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

Blood Pressure Clinical Trial

— RAFA  

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04278378
• Other study ID #: REC/11/0081
• Status: Completed
• Phase: N/A
• Start date: June 28, 2011
• Est. completion date: August 15, 2019

Study information

• Verified date: June 2021
• Source: University of Ulster
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 2564
• Est. completion date: August 15, 2019
• Est. primary completion date: August 15, 2019
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years and older

Eligibility

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

Related Conditions & MeSH terms

• Blood Pressure
• Genetic Predisposition to Disease
• Hypertension

Intervention

Dietary Supplement:
• Riboflavin
1.6 mg riboflavin / day for 24 weeks
• Folic acid
0.4 mg folic acid / day for 24 weeks
• Placebo

Locations

Country	Name	City	State
United Kingdom	Human Intervention Studies Unit, Ulster University	Coleraine	Co.Londonderry

Sponsors (1)

Lead Sponsor	Collaborator
University of Ulster

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Blood pressure	Office blood pressure	Change from baseline to 24 weeks
Secondary	Central blood pressure	Measured using SphygmoCor device	Change from baseline to 24 weeks
Secondary	Pulse wave analysis	Measured using SphygmoCor device	Change from baseline to 24 weeks
Secondary	Pulse wave velocity	Measured using SphygmoCor device	Change from baseline to 24 weeks
Secondary	Red blood cell riboflavin	Measured using erythrocyte glutathione reductase activity coefficient (EGRAC)	Change from baseline to 24 weeks
Secondary	Red blood cell folate	Measured by microbiological assay	Change from baseline to 24 weeks
Secondary	Serum homocysteine	Measured using an immunoassay	Change from baseline to 24 weeks
Secondary	Plasma vitamin B6	Measured by High Performance Liquid Chromatography	Change from baseline to 24 weeks