Treatment of mild hyperhomocysteinemia in renal transplant recipients versus hemodialysis patients

Background Mild hyperhomocysteinemia is common among maintenance hemodialys is (HD) patients and renal transplant recipients (RTR) and may contribute t o the excess incidence of afteriosclerotic outcomes experienced by both pat ient groups. Relative to their RTR counterparts, the hyperhomocysteinemia o f ED patients seems to be considerably more refractory to treatment with hi gh-dose folic acid (FA)-based B-vitamin supplementation regimens, although controlled comparison data are lacking. Methods. We compared the relative responsiveness of (n=10) RTR and (n=39) H D patients with equivalent baseline total homocysteine (tHcy) levels (i.e., RTR range=14.2-23.6 mu mol/L; HD range 14.4-24.9 mu mol/L) to 12 weeks of tHcy-lowering treatment. The RTR received 2.4 mg/day of FA, 50.0 mg/day of vitamin B6, and 0.4 mg/day of vitamin B12, while the HD patients received 1 5 mg/day of FA or an equimolar amount (I? mg/day) of the reduced folate, L- 5-methyltetrahydrofolate, in addition to 50.0 mg/day of vitamin B6, and 1.0 mg/day of vitamin B12, Results. The mean percent (%) reductions confidence interval) in tHcy were: RTR=28.1% (16.2%-40.0% HD=12.1% (6.6 -17.7%), P=0.027 for comparison of be tween-groups differences by analysis of covariance adjusted for baseline tH cy levels. Moreover, (50.0%) of 10 of the RTR versus only (5.1%) of 39 of t he KD patients had final on-treatment tHcy levels <12 mu mol/L; P=0.002 for comparison of between-groups differences by Fisher's exact test. Conclusion. Relative 60 RTR with comparable baseline tHcy levels, the mild hyperhomocysteinemia of maintenance RD patients is much more refractory to tHcy-fowering E-vitamin treatment regimens featuring supraphysiological amo unts of FA or the reduced folate, L-5-methyltetrahydrofolate. Accordingly, RTR are a preferable target population for controlled clinical trials testi ng the hypothesis that tHcy-lowering B-vitamin intervention may reduce arte riosclerotic cardiovascular disease event rates in patients with chronic re nal disease.