Elevated blood pressure: Our family’s fault? The genetics of essential hypertension

Utilization obstacles to hypertension services provided at comprehensive health centers: a content analysis study

INTRODUCTION

Hypertensive patients' failure to refer to health centers for the management of their disease is the most fundamental public health challenge in most societies. The aim of this study was to identify the utilization obstacles to hypertension services provided at comprehensive health centers (CHCs) from the perspective of patients and the staff of health centers.

METHODS

This was a qualitative study using conventional content analysis which was conducted in 2022. Participants included 15 hypertensive patients referring to CHCs and 10 staff (including personnel of CHCs and expert staff) of Ahvaz Jundishapur University of Medical Sciences, Ahvaz, southwest of Iran. Data were collected using semi-structured interviews. Interviews were analyzed using content analysis method, and coding was done manually.

RESULTS

In total, 15 codes and 8 categories were extracted from the interviews which were organized in two main themes of "individual problems" and "systemic problems". More particularly, the main theme of "individual problems" involved attitudinal obstacles, occupational obstacles, and economic obstacles. The main theme of "systemic problems" included educational obstacles, motivational obstacles, procedural obstacles, structural obstacles, and managerial obstacles.

CONCLUSION

In order to address individual problems associated with the patients' failure to refer to CHCs, we need to take appropriate measures. These include using motivational interviewing techniques and utilizing the effective activity of healthcare liaisons and volunteers in CHCs to increase patients' awareness and change their negative attitudes and misconceptions. To solve systemic problems, it is imperative that effective training courses be held for health center staff.

Quercetin inhibits angiotensin II-induced vascular smooth muscle cell proliferation and activation of JAK2/STAT3 pathway: A target based networking pharmacology approach

The rapid growth of vascular smooth muscle cells (VSMCs) represents crucial pathological changes during the development of hypertensive vascular remodeling. Although quercetin exhibits significantly therapeutic effects on antihypertension, the systematic role of quercetin and its exact mode of action in relation to the VSMCs growth and its hypertension-related networking pharmacology is not well-documented. Therefore, the effect of quercetin was investigated using networking pharmacology followed by in vitro strategies to explore its efficacy against angiotensin II (Ang II)-induced cell proliferation. Putative genes of hypertension and quercetin were collected using database mining, and their correlation was investigated. Subsequently, a network of protein-protein interactions was constructed and gene ontology (GO) analysis was performed to identify the role of important genes (including CCND1) and key signaling pathways [including cell proliferation and Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway]. We therefore further investigated the effects of quercetin in Ang II-stimulated VSMCs. This current research revealed that quercetin significantly reduced the cell confluency, cell number, and cell viability, as well as expression of proliferating cell nuclear antigen (PCNA) in Ang II-stimulated VSMCs. Mechanistic study by western blotting confirmed that quercetin treatment attenuated the activation of JAK2 and STAT3 by reducing its phosphorylation in Ang II stimulated VSMCs. Collectively, the current study revealed the inhibitory effects of quercetin on proliferation of Ang II stimulated VSMCs, by inhibiting the activation of JAK2/STAT3 signaling might be one of underlying mechanisms.

Circulating RNA Transcriptome of Pregnant Women with TSH Just Above the Trimester-Specific Reference and its Correlation with the Hypertensive Phenotype

During gestation, a woman’s body undergoes physiological changes that alter thyroid function. Pregnant women with hypothyroidism may exhibit gestational complications, including hypertension and preeclampsia. We investigated differentially expressed genes (DEGs) in circulating RNAs from pregnant women with TSH levels just above the normal range to determine the impact of a mild elevation of TSH in pregnancy. We selected three women with healthy thyroid pregnancy (HTP), three pregnant women with gestational hypothyroidism (GHT), and three nonpregnant women (NPG) to construct transcriptome libraries. We also compared our results with data from the GEO dataset and DisGeNET. We identified 1500 DEG in GHT and 1656 DEG in HTP. From GEO dataset, we recognized 453 DEGs in trimester-specific plasma RNA, 1263 DEGs in placental tissues from healthy women, 1031 DEGs from preeclamptic uteroplacental tissues and 1657 DEGs from placental tissues from severely preeclamptic women. In this scenario, 12.26% and 12.86% genes were shared between these datasets in GHT and HTP, respectively. We stablished 62 genes in GHT DEGs related to hypertensive phenotype hallmarks. In conclusion, even in women with a mild TSH increment, we were able to detect some DEGs that could be associated with a hypertensive phenotype.

