Effects of individualized administration of folic acid on prothrombotic state and vascular endothelial function with H-type hypertension: A double-blinded, randomized clinical cohort study

The Association Between the Dietary Inflammatory Index, Dietary Pattern, and Hypertension Among Residents in the Xinjiang Region

Background: Diet and inflammation are both associated with hypertension. We aimed to investigate the relationship between the dietary inflammation index (DII), dietary patterns, and the risk of hypertension among Xinjiang residents. Methods: A total of 930 residents aged 20-80 from Shihezi and Tumushuk were selected as participants using a stratified whole cluster random sampling method. General demographic information, dietary data, and physical examination results were collected from the participants and DII scores were calculated. Restricted cubic spline was used to analyze the dose-response relationship between the DII and the risk of hypertension. LASSO regression was used to screen dietary factors associated with hypertension. Factor analysis was used to extract dietary patterns. Finally, logistic regression modeling was used to analyze the association between the DII, dietary patterns, and the risk of hypertension. Results: The DII was linearly and positively associated with the risk of developing hypertension. Logistic regression analysis showed that the prevalence of hypertension was 2.23 (95% CI: 1.53, 3.23) and 3.29 (95% CI: 2.26, 4.79) in the T2 and T3 groups, respectively, compared with the T1 group. Riboflavin and folate were associated with the risk of hypertension. In the vegetable-egg dietary pattern, the risk of hypertension was reduced by 33%, 39%, and 37% in groups Q2, Q3, and Q4, respectively, compared with group Q1 (Q2: OR = 0.67, 95% CI: 0.45, 0.99; Q3: OR = 0.61, 95% CI: 0.41, 0.92; Q4: OR = 0.63, 95% CI: 0.42, 0.96). Conclusions: The higher the DII score, the higher the risk of hypertension among residents of Xinjiang. In addition, vegetable-egg dietary patterns can reduce the risk of hypertension. Therefore, local residents should be scientifically instructed to increase their intake of vegetables and eggs.

Efficacy of Vitamin-D supplementation in improving the prognosis of H-type hypertension in elderly patients

Objective

To investigate the correlation between 25-hydroxyvitamin D and H-type hypertension in elderly patients, and to observe the clinical efficacy of vitamin D supplementation in those patients.

Methods

This was a retrospective study. One hundred and twenty elderly hypertensive patients treated at The Affiliated Hospital of Hebei University from June 2022 to June 2023 were randomly divided into Group-A (n=60) with hypertension and elevated homocysteine (Hcy) levels (H-type hypertension), and Group-B(n=60) with hypertension and normal Hcy levels. Blood levels of 25-hydroxyvitamin D and 24 hours ambulatory blood pressure were assessed in both groups of patients upon admission, with the correlation analysis performed simultaneously. The therapeutic effects were compared between the two groups.

Results

Through Pearson correlation analysis, there were negative correlations of serum 25-hydroxyvitamin D levels with 24 hours SSD, 24 hours DSD, dnSBP, and nDBP(all p<0.05). After 12 weeks of treatment, the treatment group had higher 25-hydroxyvitamin D levels and lower 24 hours SBP, 24h DBP, dSBP, dDBP, nSBP, nDBP levels than those of the control group(p<0.05). After treatment, the treatment group had lower blood Hcy, IMT, TC, TG, and LDL-C levels(p<0.05), and higher HDL-C levels(p<0.05) than those of the control group.

Conclusion

Serum 25-hydroxyvitamin D levels in elderly patients with H-type hypertension have negative correlations with 24 hours SSD, 24 hours DSD, dnSBP, and nDBP. Oral vitamin D supplementation for H-type hypertensive patients exhibits significant therapeutic effects, with improvements in 24 hours ambulatory blood pressure monitoring results, blood lipid levels, IMT, and blood Hcy levels after treatment.

