Low circulating folate and vitamin B6 concentrations: risk factors for stroke, peripheral vascular disease, and coronary artery disease. European COMAC Group

Urate-lowering effect of delphinidin-3-glucoside in red kidney beans via binding to the FAD site of the XO enzyme

BACKGROUND

The incidence of hyperuricemia (HUA) is increasing globally, posing serious health risks. The discovery of natural urate-lowering agents is urgently needed.

OBJECTIVE

To discover natural urate-lowering agents and investigate their effect and action mechanisms for ameliorating HUA.

METHODS

Our study comprehensively explored the association between the intake of 13 specific legume varieties in the US population. A composition-target-metabolic (C-T-M) pathway network was constructed to identify key agents and their interactions with key proteins, which were verified by molecular dynamics simulations (MD) and surface plasmon resonance (SPR). Biochemical, in vitro, and in vivo metabolomic studies in male ICR mice were conducted to examine the effects of the key agent in red kidney beans on uric acid production and other metabolisms.

RESULTS

We found that consuming red kidney beans was robustly negatively associated with the risk of HUA. Based on the C-T-M network, delphinidin-3-glucoside (Dp-3G) was identified as the key agent in red kidney beans, focusing on its binding to xanthine oxidase (XO) enzyme. This interaction was subsequently verified by MD and SPR, revealing that Dp-3G binds to the FAD site of the XO enzyme, thereby blocking electron transfer during enzyme catalysis involving Moco, [2Fe-2S], and FAD. Dp-3G consistently reduces uric acid production under biochemical, in vitro, and in vivo conditions and reverses metabolic abnormalities related to HUA in mice, including methionine, proline, and folate.

CONCLUSIONS

This study identifies Dp-3G, a novel natural agent enriched in red kidney beans, as capable of occupying the FAD site of the XO enzyme, thereby interfering with uric acid synthesis, and suggesting its potential for preventing and treating HUA.

Association between serum pyridoxal 5'-phosphate levels and all-cause, cardiovascular mortality, and cardiovascular disease in adults: a population-based cohort study

BACKGROUND

The association between pyridoxal 5'-phosphate (PLP) and cardiovascular disease (CVD) remains a topic of discussion.

OBJECTIVES

This study aimed to explore the relationship between serum PLP levels and the incidence of all-cause mortality, cardiovascular mortality, and the risk of CVD among the US population.

DESIGN

A population-based cohort study.

METHODS

This study analyzed data from the National Health and Nutrition Examination Survey. Adjusted hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) were calculated using weighted Cox proportional hazards regression models to assess the risk associated with all-cause and cardiovascular mortality. Weighted binary logistic regression was utilized to assess the relationship between serum PLP levels and the risk of CVD. Nonlinear associations were evaluated using multivariable-adjusted restricted cubic splines.

RESULTS

There were 2546 cases of all-cause mortality and 867 cases of cardiovascular mortality over a mean follow-up of 11.36 years. In the fully adjusted model, the adjusted HRs with 95% CIs for all-cause mortality associated with increases in serum PLP levels corresponding to the interquartile ranges were 0.83 (0.74-0.93), 0.71 (0.63-0.80), and 0.64 (0.56-0.74), respectively. Similarly, cardiovascular mortality decreased by 0.78 (0.62-0.97), 0.63 (0.49-0.81), and 0.62 (0.50-0.77) with each quartile increase in serum PLP levels. Higher serum PLP levels confer protection against CVD risk (odds ratio: 0.87, 95% CI: 0.79-0.96). Serum PLP levels showed nonlinear relationships with risk of all-cause mortality, cardiovascular mortality, and CVD.

CONCLUSION

The results of this study provide evidence that serum PLP serves as a protective factor against all-cause mortality, cardiovascular mortality, and CVD in US adults, with dose-response relationships.

The Efficacy of Vitamins in the Prevention and Treatment of Cardiovascular Disease

Vitamins are known to affect the regulation of several biochemical and metabolic pathways that influence cellular function. Adequate amounts of both hydrophilic and lipophilic vitamins are required for maintaining normal cardiac and vascular function, but their deficiencies can contribute to cardiovascular abnormalities. In this regard, a deficiency in the lipophilic vitamins, such as vitamins A, D, and E, as well as in the hydrophilic vitamins, such as vitamin C and B, has been associated with suboptimal cardiovascular function, whereas additional intakes have been suggested to reduce the risk of atherosclerosis, hypertension, ischemic heart disease, arrhythmias, and heart failure. Here, we have attempted to describe the association between low vitamin status and cardiovascular disease, and to offer a discussion on the efficacy of vitamins. While there are inconsistencies in the impact of a deficiency in vitamins on the development of cardiovascular disease and the benefits associated with supplementation, this review proposes that specific vitamins may contribute to the prevention of cardiovascular disease in individuals at risk rather than serve as an adjunct therapy.

From Gut to Brain: Uncovering Potential Serum Biomarkers Connecting Inflammatory Bowel Diseases to Neurodegenerative Diseases

Inflammatory bowel diseases (IBDs) are characterized by chronic gastrointestinal inflammation due to abnormal immune responses to gut microflora. The gut-brain axis is disrupted in IBDs, leading to neurobiological imbalances and affective symptoms. Systemic inflammation in IBDs affects the brain's inflammatory response system, hormonal axis, and blood-brain barrier integrity, influencing the gut microbiota. This review aims to explore the association between dysregulations in the gut-brain axis, serum biomarkers, and the development of cognitive disorders. Studies suggest a potential association between IBDs and the development of neurodegeneration. The mechanisms include systemic inflammation, nutritional deficiency, GBA dysfunction, and the effect of genetics and comorbidities. The objective is to identify potential correlations and propose future research directions to understand the impact of altered microbiomes and intestinal barrier functions on neurodegeneration. Serum levels of vitamins, inflammatory and neuronal damage biomarkers, and neuronal growth factors have been investigated for their potential to predict the development of neurodegenerative diseases, but current results are inconclusive and require more studies.

Navigating the B vitamins: Dietary diversity, microbial synthesis, and human health

B vitamins are intricately involved in various physiological processes vital for health. Their significance is complicated by the heterogeneous landscape of B vitamin distribution in diets and the contributions of the gut microbiota. Here, we delve into the impact of these factors on B vitamins and introduce strategies, with a focus on microbiota-based therapeutic options, to enhance their availability for improved well-being. Additionally, we provide an ecological and evolutionary perspective on the importance of B vitamins to human-microbiota interactions. In the dynamic realms of nutrition and microbiome science, these essential micronutrients continue to play a fundamental role in our understanding of disease development.

The Multitarget Action of Vitamins in the Ischemic Stroke

A stroke, also known as a cerebral hemorrhage, occurs when there is an interruption in the blood supply to a part of the brain, resulting in damage to brain cells. This issue is one of the leading causes of death in developed countries, currently killing about 5 million people annually. Individuals who survive ischemic stroke often face serious vision problems, paralysis, dementia, and other sequelae. The numerous efforts to prevent and/or treat stroke sequelae seem insufficient, which is concerning given the increasing global elderly population and the well-known association between aging and stroke risk. In this review, we aim to present and discuss the importance of vitamins in stroke prevention and/or incidence. Vitamins from diet or dietary supplements influence the body at various levels; they are a relevant factor but are reported only in isolated articles. This review reports and updates the multitarget role of vitamins involved in reducing stroke risk.

Rapid Diagnostic Platform for Personalized Vitamin B6 Detection in Erythrocytes via PLP Cofactor Mimics

Personalized assessment of vitamin levels in point-of-care (POC) devices is urgently needed to advance the recognition of diseases associated with malnutrition and unbalanced diets. We here introduce a diagnostic platform, which showcases an easy and rapid readout of vitamin B6 (pyridoxal phosphate, PLP) levels in erythrocytes as a first step toward a home-use POC. The technology is based on fluorescent probes, which bind to PLP-dependent enzymes (PLP-DEs) and thereby indirectly report their occupancy with endogenous B6. For example, low vitamin levels result in high probe binding, yielding a strong signal and vice versa. Antibodies against signature human PLP-DEs were immobilized on microarrays to capture probe labeled enzymes for fluorescent detection. Calibrating the system with defined B6 levels revealed a concentration-depended readout as well as sufficient sensitivity for its detection in erythrocytes. To account for individual differences in protein expression, a second antibody was used to normalize protein abundance. This sandwiched assay correctly reported relative B6 levels in human erythrocyte samples, as confirmed by classical laboratory diagnostics. In principle, the platform layout can be easily expanded to other crucial vitamins beyond B6 via an analogous probe strategy.