Human cytomegalovirus promoting endothelial cell proliferation by targeting regulator of G-protein signaling 5 hypermethylation and downregulation

Interactions between human cytomegalovirus (HCMV) infection and environmental factors can increase susceptibility to essential hypertension (EH). Although endothelial dysfunction is the initial factor of EH, the epigenetic mechanisms through which HCMV infection induces endothelial cell dysfunction are poorly understood. Here, we evaluated whether HCMV regulated endothelial cell function and assessed the underlying mechanisms. Microarray analysis in human umbilical vein endothelial cells (HUVECs) treated with HCMV AD169 strain in the presence of hyperglycemia and hyperlipidemia revealed differential expression of genes involved in hypertension. Further analyses validated that the regulator of G-protein signaling 5 (RGS5) gene was downregulated in infected HUVECs and showed that HCMV infection promoted HUVEC proliferation, whereas hyperglycemia and hyperlipidemia inhibited HUVEC proliferation. Additionally, treatment with decitabine (DAC) and RGS5 reversed the effects of HCMV infection on HUVEC proliferation, but not triggered by hyperglycemia and hyperlipidemia. In summary, upregulation of RGS5 may be a promising treatment for preventing HCMV-induced hypertension.

Prevalência autorreferida de hipertensão e fatores associados em comunidades quilombolas do Rio Grande do Sul, Brasil

Resumo Este estudo teve como objetivo identificar a prevalência e fatores associados à hipertensão arterial (HA) em adultos quilombolas do Rio Grande do Sul (RS). Trata-se de um estudo transversal de base populacional, realizado em 2011, com 589 adultos responsáveis por domicílios e amostragem proporcional ao tamanho. O desfecho foi obtido com a pergunta: “Algum médico já lhe disse que você tem hipertensão?”. Foi empregada regressão de Poisson, com variância robusta e entrada hierarquizada das variáveis. Por fim, foram calculadas as frações atribuíveis populacionais por componente (FAPC) para fatores modificáveis associados à HA. A prevalência autorreferida de HA foi de 38,3% (IC95% 31,4%-45,1%). A análise ajustada revelou associação do desfecho com faixa etária, escolaridade, consumo excessivo de álcool, circunferência da cintura acima do adequado e presença de diabetes. A análise dos FAPC revelou que, se os indivíduos tivessem maior escolaridade, a prevalência de HA seria reduzida. Diante da elevada prevalência de HA e da extrema vulnerabilidade social dessa população, políticas públicas que garantam seu acesso a direitos fundamentais (saúde, renda e escolaridade) poderiam ter impacto importante na diminuição desse desfecho.

Unravelling the Lesser Known Facets of Angiotensin II Type 1 Receptor

PURPOSE OF REVIEW

Hypertension is an important risk factor in various pathologies. Despite enormous advancements in health sciences, the number of hypertensive individuals is increasing worldwide. The complex interplay between genetic and epigenetic factors seems to be a promising pathway to exploring the pathophysiology of hypertension.

RECENT FINDINGS

Various single gene and genome wide association studies have generated huge but non-reproducible data that highlights the role of some additional but as yet unidentified factor(s) in disease outcome. Dietary pattern and epigenetic mechanism (mainly DNA methylation) have shown a profound effect on blood pressure regulation. Angiotensin II and its receptors are known to play an important role in maintaining blood pressure; hence, a larger section of antihypertensive drugs targets the renin-angiotensin system (RAS). Angiotensin II type 1 receptor (AT1R), besides maintaining blood pressure, also has a role in cancer progression. Besides other pathways, RAS still remains the main player in blood pressure regulation. Additionally, AT1R has recently emerged as a molecule with diverse roles ranging from physiologic to cancer progression.

Association between CYP3A5 genotypes with hypertension in Chinese Han population: A case-control study

BACKGROUND

The association of CYP3A5 gene polymorphisms with hypertension in the Chinese population is unknown. We explored the association between the CYP3A5 (rs776746) gene and hypertension in the Chinese Han population.

