Endothelial nitric oxide synthase polymorphism and prognosis in systolic heart failure patients

Dietary nitrate and population health: a narrative review of the translational potential of existing laboratory studies

BACKGROUND

Dietary inorganic nitrate (NO3-) is a polyatomic ion, which is present in large quantities in green leafy vegetables and beetroot, and has attracted considerable attention in recent years as a potential health-promoting dietary compound. Numerous small, well-controlled laboratory studies have reported beneficial health effects of inorganic NO3- consumption on blood pressure, endothelial function, cerebrovascular blood flow, cognitive function, and exercise performance. Translating the findings from small laboratory studies into 'real-world' applications requires careful consideration.

MAIN BODY

This article provides a brief overview of the existing empirical evidence basis for the purported health-promoting effects of dietary NO3- consumption. Key areas for future research are then proposed to evaluate whether promising findings observed in small animal and human laboratory studies can effectively translate into clinically relevant improvements in population health. These proposals include: 1) conducting large-scale, longer duration trials with hard clinical endpoints (e.g. cardiovascular disease incidence); 2) exploring the feasibility and acceptability of different strategies to facilitate a prolonged increase in dietary NO3- intake; 3) exploitation of existing cohort studies to explore associations between NO3- intake and health outcomes, a research approach allowing larger samples sizes and longer duration follow up than is feasible in randomised controlled trials; 4) identifying factors which might account for individual differences in the response to inorganic NO3- (e.g. sex, genetics, habitual diet) and could assist with targeted/personalised nutritional interventions; 5) exploring the influence of oral health and medication on the therapeutic potential of NO3- supplementation; and 6) examining potential risk of adverse events with long term high- NO3- diets.

CONCLUSION

The salutary effects of dietary NO3- are well established in small, well-controlled laboratory studies. Much less is known about the feasibility and efficacy of long-term dietary NO3- enrichment for promoting health, and the factors which might explain the variable responsiveness to dietary NO3- supplementation between individuals. Future research focussing on the translation of laboratory data will provide valuable insight into the potential applications of dietary NO3- supplementation to improve population health.

Metabolic Biomarkers in Heart Failure

Metabolomics is the study of small, organic molecules within biochemical pathways. With advancement of technology, nuclear magnetic resonance, gas chromatography, and mass spectrometry have allowed for the discovery and analysis of large databases of metabolites implicated in heart failure. Metabolomics also explores the patient and environment interactions and unlocks the link between environmental exposures and the development of cardiovascular disease. Although a relatively new field, metabolomics is poised to become a clinically impactful field that develops novel biomarkers and explores new therapeutic interventions in heart failure.

The association between an endothelial nitric oxide synthase gene polymorphism and coronary heart disease in young people and the underlying mechanism

With the development of molecular biological technology, the association between genes and diseases has drawn increasing attention of researchers; the endothelial nitric oxide synthase (eNOS) gene has been reported to be a candidate gene for cardiovascular disease (CHD). The present study aimed to investigate the association between a polymorphism of eNOS and the risk of CHD in young people (≤40 years old), in addition to the underlying mechanism. A total of 234 cases of CHD in young individuals were collected as the CHD group and 228 cases of healthy individuals as the control group. Peripheral blood was collected and the genotype of the eNOS G894T polymorphism was identified by polymerase chain reaction-restriction fragment length polymorphism, the gene frequency was calculated and the distributions of genotype and allele frequency between the two groups were compared. Bioinformatics tools were employed to analyze the differences in the local protein structures of the eNOS G894T polymorphism and the biological mechanism was preliminary discussed. The results demonstrated that there were significant differences in the distribution of genotype frequency and allele frequency of the eNOS G894T gene polymorphism between the CHD group and control group (P<0.05). The risk of CHD in GT and TT genotypes were higher compared with the GG genotype (P<0.05). The G894T polymorphism led to Glu298Asp mutation of encoded protein, which is within the active site of eNOS, and partial structures of the protein were converted from random coil to α‑helix. In conclusion, the eNOS G894T gene polymorphism was associated with the occurrence and development of CHD in young people. The potential mechanism is that the G894T polymorphism leads to altered protein structure, which affects the function of eNOS in generating nitric oxide and cardiovascular diastole. The results of the present study suggested a potential target gene for the prevention and treatment of CHD in young people (≤40 years old).

