The genetics of blood pressure regulation and its target organs from association studies in 342,415 individuals

Current genetic engineering strategies for the production of antihypertensive ACEI peptides

Hypertension is a major and highly prevalent risk factor for various diseases. Among the most frequently prescribed antihypertensive first-line drugs are synthetic angiotensin I-converting enzyme inhibitors (ACEI). However, since  their use in hypertension therapy has been linked to various side effects, interest in the application of food-derived ACEI peptides (ACEIp) as antihypertensive agents is rapidly growing. Although promising, the industrial production of ACEIp through conventional methods such as chemical synthesis or enzymatic hydrolysis of food proteins has been proven troublesome. We here provide an overview of current antihypertensive therapeutics, focusing on ACEI, and illustrate how biotechnology and bioengineering can overcome the limitations of ACEIp large-scale production. Latest advances in ACEIp research and current genetic engineering-based strategies for heterologous production of ACEIp (and precursors) are also presented. Cloning approaches include tandem repeats of single ACEIp, ACEIp fusion to proteins/polypeptides, joining multivariate ACEIp into bioactive polypeptides, and producing ACEIp-containing modified plant storage proteins. Although bacteria have been privileged ACEIp heterologous hosts, particularly when testing for new genetic engineering strategies, plants and microalgae-based platforms are now emerging. Besides being generally safer, cost-effective and scalable, these "pharming" platforms can perform therelevant posttranslational modifications and produce (and eventually deliver) biologically active protein/peptide-based antihypertensive medicines.

Metabolites and Hypertension: Insights into Hypertension as a Metabolic Disorder: 2019 Harriet Dustan Award

For over 100 years, essential hypertension has been researched from different perspectives ranging from genetics, physiology, and immunology to more recent ones encompassing microbiology (microbiota) as a previously underappreciated field of study contributing to the cause of hypertension. Each field of study in isolation has uniquely contributed to a variety of underlying mechanisms of blood pressure regulation. Even so, clinical management of essential hypertension has remained somewhat static. We, therefore, asked if there are any converging lines of evidence from these individual fields that could be amenable for a better clinical prognosis. Accordingly, here we present converging evidence which support the view that metabolic dysfunction underlies essential hypertension.

Genome-wide meta-analysis of variant-by-diuretic interactions as modulators of lipid traits in persons of European and African ancestry

Hypertension (HTN) is a significant risk factor for cardiovascular morbidity and mortality. Metabolic abnormalities, including adverse cholesterol and triglycerides (TG) profiles, are frequent comorbid findings with HTN and contribute to cardiovascular disease. Diuretics, which are used to treat HTN and heart failure, have been associated with worsening of fasting lipid concentrations. Genome-wide meta-analyses with 39,710 European-ancestry (EA) individuals and 9925 African-ancestry (AA) individuals were performed to identify genetic variants that modify the effect of loop or thiazide diuretic use on blood lipid concentrations. Both longitudinal and cross sectional data were used to compute cohort-specific interaction results, which were then combined through meta-analysis in each ancestry. These ancestry-specific results were further combined through trans-ancestry meta-analysis. Analysis of EA data identified two genome-wide significant (p < 5 × 10-8) loci with single nucleotide variant (SNV)-loop diuretic interaction on TG concentrations (including COL11A1). Analysis of AA data identified one genome-wide significant locus adjacent to BMP2 with SNV-loop diuretic interaction on TG concentrations. Trans-ancestry analysis strengthened evidence of association for SNV-loop diuretic interaction at two loci (KIAA1217 and BAALC). There were few significant SNV-thiazide diuretic interaction associations on TG concentrations and for either diuretic on cholesterol concentrations. Several promising loci were identified that may implicate biologic pathways that contribute to adverse metabolic side effects from diuretic therapy.

Vascular ageing in hypertension: Focus on mitochondria

Hypertension is a common age-related disease, along with vascular and neurodegenerative diseases. Vascular ageing increases during hypertension, but hypertension itself accelerates vascular ageing, thus creating a vicious circle. Vascular stiffening, endothelial dysfunction, impaired contractility and vasorelaxation are the main alterations related to vascular ageing, as a consequence of vascular smooth muscle and endothelial cells senescence. Several molecular mechanisms have been involved into the functional and morphological changes of the aged vessels. Among them, oxidative stress, inflammation, extracellular matrix deregulation and mitochondrial dysfunction are the best characterized. In the present review, we discuss relevant literature about the biology of vascular and cerebrovascular ageing with a particular focus on mitochondria signalling. We underline the therapeutic strategies, able to improve mitochondrial health, which may represent a promising tool to decrease vascular dysfunction associated with ageing and hypertension-related complications.

A bidirectional Mendelian randomization study supports causal effects of kidney function on blood pressure

Blood pressure and kidney function have a bidirectional relation. Hypertension has long been considered as a risk factor for kidney function decline. However, whether intensive blood pressure control could promote kidney health has been uncertain. The kidney is known to have a major role in affecting blood pressure through sodium extraction and regulating electrolyte balance. This bidirectional relation makes causal inference between these two traits difficult. Therefore, to examine the causal relations between these two traits, we performed two-sample Mendelian randomization analyses using summary statistics of large-scale genome-wide association studies. We selected genetic instruments more likely to be specific for kidney function using meta-analyses of complementary kidney function biomarkers (glomerular filtration rate estimated from serum creatinine [eGFRcr], and blood urea nitrogen from the CKDGen Consortium). Systolic and diastolic blood pressure summary statistics were from the International Consortium for Blood Pressure and UK Biobank. Significant evidence supported the causal effects of higher kidney function on lower blood pressure. Based on the mode-based Mendelian randomization method, the effect estimates for one standard deviation (SD) higher in log-transformed eGFRcr was -0.17 SD unit (95 % confidence interval: -0.09 to -0.24) in systolic blood pressure and -0.15 SD unit (95% confidence interval: -0.07 to -0.22) in diastolic blood pressure. In contrast, the causal effects of blood pressure on kidney function were not statistically significant. Thus, our results support causal effects of higher kidney function on lower blood pressure and suggest preventing kidney function decline can reduce the public health burden of hypertension.

Manganese homeostasis: from rare single-gene disorders to complex phenotypes and diseases

Manganese (Mn) participates in a variety of distinct physiological processes, including acting as a cofactor for several enzymes and metalloenzymes, in addition to playing a role in immune function, endocrine function, hematopoiesis, and oxidative stress regulation. Mn homeostasis is tightly regulated via intestinal absorption and hepatobiliary and intestinal excretion. In this issue of the JCI, Mercadante and colleagues explored the role of the metal transporter Slc30a10 in vivo using a mouse model system. The authors used whole-body and tissue-specific gene knockouts to show that Slc30a10 is paramount for Mn excretion in the liver and small intestines. These findings provide further insights into mechanisms for Mn homeostasis as well as potential targets for addressing Mn-associated disorders or environmental exposures.