Characteristics of peripheral blood cells are independently related to major adverse cardiovascular events after carotid endarterectomy

Background and aims

Patients who underwent carotid endarterectomy (CEA) still have a residual risk of 13% of developing a major adverse cardiovascular event (MACE) within 3 years. Inflammatory processes leading up to MACE are not fully understood. Therefore, we examined blood cell characteristics (BCCs), possibly reflecting inflammatory processes, in relation to MACE to identify BCCs that may contribute to an increased risk.

Methods

We analyzed 75 pretreatment BCCs from the Sapphire analyzer, and clinical data from the Athero-Express biobank in relation to MACE after CEA using Random Survival Forests, and a Generalized Additive Survival Model. To understand biological mechanisms, we related the identified variables to intraplaque hemorrhage (IPH).

Results

Of 783 patients, 97 (12%) developed MACE within 3 years after CEA. Red blood cell distribution width (RDW) (HR 1.23 [1.02, 1.68], p = 0.022), CV of lymphocyte size (LACV) (HR 0.78 [0.63, 0.99], p = 0.043), neutrophil complexity of the intracellular structure (NIMN) (HR 0.80 [0.64, 0.98], p = 0.033), mean neutrophil size (NAMN) (HR 0.67 [0.55, 0.83], p < 0.001), mean corpuscular volume (MCV) (HR 1.35 [1.09, 1.66], p = 0.005), eGFR (HR 0.65 [0.52, 0.80], p < 0.001); and HDL-cholesterol (HR 0.62 [0.45, 0.85], p = 0.003) were related to MACE. NAMN was related to IPH (OR 0.83 [0.71-0.98], p = 0.02).

Conclusions

This is the first study to present a higher RDW and MCV and lower LACV, NIMN and NAMN as biomarkers reflecting inflammatory processes that may contribute to an increased risk of MACE after CEA.

The relationship between serum homocysteine levels and sudden sensorineural hearing loss: a meta-analysis

OBJECTIVE

There was disagreement over the association between serum/plasma homocysteine (HCY) levels and sudden sensorineural hearing loss (SSNHL). Through the use of a meta-analysis, this study aims to determine whether there is a significant difference in serum homocysteine levels between the SSNHL group and the control group.

DESIGN

The Cochrane Library, EMBASE, and PubMed databases were all thoroughly searched. The two independent reviewers thoroughly examined the initially searched articles. The data results were calculated by standard mean difference (SMD) or odds ratios (OR). Review Manager (version 5.3) was applied to statistical data.

STUDY SAMPLE

There were 766 participants in the 6 trials with continuous outcomes that were part of the meta-analysis A. In addition, meta-analysis B, which included 961 people, contained a total of 3 studies with dichotomous results.

RESULTS

Both meta-analyses revealed the same conclusion that serum/plasma HCY levels in the SSNHL patients are higher than those in the controls (SMD 0.41, 95 % confidence interval (CI) 0.11 to 0.72, P < 0.01; OR 3.27, 95 % CI 2.16 to 4.94, P < 0.01).

CONCLUSION

This study demonstrated that the SSNHL patients' serum/plasma HCY levels were greater than those of the control group.

Erectile Dysfunction: Pharmacological Pathways with Understudied Potentials

Erectile dysfunction (ED) is a public health concern worldwide. In the past, it was perceived as a phenomenon attributed to age advancement. However, more individuals are affected every year that do not fall under that age criterion. Epidemiological research revealed that this abnormality has an association with endothelial dysfunction connected to several cardiovascular (CV) risk factors. Currently, ED is interpreted as a clinical marker for future adverse events and not only as a present health issue that negatively affects the quality of life. The management of ED involves lifestyle modifications, therapeutic optimization for comorbid conditions, and pharmacological and psychosexual therapy. Phosphodiesterase type 5 (PDE5) inhibitors are the first-line pharmacological agents to be prescribed for such a condition. Nonetheless, other pharmacological pathways and agents remain underinvestigated or were investigated at some stage. This review aimed to present to future researchers interested in this field with some pharmacological agents that showed favorable effects on a limited number of studies on human subjects or experimental models.

ALDH7A1 rs12514417 polymorphism may increase ischemic stroke risk in alcohol-exposed individuals

Background:

Epidemiological studies have identified common risk factors for cerebral stroke worldwide. Some of these factors include hypertension, diabetes, smoking, excessive drinking, and dyslipidemia. It is important to note, however, that genetic factors can also contribute to the occurrence of stroke. Here, we evaluated the association of ischemic stroke with rs12514417 polymorphism of the alcohol metabolizing gene, aldehyde dehydrogenase 7A1 (ALDH7A1) and alcohol consumption.

Methods:

Taiwan Biobank (TWB) data collected between 2008 and 2015 were available for 17,985 subjects. The odd ratios for stroke were obtained using logistic regression models.

Results:

Among eligible subjects (n = 17,829), 897 had ischemic stroke and 70 had hemorrhagic stroke. Subjects with ischemic stroke were older (mean ± SE, 58.45 ± 8.19 years vs. 48.33 ± 10.89 years, p < 0.0001) and had a higher body mass index (BMI) than the stroke-free individuals. The risk of ischemic stroke was significantly higher among subjects with the ALDH7A1 rs12514417 TG + GG genotype who also consumed alcohol at least 150 ml/week (odds ratio (OR), 1.79; 95% confidence interval (CI), 1.18–2.72). We found that rs12514417 genotype and alcohol consumption (at least 150 ml/week) showed a significant interaction (p for interaction = 0.0266). Stratification based on alcohol exposure and ALDH7A1 rs12514417 genotypes indicated that ischemic stroke risk was significantly higher among alcohol drinkers with the TG + GG genotype than in those with the TT genotype (OR, 1.64, 95% CI: 1.15–2.33).

Conclusion:

Our study suggests that the combination of ALDH7A1 rs12514417 TG + GG genotype and alcohol exposure of at least 150 ml/week may increase the risk of ischemic stroke in Taiwanese adults.

Detrimental health relationship between blood lead and cadmium and the red blood cell folate level

Increasing studies have demonstrated the association between heavy metal pollution and micronutrients, especially folate. However, the relationship between cadmium and folate remains rarely discussed. In this study, we aim to explore the potential correlation between cadmium and folate in human population and highlight the possible mechanism of cadmium impacting human health. We utilized the National Health and Nutrition Examination Survey (NHANES) 2017–2018 data with 5690 participants in this study. Multivariable linear regression models were adopted to investigate the serum lead and cadmium levels and RBC folate concentration. A significant reverse relationship was found between serum lead and cadmium and RBC folate. A negative relationship between serum lead and cadmium levels and the levels of RBC folate in the U.S. adult population was found in this study. Nevertheless, due to the general limitations of the NHANES data, as a cross-sectional study, a further prospective investigation is needed to discover the causality of lead and cadmium in folate status and to determine whether the folate supplement has a beneficial influence against heavy metal toxicities.

Effectiveness of Some Vitamins in the Prevention of Cardiovascular Disease: A Narrative Review

By virtue of their regulatory role in various metabolic and biosynthetic pathways for energy status and cellular integrity, both hydro-soluble and lipo-soluble vitamins are considered to be involved in maintaining cardiovascular function in health and disease. Deficiency of some vitamins such as vitamin A, B₆, folic acid, C, D, and E has been shown to be associated with cardiovascular abnormalities whereas supplementation with these vitamins has been claimed to reduce cardiovascular risk for hypertension, atherosclerosis, myocardial ischemia, arrhythmias, and heart failure. However, the data from several experimental and clinical studies for the pathogenesis of cardiovascular disease due to vitamin deficiency as well as therapy due to different vitamins are conflicting. In this article, we have attempted to review the existing literature on the role of different vitamins in cardiovascular disease with respect to their deficiency and supplementation in addition to examining some issues regarding their involvement in heart disease. Although both epidemiological and observational studies have shown some merit in the use of different antioxidant vitamins for the treatment of cardiovascular disorders, the results are not conclusive. Furthermore, in view of the complexities in the mechanisms of different cardiovascular disorders, no apparent involvement of any particular vitamin was seen in any specific cardiovascular disease. On the other hand, we have reviewed the evidence that deficiency of vitamin B₆ promoted KCl-induced Ca²⁺ entry and reduced ATP-induced Ca²⁺-entry in cardiomyocytes in addition to decreasing sarcolemmal (SL) ATP binding. The active metabolite of vitamin B₆, pyridoxal 5′-phosphate, attenuated arrhythmias due to myocardial infarction (MI) as well as cardiac dysfunction and defects in the sarcoplasmic reticulum (SR) Ca²⁺-transport in the ischemic-reperfused hearts. These observations indicate that both deficiency of some vitamins as well as pretreatments with different vitamins showing antioxidant activity affect cardiac function, metabolism and cation transport, and support the view that antioxidant vitamins or their metabolites may be involved in the prevention rather than the therapy of cardiovascular disease.

