary vascular remodeling observed in Cpc-PH and warrants further study.
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http://dx.doi.org/10.1177/2045894018773049DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5946646PMC
May 2018

CYP2D6 Protein Level Is the Major Contributor to Interindividual Variability in CYP2D6-Mediated Drug Metabolism in Healthy Human Liver Tissue.

Clin Pharmacol Ther 2018 11 13;104(5):974-982. Epub 2018 Feb 13.

Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, USA.

CYP2D6 genetic polymorphisms are considered a major contributor to the large interindividual variability in CYP2D6-mediated drug metabolism, but fail to explain a significant portion of the variability. The aim of this study was to assess the ability of the CYP2D6 activity score (AS) estimated from CYP2D6 genotype to predict CYP2D6 expression and enzyme activity. The CYP2D6 gene region was sequenced in 115 healthy human liver tissue samples to determine their CYP2D6 AS. Additionally, CYP2D6 enzyme activity, protein, and mRNA levels were estimated. CYP2D6 AS explained 23% of the interindividual variability in CYP2D6 activity, but only 7.5% in tissues assigned AS 1-2. The CYP2D6 protein level was found to be the major determinant of CYP2D6 activity, explaining 59% of variability. These findings suggest that while CYP2D6 AS is a good predictor of poor metabolizer phenotype, additional nongenetic factors may govern the rate of CYP2D6-mediated metabolism in those without the poor metabolizer phenotype.
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http://dx.doi.org/10.1002/cpt.1032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6053340PMC
November 2018

Multisite Investigation of Strategies for the Implementation of CYP2C19 Genotype-Guided Antiplatelet Therapy.

Clin Pharmacol Ther 2018 10 30;104(4):664-674. Epub 2018 Jan 30.

Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.

CYP2C19 genotype-guided antiplatelet therapy following percutaneous coronary intervention is increasingly implemented in clinical practice. However, challenges such as selecting a testing platform, communicating test results, building clinical decision support processes, providing patient and provider education, and integrating methods to support the translation of emerging evidence to clinical practice are barriers to broad adoption. In this report, we compare and contrast implementation strategies of 12 early adopters, describing solutions to common problems and initial performance metrics for each program. Key differences between programs included the test result turnaround time and timing of therapy changes, which are both related to the CYP2C19 testing model and platform used. Sites reported the need for new informatics infrastructure, expert clinicians such as pharmacists to interpret results, physician champions, and ongoing education. Consensus lessons learned are presented to provide a path forward for those seeking to implement similar clinical pharmacogenomics programs within their institutions.
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http://dx.doi.org/10.1002/cpt.1006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6019555PMC
October 2018

Multisite Investigation of Outcomes With Implementation of CYP2C19 Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention.

JACC Cardiovasc Interv 2018 01 1;11(2):181-191. Epub 2017 Nov 1.

Department of Medicine, University of Maryland, Baltimore, Maryland.

Objectives: This multicenter pragmatic investigation assessed outcomes following clinical implementation of CYP2C19 genotype-guided antiplatelet therapy after percutaneous coronary intervention (PCI).

Background: CYP2C19 loss-of-function alleles impair clopidogrel effectiveness after PCI.

Methods: After clinical genotyping, each institution recommended alternative antiplatelet therapy (prasugrel, ticagrelor) in PCI patients with a loss-of-function allele. Major adverse cardiovascular events (defined as myocardial infarction, stroke, or death) within 12 months of PCI were compared between patients with a loss-of-function allele prescribed clopidogrel versus alternative therapy. Risk was also compared between patients without a loss-of-function allele and loss-of-function allele carriers prescribed alternative therapy. Cox regression was performed, adjusting for group differences with inverse probability of treatment weights.

Results: Among 1,815 patients, 572 (31.5%) had a loss-of-function allele. The risk for major adverse cardiovascular events was significantly higher in patients with a loss-of-function allele prescribed clopidogrel versus alternative therapy (23.4 vs. 8.7 per 100 patient-years; adjusted hazard ratio: 2.26; 95% confidence interval: 1.18 to 4.32; p = 0.013). Similar results were observed among 1,210 patients with acute coronary syndromes at the time of PCI (adjusted hazard ratio: 2.87; 95% confidence interval: 1.35 to 6.09; p = 0.013). There was no difference in major adverse cardiovascular events between patients without a loss-of-function allele and loss-of-function allele carriers prescribed alternative therapy (adjusted hazard ratio: 1.14; 95% confidence interval: 0.69 to 1.88; p = 0.60).

