Blood Pressure in Treated Hypertensive Individuals With the MTHFR 677TT Genotype Is Responsive to Intervention With Riboflavin: Findings of a Targeted Randomized Trial

Intervention with riboflavin was recently shown to produce genotype-specific lowering of blood pressure (BP) in patients with premature cardiovascular disease homozygous for the 677C→T polymorphism (TT genotype) in the gene encoding the enzyme methylenetetrahydrofolate reductase (MTHFR). Whether this effect is confined to patients with high-risk cardiovascular disease is unknown. The aim of this randomized trial, therefore, was to investigate the responsiveness of BP to riboflavin supplementation in hypertensive individuals with the TT genotype but without overt cardiovascular disease. From an available sample of 1427 patients with hypertension, we identified 157 with the MTHFR 677TT genotype, 91 of whom agreed to participate in the trial. Participants were stratified by systolic BP and randomized to receive placebo or riboflavin (1.6 mg/d) for 16 weeks. At baseline, despite being prescribed multiple classes of antihypertensive drugs, >60% of participants with this genotype had failed to reach goal BP (≤140/90 mm Hg). A significant improvement in the biomarker status of riboflavin was observed in response to intervention (P