Folic Acid Supplementation Improves Glycemic Control for Diabetes Prevention and Management: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

Background: There is a growing interest in the considerable benefits of dietary supplementations, such as folic acid, on the glycemic profile. We aimed to investigate the effects of folic acid supplementation on glycemic control markers in adults. Methods: Randomized controlled trials examining the effects of folic acid supplementation on glycemic control markers published up to March 2021 were detected by searching online databases, including Scopus, PubMed, Embase, and ISI web of science, using a combination of related keywords. Mean change and standard deviation (SD) of the outcome measures were used to estimate the mean difference between the intervention and control groups at follow-up. Meta-regression and non-linear dose-response analysis were conducted to evaluate the association between pooled effect size and folic acid dosage (mg/day) and duration of the intervention (week). From 1814 detected studies, twenty-four studies reported fasting blood glucose (FBG), fasting insulin, hemoglobin A1C (HbA1C), and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) as an outcome measure. Results: Results revealed significant reductions in FBG (weighted mean difference (WMD): −2.17 mg/dL, 95% CI: −3.69, −0.65, p = 0.005), fasting insulin (WMD: −1.63 pmol/L, 95% CI: −2.53, −0.73, p < 0.001), and HOMA-IR (WMD: −0.40, 95% CI: −0.70, −0.09, p = 0.011) following folic acid supplementation. No significant effect was detected for HbA1C (WMD: −0.27%, 95% CI: −0.73, 0.18, p = 0.246). The dose-response analysis showed that folic acid supplementation significantly changed HOMA-IR (r = −1.30, p-nonlinearity = 0.045) in non-linear fashion. However, meta-regression analysis did not indicate a linear relationship between dose, duration, and absolute changes in FBG, HOMA-IR, and fasting insulin concentrations. Conclusions: Folic acid supplementation significantly reduces some markers of glycemic control in adults. These reductions were small, which may limit clinical applications for adults with type II diabetes. Further research is necessary to confirm our findings.

Beneficial effects of folic acid supplementation on lipid markers in adults: A GRADE-assessed systematic review and dose-response meta-analysis of data from 21,787 participants in 34 randomized controlled trials

Folic acid supplementation has received considerable attention in the literature, yet there is a large discrepancy in its effects on lipid markers in adults. Therefore, this systematic review and meta-analysis of 38 randomized controlled trials (RCTs) evaluated the effects of folic acid supplementation on triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol concentrations in a cohort of 21,787 participants. A systematic search current as of March 2021 was performed in PubMed/Medline, Scopus, Web of Science, and Embase using relevant keywords to identify eligible studies. A fix or random-effects model was used to estimate the weighted mean difference (WMD) and 95% confidence intervals (CIs). Thirty-four RCTs were included in this meta-analysis. The pooled analysis revealed that serum TG (WMD: -9.78 mg/dL; 95% CI: -15.5 to -4.00; p = 0.001, I²=0.0%, p = 0.965) and TC (WMD: -3.96 mg/dL; 95% CI: -6.71 to -1.21; p = 0.005, I²=46.9%, p = 0.001) concentrations were significantly reduced following folic acid supplementation compared to placebo. However, folic acid supplementation did not affect serum concentrations of LDL (WMD: -0.97 mg/dL; 95% CI: -6.82 to 4.89; p = 0.746, I²=60.6%, p < 0.001) or HDL cholesterol (WMD: 0.44 mg/dL; 95% CI: -0.53 to 1.41; p = 0.378, I²= 0.0%, p = 0.831). A significant dose-response relationship was observed between the dose of folic acid supplementation and serum concentrations of HDL cholesterols (r = 2.22, p = 0.047). Folic acid supplementation reduced serum concentrations of TG and TC without affecting LDL or HDL cholesterols. Future large RCTs on various populations are needed to show further beneficial effects of folic acid supplementation on lipid profile.

Homocysteine, B vitamins, and cardiovascular disease: a Mendelian randomization study

BACKGROUND

Whether a modestly elevated homocysteine level is causally associated with an increased risk of cardiovascular disease remains unestablished. We conducted a Mendelian randomization study to assess the associations of circulating total homocysteine (tHcy) and B vitamin levels with cardiovascular diseases in the general population.

METHODS

Independent single nucleotide polymorphisms associated with tHcy (n = 14), folate (n = 2), vitamin B6 (n = 1), and vitamin B12 (n = 14) at the genome-wide significance level were selected as instrumental variables. Summary-level data for 12 cardiovascular endpoints were obtained from genetic consortia, the UK Biobank study, and the FinnGen consortium.

RESULTS

Higher genetically predicted circulating tHcy levels were associated with an increased risk of stroke. For each one standard deviation (SD) increase in genetically predicted tHcy levels, the odds ratio (OR) was 1.11 (95% confidence interval (CI), 1.03, 1.21; p = 0.008) for any stroke, 1.26 (95% CI, 1.05, 1.51; p = 0.013) for subarachnoid hemorrhage, and 1.11 (95% CI, 1.03, 1.21; p = 0.011) for ischemic stroke. Higher genetically predicted folate levels were associated with decreased risk of coronary artery disease (ORSD, 0.88; 95% CI, 0.78, 1.00, p = 0.049) and any stroke (ORSD, 0.86; 95% CI, 0.76, 0.97, p = 0.012). Genetically predicted increased vitamin B6 levels were associated with a reduced risk of ischemic stroke (ORSD, 0.88; 95% CI, 0.81, 0.97, p = 0.009). None of these associations persisted after multiple testing correction. There was no association between genetically predicted vitamin B12 and cardiovascular disease.

CONCLUSIONS

This study reveals suggestive evidence that B vitamin therapy and lowering of tHcy may reduce the risk of stroke, particularly subarachnoid hemorrhage and ischemic stroke.

The role of B vitamins in stroke prevention

Elevated plasma levels of homocysteine (Hcy) are a recognized risk factor for stroke. This relationship represents one aspect of the debated `Hcy hypothesis'. Elevated Hcy may be an independent and treatable cause of atherosclerosis and thrombotic vascular diseases. Further observations indicate that proper dietary supplementation with B-vitamins decreases total plasma Hcy concentrations and may be an effective intervention for stroke prevention. Metabolic vitamin B₁₂ deficiency is a nutritional determinant of total Hcy and stroke risk. Genetic factors may link B vitamins with stroke severity due to the impact on Hcy metabolism of polymorphism in the genes coding for methylenetetrahydrofolate reductase, methionine-synthase, methionine synthase reductase, and cystathionine β-synthase. Several meta-analyses of large randomized controlled trials exist. However, they are not completely in agreement about B vitamins' role, particularly folic acid levels, vitamin B₁₂, and B₆, in lowering the homocysteine concentrations in people at high stroke risk. A very complex relationship exists between Hcy and B vitamins, and several factors appear to modify the preventive effects of B vitamins in stroke. This review highlights the regulating factors of the active role of B vitamins active in stroke prevention. Also, inputs for further large, well-designed studies, for specific, particularly sensitive subgroups are given.

Modification of vitamin B6 on the associations of blood lead levels and cardiovascular diseases in the US adults

Background

Cardiovascular disease (CVD) is a leading cause of death in the US population. Lead exposure is an important risk factor of CVDs, as is associated with elevated homocysteine level and oxidative stress. We aim to examine whether vitamin B6, which has been shown to reduce homocysteine level, can modify the relationship between blood lead and the risk of CVDs.

Methods

Cross-sectional data on ever-report CVDs (congestive heart failure, coronary heart disease, angina pectoris, heart attack and stroke), blood lead level (BLL) and vitamin B6 in the form of plasma pyridoxal 5'-phosphate were obtained from US National Health and Nutrition Examination Survey 2005–2006 for adults≥20 years old. The association between CVDs and quartiles of BLL was estimated using multivariate logistic regression models adjusted for demographics factors, lifestyle variables, stress variables, comorbidities and CVD biomarkers (C reactive protein, homocysteine, cholesterol) and was stratified by vitamin B6 deficiency level (<20 nmol/L) and median value of vitamin B6 (42.5 nmol/L).