METHODS

Using a case-control design, 340 cases and 254 controls were enrolled from the Third Affiliated Hospital of South Medical University between July and December of 2015. We used a standardized questionnaire to collect data regarding age, sex, smoking, drinking, family history of hypertension, and physical exercise. Height and weight were measured, and the body mass index (BMI) was calculated by weight/height². Blood pressure was measured three times after 5 min of rest with at least 15 s between measurements, and the mean was considered the final BP. A Clinical examination was conducted.

RESULTS

A total of 594 participants, including 340 cases and 254 controls, were entered into the analyses. The genotype frequencies of the CYP3A5 G>A polymorphism did not deviate from the Hardy-Weinberg equilibrium. The genotype frequencies among the cases were 38.8% (GA, 132 individuals), 42.9% (GG, 146 individuals), and 18.2% (AA, 62 individuals). The differences in genotype between the cases and the controls were statistically significant. The AA genotype was associated with an elevated risk of hypertension after adjusting for potential confounders in Model 2. There was no interaction between smoking and the CYP3A5 genotype, while the interaction between drinking and the CYP3A5 genotype was significant.

CONCLUSION

The CYP3A5 gene may be associated with the risk of hypertension in the Chinese Han population, and this effect may be exacerbated by drinking.

Minor variant of rs 16827043 in the iron regulator hemojuvelin gene (HJV) contributes to hypertension: The TAMRISK study

It is known that iron overload may lead to an increased risk for many diseases. According to GWAS studies, iron regulatory protein HFE gene variant H63D (rs1799945) was associated with hypertension, an observation which we were able to confirm also in our TAMRISK cohort. Thus, it is possible that abnormalities in iron homeostasis may predispose to hypertension. This prompted us to study whether there is an association between hypertension and another iron overload-associated gene, hemojuvelin (HJV), which has 2 common polymorphic sites (rs 16827043, rs7536827).The study included 336 hypertensive cases and 480 controls. All participants were 50- year-old Finnish men and women, and the data was collected from the Tampere adult population cardiovascular risk study (TAMRISK). Genotypes were determined using Competitive Allelic Specific PCR (KASP).We found that the minor variant of the HJV polymorphic site rs16827043 (G-allele) is a statistically significant factor associated with hypertension among 50 year-old individuals compared with the AA genotype carriers (OR = 1.66, 95% CI: 1.06 - 2.60, P = 0.03). The risk was even higher when overweight subjects (BMI>30) were excluded from the analyses. For the other polymorphic variant rs7536827, association with hypertension was found only among normal or slightly overweight A-allele carriers.In conclusion, HJV genetic variants were associated with essential hypertension in Finnish subjects from the TAMRISK cohort. Previous studies together with the present one indicate that individuals with possible dysregulation of iron metabolism may have higher risk for hypertension than those with normal iron homeostasis.

Parental vitamin D deficiency during pregnancy is associated with increased blood pressure in offspring via Panx1 hypermethylation

Vitamin D deficiency is one of the most common nutritional deficiencies worldwide. Maternal vitamin D deficiency is associated with increased susceptibility to hypertension in offspring, but the reasons for this remain unknown. The aim of this study was to determine if parental vitamin D deficiency leads to altered DNA methylation in offspring that may relate to hypertension. Male and female Sprague-Dawley rats were fed a standard or vitamin D-depleted diet. After 10 wk, nonsibling rats were mated. The conceived pups received standard chow. We observed an increased systolic and diastolic blood pressure in the offspring from depleted parents (F1-depl). Genome-wide methylation analyses in offspring identified hypermethylation of the promoter region of the Pannexin-1 (Panx1) gene in F1-depl rats. Panx1 encodes a hemichannel known to be involved in endothelial-dependent relaxation, and we demonstrated that in F1-depl rats the increase in blood pressure was associated with impaired endothelial relaxation of the large vessels, suggesting an underlying biological mechanism of increased blood pressure in children from parents with vitamin deficiency. Parental vitamin D deficiency is associated with epigenetic changes and increased blood pressure levels in offspring.

