Effect of folate supplementation on N-terminal pro-brain natriuretic peptide

Background: Increased plasma homocysteine (HCY) has been suggested as a novel risk factor for chronic heart failure (CHF). This study investigated the effect of a HCY lowering therapy by folic acid (FA) supplementation on N-terminal pro-brain natriuretic peptide (NT-proBNP) in healthy subjects. Methods: We treated 61 healthy individuals (median age [25th-75th percentile]: 57 [53-69] years with placebo, 0.4, 1.0 or 5.0 mg FA daily for 2 months. Fasting blood samples were taken after 0, 4 and 8 weeks. Serum HCY, folate, vitamin B-12 and NT-proBNP were studied. Results: Baseline HCY, folate and NT-proBNP levels were 13.6 (10.0-16.4) mu mol/L, 5.0 (3.8-6.4) mu g/L and 40.4 (21.8-67.3) ng/L, respectively. Serum folate increased during supplementation (4 weeks of placebo, 0:4, 1.0, 5.0 mg of FA: - 9%, + 131%, + 150%, +314%; 8 weeks: -72%, +152%, +185%, +62%) and HCY decreased (4 weeks: +2%, -12%, -20%, -15%; 8 weeks: -2%, -9%, -17%, - 15%) in the treatment groups. NT-proBNP did not change within groups. Pooling FA treated subjects, individuals with a baseline NT-proBNP above the median of 40 ng/L exhibited a 20% decrease of NT-proBNP (significant on a 10% level) while HCY decreased by 15%. Conclusion: FA supplementation with doses between 0.4 and 5 mg does not affect NT-proBNP in healthy subjects with an NT-proBNP concentration < 40 ng/L, but possibly lowers NT-proBNP in individuals with NT-proBNP levels > 40 ng/L. (c) 2006 Elsevier Ireland Ltd. All rights reserved.