Results

Positive associations between BLL and CVDs only appeared in the vitamin B6 deficiency group, with quartile 2 to quartile 4 of BLL showing higher risk of CVDs (OR=3.1, 95% CI 0.9 to 10.6; OR=6.5, 95% CI 1.4 to 30.8; OR=5.5, 95% CI 1.4 to 21.7) compared with quartile 1. When stratified by median value of vitamin B6, a significant association between higher CVD risk with higher BLL was only observed in subjects with low vitamin B6 (p trend=0.004).

Conclusions

Vitamin B6 could modify the association between BLL and CVDs, which suggests a potential value of vitamin B6 in influencing the effects of lead exposure on the cardiovascular system.

Red blood cell folate and severe abdominal aortic calcification: Results from the NHANES 2013-2014

BACKGROUND AND AIMS

Abdominal aortic calcification (AAC) has been introduced as a good predictor of cardiovascular disease (CVD) events, but no previous study has investigated the relationship between folate levels and AAC. The present study aims to explore the relationship between red blood cell (RBC) folate, a better indicator reflecting long-term folate intake, and severe AAC in the United States (US) middle-aged and elderly population.

METHODS AND RESULTS

Cross-sectional data were derived from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 of 2818 men and women aged 40 years or older. Multivariable logistic regression models were used to determine odds ratios (ORs) and 95% confidence intervals (CIs) for severe AAC of each RBC folate quintile category. The restricted cubic spline model was used for the dose-response analysis. A U-shaped dose-response relation between RBC folate and the odds of severe AAC was found after adjustment for multiple potential confounding factors, p for nonlinear = 0.0032. With the third quintile category of RBC folate as the reference, multivariable-adjusted ORs and 95% CIs of the lowest, second, fourth, and the highest quintile categories were 2.34 (1.37-4.00), 1.24 (0.70-2.19), 1.58 (0.92-2.70), and 2.26 (1.35-3.76), respectively.

CONCLUSIONS

Individuals with either low or high levels of RBC folate were at increased risks of severe AAC in a representative sample of US adults. While folate deficiency is widely recognized as harmful, these results highlight the need to investigate the potential adverse health outcomes of high folate level.

Sulfur-Containing Amino Acids and Lipid Metabolism

The metabolism of methionine and cysteine in the body tissues determines the concentrations of several metabolites with various biologic activities, including homocysteine, hydrogen sulfide (H2S), taurine, and glutathione. Hyperhomocysteinemia, which is correlated with lower HDL cholesterol in blood in volunteers and animal models, has been associated with an increased risk for cardiovascular diseases. In humans, the relation between methionine intake and hyperhomocysteinemia is dependent on vitamin status (vitamins B-6 and B-12 and folic acid) and on the supply of other amino acids. However, lowering homocysteinemia by itself is not sufficient for decreasing the risk of cardiovascular disease progression. Other compounds related to methionine metabolism have recently been identified as being involved in the risk of atherosclerosis and steatohepatitis. Indeed, the metabolism of sulfur amino acids has an impact on phosphatidylcholine (PC) metabolism, and anomalies in PC synthesis due to global hypomethylation have been associated with disturbances of lipid metabolism. In addition, impairment of H2S synthesis from cysteine favors atherosclerosis and steatosis in animal models. The effects of taurine on lipid metabolism appear heterogeneous depending on the populations of volunteers studied. A decrease in the concentration of intracellular glutathione, a tripeptide involved in redox homeostasis, is implicated in the etiology of cardiovascular diseases and steatosis. Last, supplementation with betaine, a compound that allows remethylation of homocysteine to methionine, decreases basal and methionine-stimulated homocysteinemia; however, it adversely increases plasma total and LDL cholesterol. The study of these metabolites may help determine the range of optimal and safe intakes of methionine and cysteine in dietary proteins and supplements. The amino acid requirement for protein synthesis in different situations and for optimal production of intracellular compounds involved in the regulation of lipid metabolism also needs to be considered for dietary attenuation of atherosclerosis and steatosis risk.

Diet Recommendations for Hospitalized Patients With Inflammatory Bowel Disease: Better Options Than Nil Per Os

Hospitalizations are a time when providers often have uncertainty about what to feed patients with inflammatory bowel disease (IBD). While there are many trials evaluating the role of diet in the management of IBD, the role of diet for the hospitalized patient is less clear. The hospitalization may serve as an opportunity to educate patients about the role of diet, try different diets, and develop dietary recommendations for after discharge. Here, we review the literature for dietary considerations during hospitalizations and acute settings, as well as upon discharge. Patients with IBD benefit from screening and nutritional support for malnutrition and nutritional deficiencies. Enteral nutrition and exclusion diets are promising as induction and maintenance therapies, but no specific recommendations during hospitalization for adult patients are available currently. There are very few reasons to enforce bowel rest or clear liquids other than bowel obstruction, uncontrolled sepsis, or need for urgent or emergent surgery; most patients - including many with penetrating or stricturing disease - benefit from feeding in whichever capacity is tolerated, with enteral and parenteral nutrition used as needed to reach nutritional goals. Future studies are needed to define how the use of different diets can influence the outcomes of patients hospitalized for IBD.

Major and Minor Risk Factors for Cardiovascular Disease in Continuous Ambulatory Peritoneal Dialysis Patients

Uremia in general and peritoneal dialysis in particular bring with them risk factors for the development of cardiovascular disease. These factors include multiple lipid abnormalities, hyperhomocysteinemia, abdominal obesity, chronic inflammation, hypoalbuminemia, oxidative stress, and AGE formation. When these are combined with conventional risk factors, one can appreciate why the incidence of cardiovascular disease is so high in peritoneal dialysis patients. Treatment strategies should address each of these risks appropriately.

Association of low alanine aminotransferase with loss of independence or death: A 5-year population-based cohort study

BACKGROUND AND AIM

Alanine aminotransferase (ALT) is an important enzyme for amino acid metabolism and gluconeogenesis, and low ALT is an indicator of vitamin B6 deficiency. However, it is unknown whether individuals with low ALT are likely to develop loss of independence (LOI) or death. We investigated the association of low ALT with LOI or death in the elderly.

METHODS

Between 2008 and 2010, 2,484 elderly individuals (≥ 65 years old) without functional dependency from the Locomotive Syndrome and Health Outcomes in the Aizu Cohort Study were enrolled. Based on baseline ALT values, the participants were divided into the following groups: ALT < 10 (n = 73), 10-20 (n = 1,372), 20-30 (reference, n = 734), 30-40 (n = 201), and ≥ 40 (n = 104) U/L groups. LOI was defined as requiring complete support for basic activities of daily living, which is care levels 3-5 in Japanese long-term care insurance certifications. The hazard ratios of LOI or death were estimated by Cox proportional hazard models adjusted for potential confounders.

RESULTS

During the median follow-up period of 5.75 (interquartile range 4.85-5.83) years, LOI or death occurred in 195 participants (7.85%). Compared with ALT 20-30 U/L, low ALT was associated with LOI or death (multivariable adjusted hazard ratios [95% confidence intervals]: 3.02 [1.57-5.81] and 1.55 [1.07-2.24] in ALT < 10 and 10-20 U/L groups, respectively), while high ALT was not (1.29 [0.72-2.31] and 1.49 [0.68-3.25] in ALT 30-40 and ≥ 40 U/L groups, respectively).

CONCLUSIONS

Clinicians should be aware of not only high ALT, indicating liver injury, but also low ALT associated with LOI or death.

Safety evaluation of calcium L-methylfolate

Calcium L-methylfolate (L-5-MTHF-Ca; CAS Number 151533-22-1) is a source of folate and an alternative to folic acid for use in human food and food supplements. The safety of L-5-MTHF-Ca was evaluated by testing for genotoxicity, subchronic and prenatal developmental toxicity. In in vitro assays L-5-MTHF-Ca was not mutagenic and did not induce other chromosomal events. Additionally, L-5-MTHF-Ca was not genotoxic in the in vivo micronucleus test nor did it induce DNA damage in rat liver cells. In a subchronic toxicity study, rats administered up to 400 mg/kg bw/day of L-5-MTHF-Ca via oral gavage for 13 weeks had no treatment-related mortalities, and no treatment-related effects were identified on behaviour, body weight, food consumption, ophthalmology, haematology, or organ weights. No treatment-related macroscopic or histopathological findings were observed. Calcium and sodium levels increased with increasing dosage, however the slight increases were within historical control ranges and reversible after the recovery period. L-5-MTHF-Ca is neither teratogenic nor embryotoxic. Based on the results of the in vitro and in vivo studies, the safe use of L-5-MTHF-Ca as an ingredient in foods is supported. The no observed adverse effect level was the highest dose in the subchronic toxicity study, i.e. 400 mg/kg bw/day for male and female rats.