An evaluation of noncoding genome annotation tools through enrichment analysis of 15 genome-wide association studies

Functionally annotating genetic variations is an essential yet challenging topic in human genetics research. As large consortia including ENCODE and Roadmap Epigenomics Project continue to generate high-throughput transcriptomic and epigenomic data, many computational frameworks have been developed to integrate these experimental data to predict functionality of genetic variations in both protein-coding and noncoding regions. Here, we compare a number of recently developed annotation frameworks for noncoding regions through enrichment analysis on genome-wide association studies (GWASs). We also compare several different strategies to quantify enrichment using GWAS summary statistics. Our analyses highlight the importance of jointly modeling context-specific annotations with genome-wide data in providing statistically powerful and biologically interpretable enrichment for complex disease associations. Our findings provide insights into when and how computational genome annotations may benefit future complex disease studies on the genome-wide scale.

Analysis of mitochondrial m1A/G RNA modification reveals links to nuclear genetic variants and associated disease processes

RNA modifications affect the stability and function of RNA species, regulating important downstream processes. Modification levels are often dynamic, varying between tissues and individuals, although it is not always clear what modulates this or what impact it has on biological systems. Here, we quantify variation in m1A/G RNA modification levels at functionally important positions in the human mitochondrial genome across 11,552 samples from 39 tissue/cell types and find that modification levels are associated with mitochondrial transcript processing. We identify links between mitochondrial RNA modification levels and genetic variants in the nuclear genome, including a missense mutation in LONP1, and find that genetic variants within MRPP3 and TRMT61B are associated with RNA modification levels across a large number of tissues. Genetic variants linked to RNA modification levels are associated with multiple disease/disease-related phenotypes, including blood pressure, breast cancer and psoriasis, suggesting a role for mitochondrial RNA modification in complex disease.

Carotid Intima-Media Thickness: Novel Loci, Sex-Specific Effects, and Genetic Correlations With Obesity and Glucometabolic Traits in UK Biobank

OBJECTIVE

Atherosclerosis is the underlying cause of most cardiovascular disease, but mechanisms underlying atherosclerosis are incompletely understood. Ultrasound measurement of the carotid intima-media thickness (cIMT) can be used to measure vascular remodeling, which is indicative of atherosclerosis. Genome-wide association studies have identified many genetic loci associated with cIMT, but heterogeneity of measurements collected by many small cohorts have been a major limitation in these efforts. Here, we conducted genome-wide association analyses in UKB (UK Biobank; N=22 179), the largest single study with consistent cIMT measurements. Approach and Results: We used BOLT-LMM software to run linear regression of cIMT in UKB, adjusted for age, sex, and genotyping chip. In white British participants, we identified 5 novel loci associated with cIMT and replicated most previously reported loci. In the first sex-specific analyses of cIMT, we identified a locus on chromosome 5, associated with cIMT in women only and highlight VCAN as a good candidate gene at this locus. Genetic correlations with body mass index and glucometabolic traits were also observed. Two loci influenced risk of ischemic heart disease.

CONCLUSIONS

These findings replicate previously reported associations, highlight novel biology, and provide new directions for investigating the sex differences observed in cardiovascular disease presentation and progression.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Identification of Circulating Proteins Associated With Blood Pressure Using Mendelian Randomization

BACKGROUND

Hypertension is a common modifiable risk factor for cardiovascular disease and mortality. Pathophysiological mechanisms leading to hypertension remain incompletely understood. Mendelian randomization (MR) allows the evaluation of the causal role of markers by minimizing the risk of biases such as reverse causation and confounding. We aimed to identify novel circulating proteins associated with blood pressure through a comprehensive screen of 227 blood biomarkers using MR.

METHODS

Genetic determinants of 227 biomarkers were identified in ORIGIN (Outcome Reduction With Initial Glargine Intervention; URL: http://www.clinicaltrials.gov. Unique identifier: NCT00069784) participants (N=4147) and combined with genetic effects on systolic blood pressure, diastolic blood pressure, mean arterial pressure, and pulse pressure from the International Consortium for Blood Pressure (74 064 individuals) using MR. Results were replicated in the UK Biobank (up to 319 103 individuals) and using another biomarker dataset (N=3301). MR analyses with cardiovascular risk factors and outcomes as well as other biomarkers were performed to further evaluate the mechanisms involved.

RESULTS

Six biomarkers were associated with blood pressure using MR after adjustment for multiple hypothesis testing. Relationships between NT-proBNP (N-terminal Pro-B-type natriuretic peptide), systolic blood pressure, and diastolic blood pressure confirmed previous reports. Novel circulating proteins associated with blood pressure were also identified. uPA (urokinase-type plasminogen activator) was related to systolic blood pressure; ADM (adrenomedullin) was related to systolic blood pressure and pulse pressure; IL (interleukin) 16 was related to diastolic blood pressure; cFn (cellular fibronectin) and IGFBP3 (insulin-like growth factor-binding protein 3) were related to pulse pressure. With the exception of IL16 and diastolic blood pressure (P=0.58), these relationships were validated in the UK Biobank (P<0.0001). Further MR analyses with cardiovascular risk factors and outcomes showed relationships between NT-proBNP and large-artery atherosclerotic stroke, IGFBP3 and diabetes mellitus as well as cFn and body mass index.

CONCLUSIONS

We identified novel biomarkers associated with blood pressure using MR. These markers could prove useful for risk assessment and as potential therapeutic targets.

Interaction Between Type 2 Diabetes Prevention Strategies and Genetic Determinants of Coronary Artery Disease on Cardiometabolic Risk Factors

Coronary artery disease (CAD) is more frequent among individuals with dysglycemia. Preventive interventions for diabetes can improve cardiometabolic risk factors (CRFs), but it is unclear whether the benefits on CRFs are similar for individuals at different genetic risk for CAD. We built a 201-variant polygenic risk score (PRS) for CAD and tested for interaction with diabetes prevention strategies on 1-year changes in CRFs in 2,658 Diabetes Prevention Program (DPP) participants. We also examined whether separate lifestyle behaviors interact with PRS and affect changes in CRFs in each intervention group. Participants in both the lifestyle and metformin interventions had greater improvement in the majority of recognized CRFs compared with placebo (P < 0.001) irrespective of CAD genetic risk (P interaction > 0.05). We detected nominal significant interactions between PRS and dietary quality and physical activity on 1-year change in BMI, fasting glucose, triglycerides, and HDL cholesterol in individuals randomized to metformin or placebo, but none of them achieved the multiple-testing correction for significance. This study confirms that diabetes preventive interventions improve CRFs regardless of CAD genetic risk and delivers hypothesis-generating data on the varying benefit of increasing physical activity and improving diet on intermediate cardiovascular risk factors depending on individual CAD genetic risk profile.

