Blood Pressure, Hypertension
Conditions
Keywords
Blood Pressure, MTHFR, Methylenetetrahydrofolate Reductase, Riboflavin, Flow-Mediated Dilation, Nitric Oxide
Brief summary
High blood pressure is the leading risk factor for heart disease and stroke. Approximately 12% of the population have a particular genetic factor (known as the TT genotype) which increases the risk of high blood pressure. Previous studies conducted at this centre have shown that taking the B-vitamin riboflavin, for up to 3 months, decreases blood pressure in adults with the TT genotype. It is currently not known how riboflavin lowers blood pressure in those with the TT genotype but it could be as a result of altering blood levels of nitric oxide. Nitric oxide causes blood vessels to expand, leading to improved blood vessel function, an important predictor of cardiovascular health. However, the effect of riboflavin supplementation on nitric oxide and blood vessel function has not been previously studied. Furthermore, it is unclear whether taking riboflavin over a shorter period of time or at doses higher than 1.6 mg/d can also lower blood pressure and improve blood vessel function in this at risk group. Therefore, the aim of this study is to assess the effects of riboflavin supplementation on blood pressure, biomarkers of nitric oxide bioavailability and blood vessel function. It is hypothesised that riboflavin supplementation will increase nitric oxide bioavailability, leading to reduced blood pressure and improved blood vessel function and, and that a higher riboflavin dose will lead to greater reductions in blood pressure.
Interventions
DIETARY_SUPPLEMENTPlacebo
Placebo
DIETARY_SUPPLEMENTRiboflavin 1.6mg/d
Riboflavin 1.6mg/d
DIETARY_SUPPLEMENTRiboflavin 5mg/d
Riboflavin 5mg/d
DIETARY_SUPPLEMENTRiboflavin 20mg/d
Riboflavin 20mg/d
Sponsors
DSM Nutritional Products, Inc.
University of Ulster
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Intervention model description
Double blind placebo controlled parallel design
Eligibility
Sex/Gender
MALE
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Male * Aged 60 years and below * Pre-screened for MTHFR 677TT genotype (TTs and CCs individuals only invited)
Exclusion criteria
* Consumer of B-vitamin supplements * Consuming medication that interferes with B-vitamin metabolism
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Systolic blood pressure | Change over 16 weeks | Branchial blood pressure |
| Diastolic blood pressure | Change over 16 weeks | Branchial blood pressure |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Endothelial function | Change over 16 weeks | Measured by Flow Mediated Dilation |
| Nitric oxide bioavailability | Change over 16 weeks | Plasma nitrite and nitrate oxide analysed by a Sievers gas-phase chemiluminescence nitric oxide analyser |
| Erythrocyte glutathione reductase activation coefficient (EGRac)(Vitamin B2 marker) | Change over 16 weeks | Measured on automatic analyser |
| Pyridoxal phosphate (Vitamin B6 marker) | Change over 16 weeks | Measured on HPLC |
Countries
United Kingdom
Outcome results
None listed