Association of the MTHFR 677C>T Polymorphism with Obesity and Biochemical Variables in a Young Population of Mexico

MTHFR Gene Polymorphisms: A Single Gene with Wide-Ranging Clinical Implications-A Review

The enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR) catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a process essential for the methylation of homocysteine to methionine. Polymorphisms in the MTHFR gene can reduce enzyme activity, disrupting the folate cycle and leading to hyperhomocysteinemia. The two most common polymorphisms associated with this gene are 667C>T (rs1801133) and 1298A>C (rs1801131). Background: This review provides a comprehensive summary of the current knowledge regarding MTHFR polymorphisms, with a particular focus on their potential impact on disease susceptibility. We hope this review will serve as a valuable resource for understanding the significance of MTHFR polymorphisms and their complex relationships with various diseases. Methods: For this review, we prioritized recent evidence, focusing on reviews and meta-analyses published between 2015 and 2025, sourced from PubMed and Google Scholar. Results: We explore the connection between these polymorphisms and a broad spectrum of medical conditions, including cardiovascular diseases and oxidative stress pathology; neurological and psychiatric disorders, such as Autism Spectrum Disorder, Alzheimer's disease, Schizophrenia, and Major Depressive Disorder; fertility, pregnancy, and neonatal complications, including recurrent pregnancy loss, pre-eclampsia, preterm birth, low birth weight, and neural tube defects; metabolic disorders, such as diabetes mellitus, inflammatory bowel disease, and non-alcoholic fatty liver disease; and oncological conditions, including breast, prostate, and ovarian cancers; as well as leukemia, and autoimmune diseases, particularly rheumatoid arthritis. Conclusions: While some diseases have a well-established association with MTHFR polymorphisms, others require further investigation. Our analysis highlights the crucial role of environmental factors, such as ethnic background and dietary folate intake, in influencing study outcomes.

The different roles of homocysteine metabolism in hypertension among normal-weight and obese patients with obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) is associated with hypertension. However, the differential mechanisms underlying OSA-related hypertension between normal-weight vs. obese patients is limited.

METHODS

We studied 92 patients with OSA and 24 patients with continuous positive airway pressure (CPAP) treatment. Blood pressure (BP) was measured twice during awake and continuously monitored during sleep. Obesity was defined as body mass index ≥28 kg/m2. Serum metabolite levels were assessed by metabolomics.

RESULTS

Among 59 normal-weight and 33 obese patients, 651 and 167 metabolites showed differences between hypertension and normotension or were associated with systolic and diastolic BP (SBP, DBP) after controlling confounders. These metabolites involved 16 and 12 Kyoto Encyclopedia of Genes and Genomes enrichment pathways in normal-weight and obese patients respectively, whereas 6 pathways overlapped. Among these 6 overlapping pathways, 4 were related to homocysteine metabolism and 2 were non-specific pathways. In homocysteine metabolism pathway, 13 metabolites were identified. Interestingly, the change trends of 7 metabolites associated with SBP (all interaction-p≤0.083) and 8 metabolites associated with DBP (all interaction-p≤0.033) were opposite between normal-weight and obese patients. Specifically, increased BP was associated with down-regulated folate-dependent remethylation and accelerated transsulfuration in normal-weight patients, whereas associated with enhanced betaine-dependent remethylation and reduced transsulfuration in obese patients. Similar findings were observed in ambulatory BP during sleep. After CPAP treatment, baseline low homocysteine levels predicted greater decrease in DBP among normal-weight but not obese patients.

CONCLUSIONS

Mechanisms in OSA-related hypertension differ between normal-weight and obese patients, which are explained by different changes in homocysteine metabolism.

The Implication of a Polymorphism in the Methylenetetrahydrofolate Reductase Gene in Homocysteine Metabolism and Related Civilisation Diseases

Methylenetetrahydrofolate reductase (MTHFR) is a key regulatory enzyme in the one-carbon cycle. This enzyme is essential for the metabolism of methionine, folate, and RNA, as well as for the production of proteins, DNA, and RNA. MTHFR catalyses the irreversible conversion of 5,10-methylenetetrahydrofolate to its active form, 5-methyltetrahydrofolate, a co-substrate for homocysteine remethylation to methionine. Numerous variants of the MTHFR gene have been recognised, among which the C677T variant is the most extensively studied. The C677T polymorphism, which results in the conversion of valine to alanine at codon 222, is associated with reduced activity and an increased thermolability of the enzyme. Impaired MTHFR efficiency is associated with increased levels of homocysteine, which can contribute to increased production of reactive oxygen species and the development of oxidative stress. Homocysteine is acknowledged as an independent risk factor for cardiovascular disease, while chronic inflammation serves as the common underlying factor among these issues. Many studies have been conducted to determine whether there is an association between the C677T polymorphism and an increased risk of cardiovascular disease, hypertension, diabetes, and overweight/obesity. There is substantial evidence supporting this association, although several studies have concluded that the polymorphism cannot be reliably used for prediction. This review examines the latest research on MTHFR polymorphisms and their correlation with cardiovascular disease, obesity, and epigenetic regulation.

