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

Serum 5-Methyltetrahydrofolate Status Is Associated with One-Carbon Metabolism-Related Metabolite Concentrations and Enzyme Activity Indicators in Young Women

Maintaining optimal one-carbon metabolism (OCM) is essential for health and pregnancy. In this cross-sectional study, folate status was assessed based on 5-methyltetrahydrofolate (5-MTHF) levels, and the association between 5-MTHF and OCM-related metabolites was investigated in 227 female Japanese university students aged 18-25 years. The participants were divided into high and low 5-MTHF groups based on their folate status. Serum samples of the participants were collected while they were fasting, and 18 OCM-related metabolites were measured using stable-isotope dilution liquid chromatography-electrospray tandem mass spectrometry. The association between serum 5-MTHF and OCM-related metabolite concentrations was assessed using Spearman's rank correlation coefficient. Serum 5-MTHF concentrations were negatively correlated with total homocysteine (tHcy) concentrations and positively correlated with S-adenosylmethionine (SAM) and total cysteine (tCys) concentrations. Serum 5-MTHF concentrations demonstrated a stronger negative correlation with tHcy/tCys than with tHcy alone. The negative correlation between betaine and tHcy concentrations was stronger in the low 5-MTHF group than in the high 5-MTHF group. The 5-MTHF status could be linked to Hcy flux into the transsulfuration pathway via SAM. Therefore, the tHcy/tCys ratio may be a more sensitive indicator of the 5-MTHF status than tHcy alone. Furthermore, a low 5-MTHF status can enhance Hcy metabolism via betaine.

Effect of methylenetetrahydrofolate reductase C677T polymorphism on serum folate but not vitamin B12 levels in patients with H-type hypertension

BACKGROUND

Hyperhomocysteinemia (HHcy) is a common complication in Chinese hypertensive patients and associated with methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, folate, and vitamin B12 (Vit B12) status. This study evaluated the associations of MTHFR C677T polymorphism, folate, and Vit B12 with H-type hypertension.

METHODS AND RESULTS

887 eligible patients with essential hypertension were included. Patients were divided into two groups according to the Hcy level, the H-type hypertension group and the normal hypertension group. Related risk factors such as MTHFR polymorphism, folate and Vit B12 status were analyzed in the two groups. Age, gender, SBP, DBP, MTHFR C677T genotype, folate and Vit B12 differed significantly between H-type hypertension and normal hypertension groups (P < 0.05). MTHFR 677TT variant, gender, folate, and Vit B12 were independent risk factors for the occurrence of H-type hypertension. The risk for TT carriers was 8 times higher than that of CC and CT carriers [OR (95% CI) 8.248 (5.274-12.899)]. Male patients had almost fivefold higher odds than female patients [OR (95% CI) 4.923 (2.741-8.842)]. Folate level of patients with H-type hypertension decreased with the C to T substitution of MTFHR C677T gene (P < 0.05), while Vit B12 level was not associated with the gene (P > 0.05).

CONCLUSIONS

MTHFR 677TT variant, gender, folate, and Vit B12 were risk factors for the occurrence of H-type hypertension. Folate but not Vit B12 was associated with MTFHR C677T polymorphism in patients with H-type hypertension. Accordingly, the above factors may be considered in the prevention and treatment of hypertension.