Comprehensive epigenome characterization reveals diverse transcriptional regulation across human vascular endothelial cells

Background

Endothelial cells (ECs) make up the innermost layer throughout the entire vasculature. Their phenotypes and physiological functions are initially regulated by developmental signals and extracellular stimuli. The underlying molecular mechanisms responsible for the diverse phenotypes of ECs from different organs are not well understood.

Results

To characterize the transcriptomic and epigenomic landscape in the vascular system, we cataloged gene expression and active histone marks in nine types of human ECs (generating 148 genome-wide datasets) and carried out a comprehensive analysis with chromatin interaction data. We developed a robust procedure for comparative epigenome analysis that circumvents variations at the level of the individual and technical noise derived from sample preparation under various conditions. Through this approach, we identified 3765 EC-specific enhancers, some of which were associated with disease-associated genetic variations. We also identified various candidate marker genes for each EC type. We found that the nine EC types can be divided into two subgroups, corresponding to those with upper-body origins and lower-body origins, based on their epigenomic landscape. Epigenomic variations were highly correlated with gene expression patterns, but also provided unique information. Most of the deferentially expressed genes and enhancers were cooperatively enriched in more than one EC type, suggesting that the distinct combinations of multiple genes play key roles in the diverse phenotypes across EC types. Notably, many homeobox genes were differentially expressed across EC types, and their expression was correlated with the relative position of each organ in the body. This reflects the developmental origins of ECs and their roles in angiogenesis, vasculogenesis and wound healing.

Conclusions

This comprehensive analysis of epigenome characterization of EC types reveals diverse transcriptional regulation across human vascular systems. These datasets provide a valuable resource for understanding the vascular system and associated diseases.

Endothelium structure and function in kidney health and disease

The kidney harbours different types of endothelia, each with specific structural and functional characteristics. The glomerular endothelium, which is highly fenestrated and covered by a rich glycocalyx, participates in the sieving properties of the glomerular filtration barrier and in the maintenance of podocyte structure. The microvascular endothelium in peritubular capillaries, which is also fenestrated, transports reabsorbed components and participates in epithelial cell function. The endothelium of large and small vessels supports the renal vasculature. These renal endothelia are protected by regulators of thrombosis, inflammation and complement, but endothelial injury (for example, induced by toxins, antibodies, immune cells or inflammatory cytokines) or defects in factors that provide endothelial protection (for example, regulators of complement or angiogenesis) can lead to acute or chronic renal injury. Moreover, renal endothelial cells can transition towards a mesenchymal phenotype, favouring renal fibrosis and the development of chronic kidney disease. Thus, the renal endothelium is both a target and a driver of kidney and systemic cardiovascular complications. Emerging therapeutic strategies that target the renal endothelium may lead to improved outcomes for both rare and common renal diseases.

Genetic Susceptibility, Dietary Protein Intake, and Changes of Blood Pressure: The POUNDS Lost Trial

High blood pressure (BP) is closely related to obesity, and weight loss lowers BP. Evidence has shown considerable interpersonal variation of changes in BP among people experiencing weight loss, and such variation might be partly determined by genetic factors. We assessed the changes in systolic and diastolic BP (SBP/DBP) among 692 participants randomly assigned to 1 of 4 diets varying in macronutrient content for 2 years. Two separate polygenic scores (SBP/DBP-PGS derived from 52/50 single nucleotide polymorphisms) were built for each participant based on 66 BP-associated single nucleotide polymorphisms. During a 2-year intervention, participants in the bottom versus upper tertile of SBP/DBP-PGS had a greater decrease in SBP (△SBP at 6, 12, and 24 months: -3.84 versus -1.61, -4.76 versus -2.75, -2.49 versus -1.63; P=0.001) or in DBP (△DBP at 6, 12, and 24 months: -3.09 versus -1.34, -2.69 versus -1.44, -1.82 versus -0.53; P<0.001). We also found gene-diet interaction on changes in SBP from baseline to 24 months (Pinteraction=0.009). Among participants assigned to a high-protein diet, those with a lower SBP-polygenic scores had greater decreases in SBP at months 6 (P=0.018), months 12 (P=0.007), and months 24 (P=0.089); while no significant difference was observed across the SBP-polygenic scores tertile groups among those assigned to an average-protein diet (all P values >0.05). Our data indicate that genetic susceptibility may affect BP changes in response to weight-loss diet interventions, and protein intake may modify the genetic associations with changes in BP. This trial was registered at URL: http://www.clinicaltrials.gov. Unique identifier: NCT00072995.

The Molecular Genetics of Gordon Syndrome

Gordon syndrome is a rare inherited monogenic form of hypertension, which is associated with hyperkalaemia and metabolic acidosis. Since the recognition of this predominantly autosomal dominant condition in the 1960s, the study of families with Gordon syndrome has revealed four genes WNK1, WNK4, KLHL3, and CUL3 to be implicated in its pathogenesis after a phenotype–genotype correlation was realised. The encoded proteins Kelch-like 3 and Cullin 3 interact to form a ring-like complex to ubiquitinate WNK-kinase 4, which, in normal circumstances, interacts with the sodium chloride co-symporter (NCC), the epithelial sodium channel (ENaC), and the renal outer medullary potassium channel (ROMK) in an inhibitory manner to maintain normokalaemia and normotension. WNK-kinase 1 has an inhibitory action on WNK-kinase 4. Mutations in WNK1, WNK4, KLHL3, and CUL3 all result in the accumulation of WNK-kinase 4 and subsequent hypertension, hyperkalaemia, and metabolic acidosis. This review explains the clinical aspects, disease mechanisms, and molecular genetics of Gordon syndrome.

Over 1000 genetic loci influencing blood pressure with multiple systems and tissues implicated

High blood pressure (BP) remains the major heritable and modifiable risk factor for cardiovascular disease. Persistent high BP, or hypertension, is a complex trait with both genetic and environmental interactions. Despite swift advances in genomics, translating new discoveries to further our understanding of the underlying molecular mechanisms remains a challenge. More than 500 loci implicated in the regulation of BP have been revealed by genome-wide association studies (GWAS) in 2018 alone, taking the total number of BP genetic loci to over 1000. Even with the large number of loci now associated to BP, the genetic variance explained by all loci together remains low (~5.7%). These genetic associations have elucidated mechanisms and pathways regulating BP, highlighting potential new therapeutic and drug repurposing targets. A large proportion of the BP loci were discovered and reported simultaneously by multiple research groups, creating a knowledge gap, where the reported loci to date have not been investigated in a harmonious way. Here, we review the BP-associated genetic variants reported across GWAS studies and investigate their potential impact on the biological systems using in silico enrichment analyses for pathways, tissues, gene ontology and genetic pleiotropy.

