Nephrol Dial Transplant (2000) 15: 1410-1413
© 2000 European Renal Association-European Dialysis and Transplant Association
Vitamin B6 supplementation can improve peripheral polyneuropathy in patients with chronic renal failure on high-flux haemodialysis and human recombinant erythropoietin
1 Department of Nephrology, Saitama Medical College, and 2 Yoshizawa Clinic, Saitama, Japan
Background. High-flux haemodialysis (HD) has recently been vigorously promoted as a novel standard, and it can indeed efficiently reduce the occurrence of most uraemic symptoms due to middle molecular toxins and/or underdialysis. However, some symptoms remain problematical, particularly peripheral polyneuropathy (PPN). One of the possible reasons for this is that the patients may have low concentrations of some nutrients, e.g. vitamin B6, necessary for normal peripheral neuron function.
Methods. Predialysis serum pyridoxal-5'-phosphate (P5P) level was determined in 36 chronic HD patients who were undergoing high-flux HD and receiving human recombinant erythropoietin. Among them, 26 patients suffered from PPN. Prior to supplementation, these 26 patients were examined and their neurological symptoms were ranked according to our PPN symptom score. Vitamin B6 (60 mg/day) was randomly prescribed to 14 of them, and vitamin B12 (500 µg/day) was prescribed to the others. After 4 weeks, all the patients were re-examined.
Results. We found that predialysis serum P5P levels of HD patients with PPN were not significantly lower than those of matched HD patients without PPN. Nonetheless, it was demonstrated that supplementation with vitamin B6 for 4 weeks significantly increased the predialysis level of P5P and dramatically attenuated PPN symptoms compared with initial symptoms. No improvement was observed in response to vitamin B12 supplementation.
Conclusion. This result suggests that although vitamin B6 deficiency could not be demonstrated in patients with chronic renal failure on high-flux HD, vitamin B6 supplementation was effective in improving PPN symptoms of various aetiologies, possibly because of vitamin B6 resistance to PPN in these patients.
Keywords: high-flux haemodialysis; human recombinant erythropoietin; peripheral polyneuropathy; vitamin B6
Correspondence and offprint requests to: Hiromichi Suzuki MD PhD, Department of Nephrology, Saitama Medical College, 38 Morohongo, Moroyama-machi, Irumagun, Saitama 350–04, Japan.