Hyperhomocysteinemia and Lupus Nephritis

Background  In SLE, both disease-specific and traditional risk factors are important. Increased serum homocysteine levels are seen in approximately 15% of patients with systemic lupus erythematosus and are associated with an increased risk of atherothrombotic events in this population. The serum level of homocysteine in patients with lupus nephritis has not been well described. Methods We performed a retrospective review of patients who had both biopsy-proven lupus nephritis (class II-VI) and measured homocysteine levels during routine evaluation. Clinical and laboratory data were obtained from reviews of medical records. Results Of the 15 patients with lupus nephritis, 10 had elevated homocysteine levels. The ages ranged from 21-68 years and were predominately African-American females. There were three patients with class III, one with class III-V, two with class IV, and two with class V lupus nephritis. Two patients had more than one biopsy each, one with class III, IV-V, and one with III and IV. At the time, when the serum homocysteine level was measured, of the 10 patients with elevated homocysteine levels, five patients had positive anti-dsDNA, and four had hypocomplementemia predominately low C3 (three patients). All patients were on hydroxychloroquine. Conclusions  This study demonstrates that patients with lupus nephritis are at a higher risk (66.6%) for developing elevated homocysteine levels.

Computational modelling folate metabolism and DNA methylation: implications for understanding health and ageing

Dietary folates have a key role to play in health, as deficiencies in the intake of these B vitamins have been implicated in a wide variety of clinical conditions. The reason for this is folates function as single carbon donors in the synthesis of methionine and nucleotides. Moreover, folates have a vital role to play in the epigenetics of mammalian cells by supplying methyl groups for DNA methylation reactions. Intriguingly, a growing body of experimental evidence suggests that DNA methylation status could be a central modulator of the ageing process. This has important health implications because the methylation status of the human genome could be used to infer age-related disease risk. Thus, it is imperative we further our understanding of the processes which underpin DNA methylation and how these intersect with folate metabolism and ageing. The biochemical and molecular mechanisms, which underpin these processes, are complex. However, computational modelling offers an ideal framework for handling this complexity. A number of computational models have been assembled over the years, but to date, no model has represented the full scope of the interaction between the folate cycle and the reactions, which governs the DNA methylation cycle. In this review, we will discuss several of the models, which have been developed to represent these systems. In addition, we will present a rationale for developing a combined model of folate metabolism and the DNA methylation cycle.

Arsenic, one carbon metabolism and diabetes-related outcomes in the Strong Heart Family Study

BACKGROUND

Inorganic arsenic exposure and inter-individual differences in its metabolism have been associated with cardiometabolic risk. A more efficient arsenic metabolism profile (lower MMA%, higher DMA%) has been associated with reduced risk for arsenic-related health outcomes; however, this profile has also been associated with increased risk for diabetes-related outcomes. The mechanism behind these contrasting associations is equivocal; we hypothesized one carbon metabolism (OCM) may play a role.

METHODS

We evaluated the association between OCM-related variables (nutrient intake and genetic variants) and both arsenic metabolism biomarkers (iAs%, MMA% and DMA%) and diabetes-related outcomes (metabolic syndrome, diabetes, HOMA2-IR and waist circumference) in 935 participants free of prevalent diabetes and metabolic syndrome from the Strong Heart Family Study, a family-based prospective cohort comprised of American Indian tribal members aged 14+ years.

RESULTS

Of the 935 participants free of both diabetes and metabolic syndrome at baseline, 279 (29.8%) developed metabolic syndrome over a median of 5.3 years of follow-up and of the 1458 participants free of diabetes at baseline, 167 (11.3%) developed diabetes over follow-up. OCM nutrients were not associated with arsenic metabolism, however, higher vitamin B₆ was associated with diabetes-related outcomes (higher HOMA2-IR and increased risk for diabetes and metabolic syndrome). A polymorphism in an OCM-related gene, methionine synthase (MTR), was associated with both higher MMA% (β = 2.57, 95% CI: 0.22, 4.92) and lower HOMA2-IR (GMR = 0.79, 95% CI = 0.66, 0.93 per 5 years of follow-up). Adjustment for OCM variables did not affect previously reported associations between arsenic metabolism and diabetes-related outcomes; however, the association between the MTR variant and diabetes-related outcomes were attenuated after adjustment for arsenic metabolism.

CONCLUSIONS

Our findings suggest MMA% may be a partial mediator in the association between OCM and diabetes-related outcomes. Additional mediation analyses with longer follow-up period are needed to confirm this finding. Further research is needed to determine whether excess B vitamin intake is associated with increased risk for diabetes-related outcomes.

Serum folic acid levels are associated with the presence and severity of liver steatosis in Chinese adults

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is a common and strong risk factor for cardiovascular disease and hepatocellular carcinoma. The rapid acceleration of the increase in NAFLD prevalence has exceeded the trends observed for obesity, and has been driven by multiple factors. The aim of this study was to investigate the correlation between the serum levels of folic acid, the endogenous source of methyl groups for DNA methylation, and NAFLD in Chinese adults.

METHODS

The correlations between the serum folic acid levels and NAFLD were investigated in two independent cohorts of 70 subjects who underwent a liver biopsy and 130 subjects with varying liver fat contents, as measured using proton magnetic resonance spectroscopy (1H-MRS). Independent correlations between serum folic acid levels and liver steatosis grades were detected using a multivariate ordinal regression analysis. The diagnostic performances of serum folic acid levels alone and in combination with existing NAFLD prediction scores were compared with those of traditional NAFLD prediction parameters using receiver operating characteristic (ROC) curve analyses.

RESULTS

Serum folic acid concentrations were inversely correlated with liver histological steatosis grades (ρ = -0.371, P < 0.001) and the 1H-MRS-measured liver fat content (r = -0.199, P = 0.038). According to the multivariate ordinal regression analysis, serum folic acid levels were inversely correlated with liver steatosis grades (OR 0.739 [0.594-0.918], P = 0.006) independent of age, gender, BMI, components of metabolic syndrome and the serum TC, LDL-c and HOMA-IR levels. The AUROC of serum folic acid for the diagnosis of NAFLD was 0.75 (0.65-0.83), and the addition of serum folic acid to NAFLD prediction scores significantly improved the diagnostic prediction of NAFLD (AUROC = 0.88 [0.81-0.94]).

CONCLUSION

Low serum folic acid levels were identified as an independent risk factor for NAFLD in the Chinese population. The addition of the serum folic acid levels to the current existing NAFLD prediction scores significantly improved the prediction of NAFLD.

Plasma Cystathionine and Risk of Incident Stroke in Patients With Suspected Stable Angina Pectoris

Background Cystathionine is an intermediate product in the transsulfuration pathway and formed during the B6-dependent conversion of methionine to cysteine. Elevated plasma cystathionine has been related to atherosclerosis, which is a major etiological factor for ischemic stroke. However, the role of cystathionine in stroke development is unknown. Therefore, we prospectively assessed the association of circulating levels of cystathionine with risk of total and ischemic stroke. Methods and Results Two-thousand thirty-six patients (64% men; median age, 62 years) undergoing coronary angiography for suspected stable angina pectoris were included. Stroke cases were identified by linkage to the CVDNOR (Cardiovascular Disease in Norway) project. Hazard ratios with confidence intervals (95% confidence interval) were estimated by using Cox-regression analyses. During 7.3 years of median follow-up, 124 (6.1%) incident strokes were ascertained, which comprised 100 cases of ischemic stroke. There was a positive association of plasma cystathionine with risk of total stroke and ischemic stroke. Comparing the fourth versus the first cystathionine quartiles, age- and sex-adjusted hazard ratios (95% confidence interval) were 2.11 (1.19-3.75) and 2.56 (1.31-4.99) for total and ischemic stroke, respectively. Additional adjustment for major stroke risk factors only slightly attenuated the associations, which tended to be stronger in patients without previous or existing atrial fibrillation at baseline (hazard ratio [95% confidence interval], 2.43 [1.27-4.65] and 2.88 [1.39-5.98] for total and ischemic stroke, respectively). Conclusions In patients with suspected stable angina pectoris, plasma cystathionine was independently related to increased risk of total stroke and, in particular, ischemic stroke. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 00354081.