Homocysteine, hyperhomocysteinemia, and H-type hypertension

Homocysteine (Hcy) is a sulphur-containing nonessential amino acid derived from the intermediate metabolites of methionine. Methionine is obtained from dietary proteins, such as poultry, meat, eggs, seafood, and dairy products. Abnormalities in Hcy metabolic pathways, deficiencies in dietary methionine, folate, and vitamins B12, B6, and B2 and genetic defects, polymorphisms, or mutations in Hcy metabolism-related enzymes may lead to an increase in plasma Hcy levels. Generally, a plasma Hcy level higher than 10 or 15 μmol/L has been defined as hyperhomocysteinemia (HHcy). An individual with essential hypertension complicated with HHcy is considered to have H-type hypertension (HTH). Currently, HHcy is considered a novel independent risk factor for various cardiovascular diseases. To provide a useful reference for clinicians, the research progress on Hcy, HHcy, and HTH in recent years was systematically reviewed here, with a focus on the source and metabolic pathways of Hcy, plasma Hcy levels and influencing factors, detection methods for plasma Hcy levels, relationship between Hcy concentration and hypertension, pathogenesis of HTH, cardiovascular complications of HTH, and treatment of HTH.

H-type Hypertension Status and Influencing Factors of the Elderly People Over 80 Years Old Based on Random Forest Model

Hypertension is a common chronic disease in elderly people over 80 years old. Clinically, H-type hypertension occurs when hypertension coexists with hyperhomocysteinemia level of ≥ 10 umol/L. Effective identification of risk factors for H-type hypertension in the elderly can greatly improve patient prognosis.Consecutively, 494 patients with hypertension admitted to the Fourth Affiliated Hospital of Harbin Medical University from January 2019 to December 2021 were selected as the study population. They were divided into H-type hypertension (n = 197) and non-H-type hypertension groups (n = 297). Patient data were collected, including basic information, history, and clinical data. The random forest model and LASSO analysis were used to screen the influencing factors for H-type hypertension. Multiple stepwise regression analysis was used to analyze the selected variables.A total of 197 elderly people over 80 years old suffered from H-type hypertension, with an incidence rate of 39.88%. The random forest model and LASSO analysis results showed that the top 8 independent variables in importance ranking were ejection fraction (EF), fibrinogen, glycated hemoglobin (HbA1c), B-type natriuretic peptide, creatinine, fasting blood glucose, uric acid, and serum triiodothyronine levels. The results of multivariate analysis showed that EF was the protective factor, while fibrinogen, HbA1c, and creatinine were the risk factors for H-type hypertension in elderly people over 80 years old (P < 0.05).Healthcare professionals can indirectly assess the prevalence of H-type hypertension by focusing on EF, fibrinogen, creatinine, and HbA1c in elderly hypertensive patients. This provided proactive intervention and medical services to improve prognosis outcomes.

Effect of vitamin B2, vitamin C, vitamin D, vitamin E and folic acid in adults with essential hypertension: a systematic review and network meta-analysis

OBJECTIVES

The objective of the current study is to compare the treatment effects of different vitamins on essential hypertension to provide an initial basis for developing evidence-based practices.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Five electronic databases (PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov) were searched from their inception to 25 September 2023.

OUTCOMES

The primary outcomes were the difference between the intervention group and the control group in changes in office systolic blood pressure (SBP) and office diastolic blood pressure (DBP) from baseline. The secondary outcomes were the difference between the intervention group and the control group in changes in 24-hour mean ambulatory systolic blood pressure (24 hours SBP), 24-hour mean ambulatory diastolic blood pressure (24 hours DBP) and heart rate (HR) from baseline.

RESULTS

A total of 23 studies comparing five vitamins (vitamin B2, vitamin C, vitamin D, vitamin E, folic acid) and involving 2218 participants were included. The included trials were all vitamin versus placebo, so the network was star-shaped. Among the five vitamins, only vitamin E was significantly more effective at reducing SBP (mean difference: -14.14 mm Hg, 95% credible intervals: -27.62 to -0.88) than placebo. In addition, no evidence was found that any of the five vitamins influenced DBP, 24 hours SBP, 24 hours DBP, or HR. The dose of vitamins, geographical region and percentage of males (only SBP) might be sources of heterogeneity. Sensitivity and subgroup analysis revealed that the effect of vitamin intervention on blood pressure varies according to different doses of vitamins.