Conclusions: These data from real-world observations demonstrate a higher risk for cardiovascular events in patients with a CYP2C19 loss-of-function allele if clopidogrel versus alternative therapy is prescribed. A future randomized study of genotype-guided antiplatelet therapy may be of value.
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http://dx.doi.org/10.1016/j.jcin.2017.07.022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5775044PMC
January 2018

Implementation of inpatient models of pharmacogenetics programs.

Am J Health Syst Pharm 2016 Dec;73(23):1944-1954

Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics, University of Florida, Gainesville, FL.

Purpose: The operational elements essential for establishing an inpatient pharmacogenetic service are reviewed, and the role of the pharmacist in the provision of genotype-guided drug therapy in pharmacogenetics programs at three institutions is highlighted.

Summary: Pharmacists are well positioned to assume important roles in facilitating the clinical use of genetic information to optimize drug therapy given their expertise in clinical pharmacology and therapeutics. Pharmacists have assumed important roles in implementing inpatient pharmacogenetics programs. This includes programs designed to incorporate genetic test results to optimize antiplatelet drug selection after percutaneous coronary intervention and personalize warfarin dosing. Pharmacist involvement occurs on many levels, including championing and leading pharmacogenetics implementation efforts, establishing clinical processes to support genotype-guided therapy, assisting the clinical staff with interpreting genetic test results and applying them to prescribing decisions, and educating other healthcare providers and patients on genomic medicine. The three inpatient pharmacogenetics programs described use reactive versus preemptive genotyping, the most feasible approach under the current third-party payment structure. All three sites also follow Clinical Pharmacogenetics Implementation Consortium guidelines for drug therapy recommendations based on genetic test results.

Conclusion: With the clinical emergence of pharmacogenetics into the inpatient setting, it is important that pharmacists caring for hospitalized patients are well prepared to serve as experts in interpreting and applying genetic test results to guide drug therapy decisions. Since genetic test results may not be available until after patient discharge, pharmacists practicing in the ambulatory care setting should also be prepared to assist with genotype-guided drug therapy as part of transitions in care.
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http://dx.doi.org/10.2146/ajhp150946DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5359627PMC
December 2016

Genome-Wide Analysis Identifies IL-18 and FUCA2 as Novel Genes Associated with Diastolic Function in African Americans with Sickle Cell Disease.

PLoS One 2016 16;11(9):e0163013. Epub 2016 Sep 16.

Department of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America.

Background: Diastolic dysfunction is common in sickle cell disease (SCD), and is associated with an increased risk of mortality. However, the molecular pathogenesis underlying this development is poorly understood. The aim of this study was to identify a gene expression profile that is associated with diastolic function in SCD, potentially elucidating molecular mechanisms behind diastolic dysfunction development.

Methods: Diastolic function was measured via echocardiography in 65 patients with SCD from two independent study populations. Gene expression microarray data was compared with diastolic function in both study cohorts. Candidate genes that associated in both analyses were tested for validation in a murine SCD model. Lastly, genotyping array data from the replication cohort was used to derive cis-expression quantitative trait loci (cis-eQTLs) and genetic associations within the candidate gene regions.

Results: Transcriptome data from both patient cohorts implicated 7 genes associated with diastolic function, and mouse SCD myocardial expression validated 3 of these genes. Genetic associations and eQTLs were detected in 2 of the 3 genes, FUCA2 and IL18.

Conclusions: FUCA2 and IL18 are associated with diastolic function in SCD patients, and may be involved in the pathogenesis of the disease. Genetic polymorphisms within the FUCA2 and IL18 gene regions are also associated with diastolic function in SCD, likely by affecting expression levels of the genes.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0163013PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5026353PMC
August 2017

Clopidogrel pharmacogenetics: from evidence to implementation.

