Blood Pressure Lowering Effect of B-vitamins in Adults With a Genetic Pre-disposition to Elevated Blood Pressure. (RAFA)

Ulster University

Status: Completed

Conditions: Blood Pressure

Treatments: Dietary Supplement: Placebo; Dietary Supplement: Folic acid; Dietary Supplement: Riboflavin

Study type: Interventional

Funder types: Other

Identifiers

NCT04278378

REC/11/0081

Details and patient eligibility

About

Approximately 12% of the world's population have a have a common C677T polymorphism in the gene encoding the folate metabolising enzyme, methylenetetrahydrofolate reductase (MTHFR). Homozygosity for the polymorphism (TT genotype) causes an increased requirement for the B-vitamins folic acid and riboflavin and more importantly results in an increased risk of developing high blood pressure (BP). Previous work from our Centre has demonstrated significantly higher BP in those with the TT genotype. This work has been conducted in cohorts with premature cardiovascular disease (CVD) and hypertension without overt CVD, but the effect in younger, healthier individuals is unexplored. To date our studies have also focused on BP as the primary outcome, but newer markers of vascular health including central pressure and hemodynamics have emerged as superior prognostic indicators of CVD. The effect of the TT genotype on these measures is an area for investigation and may help us understand the mechanism linking the genotype with BP, which is currently unknown. As adults with the TT genotype have increased requirements for riboflavin and folic acid, and BP in TT adults appears to be riboflavin dependent, the influence of these vitamins on central measures is an area for consideration. Study Design This is an observational study investigating the blood pressure profiles of healthy adults aged 18-65 years, stratified by MTHFR genotype. Apparently healthy adults will be recruited from workplaces and the general community across Northern Ireland and screened for the polymorphism via buccal swab. Those with the TT genotype and a similar number of non-TT (i.e. CC/CT) genotype individuals will be contacted and asked to come to a one-off appointment. Brachial BP will be assessed by an electronic BP monitor, central BP and central haemodynamics (augmentation index, augmentation pressure and pulse wave velocity) will be assessed by SphygmoCor XCEL. In addition, anthropometric measurements, health and lifestyle infromation and a blood sample will be obtained. Data will be statistically analysed using SPSS software to if determine differences between gentoype groups exist.

Enrollment: 2,564 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• MTHFR 677TT genotype, aged at least 18 years old

Exclusion criteria

• Taking supplements containing B-vitamins
• Pregnant or planning to conceive
• Taking medications interfering with folate metabolism
• Renal or gastrointestinal disease

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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2,564 participants in 4 patient groups, including a placebo group

Riboflavin

Active Comparator group

Description:

1.6 mg riboflavin / day for 24 weeks

Treatment:

Dietary Supplement: Riboflavin

Folic Acid

Experimental group

Description:

0.4 mg folic acid/ day for 24 weeks

Treatment:

Dietary Supplement: Folic acid

Riboflavin + Folic Acid

Experimental group

Description:

1.6mg Riboflavin + 0.4 mg Folic Acid / day for 24 weeks

Treatment:

Dietary Supplement: Folic acid

Dietary Supplement: Riboflavin

Placebo

Placebo Comparator group

Treatment:

Dietary Supplement: Placebo