CONCLUSIONS

According to the results, vitamin E might be an effective measure to reduce SBP, but more research is needed to validate this finding.

PROSPERO REGISTRATION NUMBER

CRD42022352332.

Folic acid enhances the cardiovascular protective effect of amlodipine in renal hypertensive rats with elevated homocysteine

OBJECTIVES

To investigate the actions of amlodipine-folic acid (amlodipine-FA) preparation on hypertension and cardiovascular in renal hypertensive rats with hyperhomocysteinemia (HHcy), so as to provide experimental basis for clinical research of amlodipine folic acid tablets.

METHODS

Rats model of renal hypertension with HHcy were established. The rats were randomly divided into groups of model, amlodipine, folic acid (FA) and amlodipine-FA of various dosages. Normal rats were used as normal control group. Blood pressure, Hcy as well as plasma NO, ET-1 and hemodynamics were assayed. Histological alterations of heart and abdominal aorta were also examined.

RESULTS

Compared with the normal group, blood pressure, plasma Hcy, and NO of the rats in model group were significantly increased, while the plasma ET-1 was decreased. Compared with the normal group, the animals in the model group had reduced cardiac function, thickened wall of the aorta and narrowed lumen. In FA group and amlodipine group, the rat plasma NO was increased while ET-1 was decreased, the protective effect of amlodipine-FA group on endothelial cells was further enhanced. In amlodipine group, the rat hemodynamics (LVSP, LVEDP and ±dp/dt_max, et al.) and vascular damage were significantly reduced, while in amlodipine-FA group, the heart function were further improved, and myocardial and vascular hypertrophy were significantly reduced.

CONCLUSIONS

As compared to amlodipine alone, amlodipine -FA can lower both blood pressure and plasma Hcy, significantly enhancing vascular endothelial function to protect the heart and blood vessel in renal hypertensive rats with HHcy.

Methylenetetrahydrofolate reductase polymorphisms in dental caries-induced pulp inflammation and regeneration of dentine-pulp complex: Future perspectives

Dental caries (DC)-induced pulp infections usually undergo the common endodontic treatment, root canal therapy (RCT). Endodontically treated teeth are devitalized, become brittle and susceptible for re-infection which eventually results in dental loss. These complications arise because the devitalized pulp losses its ability for innate homeostasis, repair and regeneration. Therefore, restoring the vitality, structure and function of the inflamed pulp and compromised dentin have become the focal points in regenerative endodontics. There are very few evidences, so far, that connect methylenetetrahydrofolate reductase single nucleotide polymorphisms (MTHFR-SNPs) and dental disorders. However, the primary consequences of MTHFR-SNPs, in terms of excessive homocysteine and folate deficiency, are well-known contributors to dental diseases. This article identifies the possible mechanisms by which MTHFR-SNP-carriers are susceptible for DC-induced pulp inflammation (PI); and discusses a cell-homing based strategy for in vivo transplantation in an orthotopic model to regenerate the functional dentine-pulp complex which includes dentinogenesis, neurogenesis and vasculogenesis, in the SNP-carriers.

Relationship between the methylenetetrahydrofolate reductase (MTHFR) rs1801133 SNP and serum homocysteine levels of Zhuang hypertensive patients in the central region of Guangxi

BACKGROUND

The relationship between the methylenetetrahydrofolate reductase (MTHFR) single nucleotide polymorphism (SNP) and serum homocysteine (Hcy) levels or H-type hypertension in different populations is inconsistent. This study aimed to explore the association between the MTHFR rs1801133 SNP and serum Hcy levels of Zhuang hypertensive patients in the central region of Guangxi.