Future Cardiol 2016 09 19;12(5):511-4. Epub 2016 Aug 19.

Department of Pharmacotherapy & Translational Research & Center for Pharmacogenomics, University of Florida, 1333 Center Drive, PO Box 100486, Gainesville, FL 32610, USA.

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http://dx.doi.org/10.2217/fca-2016-0045DOI Listing
September 2016

Circulating Procollagen Type III N-Terminal Peptide and Mortality Risk in African Americans With Heart Failure.

J Card Fail 2016 Sep 22;22(9):692-9. Epub 2015 Dec 22.

Department of Pharmacy Practice, University of Illinois at Chicago, Chicago, Illinois. Electronic address:

Background: Procollagen type III N-terminal peptide (PIIINP) is a biomarker of cardiac fibrosis that is associated with heart failure prognosis in whites. Its prognostic significance in African Americans is unknown. We sought to determine whether PIIINP is associated with outcomes in African Americans with heart failure.

Methods And Results: Blood was collected from 138 African Americans with heart failure for determining PIIINP and genetic ancestry, and patients were followed prospectively for death or hospitalization for heart failure. PIIINP was inversely correlated with West African ancestry (R(2) = 0.061; P = .010). PIIINP > 4.88 ng/mL was associated with all-cause mortality on univariate (hazard ratio [HR] 4.9, 95% confidence interval [CI] 2.2-11.0; P < .001) and multivariate (HR 5.8; 95% CI 1.9-17.3; P = .002) analyses over a median follow-up period of 3 years. We also observed an increased risk for the combined outcome of all-cause mortality or hospitalization for heart failure with PIIINP > 4.88 ng/mL on univariate (HR 2.6, 95% CI 1.6-5.0; P < .001) and multivariate (HR 2.4, 95% CI 1.2-4.7; P = .016) analyses.

Conclusions: High circulating PIIINP is associated with poor outcomes in African Americans with chronic heart failure, suggesting that PIIINP may be useful in identifying African Americans who may benefit from additional therapy to combat fibrosis as a means of improving prognosis.
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http://dx.doi.org/10.1016/j.cardfail.2015.12.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4917490PMC
September 2016

Pharmacogenomics of hypertension and heart disease.

Curr Hypertens Rep 2015 Sep;17(9):586

Department of Pharmacy Practice, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL, USA,

Heart disease is a leading cause of death in the United States, and hypertension is a predominant risk factor. Thus, effective blood pressure control is important to prevent adverse sequelae of hypertension, including heart failure, coronary artery disease, atrial fibrillation, and ischemic stroke. Over half of Americans have uncontrolled blood pressure, which may in part be explained by interpatient variability in drug response secondary to genetic polymorphism. As such, pharmacogenetic testing may be a supplementary tool to guide treatment. This review highlights the pharmacogenetics of antihypertensive response and response to drugs that treat adverse hypertension-related sequelae, particularly coronary artery disease and atrial fibrillation. While pharmacogenetic evidence may be more robust for the latter with respect to clinical implementation, there is increasing evidence of genetic variants that may help predict antihypertensive response. However, additional research and validation are needed before clinical implementation guidelines for antihypertensive therapy can become a reality.
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http://dx.doi.org/10.1007/s11906-015-0586-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4730880PMC
September 2015

Genes affecting warfarin response-interactive or additive?

J Clin Pharmacol 2015 03 30;55(3):258-60. Epub 2014 Dec 30.

Department of Pharmacy Practice, University of Illinois at Chicago, Chicago, IL, USA.

Genotypes for cytochrome P450 (CYP) 2C9 and vitamin K epoxide reductase complex 1 (VKORC1) contribute significantly to the inter-patient variability in warfarin dose requirements. These genotypes in addition to clinical factors explain approximately 50% of the dose variability in Europeans, but less in other populations. Thus, a large portion of the variability remains unexplained and has been the focus of on-going research. Trials evaluating the clinical utility of genotype-guided warfarin dosing have shown a benefit in Europeans, but not in an ethnically diverse cohort. Identifying and accounting for variants important in non-European populations will likely be necessary before a benefit with genotype-guided dosing will be realized in these populations.
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http://dx.doi.org/10.1002/jcph.425DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5639939PMC
March 2015

Genotype- and phenotype-directed antiplatelet therapy selection in patients with acute coronary syndromes.

