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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #125929
Title: L-FOLINIC ACID VERSUS FOLIC ACID FOR THE TREATMENT OF HYPERHOMOCYSTEINEMIA IN HEMODIALYSIS PATIENTS

Author
item YANGO, ANGELITO - MEMORIAL HOSP, RI
item SHEMIN, DOUGLAS - MEMORIAL HOSP, RI
item HSU, NATALIE - MEMORIAL HOSP, RI
item JACQUES, PAUL - HNRCA
item DWORKIN, LANCE - MEMORIAL HOSP, RI
item SELHUB, JACOB - HNRCA
item BOSTOM, ANDREW - HNRCA

Submitted to: Kidney International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/27/2000
Publication Date: 2/1/2001
Citation: N/A

Interpretive Summary: Homocysteine is an amino acid which has important function in the body but elevated blood levels of homocysteine are harmful. This level is usually controlled by some of the B vitamins, including folic acid, B12 and B6. Patients who undergo kidney dialysis have high level of homocysteine in their blood which cannot be lowered by the recommended dietary intake of B vitamins. We tested folic acid and folinic acid, two forms of folic acid, at much higher doses than normally consumed in vitamin supplements. We found a modest decrease in blood homocysteine levels which was similar for the two forms of folic acid.

Technical Abstract: The hyperhomocysteinemia found in most hemodialysis patients is refractory to combined oral B-vitamin supplementation featuring supraphysiological doses of folic acid (FA). We evaluated whether a high-dose L-folinic acid- based regimen provided improved total homocysteine (tHcy)-lowering efficacy in chronic hemodialysis patients, as suggested by a recent uncontrolled report. We block-randomized 48 chronic, stable hemodialysis patients based on their screening predialysis tHcy levels, sex, and dialysis center into 2 groups of 24 subjects treated for 12 weeks with oral FA at 15 mg/day or an equimolar amount (20 mg/day) of oral L-folinic acid (FNA) [L-5 formyltetrahydrofolate]. All 48 subjects also received 50 mg/day of oral vitamin B6 and 1 mg/day of oral vitamin B12. The mean percentage (%) reductions (with 95% CIs) in predialysis tHcy were not significantly different [FNA=22.1% (11.8 to 31.4%), FA=20.7% (11.7 to 30.5%), P=0.950 by paired t test]. Final on-treatment values (mean with 95% CI) were: FNA, 15.9 &mgr;mol/L (14.0 to 18.0); FA, 16.9 &mgr;mol/L (14.8 to 18.8). In those subjects with baseline tHcy levels >/=14 &mgr;mol/L, neither treatment resulted in normalization of tHcy levels (ie, final on treatment values <12 &mgr;mol/L) among a significantly different or clinically meaningful number of patients [FNA=2 out of 22 (9.1%); FA=2 out of 24 (8.3%); Fisher's exact test of between groups difference, P=1.000]. Relative to high-dose FA, high-dose oral L-folinic acid-based supplementation does not afford improved tHcy-lowering efficacy in hemodialysis patients. Most hemodialysis patients (>90%) exhibits mild hyperhomocysteinemia refractory to treatment with either regimen.