METHODS

A total of 606 Zhuang inpatients with essential hypertension were recruited in our hospital from August 2016 to December 2018. The patients were divided into H-type hypertension (Hcy > 10 µmol/L, n = 528) and non-H-type hypertension (Hcy ≤ 10 µmol/L, n = 78) groups. At the same time, an age- and sex-matched group of 379 subjects with normal physical examination in our hospital were selected as the control group. Blood biochemical measurements and genotyping of the MTHFR rs1801133 SNP were performed.

RESULTS

The prevalence of H-type hypertension was 87.13%. The levels of serum Hcy in patients with hypertension were higher than those in control group (14.20 ± 5.78 μmol/L vs. 11.97 ± 5.39 μmol/L, P < 0.001), especially in patients with H-type hypertension (15.08 ± 5.65 μmol/L, P < 0.001). The frequencies of TT genotype (22.73%) and T allele (46.21%) in patients with H-type hypertension were significantly higher than those in control group (11.35% and 30.47%, respectively) and non-H-type hypertension group (10.26% and 28.85%, respectively; P < 0.001 for all). Multivariate linear regression analysis showed that serum Hcy levels were significantly correlated with creatinine, low-density lipoprotein cholesterol, endogenous creatinine clearance rate, and the MTHFR rs1801133 genotypes in control group, while serum Hcy levels were significantly correlated with creatinine, triglyceride, low-density lipoprotein cholesterol, endogenous creatinine clearance rate, glycosylated hemoglobin, and the MTHFR rs1801133 genotypes in H-type hypertension group (P < 0.05-0.001). Serum Hcy levels in the T allele carriers were higher than those in the T allele noncarriers in both H-type hypertension and control groups.

CONCLUSIONS

There was closely related between the MTHFR rs1801133 SNP and serum Hcy levels in Zhuang patients with H-type hypertension in the central region of Guangxi. The MTHFR SNP may be an important reason for the increase of serum Hcy levels in Zhuang patients with H-type hypertension in this region.

Association of folic acid dosage with circulating unmetabolized folic acid in Chinese adults with H-type hypertension: a multicenter, double-blind, randomized controlled trial

Background

There is growing concern regarding elevated levels of circulating unmetabolized folic acid (UMFA) due to excessive intake of folic acid (FA). However, no randomized clinical trial has been conducted to examine the FA-UMFA dose-response relationship.

Objective

This study aimed to investigate the FA-UMFA dose-response relationship in Chinese adults with hypertension and elevated homocysteine (H-type hypertension), a population with clear clinical indication for FA treatment.

Methods

The data for this study were derived from a randomized, double-blind, multicenter clinical trial of 8 FA dosages on efficacy of homocysteine (Hcy) lowering. The parent trial had three 3 stages: screening period (2-10 days), run-in period (0-2 weeks, baseline visit), and double-blind treatment period (8 weeks) with follow-up visits at the end of the 2nd, 4th, 6th, and 8th weeks of treatment. Participants were randomly assigned to 8 treatment groups corresponding to FA dosages of 0, 0.4, 0.6, 0.8, 1.2, 1.6, 2.0 mg to 2.4 mg.

Results

This study included 1,567 Chinese adults aged ≥45 years with H-type hypertension. There was a positive but non-linear association between FA supplementation and UMFA levels in the dosage range of 0 mg to 2.4 mg. In the regression analysis, the coefficients for the linear and quadratic terms of FA dosage were both statistically significant (P < 0.001). Notably, the slope for UMFA was greater for FA dosages >0.8 mg (ß = 11.21, 95% CI: 8.97, 13.45) compared to FA dosages ≤0.8 mg (ß = 2.94, 95% CI: 2.59, 3.29). Furthermore, FA dosages higher than 0.8 mg did not confer additional benefits in terms of increasing 5-methyl tetrahydrofolic acid (5-MTHF, active form of folate) or reducing homocysteine (Hcy).