Expert Rev Cardiovasc Ther 2014 Nov;12(11):1289-303

Department of Medicine, University of Illinois, Chicago, IL, USA.

Although dual antiplatelet therapy (DAPT) has been a standard treatment in patients with acute coronary syndrome (ACS) for over a decade, only recently have therapeutic options beyond aspirin and clopidogrel become available. Additional treatment options are particularly useful because of the documented history of variability in antiplatelet response. This article reviews the current treatment options for DAPT in ACS, and reviews both genotype- and phenotype-guided methods for determining optimal antiplatelet therapy for patients with ACS. Additionally, recommendations from current guidelines as well as expert commentary are provided for the use of available testing methods to determine optimal DAPT for ACS patients.
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http://dx.doi.org/10.1586/14779072.2014.970180DOI Listing
November 2014

Feasibility of implementing a comprehensive warfarin pharmacogenetics service.

Pharmacotherapy 2013 Nov 17;33(11):1156-64. Epub 2013 Jul 17.

Department of Pharmacy Practice, University of Illinois at Chicago, Chicago, IL.

Study Objective: To determine the procedural feasibility of a pharmacist-led interdisciplinary service for providing genotype-guided warfarin dosing for hospitalized patients newly starting warfarin.

Design: Prospective observational study.

Setting: A 438-bed tertiary care hospital affiliated with a large academic institution.

Patients: Eighty patients who started warfarin therapy and were managed by a newly implemented pharmacogenetics service.

Intervention: All patients received routine warfarin genotyping and clinical pharmacogenetics consultation.

Measurements And Main Results: The primary outcomes were percentage of genotype-guided dose recommendations available prior to the second warfarin dose and adherence of the medical staff to doses recommended by the pharmacogenetics service. Of 436 genotype orders placed during the first 6 months of the service, 190 (44%) were deemed appropriate. For the 80 patients on the service who consented to data collection, 76% of the genotypes were available prior to the second warfarin dose. The median (range) time from genotype order to genotype result was 26 hours (7-80 hrs), and the time to genotype-guided dose recommendation was 30 hours (7-80 hrs). A total of 73% of warfarin doses ordered by the medical staff were within 0.5 mg of the daily dose recommended by the pharmacogenetics consult service.

Conclusion: Providing routine genotype-guided warfarin dosing supported by a pharmacogenetics consult service is feasible from a procedural standpoint, with most genotypes available prior to the second warfarin dose and good adherence to genotype-guided dose recommendations by the medical staff.
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http://dx.doi.org/10.1002/phar.1329DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3985126PMC
November 2013

Epigenetics primer: why the clinician should care about epigenetics.

Authors:
Julio D Duarte

Pharmacotherapy 2013 Dec 17;33(12):1362-8. Epub 2013 Jul 17.

Department of Pharmacy Practice, Institute for Personalized Respiratory Medicine, University of Illinois at Chicago, Chicago, Illinois.

Epigenetics describes heritable alterations of gene expression that do not involve DNA sequence variation and are changeable throughout an organism's lifetime. Not only can epigenetic status influence drug response, but it can also be modulated by drugs. In this review, the three major epigenetic mechanisms are described: covalent DNA modification, histone protein modification, and regulation by noncoding RNA. Further, this review describes how drug therapy can influence, and be influenced by, these mechanisms. Drugs with epigenetic mechanisms are already in use, with many more likely to be approved within the next few years. As the understanding of epigenetic processes improves, so will the ability to use these data in the clinic to improve patient care.
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http://dx.doi.org/10.1002/phar.1325DOI Listing
December 2013

Personalized medicine in cardiology: the time for genotype-guided therapy is now.

Future Cardiol 2013 Jul;9(4):459-64

Department of Pharmacy Practice, University of Illinois at Chicago, 833 South Wood Street, Room 164, Chicago, IL 60612-7230, USA.

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http://dx.doi.org/10.2217/fca.13.35DOI Listing
July 2013

Pharmacologic treatments for pulmonary hypertension: exploring pharmacogenomics.