Circular RNAs in hypertension: challenges and clinical promise

Hypertension (HT), or high blood pressure (BP), is a chronic disease that is common among populations worldwide. The occurrence of HT is one of the leading causes of cardiovascular morbidity and mortality in adults. Although multiple studies have stressed the multifactorial and multigenic nature of HT, uncertainties about its etiology persist, and current diagnostic biomarkers can explain only a small part of the phenotypic variance of BP. Hence, the search for novel biomarkers that enable early disease prevention and guided therapy is warranted. Regulatory circRNAs have emerged as the newest player in HT-related gene networks and hold promise for improving the accuracy of diagnosis. These RNAs are genome products that are formed through back-splicing of specific regions of pre-mRNAs. Evidence suggests that these RNA species are involved in various metabolic diseases. Recent studies have revealed that aberrant expression of circRNAs is relevant to the occurrence and development of HT. Accordingly, circRNAs are proposed as a new generation of predictive biomarkers and potential therapeutic targets for different forms of HT, including pulmonary hypertension and preeclampsia. This paper presents an overview of the findings from current research focusing on the emerging role of circRNAs in the pathogenesis of hypertension. Furthermore, some of the challenges encountered by circRNA studies are highlighted, and perspectives are provided on the future of research in this area.

Identification of Phosphorylation Associated SNPs for Blood Pressure, Coronary Artery Disease and Stroke from Genome-wide Association Studies

PURPOSE

Phosphorylation-related SNP (phosSNP) is a non-synonymous SNP that might influence protein phosphorylation status. The aim of this study was to assess the effect of phosSNPs on blood pressure (BP), coronary artery disease (CAD) and ischemic stroke (IS).

METHODS

We examined the association of phosSNPs with BP, CAD and IS in shared data from genome-wide association studies (GWAS) and tested if the disease loci were enriched with phosSNPs. Furthermore, we performed quantitative trait locus analysis to find out if the identified phosSNPs have impacts on gene expression, protein and metabolite levels.

RESULTS

We found numerous phosSNPs for systolic BP (count=148), diastolic BP (count=206), CAD (count=20) and IS (count=4). The most significant phosSNPs for SBP, DBP, CAD and IS were rs1801131 in MTHFR, rs3184504 in SH2B3, rs35212307 in WDR12 and rs3184504 in SH2B3, respectively. Our analyses revealed that the associated SNPs identified by the original GWAS were significantly enriched with phosSNPs and many well-known genes predisposing to cardiovascular diseases contain significant phosSNPs. We found that BP, CAD and IS shared for phosSNPs in loci that contain functional genes involve in cardiovascular diseases, e.g., rs11556924 (ZC3HC1), rs1971819 (ICA1L), rs3184504 (SH2B3), rs3739998 (JCAD), rs903160 (SMG6). Four phosSNPs in ADAMTS7 were significantly associated with CAD, including the known functional SNP rs3825807. Moreover, the identified phosSNPs seemed to have the potential to affect transcription regulation and serum levels of numerous cardiovascular diseases-related proteins and metabolites.

CONCLUSION

The findings suggested that phosSNPs may play important roles in BP regulation and the pathological mechanisms of CAD and IS.

Systematic review of the evidence on the cost-effectiveness of pharmacogenomics-guided treatment for cardiovascular diseases

PURPOSE

To examine the evidence on the cost-effectiveness of implementing pharmacogenomics (PGx) in cardiovascular disease (CVD) care.

METHODS

We conducted a systematic review using multiple databases from inception to 2018. The titles and abstracts of cost-effectiveness studies on PGx-guided treatment in CVD care were screened, and full texts were extracted.

RESULTS

We screened 909 studies and included 46 to synthesize. Acute coronary syndrome and atrial fibrillation were the predominantly studied conditions (59%). Most studies (78%) examined warfarin-CYP2C9/VKORC1 or clopidogrel-CYP2C19. A payer's perspective was commonly used (39%) for cost calculations, and most studies (46%) were US-based. The majority (67%) of the studies found PGx testing to be cost-effective in CVD care, but cost-effectiveness varied across drugs and conditions. Two studies examined PGx panel testing, of which one examined pre-emptive testing strategies.

CONCLUSION

We found mixed evidence on the cost-effectiveness of PGx in CVD care. Supportive evidence exists for clopidogrel-CYP2C19 and warfarin-CYP2C9/VKORC1, but evidence is limited in other drug-gene combinations. Gaps persist, including unclear explanation of perspective and cost inputs, underreporting of study design elements critical to economic evaluations, and limited examination of PGx panel and pre-emptive testing for their cost-effectiveness. This review identifies the need for further research on economic evaluations of PGx implementation.

A genome-wide association and replication study of blood pressure in Ugandan early adolescents

BACKGROUND

Genetic association studies of blood pressure (BP) have mostly been conducted in non-African populations. Using the Entebbe Mother and Baby Study (EMaBS), we aimed to identify genetic variants associated with BP among Ugandan adolescents.

METHODS

Systolic and diastolic BP were measured among 10- and 11-year olds. Whole-genome genotype data were generated using Illumina omni 2.5M arrays and untyped variants were imputed. Genome-wide association study (GWAS) was conducted using linear mixed model regression to account for population structure. Linear regression analysis was used to assess whether variants previously associated with BP (p < 5.0 × 10-8 ) in published BP GWASs were replicated in our study.

RESULTS

Of the 14 million variants analyzed among 815 adolescents, none reached genome-wide significance (p < 5.0×10-8 ) for association with systolic or diastolic BP. The most strongly associated variants were rs181430167 (p = 6.8 × 10-7 ) for systolic BP and rs12991132 (p = 4.0 × 10-7 ) for diastolic BP. Thirty-three (17 single nucleotide polymorphisms (SNPs) for systolic BP, 15 SNPs for diastolic BP and one SNP for both) of 330 variants previously identified as associated with BP were replicated in this study, but none remained significant after accounting for multiple testing.

CONCLUSION

Variants showing suggestive associations are worthy of future investigation. Replication results suggest that variants influencing adolescent BP may overlap somewhat with those already established in previous studies, largely based on adults in Western settings.

Complex assessment of blood pressure regulation system in hypertension patients

Introduction. There are almost no studies characterizing the integrative level of blood pressure (BP) regulation.

