Hyperhomocysteinemia in Patients with Newly Diagnosed Primary Hypertension in Can Tho City, Vietnam

The impact of homocysteine on patients with diabetic nephropathy: a mendelian randomization study

BACKGROUND/AIMS

Homocysteine (Hcy) has been associated with an increased risk of diabetic nephropathy (DN) in patients, but there is still controversy. This study aims to investigate the causal relationship between plasma Hcy and DN.

METHODS

A Mendelian randomization (MR) study using data from 2 samples was employed to infer causal relationships. The aggregated genetic data associated with Hcy was derived from the largest genome-wide association study (GWAS) to date, involving 44,147 individuals of European ancestry.Data on SNP-diabetic nephropathy, creatinine, and urea nitrogen were obtained from the IEU GWAS database. The analysis method employed a fixed-effect or random-effect inverse variance-weighted approach to estimate effects.Additional analysis methods were used to assess stability and sensitivity. The potential for pleiotropy was evaluated using the MR-Egger intercept test.

RESULTS

Using 12 SNPs as instrumental variables, two-sample MR analysis revealed no evidence of a causal relationship between genetically predicted plasma Hcy levels and diabetic nephropathy, as well as creatinine and blood urea nitrogen levels. This finding is consistent with the results obtained from other testing methods.

CONCLUSIONS

Two-sample Mendelian Randomization analysis found no evidence of a causal relationship between plasma homocysteine levels and diabetic nephropathy, creatinine, or urea.

Genetic Polymorphisms of Endothelial Nitric Oxide Synthase Associated with Hypertension and Blood Homocysteine Levels

Purpose

Endothelial dysfunction is a key mechanism in the development of hypertension and is closely linked to impairment of endothelial nitric oxide synthase (eNOS) and hyperhomocysteinemia. Genetic polymorphisms of eNOS (rs1799983 and rs2070744) are strongly associated with the risk of hypertension in individuals of Asian ethnicities. This study aimed to investigate the relationship between these polymorphisms and the risk of hypertension associated with homocysteine levels.

Participants and Methods

For this cross-sectional study, we enrolled 370 Thai men aged 40-60 years from the Electricity Generating Authority of Thailand cohort study for both variants genotyping by TaqMan allelic discrimination analysis. Clinical, anthropometric, and biochemical parameters were also analyzed.

Results

In the high blood pressure group (n = 267), systolic and diastolic blood pressure and triglyceride levels were higher in those with homocysteine levels ≥ 15 µmol/L than in those with homocysteine levels < 15 µmol/L (p < 0.05). Significant risk of hypertension was found in GG and GT of rs1799983 (G894T), and in TT and TC of rs2070744 (T-786C), with higher ORs in heterozygous genotypes (all p values < 0.05). Further evaluation of the interactions between SNPs and HCY revealed that individuals with the GT or TC genotype, together with hyperhomocysteinemia, had an increased risk of hypertension (all p<0.05).

Conclusion

eNOS variants rs1799983 and rs2070744 may be risk factors for hypertension linked to hyperhomocysteinemia. These findings provide potentially useful healthcare strategies for the management of hypertension.

The role of the mitochondrial trans-sulfuration in cerebro-cardio renal dysfunction during trisomy down syndrome

One in 700 children is born with the down syndrome (DS). In DS, there is an extra copy of X chromosome 21 (trisomy). Interestingly, the chromosome 21 also contains an extra copy of the cystathionine beta synthase (CBS) gene. The CBS activity is known to contribute in mitochondrial sulfur metabolism via trans-sulfuration pathway. We hypothesize that due to an extra copy of the CBS gene there is hyper trans-sulfuration in DS. We believe that understanding the mechanism of hyper trans-sulfuration during DS will be important in improving the quality of DS patients and towards developing new treatment strategies. We know that folic acid "1-carbon" metabolism (FOCM) cycle transfers the "1-carbon" methyl group to DNA (H3K4) via conversion of s-adenosyl methionine (SAM) to s-adenosyl homocysteine (SAH) by DNMTs (the gene writers). The demethylation reaction is carried out by ten-eleven translocation methylcytosine dioxygenases (TETs; the gene erasers) through epigenetics thus turning the genes off/on and opening the chromatin by altering the acetylation/HDAC ratio. The S-adenosyl homocysteine hydrolase (SAHH) hydrolyzes SAH to homocysteine (Hcy) and adenosine. The Hcy is converted to cystathionine, cysteine and hydrogen sulfide (H2S) via CBS/cystathioneγ lyase (CSE)/3-mercaptopyruvate sulfurtransferase (3MST) pathways. Adenosine by deaminase is converted to inosine and then to uric acid. All these molecules remain high in DS patients. H2S is a potent inhibitor of mitochondrial complexes I-IV, and regulated by UCP1. Therefore, decreased UCP1 levels and ATP production can ensue in DS subjects. Interestingly, children born with DS show elevated levels of CBS/CSE/3MST/Superoxide dismutase (SOD)/cystathionine/cysteine/H2S. We opine that increased levels of epigenetic gene writers (DNMTs) and decreased in gene erasers (TETs) activity cause folic acid exhaustion, leading to an increase in trans-sulphuration by CBS/CSE/3MST/SOD pathways. Thus, it is important to determine whether SIRT3 (inhibitor of HDAC3) can decrease the trans-sulfuration activity in DS patients. Since there is an increase in H3K4 and HDAC3 via epigenetics in DS, we propose that sirtuin-3 (Sirt3) may decrease H3K4 and HDAC3 and hence may be able to decrease the trans-sulfuration in DS. It would be worth to determine whether the lactobacillus, a folic acid producing probiotic, mitigates hyper-trans-sulphuration pathway in DS subjects. Further, as we know that in DS patients the folic acid is exhausted due to increase in CBS, Hcy and re-methylation. In this context, we suggest that folic acid producing probiotics such as lactobacillus might be able to improve re-methylation process and hence may help decrease the trans-sulfuration pathway in the DS patients.

