Interactions of Genes and Sodium Intake on the Development of Hypertension: A Cohort-Based Case-Control Study

Emerging Perspectives on the Set of Conditions That Lead to the Emergence of Metabolic Syndrome

Metabolic syndrome, as a medical condition, presents multifactorial complexity that is characterized by the resulting damage from genetic, environmental, and lifestyle factors (presence or absence of physical activity, food choices). Thus, metabolic syndrome qualifies unequivocally as a medical condition in which there are, simultaneously, several independent metabolic risk factors, namely, abdominal obesity, high triglyceride level, low HDL cholesterol level, arterial hypertension, and high glycemic level. Although age, sex, socio-economic status, and the precise definition of metabolic syndrome all influence the prevalence and risk of developing the condition, clinical and epidemiological studies clearly show that central obesity, as measured by an increased abdominal circumference, is the main risk factor. Thus, due to the growing global incidence of obesity, there has been an increase in the incidence of metabolic syndrome. Starting with obesity, all other metabolic risk factors are influenced: for example, as a result of insulin resistance with hyperglycemia, diabetes is linked to an increased risk of cardiovascular disease due to increased abdominal circumference. Through this review, we aimed to highlight the latest research studies and dietary nutritional interventions useful in the prevention of this disease but also implementation strategies for primary prevention among the healthy population.

G Protein Subunit Beta 3 (GNB3) Variant Is Associated with Biochemical Changes in Brazilian Patients with Hypertension

BACKGROUND

Central Illustration : G Protein Subunit Beta 3 (GNB3) Variant Is Associated with Biochemical Changes in Brazilian Patients with Hypertension.

BACKGROUND

Genes and their variants associated with environmental factors contribute to the development of the hypertensive phenotype. The G protein beta 3 subunit gene (GNB3) is involved in the intracellular signaling process, and its variants have been related to susceptibility to arterial hypertension.

OBJECTIVE

To determine the association of the GNB3 variant (rs5443:C>T) with arterial hypertension, biochemical parameters, age, and obesity in hypertensive and normotensive individuals from Ouro Preto, Minas Gerais, Brazil.

METHOD

The identification of variants was performed by real-time PCR, using the TaqMan® system, in 310 samples (155 hypertensive and 155 normotensive). Biochemical analyses (renal function, lipid profile and glycemia) were performed from the serum using UV/Vis spectrophotometry and ion-selective electrode. A multiple logistic regression model was used to identify factors associated with arterial hypertension. The analysis of continuous variables with normal distribution was performed using the unpaired Student's t test; non-normal data were analyzed using Mann-Whitney. P < 0.05 was considered significant.

RESULTS

The rs5443:C>T variant was not associated with arterial hypertension in the evaluated population (p = 0.88). Regarding biochemical measures, the T allele was associated with high levels of triglycerides, glucose and uric acid in hypertensive individuals (p < 0.05).

CONCLUSION

These results show the importance of genetic diagnosis to prevent the causes and consequences of diseases and imply that the GNB3 rs5443:C>T variant may be associated with changes in the biochemical profile in hypertensive individuals.

Meta-analysis of the genetic association between maternal GNB3 C825T polymorphism and risk of pre-eclampsia

BACKGROUND

The relationship between the C825T polymorphism of GNB3 (encoding G-protein β3 subunit) and pre-eclampsia risk is unclear.

OBJECTIVE

To systematically explore the association between GNB3 C825T and pre-eclampsia.

SEARCH STRATEGY

PubMed, EMBASE, Google Scholar, and Chinese National Knowledge Infrastructure (CNKI) databases were searched to September 1, 2020, using keywords including "GNB3 C825T" and "pre-eclampsia".

SELECTION CRITERIA

Case-control and cohort studies investigating the relationship between GNB3 C825T polymorphism and pre-eclampsia were included.

DATA COLLECTION AND ANALYSIS

Two reviewers collected the data independently and calculate odds ratios (ORs) with 95% confidence intervals (CIs).

MAIN RESULTS

The meta-analysis involved eight studies from seven publications, including 2071 cases and 3419 controls. Overall analysis showed that GNB3 C825T was associated with increased pre-eclampsia risk in the recessive model (OR, 1.21; 95% CI, 1.01-1.44; P = 0.04). Subgroup analysis stratified by Hardy-Weinberg equilibrium revealed a relationship between GNB3 C825T and increased risk of pre-eclampsia in the allelic (OR, 1.66; 95% CI, 1.34-2.05; P < 0.001), homozygous (OR, 2.12, 95% CI, 1.04-4.32; P  = 0.04), dominant (OR, 1.91; 95% CI, 1.18-3.11; P = 0.009), and recessive (OR, 1.70; 95% CI, 1.03-2.81; P = 0.04) models.

CONCLUSIONS

Maternal GNB3 C825T polymorphism seems to be a risk factor for pre-eclampsia.

Association of the interaction between the rs9619311 and rs402007 polymorphisms and smoking with essential hypertension in Chinese Han population

BACKGROUND

To assess the association of the interaction between the rs9619311 and rs402007 polymorphisms and smoking with essential hypertension (EH) in a Chinese Han population.