Materials and methods. 277 people of both genders aged 58.6±6.4 with stage II hypertension disease were randomized into six groups. The monotherapy of hypertension disease was conducted in five groups, using nebivolol, lisinopril, indapamide, amlodipine, and losartan. The sixth group had a combined therapy (lisinopril/indapamide). The therapy effectiveness was assessed at four levels of blood pressure regulation, using the following methods: 1) laser Doppler flowmetry, determination of the level of tumor necrosis factor-α and interleukin-10; 2) echocardiography and Doppler sonography, ultrasound examination of the renal blood flow, ECG, Holter monitoring of ECG; 3) an examination of the heart rate variability level and a quantitative assessment of beta-adrenoreception of erythrocyte cell membranes; 4) the regulatory and adaptive status was assessed, using the method of cardio-respiratory synchronism.

Results and discussion. A more significant BP decrease was revealed during a combination therapy (by 20.4% of the baseline daily value). At the integrative level, an index of the regulatory and adaptive status (iRAS) increased in the treatment with lisinopril/indapamide combination (by 40.5%), amlodipine (by 40.5%), losartan (by 35.3%), and lisinopril (by 30.2%). Nebivolol administration resulted in a 13.5% decrease in iRAS. Indapamide therapy had no significant effect on iRAS.

Conclusion. A comprehensive assessment of the blood pressure regulation system makes it possible to control the effectiveness of the therapy not only on a target organ or function, but also on the condition of the organism as an integral system.

Effect of Systolic Blood Pressure on Left Ventricular Structure and Function: A Mendelian Randomization Study

We aimed to estimate the effects of a lifelong exposure to high systolic blood pressure (SBP) on left ventricular (LV) structure and function using Mendelian randomization. A total of 5596 participants of the UK Biobank were included for whom cardiovascular magnetic resonance imaging and genetic data were available. Major exclusion criteria included nonwhite ethnicity, major cardiovascular disease, and body mass index >30 or <18.5 kg/m². A genetic risk score to estimate genetically predicted SBP (gSBP) was constructed based on 107 previously established genetic variants. Manual cardiovascular magnetic resonance imaging postprocessing analyses were performed in 300 individuals at the extremes of gSBP (150 highest and lowest). Multivariable linear regression analyses of imaging biomarkers were performed using gSBP as continuous independent variable. All analyses except myocardial strain were validated using previously derived imaging parameters in 2530 subjects. The mean (SD) age of the study population was 62 (7) years, and 52% of subjects were female. Corrected for age, sex, and body surface area, each 10 mm Hg increase in gSBP was significantly (P<0.0056) associated with 4.01 g (SE, 1.28; P=0.002) increase in LV mass and with 2.80% (SE, 0.97; P=0.004) increase in LV global radial strain. In the validation cohort, after correction for age, sex, and body surface area, each 10 mm Hg increase in gSBP was associated with 5.27 g (SE, 1.50; P<0.001) increase in LV mass. Our study provides a novel line of evidence for a causal relationship between SBP and increased LV mass and with increased LV global radial strain.

Genomic Association Analysis Reveals Variants Associated With Blood Pressure Response to Beta-Blockers in European Americans

European Americans (EA) have a better antihypertensive response to β-blockers when compared with African Americans, albeit with some variability. We undertook a genomewide association study to elucidate the underlying genetic determinants in EA contributing to this variability in blood pressure (BP) response. A discovery genomewide association study of change in BP post-metoprolol treatment was performed in EA participants (n = 201) from the Pharmacogenomic Evaluation of Antihypertensive Responses-2 (PEAR-2) study and tested for replication in the atenolol-treated EA from the PEAR study (n = 233). Rs294610 in the FGD5, which encodes for FYVE, RhoGEF and PH Domain Containing 5, (expression quantitative trait loci for FGD5 in the small intestine) was significantly associated with increased diastolic BP response to β-blockers in the PEAR-2 study (P = 3.41 × 10-6 , β = -2.70) and replicated (P = 0.01, β = -1.17) in the PEAR study. Post-meta-analysis of these studies, an additional single nucleotide polymorphism rs45545233 in the SLC4A1, encoding for Solute Carrier Family 4 Member 1, (expression quantitative trait loci for dual specificity phosphatase 3 in the artery tibial) was identified that was significantly associated with a poor response to β-blockers (P = 3.43 × 10-6 , β = 4.57) and was replicated in the atenolol add-on cohort (P = 0.007, β = 4.97). We identified variants in FGD5 and SLC4A1, which have been previously cited as candidate genes for hypertension, to be associated with a β-blocker BP response in EA. Further elucidation is warranted of the underlying mechanisms of these variants and genes by which they influence the BP response to β-blockers.

Fecal Microbial Transplantation for Diseases Beyond Recurrent Clostridium Difficile Infection

As microbiome research has moved from associative to mechanistic studies, the activities of specific microbes and their products have been investigated in the development of inflammatory bowel diseases, cancer, metabolic syndrome, and neuropsychiatric disorders. Findings from microbiome research have already been applied to the clinic, such as in fecal microbiota transplantation for treatment of recurrent Clostridium difficile infection. We review the evidence for associations between alterations in the intestinal microbiome and gastrointestinal diseases and findings from clinical trials of fecal microbiota transplantation. We discuss opportunities for treatment of other diseases with fecal microbiota transplantation, based on findings from small clinical and preclinical studies.

When drug treatments bias genetic studies: Mediation and interaction

Background

Increasingly, genetic analyses are conducted using information from subjects with established disease, who often receive concomitant treatment. We determined when treatment may bias genetic associations with a quantitative trait.

Methods

Graph theory and simulated data were used to explore the impact of drug prescriptions on (longitudinal) genetic effect estimates. Analytic derivations of longitudinal genetic effects are presented, accounting for the following scenarios: 1) treatment allocated independently of a genetic variant, 2) treatment that mediates the genetic effect, 3) treatment that modifies the genetic effect. We additionally evaluate treatment modelling strategies on bias, the root mean squared error (RMSE), coverage, and rejection rate.

Results

We show that in the absence of treatment by gene effect modification or mediation, genetic effect estimates will be unbiased. In simulated data we found that conditional models accounting for treatment, confounding, and effect modification were generally unbiased with appropriate levels of confidence interval coverage. Ignoring the longitudinal nature of treatment prescription, however (e.g. because of incomplete records in longitudinal data), biased these conditional models to a similar degree (or worse) as simply ignoring treatment.