Prevalence and clinical correlates of hyperhomocysteinemia in Chinese urban population with hypertension

Context

The coexistence of hypertension and elevated homocysteine (Hcy) levels has a mutually reinforcing impact on the susceptibility to cardio-cerebrovascular disease.

Objective

The aim was to assess the prevalence, clinical correlation, and demographic characteristics of hyperhomocysteinemia (HHcy) within the Chinese urban population with hypertension.

Methods

A cohort of 473 individuals with hypertension were selected from four communities in Shenzhen, China. Demographic attributes, clinical profiles, and lifestyle behaviors were gathered and compared between individuals with and without HHcy. A logistic regression model was employed to examine potential factors associated with the prevalence of HHcy. Correlation between Hcy levels and clinical characteristics was assessed through multiple linear regression analysis.

Results

The prevalence of HHcy in the population with hypertension was 31.3%. In comparison to individuals without HHcy, those with HHcy exhibited a higher proportion of males, a higher prevalence of smoking and alcohol consumption, and a higher proportion of cases with the homozygous (TT) genotype at the MTHFR C677T polymorphism. Moreover, individuals with HHcy had lower levels of folic acid (FA), and lower fruit and vitamin B12 intake. Furthermore, the risk factors for HHcy were male (B = 1.430, OR = 4.179) and MTHFR (TT) (B = 1.086, OR = 2.961). In addition, the multiple linear regression analysis revealed a significant association between Hcy levels and gender (B = -2.784, P = 0.004), MTHFR genotypes (B = 1.410, P = 0.005), and FA levels (B = -0.136, P = 0.030).

Conclusion

The high prevalence of HHcy among hypertensive patients in this Chinese urban population underscores the necessity for interventions targeting modifiable risk factors such as dietary choices and lifestyle practices.

Preliminary Consequences of Blood Pressure Management and Blood Homocysteine Levels with Perindopril in Newly Diagnosed Hypertensive Patients in the Vietnamese Population

Background

Perindopril is an ACE inhibitor that aids in both blood pressure regulation and homocysteine reduction.

Objectives

Our study aimed to evaluate the results of controlling blood pressure and blood homocysteine levels by perindopril in patients with primary hypertension.

Materials and Methods

A cross-sectional descriptive study with a longitudinal follow-up was conducted on 105 primary hypertensive patients treated with perindopril.

Results

The results of our study showed that after 6 weeks of treatment with perindopril, the proportion of patients with the target blood pressure (BP) level accounted for 70.5%, the rate of grade 1 hypertension decreased from 61.0% to 25.7%, grade 2 blood pressure decreased from 17.1% to 3.8%, and there was no case of grade 3 hypertension. At the same time, we also found that the rate of BP control in the group of patients who controlled Hcy below a threshold of 15 μmol/L was significantly higher than in the other group (p  <  0.05). Concerning the efficacy of decreasing homocysteine in blood, we discovered that after 6 weeks of treatment with perindopril, the proportion of patients with elevated homocysteine reduced considerably from 74.3% to 40% (p  <  0.05). In addition, the homocysteine concentration was 4.33 mol/L lower after treatment than before treatment (95% CI: 3.69-4.97) (p  <  0.05).

Conclusion

Perindopril helps control blood pressure and reduces blood homocysteine levels in patients with primary hypertension.