Future Cardiol 2013 May;9(3):335-49

Department of Pharmacy Practice, University of Illinois at Chicago College of Pharmacy, Chicago, IL 60612, USA.

Pulmonary hypertension (PH) is a disease with multiple etiologies and is categorized into five broad groups. Of these groups, pulmonary arterial hypertension (PAH) is the most studied and, therefore, all of the currently available drug classes (prostacyclin analogs, endothelin receptor antagonists and phosphodiesterase type 5 inhibitors) were developed to treat PAH. Thus, limited treatment data exist for the less-studied non-PAH forms of PH. Pharmacogenomics can be a tool to better understand the pathways involved in PH, as well as to improve personalization of therapy. However, little pharmacogenomic research has been carried out on this disease. New treatments for PH are on the horizon, deriving from both repurposed currently available drugs and novel therapeutics.
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http://dx.doi.org/10.2217/fca.13.6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3864092PMC
May 2013

Association of variants in NEDD4L with blood pressure response and adverse cardiovascular outcomes in hypertensive patients treated with thiazide diuretics.

J Hypertens 2013 Apr;31(4):698-704

Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics, University of Florida, College of Pharmacy, Gainesville, Florida 32610-0486, USA.

Objective: Single-nucleotide polymorphisms (SNPs) in NEDD4L may influence the ability of the NEDD4L protein to reduce epithelial sodium channel expression. A variant in NEDD4L, rs4149601, was associated with antihypertensive response and cardiovascular outcomes during treatment with thiazide diuretics and β-blockers in a Swedish population. We sought to further evaluate associations between NEDD4L polymorphisms, blood pressure response and cardiovascular outcomes with thiazide diuretics and β-blockers.

Methods: Four SNPs, rs4149601, rs292449, rs1008899 and rs75982813, were genotyped in 767 patients from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) clinical trial and association was assessed with blood pressure response to hydrochlorothiazide and atenolol. One SNP, rs4149601, was also genotyped in 1345 patients from the International Verapmil SR Trandolapril Study (INVEST), and association was examined with adverse cardiovascular outcomes relative to hydrochlorothiazide treatment.

Results: Significant associations or trends were found between rs4149601, rs292449, rs75982813 and rs1008899 and decreases in blood pressure in whites on hydrochlorothiazide, and a significant association was observed with increasing copies of the GC rs4149601-rs292449 haplotype and greater blood pressure response to hydrochlorothiazide in whites (P = 0.0006 and 0.006, SBP and DBP, respectively). Significant associations were also seen with rs4149601 and an increased risk for adverse cardiovascular outcomes in whites not treated with hydrochlorothiazide [P = 0.022, odds ratio (95% confidence interval) = 10.65 (1.18-96.25)].

Conclusion: NEDD4L rs4149601, rs292449 and rs75982813 may be predictors for blood pressure response to hydrochlorothiazide in whites, and NEDD4L rs4149601 may be a predictor for adverse cardiovascular outcomes in whites not treated with hydrochlorothiazide.
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http://dx.doi.org/10.1097/HJH.0b013e32835e2a71DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3756535PMC
April 2013

Effects of genetic variation in H3K79 methylation regulatory genes on clinical blood pressure and blood pressure response to hydrochlorothiazide.

J Transl Med 2012 Mar 22;10:56. Epub 2012 Mar 22.

Center for Pharmacogenomics and Department of Pharmacotherapy and Translational Research, University of Florida, Gainesville, FL 32610, USA.

Background: Nearly one-third of the United States adult population suffers from hypertension. Hydrochlorothiazide (HCTZ), one of the most commonly used medications to treat hypertension, has variable efficacy. The renal epithelial sodium channel (ENaC) provides a mechanism for fine-tuning sodium excretion, and is a major regulator of blood pressure homeostasis. DOT1L, MLLT3, SIRT1, and SGK1 encode genes in a pathway that controls methylation of the histone H3 globular domain at lysine 79 (H3K79), thereby modulating expression of the ENaCα subunit. This study aimed to determine the role of variation in these regulatory genes on blood pressure response to HCTZ, and secondarily, untreated blood pressure.