Conclusion

The mere presence of (drug) treatment affecting a GWAS phenotype is insufficient to bias genetic associations with quantitative traits. While treatment may bias associations through effect modification and mediation, this might not occur frequently enough to warrant general concern at the presence of treated subjects in GWAS. Should treatment by gene effect modification or mediation be present however, current GWAS approaches attempting to adjust for treatment insufficiently account for the multivariable and longitudinal nature of treatment trajectories and hence genetic estimates may still be biased.

Blood Pressure-Associated Genetic Variants in the Natriuretic Peptide Receptor 1 Gene Modulate Guanylate Cyclase Activity

BACKGROUND

Human genetic variation in the NPR1 (natriuretic peptide receptor 1 gene, encoding NPR-A, atrial natriuretic peptide receptor 1) was recently shown to affect blood pressure (BP). NPR-A catalyzes the intracellular conversion of guanosine triphosphate to cGMP (cyclic 3',5'-guanosine monophosphate) on binding of ANP, BNP (atrial or brain natriuretic peptide). Increased levels of cGMP decrease BP by inducing natriuresis, diuresis, and vasodilation.

METHODS

We performed a meta-analysis of low-frequency and rare NPR1 variants for BP association in up to 491 584 unrelated individuals. To examine whether the identified BP-associated variants affect NPR-A function, the cGMP response to ANP and BNP was measured in cells expressing wild-type NPR1 and cells expressing the NPR1 variants.

RESULTS

In this study, we identified BP associations of 3 amino acid altering variants of NPR1. The minor alleles of rs35479618 (p.E967K, gnomAD non-Finnish European allele frequency 0.017) and rs116245325 (p.L1034F, allele frequency 0.0007) were associated with higher BP (P=4.0×10^-25 and P=9.9×10^-8, respectively), while the minor allele of rs61757359 (p.G541S, allele frequency 0.003) was associated with lower BP (P=1.8×10^-9). Cells transiently expressing 967K or 1034F NPR-A displayed decreased cGMP production in response to ANP and BNP (all P<10^-6), while cells expressing 541S NPR-A produced more cGMP compared with cells expressing wild-type NPR-A (P≤4.13×10^-5 for ANP and P≤4.24×10^-3 for BNP).

CONCLUSIONS

In summary, the loss or gain of guanylate cyclase activity for these NPR1 allelic variants could explain the higher or lower BP observed for carriers in large population-based studies.

A multi-ancestry genome-wide study incorporating gene-smoking interactions identifies multiple new loci for pulse pressure and mean arterial pressure

Elevated blood pressure (BP), a leading cause of global morbidity and mortality, is influenced by both genetic and lifestyle factors. Cigarette smoking is one such lifestyle factor. Across five ancestries, we performed a genome-wide gene-smoking interaction study of mean arterial pressure (MAP) and pulse pressure (PP) in 129 913 individuals in stage 1 and follow-up analysis in 480 178 additional individuals in stage 2. We report here 136 loci significantly associated with MAP and/or PP. Of these, 61 were previously published through main-effect analysis of BP traits, 37 were recently reported by us for systolic BP and/or diastolic BP through gene-smoking interaction analysis and 38 were newly identified (P < 5 × 10-8, false discovery rate < 0.05). We also identified nine new signals near known loci. Of the 136 loci, 8 showed significant interaction with smoking status. They include CSMD1 previously reported for insulin resistance and BP in the spontaneously hypertensive rats. Many of the 38 new loci show biologic plausibility for a role in BP regulation. SLC26A7 encodes a chloride/bicarbonate exchanger expressed in the renal outer medullary collecting duct. AVPR1A is widely expressed, including in vascular smooth muscle cells, kidney, myocardium and brain. FHAD1 is a long non-coding RNA overexpressed in heart failure. TMEM51 was associated with contractile function in cardiomyocytes. CASP9 plays a central role in cardiomyocyte apoptosis. Identified only in African ancestry were 30 novel loci. Our findings highlight the value of multi-ancestry investigations, particularly in studies of interaction with lifestyle factors, where genomic and lifestyle differences may contribute to novel findings.

Analysis of polygenic risk score usage and performance in diverse human populations

A historical tendency to use European ancestry samples hinders medical genetics research, including the use of polygenic scores, which are individual-level metrics of genetic risk. We analyze the first decade of polygenic scoring studies (2008–2017, inclusive), and find that 67% of studies included exclusively European ancestry participants and another 19% included only East Asian ancestry participants. Only 3.8% of studies were among cohorts of African, Hispanic, or Indigenous peoples. We find that predictive performance of European ancestry-derived polygenic scores is lower in non-European ancestry samples (e.g. African ancestry samples: t = −5.97, df = 24, p = 3.7 × 10⁻⁶), and we demonstrate the effects of methodological choices in polygenic score distributions for worldwide populations. These findings highlight the need for improved treatment of linkage disequilibrium and variant frequencies when applying polygenic scoring to cohorts of non-European ancestry, and bolster the rationale for large-scale GWAS in diverse human populations.

Predominant participation of European-ancestry individuals in genetic studies has hindered the better understanding of genetic risk in non-European ancestry individuals. Here, Duncan et al. quantify polygenic risk score use and performance in worldwide populations.

Big data management challenges in health research-a literature review

Big data management for information centralization (i.e. making data of interest findable) and integration (i.e. making related data connectable) in health research is a defining challenge in biomedical informatics. While essential to create a foundation for knowledge discovery, optimized solutions to deliver high-quality and easy-to-use information resources are not thoroughly explored. In this review, we identify the gaps between current data management approaches and the need for new capacity to manage big data generated in advanced health research. Focusing on these unmet needs and well-recognized problems, we introduce state-of-the-art concepts, approaches and technologies for data management from computing academia and industry to explore improvement solutions. We explain the potential and significance of these advances for biomedical informatics. In addition, we discuss specific issues that have a great impact on technical solutions for developing the next generation of digital products (tools and data) to facilitate the raw-data-to-knowledge process in health research.

Improved detection of common variants in coronary artery disease and blood pressure using a pleiotropy cFDR method

Plenty of genome-wide association studies (GWASs) have identified numerous single nucleotide polymorphisms (SNPs) for coronary artery disease (CAD) and blood pressure (BP). However, these SNPs only explain a small proportion of the heritability of two traits/diseases. Although high BP is a major risk factor for CAD, the genetic intercommunity between them remain largely unknown. To recognize novel loci associated with CAD and BP, a genetic-pleiotropy-informed conditional false discovery rate (cFDR) method was applied on two summary statistics of CAD and BP from existing GWASs. Stratified Q-Q and fold enrichment plots showed a high pleiotropic enrichment of SNPs associated with two traits. Adopting a cFDR of 0.05 as a threshold, 55 CAD-associated loci (25 variants being novel) and 47 BP loci (18 variants being novel) were identified, 25 of which were pleiotropic loci (13 variants being novel) for both traits. Among the 32 genes these 25 SNPs were annotated to, 20 genes were newly detected compared to previous GWASs. This study showed the cFDR approach could improve gene discovery by incorporating GWAS datasets of two related traits. These findings may provide novel understanding of etiology relationships between CAD and BP.