Personalized Therapy of Hypertension: the Past and the Future

During the past 20 years, the studies on genetics or pharmacogenomics of primary hypertension provided interesting results supporting the role of genetics, but no actionable finding ready to be translated into personalized medicine. Two types of approaches have been applied: a "hypothesis-driven" approach on the candidate genes, coding for proteins involved in the biochemical machinery underlying the regulation of BP, and an "unbiased hypothesis-free" approach with GWAS, based on the randomness principles of frequentist statistics. During the past 10-15 years, the application of the latter has overtaken the application of the former leading to an enlargement of the number of previously unknown candidate loci or genes but without any actionable result for the therapy of hypertension. In the present review, we summarize the results of our hypothesis-driven approach based on studies carried out in rats with genetic hypertension and in humans with essential hypertension at the pre-hypertensive and early hypertensive stages. These studies led to the identification of mutant adducin and endogenous ouabain as candidate genetic-molecular mechanisms in both species. Rostafuroxin has been developed for its ability to selectively correct Na(+) pump abnormalities sustained by the two abovementioned mechanisms and to selectively reduce BP in rats and in humans carrying the gene variants underlying the mutant adducin and endogenous ouabain (EO) effects. A clinical trial is ongoing to substantiate these findings. Future studies should apply both the candidate gene and GWAS approaches to fully exploit the potential of genetics in optimizing the personalized therapy.

Functional Inducible Nitric Oxide Synthase Gene Variants Associate With Hypertension: A Case-Control Study in a Finnish Population-The TAMRISK Study

Increased inducible nitric oxide synthase (iNOS) activity and expression has been associated with hypertension, but less is known whether the 2 known functional polymorphic sites in the iNOS gene (g.-1026 C/A (rs2779249), g.2087 G/A (rs2297518)) affect susceptibility to hypertension. The objective of this study was to investigate the association between the genetic variants of iNOS and diagnosed hypertension in a Finnish cohort.This study included 320 hypertensive cases and 439 healthy controls. All participants were 50-year-old men and women and the data were collected from the Tampere adult population cardiovascular risk study (TAMRISK). DNA was extracted from buccal swabs and iNOS single nucleotide polymorphisms (SNPs) were analyzed using KASP genotyping PCR. Data analysis was done by logistic regression.At the age of 50 years, the SNP rs2779249 (C/A) associated significantly with hypertension (P = 0.009); specifically, subjects carrying the A-allele had higher risk of hypertension compared to those carrying the CC genotype (OR = 1.47; CI = 1.08-2.01; P = 0.015). In addition, a 15-year follow-up period (35, 40, and 45 years) of the same individuals showed that carriers of the A-allele had more often hypertension in all of the studied age-groups. The highest risk for developing hypertension was obtained among 35-year-old subjects (odds ratio [OR] 3.83; confidence interval [CI] = 1.20-12.27; P = 0.024). Those carrying variant A had also significantly higher readings of both systolic (P = 0.047) and diastolic (P = 0.048) blood pressure during the follow-up. No significant associations between rs2297518 (G/A) variants alone and hypertension were found. However, haplotype analysis of rs2779249 and rs2297518 revealed that individuals having haplotype H3 which combines both A alleles (CA-GA, 19.7% of individuals) was more commonly found in the hypertensive group than in the normotensive group (OR = 2.01; CI = 1.29-3.12; P = 0.002).In conclusion, there was a significant association between iNOS genetic variant (rs2779249) and hypertension in the genetically homogenous Finnish population. Those who carried the rare A-allele of the gene had higher risk for hypertension already at the age of 35 years.

Vitamin D deficiency and essential hypertension

Essential hypertension (EH) results when the balance between vasoconstriction and vasodilation is shifted in favor of vasoconstriction. This balance is controlled by the interaction of genetic and epigenetic factors. When there is an unstable balance, vitamin D deficiency as an epigenetic factor triggers a shift to the side of vasoconstriction. In this article, we critically analyze clinical findings on the effect of vitamin D on blood pressure, combined with progress in molecular mechanisms. We find that vitamin D repletion exerts a clinically significant antihypertensive effect in vitamin D-deficient EH patients. Of note, a few trials reported no antihypertensive effect from vitamin D due to suboptimal study design. Short-term vitamin D supplementation has no effect on blood pressure in normotensive subjects. This could explain the mixed results and may provide a theoretical basis for future trials to identify beneficial effects of vitamin D in intervention for EH.

