Prevalence of hyperhomocysteinemia (HHcy) and its major determinants among hypertensive patients over 35 years of age

Mild hyperhomocysteinemia alters oxidative stress profile via Nrf2, inflammation and cholinesterases in cardiovascular system of aged male rats

Homocysteine (Hcy) is an independent cardiovascular disease (CVD) risk factor, whose mechanisms are poorly understood. We aimed to explore mild hyperhomocysteinemia (HHcy) effects on oxidative status, inflammatory, and cholinesterase parameters in aged male Wistar rats (365 days old). Rats received subcutaneous Hcy (0.03 μmol/g body weight) twice daily for 30 days, followed by euthanasia, blood collection and heart dissection 12 h after the last injection. Results revealed increased dichlorofluorescein (DCF) levels in the heart and serum, alongside decreased antioxidant enzyme activities (superoxide dismutase, catalase, glutathione peroxidase), reduced glutathione (GSH) content, and diminished acetylcholinesterase (AChE) activity in the heart. Serum butyrylcholinesterase (BuChE) levels also decreased. Furthermore, nuclear factor erythroid 2-related factor 2 (Nrf2) protein content decreased in both cytosolic and nuclear fractions, while cytosolic nuclear factor kappa B (NFκB) p65 increased in the heart. Additionally, interleukins IL-1β, IL-6 and IL-10 showed elevated expression levels in the heart. These findings could suggest a connection between aging and HHcy in CVD. Reduced Nrf2 protein content and impaired antioxidant defenses, combined with inflammatory factors and altered cholinesterases activity, may contribute to understanding the impact of Hcy on cardiovascular dynamics. This study sheds light on the complex interplay between HHcy, oxidative stress, inflammation, and cholinesterases in CVD, providing valuable insights for future research.

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.

Genome-wide analysis of DNA methylation and its relationship with serum homocysteine levels in patients with hypertension

BACKGROUND

Homocysteine (Hcy) is an independent risk factor for cardiovascular diseases, and elevated plasma Hcy levels could aggravate vascular injury in hypertension. Hyperhomocysteinemia can change the methylation status of global DNA and specific genes. In the present study, we aim to examine the comprehensive influence of Hcy levels on DNA methylation status in patients with hypertension.

METHODS

Epigenome-wide methylation profiles of the peripheral leukocyte DNA of 218 patients with hypertension were analyzed using the Illumina Infinium Methylation EPIC BeadChip. Differentially methylated positions (DMPs) associated with serum Hcy levels were identified by mixed linear regression with the adjustment of potential confounders. Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis were conducted to determine the potential functions of the identified DMPs. The association between the methylation level of DMPs and carotid-femoral pulse wave velocity (Cf-PWV) was also analyzed.

RESULTS

Five DMPs at cg13169662, cg03179312, cg21976560, cg25262698, and cg09433843 showed significant association with serum Hcy levels (false discovery rate-corrected P  < 0.05). An additional six CpG sites met the threshold for suggestive significance ( P  < 1 × 10 -6 ), among which three DMPs (cg25781123, cg26463106, and cg06679221) were annotated to THUMPD3 . Furthermore, the methylation levels of cg13169662 and cg25262698 (RPRD1A) were significantly associated with Cf-PWV.

CONCLUSION

Our results suggest that Hcy could induce DNA methylation alteration in patients with hypertension. Further functional research is warranted to elucidate the concrete role of DMPs in hypertension.

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

Background: Elevated levels of blood total homocysteine is one of the cardiovascular risk factors in hypertensive patients. Objectives: Determine the prevalence of hyperhomocysteinemia and its associated factors in newly diagnosed primary hypertension patients. Materials and methods: A cross-sectional descriptive study on 105 patients with newly diagnosed primary hypertension at Can Tho University of Medicine and Pharmacy Hospital from May 2017 to May 2018. Total homocysteine levels and related factors were collected at the study time. Results: The mean plasma total homocysteine level was 16.24 ± 4.49 µmol/L. There were 78 patients with elevated plasma total homocysteine levels ≥15 µmol/L, accounting for 74.3% of all patients. Being elderly, gender, hypertension stage, and diabetes were factors associated with hyperhomocysteinemia (p < 0.05). Total homocysteine levels were positively correlated with SBP, DBP, and age with r(SBP) = 0.696, r(DBP) = 0.585, and r(age) = 0.286. Conclusion: Research on the subpopulation of Vietnamese people shows that hyperhomocysteinemia is common in patients with newly diagnosed primary hypertension, and high blood total homocysteine levels are often related to age, sex, hypertension stage, and diabetes.

