Effective homocysteine-lowering vitamin B treatment in peritoneal dialysis patients.

BACKGROUND: Hyperhomocysteinemia, a risk factor for atherosclerosis, is frequently detected in patients with renal failure. Vitamin B supplementation reduces but rarely normalizes homocysteine (Hcy) levels in hemodialysis patients. There are no data about the effects of vitamin B therapy on Hcy levels in patients on peritoneal dialysis (PD). AIMS: We performed this trial both to observe baseline plasma Hcy levels in PD patients and to assess the effects of vitamin B therapy on Hcy levels in continuous ambulatory PD patients. METHODS: We conducted a 6-month prospective study of the effects of vitamin B therapy on plasma Hcy levels. Biochemical analyses were obtained at baseline and after every phase of treatment with folic acid, folic acid plus vitamin B12, and folic acid plus vitamin B12 plus vitamin B6. Eighteen of the 25 enrolled patients finished the study. RESULTS: Hyperhomocysteinemia was present in 83% of PD patients. We detected a trend toward a significant inverse relationship between baseline Hcy and folate levels. There were no significant correlations between baseline Hcy and vitamin B12, peritoneal membrane permeability, dialytic efficiency, or computed peritoneal Hcy clearance. We obtained an effective decrease in mean Hcy concentration from 20 to 14.8 micromol/L after folic acid and vitamin B12 treatment. We observed a further reduction in mean Hcy level to 12.8 micromol/L using the triple therapy; 72% of patients normalized their Hcy value. CONCLUSIONS: High doses of folic acid, vitamin B6, and vitamin B12 normalize Hcy values in the majority of PD patients. This treatment may be important in reducing cardiovascular morbidity and mortality.

Effects of folic acid treatment on homocysteine levels and vascular disease in hemodialysis patients.

BACKGROUND: Cardiovascular disease is the most important cause of morbidity and mortality in hemodialysis patients. These patients frequently have hyperhomocysteinemia, a putative risk factor for cardiovascular disease. Treatment with folate, B6 and B12 partially reduces hyperhomocysteinemia. We conducted a long-term study to evaluate whether 15 mg is more effective than 5 mg oral folic acid as a daily dosage to decrease hyperhomocysteinemia, and to assess whether homocysteine-lowering treatment reduces the risk of cardiovascular disease in hemodialysis patients. MATERIAL/METHODS: In a 1-year prospective randomised trial, 81 chronic hemodialysis patients, matched for age, gender and dialytic age, were divided into three groups: 30 untreated patients, 26 patients receiving 5 mg per day, and 25 patients receiving 15 mg per day. RESULTS: There was a significant reduction in hyperhomocysteinemia over time in treated patients as compared to untreated, but there were no significant differences between the two treated groups. Only 12% of the treated patients reached normal total homocysteine plasma levels. We observed a trend towards a significant difference in survival rate in cardiovascular morbidity between treated and untreated patients. Furthermore, hemodialysis patients with new vascular events showed higher homocysteine levels than patients without events. CONCLUSIONS: High-dose folic acid treatment did not improve outcome in hyperhomocysteinemia, and 88% of treated patients maintained higher than normal homocysteine levels. There was a trend towards a decreased rate of cardiovascular events in treated participants as compared to untreated ones.