There are 5 clinical trials

Clinical Trials

1 Pilot Evaluation of the Effect of Riboflavin Supplementation on Blood Pressure and Possible Effect Modification by the MTHFR C677T Genotype

Hypertension, which results from a combination of multiple lifestyle and genetic factors, is a global public health problem affecting 1 billion people worldwide. The identification of cheap treatment interventions without adverse side effects would be hugely advantageous particularly in low-income settings with high prevalence of hypertension such as sub-Saharan Africa where up to 46% of adults are affected. Emerging evidence links a functional polymorphism in the MTHFR gene (rs1801133 C677T), encoding the folate-metabolising enzyme methylenetetrahydrofolate reductase to high blood pressure in adults. Variation at rs1801133 is relatively common and has 3 genotypes; homozygous "normal" CC, heterozygous CT and homozygous "variant" TT genotypes. Of these genotypes, the homozygous "variant" TT is more strongly associated with a higher BP. The precise mechanism by which MTHFR is associated with BP remains unclear. It has been recently shown in 3 separate randomized controlled trials that BP is highly responsive to riboflavin and that this response is differential by MTHFR rs1801133 genotype. In all these clinical trials, significant reduction in both systolic and diastolic blood pressure was observed in the homozygous variant TT genotype and an intermediate effect seen in those with the heterozygous CT genotype. The aim of this study is to evaluate the effect of riboflavin supplementation on blood pressure in a riboflavin-deplete population as well as comparing plasma riboflavin status before and after supplementation. This will be achieved by conducting a randomized single-blind placebo controlled trial over a period of 16 weeks. The Investigators will use the Keneba biobank to invite about 100 adults with the CT genotype and a similar number of age-, sex and village-matched CC homozygotes. Participants within each of the groups will be randomized to receive either riboflavin (5mg/d) or a matching placebo which would be supplied on a weekly basis. Blood sample, blood pressure measurement, socio-demographic data and their anthropometric measurements (height, weight, waist and hip circumference and body composition by BIA) will be taken during the initial visit. An additional blood sample will be taken at the end of the study whilst additional BP measurements will be taken respectively at 8 weeks and at the end of the intervention. The possibility that riboflavin deficiency represents a new, easily-correctible causal factor in hypertension in sub-Saharan Africa would require further large-scale interventions if this pilot study yields encouraging results.

NCT03151096 High Blood Pressure MTHFR C677T Genotype Dietary Supplement: Riboflavin Dietary Supplement: Placebo

MeSH:Hypertension

HPO:Hypertension

Emerging evidence links a functional polymorphism in the MTHFR gene (rs1801133 C677T), encoding the folate-metabolising enzyme methylenetetrahydrofolate reductase to high blood pressure in adults.

Variation at rs1801133 is relatively common and has 3 genotypes; homozygous "normal" CC, heterozygous CT and homozygous "variant" TT genotypes.

It has been recently shown in 3 separate randomized controlled trials that BP is highly responsive to riboflavin and that this response is differential by MTHFR rs1801133 genotype.

We would like to investigate if there is any effect modification in CC vs CT variants of rs1801133 in the MTHFR gene in response to riboflavin supplementation vs placebo.

2 The Effect of Betaine Supplementation on Body Composition and Physical Capacity of Speed-strength Male Athletes

The study is aimed at assessing the influence of two betaine doses (2.5 g∙d-1 and 5 g∙d-1) supplemented for three weeks in a group of speed-strength trained athletes on anaerobic capacity in Wingate test, performance in CrossFit-like exercise test - Fight Gone Bad, alterations in body compositions and total body water.

NCT03702205 Supplementation Sport Dietary Supplement: Betaine supplementation Dietary Supplement: Placebo treatment

Difference in response to betaine supplementation depending on MTHFR (rs1801133) polymorphism.

MTHFR (rs1801133) polymorphism.

3 Association of the C677T and A1298C MTHFR Polymorphisms With Chemotherapy Effectiveness Among Patients With Metastatic Colorectal Cancer

Fluoropyrimidines are the backbone of chemotherapy regimes used to treat metastatic colorectal cancer (CRC). These drugs act in different pathways of folate metabolism altering DNA synthesis mainly by inhibition of the tymidylate synthase. For this reaction the 5,10-methylenetetrahydrofolate acts as cofactor. It has been demonstrated that A1298C and C677T polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene result in reduced enzyme activity that leads to reduced availability of this important cofactor. Hence, we hypothesized that the presence of these polymorphisms are related to the efficacy and toxicity of fluoropyrimidines in patients with CRC.

NCT03852290 Colon Cancer MTHFR Gene Mutation Chemotherapeutic Toxicity Chemotherapy Effect

MeSH:Colonic Neoplasms

HPO:Colon cancer Neoplasm of the colon

DNA extraction will be done from blood and tissue samples to determine the C677T (rs1801133) and 1298 A>C (rs18011131) polymorphisms of the MTHFR gene.

4 Is Natural Folate as Effective as Synthetic Folic Acid in Increasing Serum and Red Blood Cell Folate Concentrations During Pregnancy? A Proof-of-concept Pilot Study

In this two-arm, double-blind randomized pilot study, the investigators will recruit 60 generally healthy, low-risk pregnant women aged 19-42 years living in Vancouver, Canada. Participants will be randomized to supplement with either 0.6 mg/day folic acid or an equimolar dose (0.625 mg/day) of (6S)-5-methyltetrahydrofolic acid for 16-weeks of their pregnancy. Randomization will occur at 8-21 weeks gestation (after neural tube closure) to reduce the risk of harm should the natural folate prove less effective. All participants will also receive a prenatal multivitamin not containing any form of folate, to ensure adequacy of other nutrients (e.g. iron) required during pregnancy. Three-hour fasting venous blood samples will be collected at baseline and endline to measure serum and red blood cell folate, unmetabolized folic acid and other related biomarkers. Women will be given the option to continue supplementing until 1-week postpartum, and provide a small (3mL) breastmilk sample in order to measure differences in folates in breastmilk. These pilot data will be used to inform a definitive trial regarding the most effective form of folate supplementation for mothers and their babies.

NCT04022135 Pregnancy Dietary Supplement: Folic acid Dietary Supplement: (6S)-5-methyltetrahydrofolic acid

Gene variant assessment of MTHFR (677 C>T, rs1801133, and 1298 A>C, rs1801131) and DHFR (rs1643649 and rs70991108) and differences in DNA methylation.

5 A Retrospective Cohort Study: The Influence of MTHFR C677T and A1298C on the High-dose Methotrexate-Related Toxicities in Pediatric Patients With Non-Hodgkin Lymphoma

We hypothesized that polymorphism MTHFR C677T and A1298C should be associated with HD-MTX-related toxicities in children with NHL. Therefore, we aimed to retrospectively explore their relationships in this analysis.

NCT04283955 Pediatric NHL Drug: High-dose MTX based chemotherapy

MeSH:Lymphoma, Non-Hodgkin

HPO:Non-Hodgkin lymphoma

The most two extensively studied SNPs of MTHFR in relation to the toxicities of MTX are the C677T variant (Ala222Val, rs1801133) and A1298C variant (Glu 429Ala, rs1801131), both dampening the enzyme activity by 40-70%.

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