Polymorphisms in catechol-O-methyltransferase modify treatment effects of aspirin on risk of cardiovascular disease

The Impact of Sex on Antiplatelet and Anticoagulant Thromboprophylaxis in Patients With Peripheral Artery Disease Post-revascularization

OBJECTIVE

The aim of this prospective study was to (1) objectively quantify the impact of sex on platelet function in patients with peripheral artery disease (PAD) taking antiplatelet and anticoagulant medications and (2) to develop and test a personalized, iterative algorithm that personalizes thromboprophylaxis that incorporates platelet function testing.

BACKGROUND

Women with PAD have worse outcomes as compared with their male counterparts despite having lower risk factors. This health disparity may be mitigated by personalizing thromboprophylaxis regimens.

METHODS

Patients undergoing revascularization were enrolled. Serial thromboelastography (TEG) and TEG with platelet mapping (TEG-PM) were performed up to 6 months postoperatively to determine objective coagulation profiles. In a subset of patients, the Antiplatelet Coagulation Exactness (ACE) algorithm was implemented, where patients were iteratively evaluated with TEG and given antiplatelet medications to maintain platelet inhibition at >29%. Statistical analysis was performed using unpaired t test, analysis of variance, and Fisher exact test.

RESULTS

One hundred eighty-one patients met the study criteria. Fifty-eight (32%) patients were females and 123 (68%) were males. In the Aspirin cohort, females showed significantly greater clot strength as maximum amplitude - arachidonic acid (MA AA ) and significantly lower platelet inhibition than males: (37.26 vs 32.38, P <0.01) and (52.95% vs 61.65%, P <0.05), respectively. In the Clopidogrel cohort, females showed higher Maximum Amplitude - Adenosine Diphosphate (MA ADP ) (42.58 vs 40.35, P = not significant [NS]) compared with males. Females on dual antiplatelet therapy had higher MA ADP (39.74 vs 35.07, P =NS) and lower platelet inhibition (45.25% vs 54.99%, P= NS) than males. The incidence of thrombosis of the revascularized segment, defined as thrombotic event, was objectively identified on an arterial duplex. Women showed significantly higher thrombotic events than men (22.95% vs 10.57%, P< 0.05) on the same medication. In our pilot study, implementation of the ACE algorithm led to a significant decrease in the thrombosis rate (3%), including nonthrombotic events for females, versus the historic thrombotic rate (22%) from our institution.

CONCLUSIONS

Women with PAD exhibited higher platelet reactivity, clot strength, and reduced platelet inhibition in response to antiplatelet therapy. The use of the ACE algorithm to tailor antiplatelet medication in patients with PAD post-revascularization, resulted in a significant decrease in thrombotic event rates. This may serve as an opportune way to mitigate outcome sex-specific disparities caused by inadequate thromboprophylaxis in women.

Interaction between vitamin E intake and a COMT gene variant on colorectal cancer risk among Korean adults: a case-control study

OBJECTIVES

Previous human trials have not supported the anticarcinogenic effect of vitamin E despite biological plausibility and considerable epidemiological evidence. A possible explanation for this inconsistency is the interactive effect of the catechol-O-methyltransferase (COMT) gene and supplemental vitamin E on cancer. We examined whether a COMT gene variant modulates the effect of dietary vitamin E intake on colorectal cancer (CRC) risk.

METHODS

In this case-control study of Korean adults (975 cases and 975 age- and sex-matched controls), dietary vitamin E density (mg/1,000 kcal) was measured using a semiquantitative food frequency questionnaire, COMT single nucleotide polymorphism (SNP) rs740603 (A>G) was genotyped, and CRC was verified histologically. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression models with adjustments for potential confounders.

RESULTS

Higher vitamin E density was associated with a lower risk of CRC (highest vs. lowest quartiles: OR, 0.72; 95% CI, 0.55 to 0.96; p-for-trend=0.002). When stratified by COMT SNP rs740603 genotype, the inverse association between vitamin E density and CRC risk was confined to those with at least 1 A allele (≥median vs.

CONCLUSIONS

Our findings support a role for a genetic polymorphism in COMT in modifying the association between dietary vitamin E intake and CRC.