Conclusion

In Chinese adults with H-type hypertension, this study showed a positive, non-linear, dosage-response relationship between FA supplementation ranging from 0 to 2.4 mg and circulating UMFA levels. It revealed that 0.8 mg FA is an optimal dosage in terms of balancing efficacy (increasing 5-MTHF and lowering Hcy) while minimizing undesirable elevation of UMFA.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT03472508?term=NCT03472508&draw=2&rank=1, identifier NCT03472508.

Amlodipine downregulates gene expression that involved in the signaling pathways of coagulation process in COVID-19 patients: An observational clinical study

The SARS-CoV-2 virus has the property of activating the coagulation process, which is responsible for producing thrombotic events which is considered as one of the most serious COVID-19 complications. Hypertension is a hazard factor for COVID-19 complications, and people who are treated with calcium entry blockers may halt the occurrence of thrombotic events. to evaluate the effect of amlodipine on some genes involved in the activation of the coagulation procedure in COVID-19 patients with hypertensive. observational, cross-sectional study. This study was carried out in the Department of Pharmacy at Al-Kut University College in Wasit, Iraq, in conjunction with Al Zahraa Hospital from June 2021 to March 2022. A total of 45 COVID-19 patients participated in this study who were grouped into as follows: Group I (n = 23) who had no previous history of hypertension and Group II (n = 22) who had previous hypertension and were treated with amlodipine. Expression of the calcium-sensing receptor (CaSR), coagulation factor V (F5), and methylenetetrahydrofolate dehydrogenase (NADP+ dependent) 1 Like (MTHFD1L) genes was determined. P values were calculated by Chi-square test for categorized facts and the Mann-Whitney test for incessant data. P ≤ 0.05 was considered statistically significant. Group II patients had significantly lower levels of CaSR, F5, and MTHFD1L gene expression compared with the corresponding levels in Group I patients. The expression level of MTHFD1L was elevated significantly in patients who had currently high blood pressure compared with normotensive patients in both the groups. Amlodipine is preferred in hypertensive patients who have COVID-19 because it attenuates the levels of gene expression that have an impact on the coagulation process.

H-type hypertension is a risk factor for chronic total coronary artery occlusion: a cross-sectional study from southwest China

BACKGROUND

Chronic total coronary occlusion (CTO) is serious and the "last bastion" of percutaneous coronary intervention. Hypertension and hyperhomocysteinemia (HHCY) are synergistic and significantly increase cardiovascular event risk. The relationship between H-type hypertension and CTO remains unclear; thus, this cross-sectional study investigated this potential association.

METHODS

Between January 2018 and June 2022, 1446 individuals from southwest China were recruited to participate in this study. CTO was defined as complete coronary artery occlusion persisting for over three months. H-type hypertension was defined as hypertension with plasma homocysteine levels ≥ 15 µmol/L. Multivariate logistic regression models were applied to assess the association between H-type hypertension and CTO. Receiver operating characteristic (ROC) curves were generated to determine the accuracy of H-type hypertension in predicting CTO.

RESULTS

Of the 1446 individuals, 397 had CTO, and 545 had H-type hypertension. After multivariate adjustment, the odds ratio (OR) for CTO in individuals with H-type hypertension was 2.3-fold higher (95% CI 1.01-5.26) than that in healthy controls. The risk of CTO is higher in individuals with H-type hypertension than in those with isolated HHCY and hypertension. The area under the ROC curve for CTO was 0.685 (95% CI, 0.653-0.717) for H-type hypertension.

CONCLUSIONS

In southwest China, H-type hypertension is significantly related to the occurrence of CTO.

TRIAL REGISTRATION

This retrospective study was registered with the Chinese Clinical Trials Registry ( http://www.chictr.org.cn , ChiCTR2100050519.2.2).

Associations of MTHFR gene polymorphism with lipid metabolism and risk of cerebral infarction in the Northwest Han Chinese population

Objective

Genetic variation in the methylenetetrahydrofolate reductase (MTHFR) gene may contribute to the development of cerebral infarction (CI); however, results have been inconsistent across studies with different populations, including studies of the Chinese population. The aim of this study was to analyze the effect of MTHFR gene polymorphism on serum lipid and homocysteine levels among patients with CI in the Northwest Chinese Han population.