A Single Nucleotide Polymorphism near the CYP17A1 Gene Is Associated with Left Ventricular Mass in Hypertensive Patients under Pharmacotherapy

Cytochrome P450 17A1 (CYP17A1) catalyses the formation and metabolism of steroid hormones. They are involved in blood pressure (BP) regulation and in the pathogenesis of left ventricular hypertrophy. Therefore, altered function of CYP17A1 due to genetic variants may influence BP and left ventricular mass. Notably, genome wide association studies supported the role of this enzyme in BP control. Against this background, we investigated associations between single nucleotide polymorphisms (SNPs) in or nearby the CYP17A1 gene with BP and left ventricular mass in patients with arterial hypertension and associated cardiovascular organ damage treated according to guidelines. Patients (n = 1007, mean age 58.0 ± 9.8 years, 83% men) with arterial hypertension and cardiac left ventricular ejection fraction (LVEF) ≥ 40% were enrolled in the study. Cardiac parameters of left ventricular mass, geometry and function were determined by echocardiography. The cohort comprised patients with coronary heart disease (n = 823; 81.7%) and myocardial infarction (n = 545; 54.1%) with a mean LVEF of 59.9% ± 9.3%. The mean left ventricular mass index (LVMI) was 52.1 ± 21.2 g/m2.7 and 485 (48.2%) patients had left ventricular hypertrophy. There was no significant association of any investigated SNP (rs619824, rs743572, rs1004467, rs11191548, rs17115100) with mean 24 h systolic or diastolic BP. However, carriers of the rs11191548 C allele demonstrated a 7% increase in LVMI (95% CI: 1%-12%, p = 0.017) compared to non-carriers. The CYP17A1 polymorphism rs11191548 demonstrated a significant association with LVMI in patients with arterial hypertension and preserved LVEF. Thus, CYP17A1 may contribute to cardiac hypertrophy in this clinical condition.

Polymorphisms within angiotensin II receptor type 1 gene associated with essential hypertension in Chinese Hani and Yi minorities

INTRODUCTION

Angiotensin II receptor type 1 mediates the major cardiovascular effects of angiotensin II to regulate blood pressure. Polymorphisms of angiotensin II receptor type 1 are associated with essential hypertension, but the results are inconsistent and conflicting. The aim of the present study is to assess the association between angiotensin II receptor type 1 polymorphisms and essential hypertension risk in Chinese Hani and Yi minorities.

METHODS

This study recruited 692 unrelated Chinese Hani subjects (case vs. control = 346:346) and 615 unrelated Chinese Yi subjects (case vs. control = 303:312). Twelve selected single nucleotide polymorphisms in the angiotensin II receptor type 1 gene were genotyped using a polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

Statistical analysis indicated that the GC+CC genotype of rs387967 was significantly associated with the decreased susceptibility to essential hypertension compared with GG in a Yi population (odds ratio = 0.58, 95% confidence intervals 0.41-0.83, P = 0.003). Allele C was a protective allele for essential hypertension (odds ratio = 0.78, 95% confidence intervals 0.61-0.99, P = 0.040). This association was confirmed respectively by comparing systolic blood pressure and diastolic blood pressure between different genotypes and between different alleles, which indicated that the genotype (GC+CC) had a tendency of lower systolic blood pressure and diastolic blood pressure than GG (PSBP = 3.716 × 10(-4), PDBP = 1.187 × 10(-3)); Carriers with C had lower systolic blood pressure and diastolic blood pressure (PSBP = 7.301 × 10(-3), PDBP = 9.142 × 10(-4)). Another single nucleotide polymorphism (rs2638360) was analysed in a Hani minority, then replicated in a Yi minority. The C allele showed a consistent risk trend for essential hypertension in two independent populations (Hani: odds ratio = 1.74, 95% confidence intervals 1.01-2.99, P = 0.046; Yi: odds ratio = 1.27, 95% confidence intervals 0.82-1.96, P = 0.277). Meta-analysis revealed that the C allele could significantly increase the risk of essential hypertension (odds ratio = 1.44, 95% confidence intervals 1.02-2.02, P = 0.037).

CONCLUSION

Our findings suggest that rs387967 is associated with the susceptibility to essential hypertension in a Yi population and the tendency was replicated in systolic blood pressure and diastolic blood pressure detection. Meta-analysis revealed that C allele of rs2638360 could significantly increase the risk of essential hypertension. The two single nucleotide polymorphisms maybe play a role in the pathology of essential hypertension.