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Key Words

• Case-control studies
• Catechol-O-methyltransferase
• Colorectal cancer
• Gene-environment interaction
• Single nucleotide polymorphism
• Vitamin E

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MESH Headings

• Adult
• Humans
• Catechol O-Methyltransferase/genetics
• Case-Control Studies
• Polymorphism, Single Nucleotide
• Vitamin E
• Logistic Models
• Colorectal Neoplasms/epidemiology
• Colorectal Neoplasms/genetics
• Republic of Korea/epidemiology
• Risk Factors

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Grants

• National Research Foundation of Korea
• 2021R1A6A3A01087058 Ministry of Education
• 2021R1A2C2008439 Ministry of Science and ICT

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Affiliation(s)

Shinyoung Jun Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang, Korea
Madhawa Gunathilake Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang, Korea
Jeonghee Lee Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang, Korea
Jae Hwan Oh Center for Colorectal Cancer, National Cancer Center, Goyang, Korea
Hee Jin Chang Center for Colorectal Cancer, National Cancer Center, Goyang, Korea
Dae Kyung Sohn Center for Colorectal Cancer, National Cancer Center, Goyang, Korea
Aesun Shin Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea Cancer Research Institute, Seoul National University, Seoul, Korea
Jeongseon Kim Department of Cancer, AI & Digital Health, National Cancer Center Graduate School of Cancer Science and Policy, Goyang, Korea

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VAL158MET catechol O-methyltransferase polymorphism contributes to the development of preeclampsia

Objectives: Establishment of association between: (a) Val158Met COMT (G1947A) polymorphism and preeclampsia; (b) cytokines gene expression and COMT genotypes. Methods: 50 preeclampsia and 50 healthy pregnant women were enrolled. COMT genotyping was done by PCR/RFLP. TNF-α, IL-1β, and IL-6 mRNA levels were determined by Real-time PCR. Results: Variant (AA) homozygotes carried 3.7-fold increased preeclampsia odds, especially for severe (OR = 9.0, 95%CI (2.09-38.799)) and early forms (OR = 6.6, 95%CI (1.62-26.87)). AA homozygotes with PE had higher TNF-α levels compared to controls (P = 0.012). Conclusions: Val158Met COMT polymorphism increases preeclampsia risk. TNF-α expression and Val158Met COMT polymorphism have concomitant roles in PE pathogenesis.

Historical Controls in Randomized Clinical Trials: Opportunities and Challenges

Randomized control trials (RCTs) with placebo are the gold standard for determining efficacy of novel pharmaceutical treatments. Since their inception, over 75 years ago, researchers have amassed a large body of underutilized data on outcomes in the placebo control arms of these trials. Although rare disease indications have used these historical placebo data as synthetic controls to reduce burden on patients and accelerate drug discovery, broad use of historical controls is in its infancy. Large-scale historical placebo data could be leveraged to benefit both drug developers and patients if warehoused and made more available to guide trial design and analysis. Here, we examine challenges in utilizing historical controls related to heterogeneity in trial design, outcome ascertainment, patient characteristics, and unmeasured pharmacogenomic effects. We then discuss the advantages and disadvantages of current approaches and propose a path forward to broader use of historical controls in RCTs.

Precision (Personalized) Nutrition: Understanding Metabolic Heterogeneity

People differ in their requirements for and responses to nutrients and bioactive molecules in the diet. Many inputs contribute to metabolic heterogeneity (including variations in genetics, epigenetics, microbiome, lifestyle, diet intake, and environmental exposure). Precision nutrition is not about developing unique prescriptions for individual people but rather about stratifying people into different subgroups of the population on the basis of biomarkers of the above-listed sources of metabolic variation and then using this stratification to better estimate the different subgroups’ dietary requirements, thereby enabling better dietary recommendations and interventions. The hope is that we will be able to subcategorize people into ever-smaller groups that can be targeted in terms of recommendations, but we will never achieve this at the individual level, thus, the choice of precision nutrition rather than personalized nutrition to designate this new field. This review focuses mainly on genetically related sources of metabolic heterogeneity and identifies challenges that need to be overcome to achieve a full understanding of the complex interactions between the many sources of metabolic heterogeneity that make people differ from one another in their requirements for and responses to foods. It also discusses the commercial applications of precision nutrition.

Catechol-O-Methyltransferase and Cardiovascular Disease: MESA

Background

Genetic variation in catechol‐O‐methyltransferase (COMT), a key enzyme in estrogen and catecholamine metabolism, has plausible physiological links to cardiovascular disease (CVD) and its risk factors. In WHS (Women's Health Study), COMT variants rs4818 and rs4680 were associated with a lower risk of CVD among women receiving placebo but not aspirin, suggesting a possible role of COMT in thrombosis.

Methods and Results

To evaluate potential pathways linking COMT with CVD, and COMT effect modification of aspirin in prevention, we examined COMT association with CVD risk and subclinical measures, coronary artery calcium, and carotid intima‐media thickness in MESA (Multi‐Ethnic Study of Atherosclerosis). In 65 957 person‐years of follow‐up, during which 498 events occurred, COMT rs4818 was associated with lower CVD risk (hazard ratio, 0.85; 95% CI, 0.74–0.97 [P=0.02]). This association remained virtually unchanged after adjusting for common CVD risk factors. Fibrinogen was the only risk factor associated with rs4818 (β, −3.65; SE, 1.35 mg/dL [P=0.007]). Results were directionally similar but not significant for rs4680. Adjusted hazard ratios for COMT rs4818 CVD association were 0.79 (95% CI, 0.65–0.95; P=0.02) among individuals who used aspirin <3 days per week and 0.89 (95% CI, 0.71–1.13; P=0.34) among more frequent users (P_interaction=0.39). Neither intima‐media thickness nor coronary artery calcium was associated with COMT.

