Riboflavin offers a targeted strategy for managing hypertension in patients with the MTHFR 677TT genotype: A 4-y follow-up

Abstract

Background: We recently reported that the elevated blood pressure (BP) observed in patients with cardiovascular disease who are homozygous for the 677C→T polymorphism (TT genotype) in the gene encoding methylenetetrahydrofolate reductase (MTHFR) was responsive to supplementation with riboflavin - the cofactor for MTHFR. Objective: The objective was to investigate the effect of riboflavin on BP targeted at patients with the TT genotype 4 y after initial investigation, during which time major changes in the clinical guidelines for antihypertensive therapy were introduced. Design: A total of 83 patients (representing all 3 genotypes) who participated in a placebo-controlled riboflavin intervention for 16 wk in 2004 agreed to take part. Nested within this follow-up, those with the TT genotype (n = 31) proceeded to intervention with riboflavin (1.6 mg/d for 16 wk) or placebo, conducted in a crossover style whereby the 2004 treatment groups were reversed. Results: At follow-up in 2008, as in 2004, patients with the TT genotype had higher systolic BP (P < 0.01), with a nonsignificant trend noted for higher diastolic BP (P = 0.051). Despite the marked changes in antihypertensive therapy that had occurred, BP remained unchanged in patients with the TT genotype at the time of followup. Riboflavin supplementation (administered in 2004 and 2008) produced an overall decrease in systolic (-9.2 ± 12.8 mm Hg; P = 0.001) and diastolic (-6.0 ± 9.9 mm Hg; P = 0.003) BP. Conclusions: Optimizing riboflavin status offers a low-cost targeted strategy for managing elevated BP in this genetically at-risk group. These findings, if confirmed in the general population, could have important implications for the prevention of hypertension. © 2012 American Society for Nutrition.