ARMC 5 Variants and Risk of Hypertension in Blacks: MH- GRID Study

Background We recently found that ARMC 5 variants may be associated with primary aldosteronism in blacks. We investigated a cohort from the MH - GRID (Minority Health Genomics and Translational Research Bio-Repository Database) and tested the association between ARMC 5 variants and blood pressure in black s. Methods and Results Whole exome sequencing data of 1377 black s were analyzed. Target single-variant and gene-based association analyses of hypertension were performed for ARMC 5, and replicated in a subset of 3015 individuals of African descent from the UK Biobank cohort. Sixteen rare variants were significantly associated with hypertension ( P=0.0402) in the gene-based (optimized sequenced kernel association test) analysis; the 16 and one other, rs116201073, together, showed a strong association ( P=0.0003) with blood pressure in this data set. The presence of the rs116201073 variant was associated with lower blood pressure. We then used human embryonic kidney 293 and adrenocortical H295R cells transfected with an ARMC 5 construct containing rs116201073 (c.*920T>C). The latter was common in both the discovery ( MH - GRID ) and replication ( UK Biobank) data and reached statistical significance ( P=0.044 [odds ratio, 0.7] and P=0.007 [odds ratio, 0.76], respectively). The allele carrying rs116201073 increased levels of ARMC5 mRNA , consistent with its protective effect in the epidemiological data. Conclusions ARMC 5 shows an association with hypertension in black s when rare variants within the gene are considered. We also identified a protective variant of the ARMC 5 gene with an effect on ARMC 5 expression confirmed in vitro. These results extend our previous report of ARMC 5's possible involvement in the determination of blood pressure in blacks.

Familial clustering of hypertensive target organ damage in the community

OBJECTIVES

Prior studies suggest that hypertensive target organ damage (TOD) is a heritable trait. However, the risk that parental TOD confers on propensity for TOD in their offspring, and how hypertensive TOD clusters in the context of parental versus offspring hypertension status remain unclear.

METHODS

We studied 3238 Framingham Heart Study participants (mean age 39 ± 8 years, 53% women) with available parental data on TOD. Parents and offspring underwent measurements for left ventricular hypertrophy, increased relative wall thickness, albuminuria and conventional risk factors.

RESULTS

Prevalence of any TOD (left ventricular hypertrophy or albuminuria) in participants with zero and at least one parents with any TOD was 7 and 13%, respectively (P < 0.001 for difference). Having at least one parent with TOD was associated with greater odds of TOD in offspring than individuals without parental TOD [multivariable-adjusted odds ratio (OR), 1.65; 95% confidence interval (95% CI), 1.27-2.14]. Similarly, parental left ventricular hypertrophy was associated with offspring left ventricular hypertrophy (OR, 2.73; 95% CI 1.92-3.89), parental increased relative wall thickness conferred increased odds of increased relative wall thickness in the offspring (OR, 1.54; 95% CI 1.16-2.04) and parental albuminuria was related to offspring albuminuria (OR, 1.49; 95% CI 1.03-2.16). These associations remained significant upon adjustment for other risk factors, including blood pressure, and in analyses of subgroups defined according to parental or offspring hypertension status.

CONCLUSION

Overall, our data suggest that familial clustering of TOD in the community is independent of blood pressure. Additional studies are warranted to confirm our observations.

A polymorphism in intron I of the human angiotensinogen gene (hAGT) affects binding by HNF3 and hAGT expression and increases blood pressure in mice

Angiotensinogen (AGT) is the precursor of one of the most potent vasoconstrictors, peptide angiotensin II. Genome-wide association studies have shown that two A/G polymorphisms (rs2493134 and rs2004776), located at +507 and +1164 in intron I of the human AGT (hAGT) gene, are associated with hypertension. Polymorphisms of the AGT gene result in two main haplotypes. Hap-I contains the variants -217A, -6A, +507G, and +1164A and is pro-hypertensive, whereas Hap-II contains the variants -217G, -6G, +507A, and +1164G and does not affect blood pressure. The nucleotide sequence of intron I of the hAGT gene containing the +1164A variant has a stronger homology with the hepatocyte nuclear factor 3 (HNF3)-binding site than +1164G. Here we found that an oligonucleotide containing +1164A binds HNF3β more strongly than +1164G and that Hap-I-containing reporter gene constructs have increased basal and HNF3- and glucocorticoid-induced promoter activity in transiently transfected liver and kidney cells. Using a knock-in approach at the hypoxanthine-guanine phosphoribosyltransferase locus, we generated a transgenic mouse model containing the human renin (hREN) gene and either Hap-I or Hap-II. We show that transgenic animals containing Hap-I have increased blood pressure compared with those containing Hap-II. Moreover, the transcription factors glucocorticoid receptor, CCAAT enhancer-binding protein β, and HNF3β bound more strongly to chromatin obtained from the liver of transgenic animals containing Hap-I than to liver chromatin from Hap-II-containing animals. These findings suggest that, unlike Hap-II variants, Hap-I variants of the hAGT gene have increased transcription rates, resulting in elevated blood pressure.

Loss of reticulocalbin 2 lowers blood pressure and restrains ANG II-induced hypertension in vivo

Hypertension affects over 1 billion people worldwide and increases the risk for heart failure, stroke, and chronic kidney disease. Despite high prevalence and devastating impact, its etiology still remains poorly understood for most hypertensive cases. Rcn2, which encodes reticulocalbin 2, is a candidate gene for atherosclerosis that we have previously reported in mice. Here, we identified Rcn2 as a novel regulator of blood pressure in mice. Rcn2 was abundantly expressed in the endothelium and adventitia of normal arteries and was dramatically upregulated in the medial layer of the artery undergoing structural remodeling. Deletion of Rcn2 lowered basal blood pressure and attenuated ANG II-induced hypertension in C57BL/6 mice. siRNA knockdown of Rcn2 dramatically increased production of the nitric oxide (NO) breakdown products nitrite and nitrate by endothelial cells but not by smooth muscle cells. Isolated carotid arteries from Rcn2-/- mice showed an increased sensitivity to the ACh-induced NO-mediated relaxant response compared with arteries of Rcn2+/+ mice. Analysis of a recent meta-data set showed associations of genetic variants near RCN2 with blood pressure in humans. These data suggest that Rcn2 regulates blood pressure and contributes to hypertension through actions on endothelial NO synthase.