Conclusions

In a multiethnic prospective cohort of men and women, the COMT rs4818G allele was associated with lower CVD risk and lower fibrinogen levels but not with radiographic measures of subclinical atherosclerosis. These results suggest a plausible role of COMT in the latter stages of CVD.

Pharmacogenomics and Placebo Response in a Randomized Clinical Trial in Asthma

Genetic variation may differentially modify drug and placebo treatment effects in randomized clinical trials. In asthma, although lung function and asthma control improvements are commonplace with placebo, pharmacogenomics of placebo vs. drug response remains unexamined. In a genomewide association study of subjective and objective outcomes with placebo treatment in Childhood Asthma Management Program of nedocromil/budesonide vs. placebo (N = 604), effect estimates for lead single nucleotide polymorphisms (SNPs) were compared across arms. The coughing/wheezing lead SNP, rs2392165 (β = 0.94; P = 1.10E-07) mapped to BBS9, a gene implicated in lung development that contains a lung function expression quantitative trait locus. The effect was attenuated with budesonide (P_interaction  = 1.48E-07), but not nedocromil (P_interaction  = 0.06). The lead forced vital capacity SNP, rs12930749 (β = -5.80; P = 1.47E-06), mapped to KIAA0556, a locus genomewide associated with respiratory diseases. The rs12930749 effect was attenuated with budesonide (P_interaction  = 1.32E-02) and nedocromil (P_interaction  = 1.09E-02). Pharmacogenomic analysis revealed differential effects with placebo and drug treatment that could potentially guide precision drug development in asthma.

Drug-Placebo Additivity in Randomized Clinical Trials

In randomized clinical trials (RCTs), it is assumed that nonspecific effects beyond action of pharmacological agents are roughly equivalent in drug and placebo treatment groups. Hence, since the inception of RCTs, drug efficacy is determined by comparing outcomes in active to those in placebo control arms. However, quantitation of efficacy is based on an unproven assumption, that drug and placebo responses are always additive. Response to treatment in RCTs can be differentially influenced by the perturbing effects of patient expectations, side effects, and pharmacogenomic interactions in both drug and placebo arms. Ability to control for these effects requires understanding of when and where they arise, how to mitigate, analyze, and even leverage their impact. Here, we examine three factors that influence additivity: expectation, side effects, and pharmacogenomics. Furthermore, to provide novel insights into nonadditivity and solutions for managing it, we introduce systems pharmacogenomics, a network approach to integrating and analyzing the effects of the numerous interacting perturbations to which a patient is exposed in RCTs.

COMT and Alpha-Tocopherol Effects in Cancer Prevention: Gene-Supplement Interactions in Two Randomized Clinical Trials

BACKGROUND

Vitamins are among the most frequently used supplements (48% of US adults). However, little is known about contributions of genetic variation to their efficacy and safety. Multiple pathways link catechol-O-methyltransferase (COMT) to the vitamin E supplement, alpha-tocopherol, and cancer.

METHODS

Here we determined if COMT exerted pharmacogenetic effects on cancer prevention in two randomized trials of alpha-tocopherol supplementation. Pharmacogenetic effects of common COMT rs4680 (val158met), which encodes a nonsynonymous valine-to-methionine substitution, were examined in the trial plus a 10-year post-trial follow-up (overall) period of The Women's Genome Health Study (WGHS, N = 23 294), a 10-year alpha-tocopherol and aspirin trial with 10 years post-trial follow-up. Results were validated in a case/control (N = 2396/2235) subset of the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (ATBC, N = 29 133). The primary outcome was total cancers. Rates of cancer types prevalent in women (colorectal, breast, lung, uterine, and lymphoma/leukemia) were also examined. All statistical tests were two-sided.

RESULTS

Random-effects meta-analysis of rs4680 genotype strata, in WGHS and ATBC overall periods, revealed differential alpha-tocopherol effects compared with placebo: met/met (hazard ratio [HR] = 0.88; 95% confidence interval [CI] = 0.80 to 0.97; P = .01), val/met (HR = 0.99; 95% CI = 0.92 to 1.06; P = .74), and val/val (HR = 1.18; 95% CI = 1.06 to 1.31; P = .002) with a statistically significant COMT by alpha-tocopherol interaction (Pinteraction <.001). Timing of effects differed, with stronger effects in WGHS trial and ATBC post-trial.

CONCLUSION

Pharmacogenetic analysis of COMT and cancer prevention in two large randomized trials revealed statistically significant COMT by alpha-tocopherol interaction, such that alpha-tocopherol was beneficial among rs4680 met-allele (28.0%), but not val-allele (22.8%) homozygotes. These effects indicate the need for additional studies of genetic variation as a determinant of the benefits and possible harms of over-the-counter supplements, like alpha-tocopherol, used for health promotion.