A kinetic spectrophotometric method for the determination of pyridoxal-5'-phosphate based on coenzyme activation of apo-d-phenylglycine aminotransferase

A new PLP assay method based on the coenzyme activation of apo-d-phenylglycine aminotransferase (apo-d-PhgAT) is reported. The assay process is comprised of two steps. First, PLP present in plasma samples is allowed to reconstitute apo-d-PhgAT, forming active holo-d-PhgAT. In the second step, the enzymatic activity of reconstituted d-PhgAT is determined using d-4-OH-phenylglycine as the amino donor substrate with 4-OH-benzoylformate (OH-BZF) as the reaction product. OH-BZF absorbs UV light strongly at 334 nm (molar absorption coefficient = 25.4 × 10³ M^-1cm^-1) and its rate of formation is monitored spectrophotometrically. The rate of the transamination reaction catalyzed by the reconstituted d-PhgAT is directly proportional to the amount of PLP in the sample. The method is applicable for determining PLP in the concentration range from 5.2 to 250 nM and requires 50 μL of plasma sample. The mean within- and between-run coefficient of variations (CVs) were 8.1% and 12.4%, respectively. Analytical recoveries ranged from 98 to 108%. The assay was specific and showed good correlation with the established method (CDC, Method No: 4002.05). The assay requires one reaction catalyzed by a single enzyme, does not require a radioactive substrate, and a derivatization reagent is not needed. This PLP determination process is relatively simple to perform and can be completed using common laboratory equipment.

The Postprandial Anti-Hyperglycemic Effect of Pyridoxine and Its Derivatives Using In Vitro and In Vivo Animal Models

In the current study, we investigated the inhibitory activity of pyridoxine, pyridoxal, and pyridoxamine, against various digestive enzymes such as α-glucosidases, sucrase, maltase, and glucoamylase. Inhibition of these enzymes involved in the absorption of disaccharide can improve post-prandial hyperglycemia due to a carbohydrate-based diet. Pyridoxal (4.14 mg/mL of IC₅₀) had the highest rat intestinal α-glucosidase inhibitory activity, followed by pyridoxamine and pyridoxine (4.85 and 5.02 mg/mL of IC₅₀, respectively). Pyridoxal demonstrated superior inhibition against maltase (0.38 mg/mL IC₅₀) and glucoamylase (0.27 mg/mLIC₅₀). In addition, pyridoxal showed significant higher α-amylase inhibitory activity (10.87 mg/mL of IC₅₀) than that of pyridoxine (23.18 mg/mL of IC₅₀). This indicates that pyridoxal can also inhibit starch hydrolyzing by pancreatic α-amylase in small intestine. Based on these in vitro results, the deeper evaluation of the anti-hyperglycemic potential of pyridoxine and its derivatives using Sprague-Dawley (SD) rat models, was initiated. The post-prandial blood glucose levels were tested two hours after sucrose/starch administration, with and without pyridoxine and its derivatives. In the animal trial, pyridoxal (p < 0.05) had a significantly reduction to the postprandial glucose levels, when compared to the control. The maximum blood glucose levels (Cmax) of pyridoxal administration group were decreased by about 18% (from 199.52 ± 22.93 to 164.10 ± 10.27, p < 0.05) and 19% (from 216.92 ± 12.46 to 175.36 ± 10.84, p < 0.05) in sucrose and starch loading tests, respectively, when compared to the control in pharmacodynamics study. The pyridoxal administration significantly decreased the minimum, maximum, and mean level of post-prandial blood glucose at 0.5 h after meals. These results indicate that water-soluble vitamin pyridoxine and its derivatives can decrease blood glucose level via the inhibition of carbohydrate-hydrolyzing and absorption-linked enzymes. Therefore, pyridoxal may have the potential to be used as a food ingredient for the prevention of prediabetes progression to type 2 diabetes.

Biochemical and Clinical Impact of Organic Uremic Retention Solutes: A Comprehensive Update

In this narrative review, the biological/biochemical impact (toxicity) of a large array of known individual uremic retention solutes and groups of solutes is summarized. We classified these compounds along their physico-chemical characteristics as small water-soluble compounds or groups, protein bound compounds and middle molecules. All but one solute (glomerulopressin) affected at least one mechanism with the potential to contribute to the uremic syndrome. In general, several mechanisms were influenced for each individual solute or group of solutes, with some impacting up to 7 different biological systems of the 11 considered. The inflammatory, cardio-vascular and fibrogenic systems were those most frequently affected and they are one by one major actors in the high morbidity and mortality of CKD but also the mechanisms that have most frequently been studied. A scoring system was built with the intention to classify the reviewed compounds according to the experimental evidence of their toxicity (number of systems affected) and overall experimental and clinical evidence. Among the highest globally scoring solutes were 3 small water-soluble compounds [asymmetric dimethylarginine (ADMA); trimethylamine-N-oxide (TMAO); uric acid], 6 protein bound compounds or groups of protein bound compounds [advanced glycation end products (AGEs); p-cresyl sulfate; indoxyl sulfate; indole acetic acid; the kynurenines; phenyl acetic acid;] and 3 middle molecules [β₂-microglobulin; ghrelin; parathyroid hormone). In general, more experimental data were provided for the protein bound molecules but for almost half of them clinical evidence was missing in spite of robust experimental data. The picture emanating is one of a complex disorder, where multiple factors contribute to a multisystem complication profile, so that it seems of not much use to pursue a decrease of concentration of a single compound.

Intake of niacin, folate, vitamin B-6, and vitamin B-12 through young adulthood and cognitive function in midlife: the Coronary Artery Risk Development in Young Adults (CARDIA) study

Background: Epidemiologic evidence regarding niacin, folate, vitamin B-6, and vitamin B-12 intake in relation to cognitive function is limited, especially in midlife.Objective: We hypothesize that higher intake of these B vitamins in young adulthood is associated with better cognition later in life.Design: This study comprised a community-based multicenter cohort of black and white men and women aged 18-30 y in 1985-1986 (year 0, i.e., baseline) from the Coronary Artery Risk Development in Young Adults (CARDIA) study (n = 3136). We examined participants' CARDIA diet history at years 0, 7, and 20 to assess nutrient intake, including dietary and supplemental B vitamins. We measured cognitive function at year 25 (mean ± SD age: 50 ± 4 y) through the use of the Rey Auditory Verbal Learning Test (RAVLT) for verbal memory, the Digit Symbol Substitution Test (DSST) for psychomotor speed, and a modified Stroop interference test for executive function. Higher RAVLT and DSST scores and a lower Stroop score indicated better cognitive function. We used multivariable-adjusted linear regressions to estimate mean differences in cognitive scores and 95% CIs.Results: Comparing the highest quintile with the lowest (quintile 5 compared with quintile 1), cumulative total intake of niacin was significantly associated with 3.92 more digits on the DSST (95% CI: 2.28, 5.55; P-trend < 0.01) and 1.89 points lower interference score on the Stroop test (95% CI: -3.10, -0.68; P-trend = 0.05). Total folate was associated with 2.56 more digits on the DSST (95% CI: 0.82, 4.31; P-trend = 0.01). We also found that higher intakes of vitamin B-6 (quartile 5 compared with quartile 1: 2.62; 95% CI: 0.97, 4.28; P-trend = 0.02) and vitamin B-12 (quartile 5 compared with quartile 1: 2.08; 95% CI: 0.52, 3.65; P-trend = 0.02) resulted in better psychomotor speed measured by DSST scores.Conclusion: Higher intake of B vitamins throughout young adulthood was associated with better cognitive function in midlife.