High-Diversity Mouse Populations for Complex Traits

Contemporary mouse genetic reference populations are a powerful platform to discover complex disease mechanisms. Advanced high-diversity mouse populations include the Collaborative Cross (CC) strains, Diversity Outbred (DO) stock, and their isogenic founder strains. When used in systems genetics and integrative genomics analyses, these populations efficiently harnesses known genetic variation for precise and contextualized identification of complex disease mechanisms. Extensive genetic, genomic, and phenotypic data are already available for these high-diversity mouse populations and a growing suite of data analysis tools have been developed to support research on diverse mice. This integrated resource can be used to discover and evaluate disease mechanisms relevant across species.

Genetic variation in CADM2 as a link between psychological traits and obesity

CADM2 has been associated with a range of behavioural and metabolic traits, including physical activity, risk-taking, educational attainment, alcohol and cannabis use and obesity. Here, we set out to determine whether CADM2 contributes to mechanisms shared between mental and physical health disorders. We assessed genetic variants in the CADM2 locus for association with phenotypes in the UK Biobank, IMPROVE, PROCARDIS and SCARFSHEEP studies, before performing meta-analyses. A wide range of metabolic phenotypes were meta-analysed. Psychological phenotypes analysed in UK Biobank only were major depressive disorder, generalised anxiety disorder, bipolar disorder, neuroticism, mood instability and risk-taking behaviour. In UK Biobank, four, 88 and 172 genetic variants were significantly (p < 1 × 10-5) associated with neuroticism, mood instability and risk-taking respectively. In meta-analyses of 4 cohorts, we identified 362, 63 and 11 genetic variants significantly (p < 1 × 10-5) associated with BMI, SBP and CRP respectively. Genetic effects on BMI, CRP and risk-taking were all positively correlated, and were consistently inversely correlated with genetic effects on SBP, mood instability and neuroticism. Conditional analyses suggested an overlap in the signals for physical and psychological traits. Many significant variants had genotype-specific effects on CADM2 expression levels in adult brain and adipose tissues. CADM2 variants influence a wide range of both psychological and metabolic traits, suggesting common biological mechanisms across phenotypes via regulation of CADM2 expression levels in adipose tissue. Functional studies of CADM2 are required to fully understand mechanisms connecting mental and physical health conditions.

Resistant Hypertension: Detection, Evaluation, and Management: A Scientific Statement From the American Heart Association

Resistant hypertension (RH) is defined as above-goal elevated blood pressure (BP) in a patient despite the concurrent use of 3 antihypertensive drug classes, commonly including a long-acting calcium channel blocker, a blocker of the renin-angiotensin system (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker), and a diuretic. The antihypertensive drugs should be administered at maximum or maximally tolerated daily doses. RH also includes patients whose BP achieves target values on ≥4 antihypertensive medications. The diagnosis of RH requires assurance of antihypertensive medication adherence and exclusion of the "white-coat effect" (office BP above goal but out-of-office BP at or below target). The importance of RH is underscored by the associated risk of adverse outcomes compared with non-RH. This article is an updated American Heart Association scientific statement on the detection, evaluation, and management of RH. Once antihypertensive medication adherence is confirmed and out-of-office BP recordings exclude a white-coat effect, evaluation includes identification of contributing lifestyle issues, detection of drugs interfering with antihypertensive medication effectiveness, screening for secondary hypertension, and assessment of target organ damage. Management of RH includes maximization of lifestyle interventions, use of long-acting thiazide-like diuretics (chlorthalidone or indapamide), addition of a mineralocorticoid receptor antagonist (spironolactone or eplerenone), and, if BP remains elevated, stepwise addition of antihypertensive drugs with complementary mechanisms of action to lower BP. If BP remains uncontrolled, referral to a hypertension specialist is advised.

Causal Effects of Genetically Predicted Cardiovascular Risk Factors on Chronic Kidney Disease: A Two-Sample Mendelian Randomization Study

Observational studies have demonstrated that cardiovascular risk factors are associated with chronic kidney disease (CKD). However, these observational associations are potentially influenced by the residual confounding, including some unmeasured lifestyle factors and interaction risk factors. Two-sample mendelian randomization analysis was conducted in this study to evaluate whether genetically predicted cardiovascular risk factors have a causal effect on the risk of CKD. We selected genetic variants associated with cardiovascular risk factors and extracted the corresponding effect sizes from the largest GWAS summary-level dataset of CKD. Cardiovascular risk factors contain high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, total cholesterol (TC), triglyceride (TG), glycated hemoglobin (HbA1c), fasting glucose, systolic blood pressure (SBP) and diastolic blood pressure (DBP). A Bonferroni corrected threshold of P = 0.006 was considered as significant, and 0.006 < P < 0.05 was considered suggestive of evidence for a potential association. Genetically predicted DBP was significantly associated with CKD [odds ratio (OR) was 1.35 (95% confidence interval (CI) (1.10, 1.65); P = 0.004)]. There was suggestive evidence for potential associations between genetically predicted higher HDL cholesterol [OR: 0.88, 95%CI (0.80, 0.98), P = 0.025] and lower adds of CKD, and between higher SBP [OR: 1.36, 95%CI (1.07, 1.73), P = 0.013] and higher adds of CKD. However, genetically predicted LDL cholesterol, TC, TG, HbA1c, and fasting glucose did not show any causal association with CKD.

Associations of the adrenomedullin gene polymorphism with prehypertension and hypertension in Lithuanian children and adolescents: a cross-sectional study

The aim of this study was to evaluate the association of ADM genetic variant and HBP among Lithuanian adolescents aged 12-15 years. This is a cross-sectional study of a randomly selected sample of 675 12-15-years-old schoolchildren who were surveyed during November 2010 to April 2012 in the baseline survey. Single-nucleotide polymorphism (SNP) of ADM gene (rs7129220) was evaluated using real-time PCR. Logistic regression analyses were used to test the associations of ADM (rs7129220) polymorphism with HBP under four inheritance models based on the Akaike Information Criterion (AIC) and to calculate the odds ratios. In the multivariate analysis, boys carrying ADM AG genotype (vs. carriers of ADM GG genotype), ADM AG + AA genotype (vs. carriers of ADM GG genotype) and ADM AG genotype (vs. carriers of ADM GG + AA genotype) had higher odds of having hypertension in codominant, dominant, and overdominant inheritance models. Girls with ADM AG + AA had increased odds of prehypertension compared to girls with the ADM GG genotype carriers in dominant inheritance model. Significant associations were observed in additive models separately for boys (hypertension) and girls (prehypertension). Our results indicate that ADM gene polymorphism was significantly associated with higher odds of HBP in Lithuanian adolescents aged 12-15 years.