Systems pharmacogenomics - gene, disease, drug and placebo interactions: a case study in COMT

Disease, drugs and the placebos used as comparators are inextricably linked in the methodology of the double-blind, randomized controlled trial. Nonetheless, pharmacogenomics, the study of how individuals respond to drugs based on genetic substrate, focuses primarily on the link between genes and drugs, while the link between genes and disease is often overlooked and the link between genes and placebos is largely ignored. Herein, we use the example of the enzyme catechol-O-methyltransferase to examine the hypothesis that genes can function as pharmacogenomic hubs across system-wide regulatory processes that, if perturbed in andomized controlled trials, can have primary and combinatorial effects on drug and placebo responses.

A longitudinal big data approach for precision health

Precision health relies on the ability to assess disease risk at an individual level, detect early preclinical conditions and initiate preventive strategies. Recent technological advances in omics and wearable monitoring enable deep molecular and physiological profiling and may provide important tools for precision health. We explored the ability of deep longitudinal profiling to make health-related discoveries, identify clinically relevant molecular pathways and affect behavior in a prospective longitudinal cohort (n = 109) enriched for risk of type 2 diabetes mellitus. The cohort underwent integrative personalized omics profiling from samples collected quarterly for up to 8 years (median, 2.8 years) using clinical measures and emerging technologies including genome, immunome, transcriptome, proteome, metabolome, microbiome and wearable monitoring. We discovered more than 67 clinically actionable health discoveries and identified multiple molecular pathways associated with metabolic, cardiovascular and oncologic pathophysiology. We developed prediction models for insulin resistance by using omics measurements, illustrating their potential to replace burdensome tests. Finally, study participation led the majority of participants to implement diet and exercise changes. Altogether, we conclude that deep longitudinal profiling can lead to actionable health discoveries and provide relevant information for precision health.

Vitamin E: Regulatory role in the cardiovascular system

Cardiovascular disease (CVD) is one of the major causes of morbidity and mortality, all around the world. Vitamin E is an important nutrient influencing key cellular and molecular mechanisms as well as gene expression regulation centrally involved in the prevention of CVD. Cell culture and animal studies have focused on the identification of vitamin E regulated signaling pathways and involvement on inflammation, lipid homeostasis, and atherosclerotic plaque stability. While some of these vitamin E functions were verified in clinical trials, some of the positive effects were not translated into beneficial outcomes in epidemiological studies. In recent years, the physiological metabolites of vitamin E, including the liver derived (long- and short-chain) metabolites and phosphorylated (α-, γ-tocopheryl phosphate) forms, have also provided novel mechanistic insight into CVD regulation that expands beyond the vitamin E precursor. It is certain that this emerging insight into the molecular and cellular action of vitamin E will help to design further studies, either in animal models or clinical trials, on the reduction of risk for CVDs. This review focuses on vitamin E-mediated preventive cardiovascular effects and discusses novel insights into the biology and mechanism of action of vitamin E metabolites in CVD. © 2019 IUBMB Life, 71(4):507-515, 2019.

Psychobiological Mechanisms of Placebo and Nocebo Effects: Pathways to Improve Treatments and Reduce Side Effects

Placebo effects constitute a major part of treatment success in medical interventions. The nocebo effect also has a major impact, as it accounts for a significant proportion of the reported side effects for many treatments. Historically, clinical trials have aimed to reduce placebo effects; however, currently, there is interest in optimizing placebo effects to improve existing treatments and in examining ways to minimize nocebo effects to improve clinical outcome. To achieve these aims, a better understanding of the psychological and neurobiological mechanisms of the placebo and nocebo response is required. This review discusses the impact of the placebo and nocebo response in health care. We also examine the mechanisms involved in the placebo and nocebo effects, including the central mechanism of expectations. Finally, we examine ways to enhance placebo effects and reduce the impact of the nocebo response in clinical practice and suggest areas for future research.

The Association Between C-Reactive Protein and Postoperative Delirium Differs by Catechol-O-Methyltransferase Genotype

OBJECTIVE

Catechol-O-methyltransferase (COMT), a key enzyme in degrading catecholamines associated with the stress response, may influence susceptibility to delirium. Individuals with the COMT (rs4680) Val/Val genotype (designated "warriors") withstand the onset of neuropsychiatric disorders and cognitive decline, whereas individuals with Met/Met and Val/Met genotypes ("nonwarriors") are more susceptible to these conditions. We evaluated whether COMT genotype modifies the established association between acute phase reactant (stress marker) C-reactive protein (CRP) and postoperative delirium.