Methylenetetrahydrofolate Reductase C677T Gene Variant in Relation to Body Mass Index and Folate Concentration in a Polish Population

BACKGROUND

Methylenetetrahydrofolate reductase (MTHFR) is an enzyme responsible for producing an active form of folate. The MTHFR T677T genotype may have adverse health effects associated with weight gain and a reduction in folate availability.

AIM

In this study, we examined the influence of the MTHFR C677T variant on BMI and determined its role as a risk factor for obesity. We also assessed the relationships between the MTHFR C677T genotype and folate and vitamin B₁₂ concentrations in subjects before and after radical weight loss.

METHODS

The study group consisted of 1712 Caucasian adults of Polish nationality with a wide range of body mass indexes (BMIs). DNA was extracted from the blood, and the C677T variant was tested with RFLP-PCR and real-time-PCR.

RESULTS

There was no significant influence found for the MTHFR 677 TT genotype on BMI or the obesity risk in codominant, dominant or recessive inheritance models. Individuals with obesity and the TT genotype had significantly lower folate concentrations. After radical weight reduction, the impact of the risk genotype, as well as homeostasis between folate and vitamin B₁₂ in TT homozygotes, seems to be attenuated.

CONCLUSION

Although the MTHFR 677TT genotype is not directly related to a higher BMI in Polish adults, it has a detrimental effect on folate concentrations in individuals with high BMI values.

Associations of plasma betaine, plasma choline, choline intake and MTHFR polymorphism (rs1801133) with anthropometric parameters of healthy adults are sex-dependent

OBJECTIVE

Choline and its metabolites seem to have relationships with body mass index (BMI), body fat, and body weight, but research results have proved inconsistent. We thus investigated the associations of plasma levels of TMAO, choline, and betaine, with anthropometric measurements, including modulatory effects of genetics and diet.

METHODS

The study was performed on a group of 421 adults aged 20 to 40, who had been recruited in Poland. Plasma concentrations of choline, betaine, and TMAO were determined using RP-UHPLC-ESI-MS. The following polymorphisms were genotyped using TaqMan probes: rs180113 (MTHFR), the rs70991108 (DHFR), rs2236225 (MTHFD1), and rs7946 and rs12325817 (PEMT). We employed multivariate linear regression to examine the associations between anthropometric measurements, one carbon metabolism metabolites, and genotypes.

RESULTS

Higher plasma choline was associated with higher BMI (β=0.17; p< 0.01), body weight (β=0.11; p< 0.05), body fat mass (β=0.10; p<0.05), and waist circumference (WC) (β=0.14; p<0.01), whereas higher choline intake was associated with lower body fat mass (β=-0.14; p< 0.01), and lower WC (β=-0.12; p<0.01). After stratification by sex, plasma betaine was found to be associated with BMI (β=-0.20; p<0.05) and body weight (β=-0.16; p<0.05) in men only, while choline intake was associated with body fat mass (β=-0.19; p<0.05), and WHR (β=-0.19; p<0.05), and MTHFR CC genotype was associated with WHR (β=0.15; p<0.05) in women only.

CONCLUSIONS

Higher plasma betaine and higher dietary choline are associated with lower fat mass and body weight, whereas higher plasma choline is positively associated with body weight status and adiposity. Moreover, these associations seem to be sex-specific. This article is protected by copyright. All rights reserved.

Single Nucleotide Polymorphisms in Apolipoprotein B, Apolipoprotein E, and Methylenetetrahydrofolate Reductase Are Associated With Serum Lipid Levels in Northern Chilean Subjects. A Pilot Study

Characterization of allelic variants is relevant to demonstrate associations among genetic background and susceptibility to develop cardiovascular diseases, which are the main cause of death in Chile. Association of APOB, APOE, and MTHFR polymorphisms with higher lipid levels and the risk of developing hypertension and cardiovascular diseases have been described. Thus, the aim of this study was to assess genotype distribution and relative allelic frequency of ApoB rs693, ApoE rs7412, ApoE rs429358, MTHFR rs1801131, and MTHFR rs1801133 allelic variants and their effects on lipid profile in young healthy men and women from Northern Chile. A group of 193 healthy subjects were enrolled for this study. Genotyping of rs693 (APOB), rs7412 and rs429358 (APOE), and rs1801131 and rs1801133 (MTHFR) polymorphisms were performed by real time PCR. In addition, lipid profiles were determined and associated to genetic data. The genotype distribution was APOB rs693 (CC = 37%, CT = 41%, and TT = 22%), APOE rs7412/rs429358 (E4 = 0.06, E3 = 0.91, and E2 = 0.03), MTHFR rs1801131 (AA = 57%, AC = 30%, and CC = 13%), and MTHFR rs1801133 (CC = 20%, CT = 47%, and TT = 33%). The association of the genetic variants with plasma lipid levels showed that women, but not men, carrying APOB mutated allele (T) and Apo E4 allele presented lower values of total cholesterol when compared with C/C homozygous genotype or E3 allele, respectively (p < 0.05). In addition, a subgroup analysis revealed that ApoB C/C homozygous women exhibited higher values of HDL-C when compared with men carrying identical genotype (p < 0.01). On the other hand, women carrying E4 allele exhibited lower values of triglycerides when compared with male carrying identical genotype (p < 0.05). Finally, women carrying mutate allele (C) for MTHFR rs1801131 showed lower levels of triglycerides when compared with A/A homozygous genotype (p < 0.05) and lower levels of LDL-C for MTHFR rs1801133 in females carrying (T) allele when compared with males carrying identical genotype (p < 0.05). In summary, the present data showed that APOB, APOE, and MTHFR single nucleotide polymorphisms are associated to lipid levels in a gender-dependent manner among healthy subjects from Northern Chile, especially in women.