Hyperhomocysteinemia Promotes Cardiac Hypertrophy in Hypertension

Hyperhomocysteinemia (HHcy) is positively linked with several cardiovascular diseases; however, its role and underlying mechanisms in pathological cardiac hypertrophy are still unclear. Here, we focused on the effects and underlying mechanisms of HHcy in hypertensive cardiac hypertrophy, one of the most common and typical types of pathological cardiac hypertrophy. By a retrospective analysis of the association between HHcy and cardiac hypertrophy in a hypertensive cohort, we found that the prevalence of HHcy was higher in patients with hypertrophy and significantly associated with the presence of cardiac hypertrophy after adjusting for other conventional risk factors. In mice, HHcy induced by a methionine (2% wt/wt) diet feeding significantly promoted cardiac hypertrophy as well as cardiac inflammation and fibrosis induced by 3-week angiotensin ІІ (AngІІ) infusion (1000 ng/kg/min), while folic acid (0.006% wt/wt) supplement corrected HHcy and attenuated AngII-stimulated cardiac phenotypes. Mechanistic studies further showed that homocysteine (Hcy) exacerbated AngII-stimulated expression of Calcineurin and nuclear factor of activated T cells (NFAT), which could be attenuated by folic acid both in mice and in neonatal rat cardiomyocytes. Moreover, treatment with cyclosporin A, an inhibitor of Calcineurin, blocked Hcy-stimulated Calcineurin-NFAT signaling and hypertrophy in neonatal rat cardiomyocytes. In conclusion, our study indicates that HHcy promotes cardiac hypertrophy in hypertension, and Calcineurin-NFAT pathway might be involved in the pro-hypertrophic effect of Hcy.

Homocysteine Solution-Induced Response in Aerosol Jet Printed OECTs by Means of Gold and Platinum Gate Electrodes

Homocysteine (Hcy) is a non-protein, sulfur-containing amino acid, which is recognized as a possible risk factor for coronary artery and other pathologies when its levels in the blood exceed the normal range of between 5 and 12 μmol/L (hyperhomocysteinemia). At present, standard procedures in laboratory medicine, such as high-performance liquid chromatography (HPLC), are commonly employed for the quantitation of total Hcy (tHcy), i.e., the sum of the protein-bound (oxidized) and free (homocystine plus reduced Hcy) forms, in biological fluids (particularly, serum or plasma). Here, the response of Aerosol Jet-printed organic electrochemical transistors (OECTs), in the presence of either reduced (free) and oxidized Hcy-based solutions, was analyzed. Two different experimental protocols were followed to this end: the former consisting of gold (Au) electrodes' biothiol-induced thiolation, while the latter simply used bare platinum (Pt) electrodes. Electrochemical impedance spectroscopy (EIS) analysis was performed both to validate the gold thiolation protocol and to gain insights into the reduced Hcy sensing mechanism by the Au-gated OECTs, which provided a final limit of detection (LoD) of 80 nM. For the OECT response based on Platinum gate electrodes, on the other hand, a LoD of 180 nM was found in the presence of albumin-bound Hcy, with this being the most abundant oxidized Hcy-form (i.e., the protein-bound form) in physiological fluids. Despite the lack of any biochemical functionalization supporting the response selectivity, the findings discussed in this work highlight the potential role of OECT in the development of low-cost point-of-care (POC) electronic platforms that are suitable for the evaluation, in humans, of Hcy levels within the physiological range and in cases of hyperhomocysteinemia.