METHODS

This was a prospective cohort study conducted at two academic medical centers. The study involved 547 patients aged 70 or older undergoing major noncardiac surgery. We collected blood, extracted DNA, and performed COMT genotyping using allele-specific polymerase chain reaction assays, considering warriors versus nonwarriors. High plasma CRP, measured on postoperative day 2 using enzyme-linked immunosorbent assay, was defined by the highest sample-based quartile (≥234.12 mg/L). Delirium was determined using the Confusion Assessment Method, augmented by a validated chart review. We used generalized linear models adjusted for age, sex, surgery type, and race/ethnicity, stratified by COMT genotype, to determine whether the association between CRP and delirium differed by COMT.

RESULTS

Prevalence of COMT warriors was 26%, and postoperative delirium occurred in 23%. Among COMT warriors, high CRP was not associated with delirium (relative risk [RR] 1.0, 95% confidence interval [CI] 0.4-2.6). In contrast, among nonwarriors, we found the expected relationship of high CRP and delirium (RR 1.5, 95% CI 1.1-2.2).

CONCLUSION

COMT warriors may be protected against the increased risk of delirium associated with high CRP on postoperative day 2. With further confirmation, COMT genotype may help target interventions for delirium prevention in the vulnerable nonwarrior group.

DNA methylation in blood as a mediator of the association of mid-childhood body mass index with cardio-metabolic risk score in early adolescence

Obesity is associated with higher cardio-metabolic risk even in childhood and adolescence; whether this association is mediated by epigenetic mechanisms remains unclear. We examined the extent to which mid-childhood body mass index (BMI) z-score (median age 7.7 years) was associated with cardio-metabolic risk score in early adolescence (median age 12.9 years) via mid-childhood DNA methylation among 265 children in the Project Viva. We measured DNA methylation in leukocytes using the Infinium Human Methylation450K BeadChip. We assessed mediation CpG-by-CpG using epigenome-wide association analyses, high-dimensional mediation analysis, and natural effect models. We observed mediation by mid-childhood DNA methylation at 6 CpGs for the association between mid-childhood BMI z-score and cardio-metabolic risk score in early adolescence in the high-dimensional mediation analysis (accounting for 10% of the total effect) and in the natural effect model (β = 0.04, P = 3.2e-2, accounting for 13% of the total effect). The natural direct effect of BMI z-score on cardio-metabolic risk score was still evident (β = 0.27, P = 1.1e-25). We also observed mediation by mid-childhood DNA methylation at 5 CpGs that was in the opposite direction from the total effect (natural effect model: β = -0.04, P = 2.0e-2). Mediation in different directions implies a complex role of DNA methylation in the association between BMI and cardio-metabolic risk and needs further investigation. Future studies with larger sample size and greater variability in cardio-metabolic risk will further help elucidate the role of DNA methylation for cardio-metabolic risk.

Potential Impact of COMT-rs4680 G > A Gene Polymorphism in Coronary Artery Disease

Purpose: Catechol-O-methyltransferase (COMT) plays a central role in DNA repair and estrogen-induced carcinogenesis. The nonsynonymous single nucleotide polymorphism (SNP) in exon 4 G > A or Val108 > 158Met or rs4680 G > A influences COMT enzyme activity. The three phenotypes of the COMT enzyme activities include COMT A/A with low enzyme activity, COMT A/G with medium enzyme activity and COMT G/G with high enzyme activity. The Met allele is associated with low enzymatic activity resulting in higher levels of prefrontal dopamine. Conversely, the Val allele is associated with high enzymatic activity and lower levels of prefrontal dopamine. The Met allele has been associated with several psychiatric disorders such as panic disorder. Many recent epidemiologic studies have investigated the association between the COMT Val158Met polymorphism and coronary artery diseases risk, but the results are inconclusive. Therefore our study was aimed to explore the association between COMT Val158Met polymorphism and the risk of coronary artery disease in India. Methology: This study was conducted on 100 clinically confirmed cases of coronary artery diseases and 100 healthy controls. COMT Val158Met genotyping was performed by allele-specific polymerase chain reaction (AS-PCR). Results: A significant correlation was observed in the COMT Val158Met genotype distribution between the coronary artery disease cases and healthy controls (p = 0.008). The frequencies of all three genotypes, GG, GA, AA, reported in the CAD patients were 10%, 70%, and 20%, and 30%, 60%, and 10% in the healthy controls respectively. An increased risk of coronary artery disease was observed in the codominant inheritance model for COMT-GA vs. GG genotype with an OR of 3.5, 95% CI (1.58–7.74) p = 0.002) and COMT-AA vs. GG genotype with an OR of 6.0 95% CI (2.11–17.3) p = 0.003). The higher risk of coronary artery disease was observed in the dominant inheritance model for COMT (GA + AA) vs. GG genotype (OR 3.85, 95% CI 1.76–8.4, p < 0.007), whereas a non-significant association was found in recessive model for COMT (GG + GA vs. AA) (OR = 2.01, 95% CI (0.86–4.7) p = 0.72). The results indicated that A allele significantly increased the risk of coronary artery disease compared to the G allele (OR = 1.8, 95% CI (1.20–2.67) p = 0.004). COMT Val158Met polymorphism leads to a 6.0, 3.5 and 1.8-fold increased risk of developing coronary artery disease in the Indian population and providing novel insights into the genetic etiology and underlying biology of coronary artery disease. Conclusions: It is concluded that COMT-AA genotype and A allele are significantly associated with an increased susceptibility to coronary artery disease in Indian population. A larger sample size can be the key to progress in establishing the genetic co-relationship of COMT polymorphism and cardiovascular disease.