MTHFR Polymorphisms in Girls with Anorexia Nervosa: Implications on Body Weight

The development of atypical vs typical anorexia nervosa (AN) might be explained by the genetic background. We assessed the link between the subtypes of AN and the genetic polymorphisms of the thrombotic panel and the methyltetrahydrofolate reductase (MTHFR) gene. This cross-sectional pilot study recruited 48 girls with AN and 10 age-matched control girls with normal menstruation. We recorded anthropometric parameters and obtained blood samples for genotyping and hormonal assessment. Classification of AN was performed according to the DSM-V criteria. Girls with AN had 2.66 times higher odds of carrying at least one genetic polymorphism from the MTHFR panel (C677T and A1298C) compared with girls without AN (OR = 2.660, p-value = 0.041; CI 95% 1.057-6.720). The presence of atypical vs typical AN was associated independently with the presence of any of the assessed MTHFR polymorphisms (C677T, OR = 4.929, 95% CI 1.076-22.579, p-value = 0.040; A1298C, OR = 0.097, 95% CI 0.011-0.866, p-value = 0.037) in age and estrogen adjusted models. The atypical presentation of AN is mainly linked with higher prevalence of the MTHFR C677T and lower prevalence of the A1298C polymorphism.

Regulatory effect of diosgenin on lipogenic genes expression in high-fat diet-induced obesity in mice

Obesity is one of the most serious health problems in the world, increasing the risk of other chronic diseases. Alterations in fatty acid synthesis related genes are crucially involved in obesity progression. Diosgenin (DG) was one of the phytosterols compounds with vital activity against lipid disorders. Therefore, this study was intended to evaluate the protective effect of DG on lipogenesis in the high-fat diet (HFD)-induced obesity in mice, via investigating the expression of two of the fatty acid synthesis–involved genes; sterol regulatory element-binding protein (SREBP-1c) and fatty acid synthase (FASN) genes. Thirty adult male mice were divided into 3 groups. Control group, fed with normal diet; HFD group, mice fed with a high-fat diet and HFD + DG group, mice fed with a high-fat diet and supplemented in parallel with DG for 6 consecutive weeks. The effect of DG on Body weights, liver enzymes, lipid profile, were evaluated. Histopathological fatty changes as well as SREBP-1c and FASN gene expression were also investigated. DG significantly alleviated body weight gain, adjusted liver enzymes, and improved lipid profile. Additionally, DG ameliorated the histopathological changes by reducing the lipid vacuoles and hence the hepatosteatosis. Accordingly, DG significantly downregulated the two-fold increase in the SREBP-1c and FASN gene expression observed in the HFD group. In conclusion, DG possesses a beneficial impact against diet-induced obesity in mice, which makes it a good candidate for NAFLD and obesity prevention.

Association of overweight and obesity with cardiovascular risk factors in patients with atherosclerotic diseases

Background

The aim of this study was to compare demographic, clinical and biochemical characteristics, including inflammatory markers, according to the nutritional status of patients with verified atherosclerotic disease.

Methods

This cross-sectional study involved 1045 consecutive patients with verified carotid disease or peripheral arterial disease (PAD). Anthropometric parameters and data on cardiovascular risk factors and therapy for hypertension and hyperlipidemia were collected for all participants.

Results

Carotid disease was positively and PAD was negatively associated with body mass index (BMI). Negative association between obesity and PAD was significant only in former smokers, not in current smokers or in patients who never smoked. Overweight and general obesity were significantly related to metabolic syndrome (p < 0.001), lower values of high - density lipoprotein cholesterol (p < 0.001), increased triglycerides (p < 0.001), hyperglycemia (p < 0.001), self-reported diabetes (p < 0.001), hypertension (p < 0.001), high serum uric acid (p < 0.001), increased high sensitivity C-reactive protein (p = 0.020) and former smoking (p = 0.005) after adjustment for age, gender and type of disease. Antihypertensive therapy seems to be less effective in patients who are overweight and obese.

Conclusions

In conclusion, overweight and general obesity were significantly related to several cardiovascular risk factors.