Metabolomic Evaluation of the Consequences of Plasma Cystathionine Elevation in Adults with Stable Angina Pectoris

Background: An elevated circulating cystathionine concentration, which arises in part from insufficiencies of vitamin B-6, B-12, or folate, has been shown to be associated with cardiovascular disease (CVD) risk. Hydrogen sulfide (H₂S) is a gasotransmitter involved in vasodilation, neuromodulation, and inflammation. Most endogenously produced H₂S is formed by pyridoxal phosphate (PLP)-dependent enzymes by noncanonical reactions of the transsulfuration pathway that yield H₂S concurrently form lanthionine and homolanthionine. Thus, plasma lanthionine and homolanthionine concentrations can provide relative information about H₂S production in vivo.Objective: To determine the metabolic consequences of an elevated plasma cystathionine concentration in adults with stable angina pectoris (SAP), we conducted both targeted and untargeted metabolomic analyses.Methods: We conducted NMR and LC-mass spectrometry (MS) metabolomic analyses on a subset of 80 plasma samples from the Western Norway Coronary Angiography Cohort and selected, based on plasma cystathionine concentrations, a group with high cystathionine concentrations [1.32 ± 0.60 μmol/L (mean ± SD); n = 40] and a group with low cystathionine concentrations [0.137 ± 0.011 μmol/L (mean ± SD); n = 40]. Targeted and untargeted metabolomic analyses were performed and assessed with the use of Student's t tests corrected for multiple testing. Overall differences between the cystathionine groups were assessed by untargeted NMR and LC-MS metabolomic methods and evaluated by partial least squares discriminant analysis (PLS-DA) with significant discriminating metabolites identified with 99% confidence.Results: Subjects with high cystathionine concentrations had 75% higher plasma lanthionine concentrations (0.12 ± 0.044 μmol/L) than subjects with low cystathionine concentrations [0.032 ± 0.013 μmol/L (P < 0.001)]. Although plasma homolanthionine concentrations were notably higher than lanthionine concentrations, they were not different between the groups (P = 0.47). PLS-DA results showed that a high plasma cystathionine concentration in SAP was associated with higher glucose, branched-chain amino acids, and phenylalanine concentrations, lower kidney function, and lower glutathione and plasma PLP concentrations due to greater catabolism. The high-cystathionine group had a greater proportion of subjects in the postprandial state.Conclusion: These data suggest that metabolic perturbations consistent with higher CVD risk exist in SAP patients with elevated plasma cystathionine concentrations.

Endothelial dysfunction in individuals born after fetal growth restriction: cardiovascular and renal consequences and preventive approaches

Individuals born after intrauterine growth restriction (IUGR) have an increased risk of perinatal morbidity/mortality, and those who survive face long-term consequences such as cardiovascular-related diseases, including systemic hypertension, atherosclerosis, coronary heart disease and chronic kidney disease. In addition to the demonstrated long-term effects of decreased nephron endowment and hyperactivity of the hypothalamic-pituitary-adrenal axis, individuals born after IUGR also exhibit early alterations in vascular structure and function, which have been identified as key factors of the development of cardiovascular-related diseases. The endothelium plays a major role in maintaining vascular function and homeostasis. Therefore, it is not surprising that impaired endothelial function can lead to the long-term development of vascular-related diseases. Endothelial dysfunction, particularly impaired endothelium-dependent vasodilation and vascular remodeling, involves decreased nitric oxide (NO) bioavailability, impaired endothelial NO synthase functionality, increased oxidative stress, endothelial progenitor cells dysfunction and accelerated vascular senescence. Preventive approaches such as breastfeeding, supplementation with folate, vitamins, antioxidants, L-citrulline, L-arginine and treatment with NO modulators represent promising strategies for improving endothelial function, mitigating long-term outcomes and possibly preventing IUGR of vascular origin. Moreover, the identification of early biomarkers of endothelial dysfunction, especially epigenetic biomarkers, could allow early screening and follow-up of individuals at risk of developing cardiovascular and renal diseases, thus contributing to the development of preventive and therapeutic strategies to avert the long-term effects of endothelial dysfunction in infants born after IUGR.

Happily (n)ever after: Aging in the context of oxidative stress, proteostasis loss and cellular senescence

Aging is a complex phenomenon and its impact is becoming more relevant due to the rising life expectancy and because aging itself is the basis for the development of age-related diseases such as cancer, neurodegenerative diseases and type 2 diabetes. Recent years of scientific research have brought up different theories that attempt to explain the aging process. So far, there is no single theory that fully explains all facets of aging. The damage accumulation theory is one of the most accepted theories due to the large body of evidence found over the years. Damage accumulation is thought to be driven, among others, by oxidative stress. This condition results in an excess attack of oxidants on biomolecules, which lead to damage accumulation over time and contribute to the functional involution of cells, tissues and organisms. If oxidative stress persists, cellular senescence is a likely outcome and an important hallmark of aging. Therefore, it becomes crucial to understand how senescent cells function and how they contribute to the aging process. This review will cover cellular senescence features related to the protein pool such as morphological and molecular hallmarks, how oxidative stress promotes protein modifications, how senescent cells cope with them by proteostasis mechanisms, including antioxidant enzymes and proteolytic systems. We will also highlight the nutritional status of senescent cells and aged organisms (including human clinical studies) by exploring trace elements and micronutrients and on their importance to develop strategies that might increase both, life and health span and postpone aging onset.

The Case for Promoting Multiple Vitamin And Mineral Supplements for Women of Reproductive Age in Developing Countries

Women in developing countries often consume inadequate amounts of micronutrients because of their limited intake of animal products, fruits, vegetables, and fortified foods. Intakes of micronutrients less than the recommended values increase a woman's risk of having micronutrient deficiencies. the adverse effects of deficiencies in vitamin A, iron, and folic acid, including night-blindness in pregnant and lactating women and iron-deficiency anaemia, are well known. Low intakes of these and other nutrients, including zinc, calcium, riboflavin, vitamin B6, and vitamin B12, also have consequences for women's health, pregnancy outcome, and the health and nutritional status of breastfed children. Multiple deficiencies coexist, so the benefit of multiple micronutrient supplements is becoming increasingly apparent. Supplementation of women with multiple vitamins and minerals should be one component of a strategy to improve micronutrient status among women in developing countries. However, there are several issues for programme managers to consider before implementing programmes. Which reference standards will be used to determine nutrient levels to include in the supplements? Which nutrients will be included and in what quantities? Which factors need to be considered in purchasing supplements? These issues are discussed, and guidance is provided on the selection of appropriate supplements for pregnant women and women of reproductive age in developing countries.

Nutritional management of a patient with obesity and pulmonary embolism: a case report

Background

The aim of this case report is to discuss the issue of nutritional therapy in patients taking warfarin. Patients are often prescribed vitamin K free diets without nutritional counseling, leading to possible health consequences.

Case presentation

A 52-year-old woman with obesity and hypertension was prescribed a low calorie diet by her family doctor in an effort to promote weight loss. After a pulmonary embolism, she was placed on anticoagulant therapy and on hospital discharge she was prescribed a vitamin K free diet to avoid interactions. Given poor control of her anticoagulant therapy, she was referred to our Nutritional Unit outpatients’ service.

Conclusions

This case illustrates the importance of a thorough medical nutrition assessment in the management of patients with obesity and the need for a change in the dietary approach of nutritional therapy in the management of vitamin K anticoagulant therapy. In patients taking warfarin, evidence suggest that the aim of nutritional therapy should be to keep dietary intake of vitamin K constant.

Dietary Factors in Reducing Risk of Cardiovascular Diseases

Diet influences many modifiable risk factors for cardiovascular diseases (CVDs). Considering this, moderation of total dietary fat, particularly trans and saturated fats, as well as cholesterol is recommended. Dietary fats should come mainly from plants and fatty fish, providing monounsaturated and polyunsaturated (including omega-3) fatty acids. Carbohydrate sources to emphasize include whole grains, legumes, vegetables, fruits, and other fiber-rich sources, rather than sugars. Although vitamins such as E, C, and some B vitamins are associated with reduced CVD risk, data do not support the use of supplements, but foods rich in these nutrients are advocated. Dietary minerals such as potassium, magnesium, and calcium may be beneficial to heart health, while reduction of dietary sodium decreases risk of hypertension. A large variety of phytonutrients are also associated with reduced CVD risk. Other dietary factors receiving research attention regarding CVD risk. Other dietary factors receiving research attention regarding CVD risk include caffeine, alcobol, and meal frequency, although more work is needed in these areas. In contrast, data are quite robust to support the importance of healthy body weight management in cardiovascular health. In general, diets based on a variety of less processed foods, mainly of plant origin, in the context of an active lifestyle, are conducive to heart health.

4-Pyridoxic Acid in the Spent Dialysate: Contribution to Fluorescence and Optical Monitoring

Aim

In this work we estimated the contribution of the fluorescence of 4-pyridoxic acid (4-PA) to the total fluorescence of spent dialysate with the aim of evaluating the on-line monitoring of removal of this vitamin B-6 metabolite from the blood of patients with end-stage renal disease (ESRD).