Pharmacogenomics and the Placebo Response

There is perhaps no more important time in the history of placebos to consider their role in clinical trials and in medicine. Increasingly well-designed pharmaceutical and academic clinical trials testing promising and established drug and surgical interventions have failed to "beat" the placebo response. The collateral damage resulting from these failures is staggering; novel treatments, many with compelling mechanisms of action and promising Phase 2 trial results, never reach the patient, adversely affecting small and large pharma alike. Recent evidence suggests that variability in placebo response may be attributed in part to genetic variation. Thus, having a better understanding of the genomic underpinnings of the placebo response, the "placebome", may pave the way to innovatively and more effectively use placebos in drug development.

The influence of dopamine-beta-hydroxylase and catechol O-methyltransferase gene polymorphism on the efficacy of insulin detemir therapy in patients with type 2 diabetes mellitus

BACKGROUND

Type II diabetes is an important health problem with a complex connection to obesity, leading to a broad range of cardiovascular complications. Insulin therapy often results in weight gain and does not always ensure adequate glycemic control. However, previous studies reported that insulin detemir is an efficient long-acting insulin with a weight sparing effect. The aim of this study was to determine the association of catechol O-methyltransferase (COMT) Val108/158Met and dopamine-beta-hydroxylase (DBH) 1021C/T polymorphisms with the effectiveness of insulin detemir in achieving glucose control and body weight control. Participants and methods: This 52-week observational study included 185 patients with inadequate glycemic control treated with premix insulin analogues, which were replaced with insulin aspart and insulin detemir, and 156 healthy controls. After DNA isolation from blood samples, genotyping of DBH-1021C/T polymorphism (rs1611115) and COMT Val108/158Met polymorphism (rs4680) was performed.

RESULTS

Our results confirmed that insulin detemir did not lead to weight gain. The most significant finding was that A carriers (the combined AG and AA genotype) of the COMT Val108/158Met achieved significantly better hemoglobin A1c (HbA1c) values compared to patients carrying GG genotype. No association between DBH-1021C/T genotypes and weight and/or glucose control was detected in diabetes patients or in healthy control subjects.

CONCLUSIONS

This study showed that the presence of one or two A allele of the COMT Val108/158Met was associated with improved glycemic response, and with a better response to insulin detemir therapy in patients with type II diabetes, separating them as best candidates for detemir therapy.

Network analysis of the genomic basis of the placebo effect

The placebo effect is a phenomenon in which patients who are given an inactive treatment (e.g., inert pill) show a perceived or actual improvement in a medical condition. Placebo effects in clinical trials have been investigated for many years especially because placebo treatments often serve as the control arm of randomized clinical trial designs. Recent observations suggest that placebo effects may be modified by genetics. This observation has given rise to the term "placebome," which refers to a group of genome-related mediators that affect an individual's response to placebo treatments. In this study, we conduct a network analysis of the placebome and identify a placebome module in the comprehensive human interactome using a seed-connector algorithm. The placebome module is significantly enriched with neurotransmitter signaling pathways and brain-specific proteins. We validate the placebome module using a large cohort of the Women's Genome Health Study (WGHS) trial and demonstrate that the placebome module is significantly enriched with genes whose SNPs modify the outcome in the placebo arm of the trial. To gain insights into placebo effects in different diseases and drug treatments, we use a network proximity measure to examine the closeness of the placebome module to different disease modules and drug target modules. The results demonstrate that the network proximity of the placebome module to disease modules in the interactome significantly correlates with the strength of the placebo effect in the corresponding diseases. The proximity of the placebome module to molecular pathways affected by certain drug classes indicates the existence of placebo-drug interactions. This study is helpful for understanding the molecular mechanisms mediating the placebo response, and sets the stage for minimizing its effects in clinical trials and for developing therapeutic strategies that intentionally engage it.