Patients and methods

A total of 521 CI patients and 524 non-CI controls were enrolled in the study. Polymerase chain reaction and hybridization were utilized to identify MTHFR gene polymorphisms. Multivariate logistic regression analysis was used to assess the associations of MTHFR gene polymorphism with risk of CI.

Results

Frequencies of the TT genotype and the T allele were markedly higher among CI patients than among controls. After stratifying our data by sex and age, we determined that these differences in frequency of the TT genotype and the T allele were statistically significant among participants of two different age brackets and among men, but not among women (i.e., there were no statistically significant differences between female patients and female controls). CI patients and control participants with the CT or TT genotype had significantly higher homocysteine (Hcy) levels than those with the CC genotype. Among CI patients, CT/TT carriers showed significantly lower high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (ApoA-I) levels as compared with CC carriers, but there was no significant difference for control participants. Multivariable logistic regression analysis showed that drinking; smoking; diabetes mellitus; levels of Hcy, direct bilirubin (DB), indirect bilirubin (IB), ApoA-I, and total protein (TP); and TT genotype were significant independent risk factors for CI.

Conclusions

The results suggested that the TT genotype of the MTHFR C677T gene polymorphism, which is associated with hyperhomocysteinemia (HHcy), might be of great clinical significance in the identification of new biomarkers for CI and in the development of individualized preventive and therapeutic strategies.

Effects of low-dose B vitamins plus betaine supplementation on lowering homocysteine concentrations among Chinese adults with hyperhomocysteinemia: a randomized, double-blind, controlled preliminary clinical trial

PURPOSE

To test the hypothesis that daily supplementation with low-dose B vitamins plus betaine could significantly reduce plasma homocysteine concentrations in Chinese adults with hyperhomocysteinemia and free from background mandatory folic acid fortification.

METHODS

One hundred apparently healthy adults aged 18-65 years with hyperhomocysteinemia were recruited in South China from July 2019 to June 2021. They were randomly assigned to either the supplement group (daily supplementation: 400 μg folic acid, 8 mg vitamin B₆, 6.4 μg vitamin B₁₂ and 1 g betaine) or the placebo group for 12 weeks. Fasting venous blood was collected at baseline, week 4 and week 12 to determine the concentrations of homocysteine, folate, vitamin B₁₂ and betaine. Generalized estimation equations were used for statistical analysis.

RESULTS

Statistically significant increments in blood concentrations of folate, vitamin B₁₂ and betaine after the intervention in the supplement group indicated good participant compliance. At baseline, there were no significant differences in plasma homocysteine concentration between the two groups (P = 0.265). After 12-week supplementation, compared with the placebo group, there was a significant reduction in plasma homocysteine concentrations in the supplement group (mean group difference - 3.87; covariate-adjusted P = 0.012; reduction rate 10.1%; covariate-adjusted P < 0.001). In the supplement group, the decreased concentration of plasma homocysteine was associated with increments of blood concentrations of both folate (β = -1.680, P = 0.004) and betaine (β = -1.421, P = 0.020) after 12 weeks of supplementation.

CONCLUSIONS

Daily supplementation with low-dose B vitamins plus betaine for 12 weeks effectively decreased plasma homocysteine concentrations in Chinese adults with hyperhomocysteinemia.

TRIAL REGISTRATION

This trial was registered at clinicaltrials.gov as NCT03720249 on October 25, 2018. Website: https://clinicaltrials.gov/ct2/show/NCT03720249 .

