Lowering Homocysteine with B Vitamins Has No Effect on Blood Pressure in Older Adults

Abstract

An elevated circulating homocysteine concentration is associated with the risk of cardiovascular disease. The mechanism by which an elevated homocysteine increases cardiovascular risk is unclear but may be mediated in part by elevating blood pressure. It is well established that supplements containing folate, vitamins B-12, and B-6 lower homocysteine concentrations. However, the effect of homocysteine-lowering vitamins on blood pressure has not been well studied. We sought to determine whether lowering homocysteine with B vitamins lowers blood pressure in healthy older people with elevated homocysteine concentrations. Two hundred seventy-six healthy older participants (≥65 y) with a homocysteine ≥13 μmol/L were randomized to receive a daily supplement containing folate (1 mg), vitamin B-12 (500 μg), and vitamin B-6 (10 mg), or a placebo, for 2 y. Plasma homocysteine was lower in the Vitamins group than the Placebo group at both 1 [−4.3 μmol/L (95% CI; −4.9, −3.7)] and 2 y [−4.4 μmol/L (95% CI: −5.3, −3.6)]. Systolic and diastolic blood pressures as well as pulse pressure in the Vitamins group did not differ from the Placebo group over the duration of the trial. The mean differences in blood pressures, adjusted for baseline values, did not exceed 1 mm Hg. Supplemental B-vitamins lowered plasma homocysteine but had no effect on blood pressure in older people with elevated baseline homocysteine concentrations.