Effect of MTHFRC677 T Gene Polymorphism on Early Morning Blood Pressure in Elderly Female Patients with H-Type Hypertension

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.

Analysis of MTHFR C677T genotype and related factors in H-type hypertension in Tibet, China

BACKGROUND AND AIMS

H-type hypertension is essential hypertension combined with high homocysteine, and both synergistically increase the risk of cardiovascular and cerebrovascular events. The aim of this study was to investigate the risk factors of H-type hypertension in Tibetan plateau population and correlation with MTHFR C677T gene.

METHODS AND RESULTS

A multi-stage cluster random sampling method was used to select the research subjects in Tibet Autonomous Region from June 2020 to November 2021. Among Tibetans, the incidence of H-type hypertension accounted for 84.31% of hypertensive patients. The logistic regression analysis demonstrated that age, uric acid (UA), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) were risk factors for the prevalence of H-type hypertension, the OR (95% CI) was 1.083(1.073-1.094), 1.002(1.001-1.004), 1.240(1.050-1.464) and 2.274(1.432-3.611), respectively. MTHFR C677T TT genotype patients with H-type hypertension OR (95% CI) was 1.629(1.004-2.643). Based on this, a nomogram model was established, and the reliability of the model was proved by area under ROC curve, Brier score and average absolute error. The model's results indicate that for every five years of age, the score increases by 6 points; for a 2mmol/L increase in TG, the score increases by 5.5 points; for a 1mmol/L increase in LDL-C, the score increases by 10 points; and individuals with the TT genotype receive 8 points. The higher the score, the greater the risk of disease.

CONCLUSION

The MTHFR C677T TT genotype is a risk locus for Tibetan patients with H-type hypertension, with age, TG, and LDL-C were identified as risk factors for the disease.

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.

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.