Protective effect of homovanillyl alcohol on cardiovascular disease and total mortality: virgin olive oil, wine, and catechol-methylation

Background: Hydroxytyrosol is a phenolic compound that is present in virgin olive oil (VOO) and wine. Hydroxytyrosol-related foods have been shown to protect against cardiovascular disease (CVD).Objective: We investigated the associations between hydroxytyrosol and its biological metabolite, 3-O-methyl-hydroxytyrosol, also known as homovanillyl alcohol (HVAL), with CVD and total mortality.Design: We included 1851 men and women with a mean ± SD age of 66.8 ± 6 y at high risk of CVD from prospective cohort data. The primary endpoint was a composite of myocardial infarction, stroke, and death from cardiovascular causes; the secondary endpoint was all-cause mortality. Twenty-four-hour urinary hydroxytyrosol and HVAL and catechol-O-methyltransferase (COMT) rs4680 genotypes were measured.Results: After multivariable adjustment, all biomarkers were associated, as a continuous variable, with lower CVD risk, but only HVAL showed a strong inverse association (HR: 0.44; 95% CI: 0.25, 0.80) for the comparison between quintiles. Only HVAL, as a continuous variable, was associated with total mortality (HR: 0.81; 95% CI: 0.70, 0.95). Individuals in the highest quintile of HVAL compared with the lowest had 9.2 (95% CI: 3.5, 20.8) and 6.3 (95% CI: 2.3, 12.1) additional years of life or years free of CVD, respectively, after 65 y. Individuals with the rs4680GG genotype had the highest HVAL concentrations (P = 0.05). There was no association between COMT genotypes and events or interaction between COMT genotypes and HVAL concentrations.Conclusions: We report, for the first time to our knowledge, an independent association between high urinary HVAL concentrations and a lower risk of CVD and total mortality in elderly individuals. VOO and wine consumption and a high metabolic COMT capacity for methylation are key factors for high HVAL concentrations. The association that stems from our results reinforces the benefits of 2 key components of the Mediterranean diet (wine and VOO). This trial was registered at www.predimed.es as ISRCTN35739639.

Genetic variation in catechol-O-methyltransferase modifies effects of clonidine treatment in chronic fatigue syndrome

Clonidine, an α2-adrenergic receptor agonist, decreases circulating norepinephrine and epinephrine, attenuating sympathetic activity. Although catechol-O-methyltransferase (COMT) metabolizes catecholamines, main effectors of sympathetic function, COMT genetic variation effects on clonidine treatment are unknown. Chronic fatigue syndrome (CFS) is hypothesized to result in part from dysregulated sympathetic function. A candidate gene analysis of COMT rs4680 effects on clinical outcomes in the Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial (NorCAPITAL), a randomized double-blinded clonidine versus placebo trial, was conducted (N=104). Patients homozygous for rs4680 high-activity allele randomized to clonidine took 2500 fewer steps compared with placebo (Pinteraction=0.04). There were no differences between clonidine and placebo among patients with COMT low-activity alleles. Similar gene-drug interactions were observed for sleep (Pinteraction=0.003) and quality of life (Pinteraction=0.018). Detrimental effects of clonidine in the subset of CFS patients homozygous for COMT high-activity allele warrant investigation of potential clonidine-COMT interaction effects in other conditions.

Catechol-O-methyltransferase association with hemoglobin A1c

AIMS

Catecholamines have metabolic effects on blood pressure, insulin sensitivity and blood glucose. Genetic variation in catechol-O-methyltransferase (COMT), an enzyme that degrades catecholamines, is associated with cardiometabolic risk factors and incident cardiovascular disease (CVD). Here we examined COMT effects on glycemic function and type 2 diabetes.

METHODS

We tested whether COMT polymorphisms were associated with baseline HbA1c in the Women's Genome Health Study (WGHS), and Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC), and with susceptibility to type 2 diabetes in WGHS, DIAbetes Genetics Replication And Meta-analysis consortium (DIAGRAM), and the Diabetes Prevention Program (DPP). Given evidence that COMT modifies some drug responses, we examined association with type 2 diabetes and randomized metformin and aspirin treatment.

RESULTS

COMT rs4680 high-activity G-allele was associated with lower HbA1c in WGHS (β=-0.032% [0.012], p=0.008) and borderline significant in MAGIC (β=-0.006% [0.003], p=0.07). Combined COMT per val allele effects on type 2 diabetes were significant (OR=0.98 [0.96-0.998], p=0.03) in fixed-effects analyses across WGHS, DIAGRAM, and DPP. Similar results were obtained for 2 other COMT SNPs rs4818 and rs4633. In the DPP, the rs4680 val allele was borderline associated with lower diabetes incidence among participants randomized to metformin (HR=0.81 [0.65-1.00], p=0.05).

CONCLUSIONS

COMT rs4680 high-activity G-allele was associated with lower HbA1c and modest protection from type 2 diabetes. The directionality of COMT associations was concordant with those previously observed for cardiometabolic risk factors and CVD.

