Study objective: To determine the efficacy of high-dose ascorbate supplementation in lowering lipoprotein(a) [Lp(a)] levels in patients with premature coronary heart disease (CHD).
Design: Randomized, double-blind, placebo-controlled trial.
Setting: Outpatient clinic.
Patients: Forty-four patients with documented premature CHD, defined as confirmed myocardial infarction and/or angiographically determined stenosis of 50% or greater in at least one major coronary artery before age 60 years.
Interventions: Patients were block randomized on the basis of age, gender, and screening Lp(a) concentrations to receive ascorbate 4.5 g/day or placebo for 12 weeks.
Measurements and main results: High-dose ascorbate was well tolerated and produced a marked elevation in mean plasma ascorbate levels (+1.2 mg/dl; p < 0.001). Multiple linear regression analysis revealed no significant effect of supplementation on postintervention Lp(a) levels (p = 0.39) in a model that included treatment group assignment, and baseline Lp(a) levels.
Conclusions: Our findings do not support a clinically important lowering effect of high-dose ascorbate on plasma Lp(a) in patients with premature CHD.