Basigin rs8259 Polymorphism Confers Decreased Risk of Chronic Heart Failure in a Chinese Population

Left ventricular remodeling is an essential risk factor contributing to the pathogenesis of chronic heart failure (CHF). Basigin (BSG) promotes cardiovascular inflammation and myocardial remodeling processes by induction of extracellular matrix metalloproteinases and inflammatory cytokines. BSG rs8259 polymorphism was associated with BSG expression and risk of acute coronary syndrome. Therefore, we investigated whether rs8259 polymorphism contributes to risk and prognosis of CHF in Chinese patients. In total 922 adult patients with CHF and 1107 matched healthy controls were enrolled. BSG rs8259 polymorphism was genotyped using PCR-restriction fragment length polymorphism. Whole blood BSG mRNA expression data from Genotype-Tissue Expression project was accessed. Evaluation of follow-up data was performed in only 15.2% (140) of the patients with CHF. BSG rs8259 TT genotype was associated with a decreased risk of CHF (OR = 0.83, 95% CI = 0.72–0.96, p = 0.010), especially in patients with hypertension (OR = 0.80, 95% CI = 0.68–0.95, p = 0.011) and coronary heart disease (OR = 0.81, 95% CI = 0.69–0.96, p = 0.013) after adjustment for multiple cardiovascular risk factors. Rs8259 T allele was associated with decreased BSG mRNA in whole blood from 338 healthy normal donors (p = 1.31 × 10⁻⁶). However, rs8259 polymorphism failed to exhibit an association with cardiovascular mortality (p = 0.283). BSG rs8259 polymorphism may contribute to decreased risk of CHF in a Chinese Han population.

Pro-atherogenic mediators and subclinical atherogenesis are related to epicardial adipose tissue thickness in patients with cardiovascular risk

Objective

To evaluate the relationship between pro-atherogenic biomarkers and epicardial adipose tissue (EAT) thickness in patients with cardiovascular risk factors.

Methods

Plasma nitric oxide (NO), soluble intercellular adhesion molecule-1 and malondialdehyde (MDA) levels, EAT thickness, flow-mediated dilation (FMD) and carotid intima media thickness (CIMT) were determined in patients aged >18 years who were referred for echocardiography for heart ischemia or non-ischemic diseases. Cardiovascular risk factors (Framingham score [FS] ≥ 20) were weighted.

Results

Hypertension, dyslipidaemia and type 2 diabetes mellitus were prevalent (≥55% of 40 patients). Patients with FS ≥ 20 (n = 21) showed significantly higher EAT and CIMT values. Globally, MDA, CIMT, age, waist circumference, high-density lipoprotein cholesterol (HDL-C) and FS were associated with EAT thickness. EAT was significantly associated with NO in patients with FS ≥ 20. Significant differences in EAT thickness were found between patients stratified by NO value, FMD, age, smoking status, dyslipidaemia, type 2 diabetes mellitus and FS. An EAT-associated atherogenic risk (CIMT ≥ 1 mm) model was statistically significant when MDA and type 2 diabetes mellitus were included.

Conclusion

EAT thickness was associated with MDA, CIMT, age, waist circumference, HDL-C and FS globally, but with NO only in patients with FS≥20. EAT may be used to identify vascular damage stage, possibly influenced by MDA and type 2 diabetes mellitus.

Elevated Inducible Nitric Oxide Levels and Decreased Hydrogen Sulfide Levels Can Predict the Risk of Coronary Artery Ectasia in Kawasaki Disease

Kawasaki disease (KD) is a vasculitis disease in children that is associated with coronary artery ectasia (CAE). We investigated whether inducible nitric oxide synthase (i-NOS) and hydrogen sulfide (H2S) could be used to predict CAE secondary to KD. We enrolled 65 children with KD (35 cases with CAE and 30 cases without CAE), 33 healthy children, and 32 children with fever but without vasculitis disease (febrile group). We measured plasma nitric oxide (NO), total nitric oxide synthase (Total-NOS), i-NOS, constructive nitric oxide synthase (c-NOS) levels, and H2S content in all patients. Plasma NO, Total-NOS, i-NOS, and H2S were higher in KD children than in healthy and febrile children (P < 0.05). The i-NOS level was higher in KD children with CAE compared to those without CAE, while the H2S was lower (both P < 0.05). Using a combination of i-NOS (higher than 10 U/mL) and H2S (lower than 3.31 μmol/L) to predict CAE had 80 % sensitivity and 81 % specificity (P < 0.05). Elevated plasma i-NOS and decreased plasma H2S levels in the acute phase of KD have good predictive value for CAE and may be used to guide appropriate clinical treatment and prevent future cardiovascular complications.