Methods

Spectrofluorometric analysis of spent dialysate, collected from hemodialysis and hemodiafiltration sessions of 10 patients receiving regularly pyridoxine injections after dialysis treatment, was performed in the range of Ex/Em 220–500 nm. 4-PA in dialysate samples was identified and quantified using HPLC with fluorescent and MS/MS detection.

Results

Averaged HPLC chromatogram of spent dialysate had many peaks in the wavelength region of Ex320/Em430 nm where 4-PA was the highest peak with contribution of 42.2±17.0% at the beginning and 47.7±18.0% in the end of the dialysis. High correlation (R = 0.88–0.95) between 4-PA concentration and fluorescence intensity of spent dialysate was found in the region of Ex310-330/Em415-500 nm, respectively.

Conclusion

4-PA elimination from the blood of ESRD patients can be potentially followed using monitoring of the fluorescence of the spent dialysate during dialysis treatments.

Inflammation, vitamin B6 and related pathways

The active form of vitamin B6, pyridoxal 5'-phosphate (PLP), serves as a co-factor in more than 150 enzymatic reactions. Plasma PLP has consistently been shown to be low in inflammatory conditions; there is a parallel reduction in liver PLP, but minor changes in erythrocyte and muscle PLP and in functional vitamin B6 biomarkers. Plasma PLP also predicts the risk of chronic diseases like cardiovascular disease and some cancers, and is inversely associated with numerous inflammatory markers in clinical and population-based studies. Vitamin B6 intake and supplementation improve some immune functions in vitamin B6-deficient humans and experimental animals. A possible mechanism involved is mobilization of vitamin B6 to the sites of inflammation where it may serve as a co-factor in pathways producing metabolites with immunomodulating effects. Relevant vitamin B6-dependent inflammatory pathways include vitamin B6 catabolism, the kynurenine pathway, sphingosine 1-phosphate metabolism, the transsulfuration pathway, and serine and glycine metabolism.

Homocysteine, a Risk Factor for Carotid Atherosclerosis, Is Not a Risk Factor for Early Recurrent Carotid Stenosis Following Carotid Endarterectomy

Homocysteine has been proposed as a risk factor for atherosclerotic disease and recurrent coronary stenosis due to neointimal hyperplasia following angioplasty. In order to evaluate homocysteine's role in human carotid neointimal hyperplasia, we have compared homocysteine levels in patients who have not developed restenosis with those who have within 2 years of carotid endarterectomy (CEA). One hundred and fifty-four patients were divided into 3 groups based on duplex scans performed 2 years after CEA. Group I (88) were patients in whom all scans showed no evidence of restenosis. Group II (35) patients exhibited some restenosis, but this did not exceed 49% diameter reduction based on our duplex criteria. Group III (31) patients developed a restenosis of >50% within 2 years. One hundred and thirteen Dacron patches (73 Group I [83%], 22 Group II [63%], and 18 Group III [58%]) were used according to surgeon preference but did not affect the statistical relevance of homocysteine evaluation. The groups were otherwise identical in terms of age, sex, smoking history, and cholesterol levels. All patients were receiving antiplatelet medication postoperatively, and none had consumed added pharmacologic folate. The average homocysteine value for the entire study group was elevated at 12.5 µmol/L. The homocysteine values for the 3 groups were not statistically different (p>1): (I, 12.5; II, 12.2; and III, 12.9 µmol/L). Elevated homocysteine levels (>10 µmol/L) appear to be associated with carotid atherosclerosis, but at levels < 30 µmol/L do not appear to play a role in restenosis following CEA.

Vitamin B-6 catabolism and long-term mortality risk in patients with coronary artery disease

BACKGROUND

Low vitamin B-6 status has been related to increased risk of coronary artery disease (CAD), which is a condition that is associated with inflammation. The most common status marker, plasma pyridoxal 5'-phosphate (PLP), decreases during inflammation; therefore, causal relations are uncertain.

OBJECTIVE

We evaluated the vitamin B-6 biomarkers PLP, pyridoxal, and pyridoxic acid (PA) and the pyridoxic acid:(pyridoxal + PLP) ratio (PAr), a proposed marker of vitamin B-6 catabolism during activated cellular immunity, as predictors of mortality.

DESIGN

Associations with risks of long-term all-cause mortality and cardiovascular mortality were evaluated with the use of Cox regression in patients who were undergoing elective coronary angiography for suspected stable angina pectoris (SAP) (n = 4131) and an independent cohort of patients who were hospitalized for acute myocardial infarction (AMI) (n = 3665).

RESULTS

Plasma PLP (AMI patients only) and PA predicted all-cause mortality in models that were adjusted for established risk predictors, but associations were attenuated or nonsignificant after additional adjustment for inflammatory markers. PAr was correlated with biomarkers of inflammation (Pearson's r ≥ 0.37) and predicted all-cause mortality and cardiovascular mortality after adjustment for established risk predictors. In SAP patients, PAr had greater predictive strength than did current smoking, diabetes, hypertension, apolipoproteins, or C-reactive protein. PAr provided multiadjusted HRs per SD of 1.45 (95% CI: 1.30, 1.63) and 1.31 (95% CI: 1.21, 1.41) in SAP and AMI patients, respectively. In both cohorts, PAr was a particularly strong predictor of all-cause mortality for patients with no previous CAD history (P-interaction ≤ 0.04).

CONCLUSION

PAr may capture unique aspects of inflammatory activation and thus provide new insights into disease mechanisms that may aid in identifying patients at increased risk of future fatal events.

Dietary Reference Values for vitamin B6

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derives Dietary Reference Values (DRVs) for vitamin B6. The Panel considers that plasma pyridoxal 5'-phosphate (PLP) concentration is the biomarker of status suitable for deriving DRVs for vitamin B6. Considering that a plasma PLP concentration of 30 nmol/L, as a population mean, is indicative of an adequate vitamin B6 status, the Panel proposes to use this cut-off value to set Average Requirements (ARs). Population Reference Intakes (PRIs) are derived for adults and children from ARs, assuming a coefficient of variation (CV) of 10%. For women, the AR and PRI are set at 1.3 and 1.6 mg/day. For men, the AR of 1.5 mg/day is derived by an allometric scaling from the AR for women, and a PRI of 1.7 mg/day is set. For all infants aged 7-11 months, an Adequate Intake of 0.3 mg/day is set, averaging the results of two extrapolation approaches based on an allometric scaling: upwards extrapolation from the estimated vitamin B6 intake of exclusively breastfed infants from birth to 6 months, and downwards extrapolation from the ARs for adults applying a growth factor. For all children, ARs are derived from adult ARs using an allometric scaling and growth factors. For children of both sexes aged 1-14 years, ARs range between 0.5 and 1.2 mg/day. For children aged 15-17 years, the Panel derives the same ARs as for adults. PRIs for children aged 1-17 years range between 0.6 and 1.7 mg/day. Extrapolation of ARs by an allometric scaling considered differences in reference body weight. For pregnant and lactating women, additional requirements are considered, based on the uptake of vitamin B6 by the fetal and maternal tissues and the losses through breast milk, and PRIs of 1.8 and 1.7 mg/day, respectively, are derived.

Hyperhomocysteinaemia in rats is associated with erectile dysfunction by impairing endothelial nitric oxide synthase activity

To investigate the effect of hyperhomocysteinaemia (HHCy) on penile erectile function in a rat model, a methionine-rich diet was used in which erectile function, the reproductive system, and nitric oxide synthase were characterized. The intracavernous pressure, apomorphine experiments, measurement of oxidative stress, hematoxylin and eosin staining, immunohistochemistry analysis, reverse transcription-polymerase chain reactions and measurement of endothelial nitric oxide synthase activity were utilized. Our results showed that erections in the middle-dose, high-dose, and interference (INF) groups were significantly lower than the control (P < 0.05). INF group, being fed with vitamins B and folic acid, demonstrated markedly improved penile erections compared with the middle-dose group (P < 0.05). HHCy-induced eNOS and phospho-eNOS protein expression was reduced and the antioxidant effect was markedly impaired. The data of the present data provide evidence that HHCy is a vascular risk factor for erectile dysfunction by impairing cavernosa endothelial nitric oxide synthase activity. Intake of vitamins B can alleviate this abnormality.