Prevalence and determinants of hyperhomocysteinemia in hemodialysis and peritoneal dialysis

Prevalence and determinants of hyperhomocysteinemia in hemodialysis and peritoneal dialysis.BackgroundHyperhomocysteinemia is an independent risk factor for atherosclerotic complications in patients with end-stage renal disease, although the mechanisms remain unclear. The major determinants of plasma homocysteine concentration are usually folate, vitamin B12, pyridoxal 5′-phosphate (vitamin B6), and glomerular filtration rate.MethodsWe measured factors, including plasma folate, vitamin B12, vitamin B6, creatinine, as well as the dose and duration of dialysis, that might affect plasma homocysteine concentrations in 130 patients on hemodialysis (HD) and compared these observations with those in 46 patients on peritoneal dialysis (PD). Independent determinants of total homocysteine were identified using a multiple logistical regression analysis.ResultsTotal homocysteine values averaged 29.8 μmol/liter in HD patients, significantly higher than the mean value of 19.9 μmol/liter observed in patients on PD (P < 0.001). The prevalence of hyperhomocysteinemia was 90.8% among HD patients, significantly higher than the prevalence of 67.4% among PD patients. Folate values in HD patients averaged 45.5nmol/liter and were significantly lower than in PD patients (104.2nmol/liter, P < 0.001). For patients on HD, the only determinant of total homocysteine concentration was plasma folate (r = -0.31, P < 0.001). In contrast, for PD patients, total homocysteine did not correlate with plasma folate, vitamin B12, or vitamin B6.ConclusionsHyperhomocysteinemia is more prevalent and intense in HD patients compared with those on PD. The homocysteine response may become refractory to excess folate supplementation in PD patients