METHOD

Peripheral blood samples were extracted from 422 EH patients and 280 normotensive (NT) patients in a Chinese Han population. A whole blood genomic DNA extraction kit was used to extract genomic DNA from the blood samples. Polymerase chain reaction restriction fragment length polymorphism was used to detect the rs402007 polymorphism of a disintegrin and metalloproteinase with thrombospondin type motifs 1 gene and the rs9619311 polymorphism of the tissue inhibitor of metalloproteinase-3 gene. The distributions of the genotypes and alleles between the 2 study groups (EH and NT) were compared. The main risk factors for EH were determined by using logistic regression analysis. The effects of gene-gene and gene-smoking interactions on EH were analyzed using multifactor dimensional reduction.

RESULTS

The frequencies of the rs402007 GC + CC genotype and the C allele were significantly different between the EH and NT groups (0.68 vs 0.57, χ = 8.99, P = .003, odds ratio [OR] = 1.19; 0.45 vs 0.32, χ = 22.16, P < .001, OR = 1.38). The frequencies of the rs9619311 TC + CC genotype and the C allele were also significantly different between the 2 groups (0.33 vs 0.25, χ = 4.51, P = .04, OR = 1.44; 0.18 vs 0.13, χ = 7.03, P = .01, OR = 1.50). Logistic regression analysis suggests that the rs402007 and rs9619311 polymorphisms are independent risk factors for EH (OR = 2.37, 1.86; P < .001, respectively). The multifactor dimensionality redundant analysis results showed that the interaction among rs402007, rs9619311, and smoking was statistically significant (P = .001).

CONCLUSIONS

A disintegrin and metalloproteinase with thrombospondin type motifs 1 rs402007 and tissue inhibitor of metalloproteinase-3 rs9619311 polymorphisms are associated with EH in a Chinese Han population, and there was a positive interaction among rs402007, rs9619311, and smoking.

Alpha2B-Adrenergic Receptor Overexpression in the Brain Potentiate Air Pollution-induced Behavior and Blood Pressure Changes

Fine ambient particulate matter (PM2.5) is able to induce sympathetic activation and inflammation in the brain. However, direct evidence demonstrating an essential role of sympathetic activation in PM2.5-associated disease progression is lacking. We assess the contribution of α2B-adrenergic receptor (Adra2b) in air pollution-associated hypertension and behavioral changes in this study. Wild-type mice and Adra2b-transgenic mice overexpressing Adra2b in the brain (Adra2bTg) were exposed to concentrated PM2.5 or filtered air for 3 months via a versatile aerosol concentrator exposure system. Mice were fed with a high salt diet (4.0% NaCl) for 1 week at week 11 of exposure to induce blood pressure elevation. Intra-arterial blood pressure was monitored by radio-telemetry and behavior changes were assessed by open field, light-dark, and prepulse inhibition tests. PM2.5 exposure increased Adra2b in the brain of wild-type mice. Adra2b overexpression enhanced the anxiety-like behavior and high salt diet-induced blood pressure elevation in response to air pollution but not filtered air exposure. Adra2b overexpression induced upregulation of inflammatory genes such as TLR2, TLR4, and IL-6 in the brain exposed to PM2.5. In addition, there were increased frequencies of activated effector T cells and increased expression of oxidative stress-related genes, such as SOD1, NQO1, Nrf2, and Gclm in Adra2bTg mice compared with wild-type mice. Our results provide new evidence of distinct behavioral changes consistent with anxiety and blood pressure elevation in response to high salt intake and air pollution exposure, highlighting the importance of centrally expressed Adra2b in the vulnerability to air pollution exposure.

Gene and environmental interactions according to the components of lifestyle modifications in hypertension guidelines

Risk factors for hypertension consist of lifestyle and genetic factors. Family history and twin studies have yielded heritability estimates of BP in the range of 34–67%. The most recent paper of BP GWAS has explained about 20% of the population variation of BP. An overestimation of heritability may have occurred in twin studies due to violations of shared environment assumptions, poor phenotyping practices in control cohorts, failure to account for epistasis, gene-gene and gene-environment interactions, and other non-genetic sources of phenotype modulation that are suspected to lead to underestimations of heritability in GWAS. The recommendations of hypertension guidelines in major countries consist of the following elements: weight reduction, a healthy diet, dietary sodium reduction, increasing physical activity, quitting smoking, and moderate alcohol consumption. The hypertension guidelines are mostly the same for each country or region, beyond race and culture. In this review, we summarize gene-environmental interactions associated with hypertension by describing lifestyle modifications according to the hypertension guidelines. In the era of precision medicine, clinicians who are responsible for hypertension management should consider the gene-environment interactions along with the appropriate lifestyle components toward the prevention and treatment of hypertension. We briefly reviewed the interaction of genetic and environmental factors along the constituent elements of hypertension guidelines, but a sufficient amount of evidence has not yet accumulated, and the results of genetic factors often differed in each study.