H-Type Hypertension among Black South Africans and the Relationship between Homocysteine, Its Genetic Determinants and Estimates of Vascular Function

Elevated homocysteine (Hcy) increases cardiovascular disease (CVD) risk. Our objective was to emphasize Hcy’s contribution in hypertension and CVD management by determining H-type hypertension (hypertension with Hcy ≥ 10 µmol/L) and associations between Hcy, blood pressure (BP) and estimates of vascular function among Black South Africans. We included 1995 adults (63% female). Plasma Hcy and cardiovascular measures (systolic and diastolic BP (SBP, DBP), pulse pressure, heart rate (HR), carotid-radialis pulse wave velocity (cr-PWV), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1) were quantified. Five Hcy-related polymorphisms (cystathionine β-synthase (CBS 844ins68, T833C, G9276A); methylenetetrahydrofolate reductase (MTHFR C677T) and methionine synthase (MTR A2756G)) were genotyped. Hcy was >10 µmol/L in 41% (n = 762), and of the 47% (n = 951) hypertensives, 45% (n = 425) presented with H-type. Hcy was higher in hypertensives vs. normotensives (9.86 vs. 8.78 µmol/L, p < 0.0001, effect size 0.56) and correlated positively with SBP, DBP, cr-PWV and ICAM-1 (r > 0.19, p < 0.0001). Over Hcy quartiles, SBP, DBP, HR, cr-PWV and ICAM-1 increased progressively (all p-trends ≤ 0.001). In multiple regression models, Hcy contributed to the variance of SBP, DBP, HR, cr-PWV and ICAM-1. H-type hypertensives also had the lowest MTHFR 677 CC frequency (p = 0.03). Hcy is positively and independently associated with markers of vascular function and raised BP.

Association between serum 5-methyltetrahydrofolate and homocysteine in Chinese hypertensive participants with different MTHFR C677T polymorphisms: a cross-sectional study

Background and aims

Clarifying the association between 5-methyltetrahydrofolate and homocysteine and the effect pattern of methylene tetrahydrofolate reductase (MTHFR C677T) may contribute to the management of homocysteine and may serve as a significant reference for a randomized controlled trial of 5-methyltetrahydrofolate intervention. This study aimed to reveal the association between these two biochemical indices.

Methods

Study population was drawn from the baseline data of the China Stroke Primary Prevention Trial (CSPPT), including 2328 hypertensive participants. 5-methyltetrahydrofolate and homocysteine were determined by stable-isotope dilution liquid chromatography-tandem mass spectrometry and automatic clinical analyzers, respectively. MTHFR C677T polymorphisms were detected using TaqMan assay. Multiple linear regression was performed to evaluate the association between serum 5-methyltetrahydrofolate and homocysteine.

Results

There was a significant inverse association between 5-methyltetrahydrofolate and homocysteine when 5-methyltetrahydrofolate was ≤ 10 ng/mL, and this association was modified by MTHFR C677T (per 1-ng/mL increment; All: β = − 0.50, P <  0.001; CC: β = − 0.14, P = 0.087; CT: β = − 0.20, P = 0.011; TT: β = − 1.19, P <  0.001). Moreover, the decline in trend in genotype TT participants was stronger than in genotype CC participants (P for difference <  0.001) and genotype CT participants (P for difference <  0.001), while there was no significant difference between genotype CC and genotype CT participants (P for difference = 0.757).

Conclusions

Our data showed a non-linear association between serum homocysteine and 5-methyltetrahydrofolate among Chinese hypertensive adults, however, it could be inversely linearly fitted when serum 5-methyltetrahydrofolate was ≤ 10 ng/mL, and this association was modified by MTHFR C677T.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-022-00786-w.

The Role of Amino Acids in Endothelial Biology and Function

The vascular endothelium acts as an important component of the vascular system. It is a barrier between the blood and vessel wall. It plays an important role in regulating blood vessel tone, permeability, angiogenesis, and platelet functions. Several studies have shown that amino acids (AA) are key regulators in maintaining vascular homeostasis by modulating endothelial cell (EC) proliferation, migration, survival, and function. This review summarizes the metabolic and signaling pathways of AAs in ECs and discusses the importance of AA homeostasis in the functioning of ECs and vascular homeostasis. It also discusses the challenges in understanding the role of AA in the development of cardiovascular pathophysiology and possible directions for future research.