Methods: We investigated associations between genetic variations in this candidate pathway and HCTZ blood pressure response in two separate hypertensive cohorts (clinicaltrials.gov NCT00246519 and NCT00005520). In a secondary, exploratory analysis, we measured associations between these same genetic variations and untreated blood pressure. Associations were measured by linear regression, with only associations with P ≤ 0.01 in one cohort and replication by P ≤ 0.05 in the other cohort considered significant.

Results: In one cohort, a polymorphism in DOT1L (rs2269879) was strongly associated with greater systolic (P = 0.0002) and diastolic (P = 0.0016) blood pressure response to hydrochlorothiazide in Caucasians. However, this association was not replicated in the other cohort. When untreated blood pressure levels were analyzed, we found directionally similar associations between a polymorphism in MLLT3 (rs12350051) and greater untreated systolic (P < 0.01 in both cohorts) and diastolic (P < 0.05 in both cohorts) blood pressure levels in both cohorts. However, when further replication was attempted in a third hypertensive cohort and in smaller, normotensive samples, significant associations were not observed.

Conclusions: Our data suggest polymorphisms in DOT1L, MLLT3, SIRT1, and SGK1 are not likely associated with blood pressure response to HCTZ. However, a possibility exists that rs2269879 in DOT1L could be associated with HCTZ response in Caucasians. Additionally, exploratory analyses suggest rs12350051 in MLLT3 may be associated with untreated blood pressure in African-Americans. Replication efforts are needed to verify roles for these polymorphisms in human blood pressure regulation.
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http://dx.doi.org/10.1186/1479-5876-10-56DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3320544PMC
March 2012

Lack of association between polymorphisms in STK39, a putative thiazide response gene, and blood pressure response to hydrochlorothiazide.

Pharmacogenet Genomics 2010 Aug;20(8):516-9

Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics, University of Florida College of Pharmacy, Gainesville, Florida 32610, USA.

STK39 was earlier implicated as a hypertension susceptibility gene and is thought to be involved in the control of Na-Cl co-transporter activity. STK39 has been implicated as a putative thiazide diuretic response gene, as Na-Cl co-transporter activity is inhibited by thiazides. Thus, we aimed to determine whether STK39 is a thiazide response gene. One hundred and ninety-five 'good' and 194 'poor' responders to hydrochlorothiazide (HCTZ) were genotyped for approximately 100 single nucleotide polymorphisms (SNPs) within 5000 bases of STK39. SNPs meeting criteria for advancement to replication analysis (P<0.01), along with those earlier associated with hypertension, were then analyzed in a second population of 201 HCTZ-treated hypertensives. Two SNPs passed screening and were further analyzed. However, neither these, nor earlier implicated SNPs met criteria for significant association with blood pressure response to HCTZ. These data suggest that common variants in STK39 likely do not have a clinically relevant role in blood pressure response to HCTZ in hypertensives.
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http://dx.doi.org/10.1097/FPC.0b013e32833b5958DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2922977PMC
August 2010

Mechanisms for blood pressure lowering and metabolic effects of thiazide and thiazide-like diuretics.

Expert Rev Cardiovasc Ther 2010 Jun;8(6):793-802

Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, 1600 SW Archer Road, Gainesville, FL 32610-0486, USA.

Thiazide and thiazide-like diuretics are among the most commonly used antihypertensives and have been available for over 50 years. However, the mechanism by which these drugs chronically lower blood pressure is poorly understood. Possible mechanisms include direct endothelial- or vascular smooth muscle-mediated vasodilation and indirect compensation to acute decreases in cardiac output. In addition, thiazides are associated with adverse metabolic effects, particularly hyperglycemia, and the mechanistic underpinnings of these effects are also poorly understood. Thiazide-induced hypokalemia, as well as other theories to explain these metabolic disturbances, including increased visceral adiposity, hyperuricemia, decreased glucose metabolism and pancreatic beta-cell hyperpolarization, may play a role. Understanding genetic variants with differential responses to thiazides could reveal new mechanistic candidates for future research to provide a more complete understanding of the blood pressure and metabolic response to thiazide diuretics.
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http://dx.doi.org/10.1586/erc.10.27DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904515PMC
June 2010