Brain white matter structure and COMT gene are linked to second-language learning in adults

Adult human brains retain the capacity to undergo tissue reorganization during second-language learning. Brain-imaging studies show a relationship between neuroanatomical properties and learning for adults exposed to a second language. However, the role of genetic factors in this relationship has not been investigated. The goal of the current study was twofold: (i) to characterize the relationship between brain white matter fiber-tract properties and second-language immersion using diffusion tensor imaging, and (ii) to determine whether polymorphisms in the catechol-O-methyltransferase (COMT) gene affect the relationship. We recruited incoming Chinese students enrolled in the University of Washington and scanned their brains one time. We measured the diffusion properties of the white matter fiber tracts and correlated them with the number of days each student had been in the immersion program at the time of the brain scan. We found that higher numbers of days in the English immersion program correlated with higher fractional anisotropy and lower radial diffusivity in the right superior longitudinal fasciculus. We show that fractional anisotropy declined once the subjects finished the immersion program. The relationship between brain white matter fiber-tract properties and immersion varied in subjects with different COMT genotypes. Subjects with the Methionine (Met)/Valine (Val) and Val/Val genotypes showed higher fractional anisotropy and lower radial diffusivity during immersion, which reversed immediately after immersion ended, whereas those with the Met/Met genotype did not show these relationships. Statistical modeling revealed that subjects' grades in the language immersion program were best predicted by fractional anisotropy and COMT genotype.

The Role of Complementary and Alternative Medicine for the Management of Fibroids and Associated Symptomatology

This article discusses the role of complementary and alternative medicine (CAM) in the management of fibroids and associated symptomatology. Since there is such a paucity of direct research related to fibroids, conditions that are implicated in the causation of uterine fibroids and symptomatology that CAM treatments may or have been shown to make a difference are also considered.

Are Genetic Tests for Atherosclerosis Ready for Routine Clinical Use?

In this review, we lay out 3 areas currently being evaluated for incorporation of genetic information into clinical practice related to atherosclerosis. The first, familial hypercholesterolemia, is the clearest case for utility of genetic testing in diagnosis and potentially guiding treatment. Already in use for confirmatory testing of familial hypercholesterolemia and for cascade screening of relatives, genetic testing is likely to expand to help establish diagnoses and facilitate research related to most effective therapies, including new agents, such as PCSK9 inhibitors. The second area, adding genetic information to cardiovascular risk prediction for primary prevention, is not currently recommended. Although identification of additional variants may add substantially to prediction in the future, combining known variants has not yet demonstrated sufficient improvement in prediction for incorporation into commonly used risk scores. The third area, pharmacogenetics, has utility for some therapies today. Future utility for pharmacogenetics will wax or wane depending on the nature of available drugs and therapeutic strategies.

Genetics and the placebo effect: the placebome

Placebos are indispensable controls in randomized clinical trials (RCTs), and placebo responses significantly contribute to routine clinical outcomes. Recent neurophysiological studies reveal neurotransmitter pathways that mediate placebo effects. Evidence that genetic variations in these pathways can modify placebo effects raises the possibility of using genetic screening to identify placebo responders and thereby increase RCT efficacy and improve therapeutic care. Furthermore, the possibility of interaction between placebo and drug molecular pathways warrants consideration in RCT design. The study of genomic effects on placebo response, 'the placebome', is in its infancy. Here, we review evidence from placebo studies and RCTs to identify putative genes in the placebome, examine evidence for placebo-drug interactions, and discuss implications for RCTs and clinical care.

Conscientiousness is modified by genetic variation in catechol-O-methyltransferase to reduce symptom complaints in IBS patients

BACKGROUND

Attention to and perception of physical sensations and somatic states can significantly influence reporting of complaints and symptoms in the context of clinical care and randomized trials. Although anxiety and high neuroticism are known to increase the frequency and severity of complaints, it is not known if other personality dimensions or genes associated with cognitive function or sympathetic tone can influence complaints. Genetic variation in catechol-O-methyltransferase (COMT) is associated with anxiety, personality, pain, and response to placebo treatment. We hypothesized that the association of complaint reporting with personality might be modified by variation in the COMT val158met genotype.

METHODS

We administered a standard 25-item complaint survey weekly over 3-weeks to a convenience sample of 187 irritable bowel syndrome patients enrolled in a placebo intervention trial and conducted a repeated measures analysis.

RESULTS

We found that complaint severity rating, our primary outcome, was negatively associated with the personality measures of conscientiousness (β = -0.31 SE 0.11, P = 0.003) and agreeableness (β = -0.38 SE 0.12, P = 0.002) and was positively associated with neuroticism (β = 0.24 SE 0.09, P = 0.005) and anxiety (β = 0.48 SE 0.09, P < 0.0001). We also found a significant interaction effect of COMT met alleles (β = -32.5 SE 14.1, P = 0.021). in patients genotyped for COMT val158met (N  = 87) specifically COMT × conscientiousness (β = 0.73 SE 0.26, P = 0.0042) and COMT × anxiety (β = -0.42 SE 0.16, P = 0.0078) interaction effects.

CONCLUSION

These findings potentially broaden our understanding of the factors underlying clinical complaints to include the personality dimension of conscientiousness and its modification by COMT.