Relationship between plasma levels of homocysteine and the related B vitamins in patients with hemodialysis adequacy or inadequacy

Objectives: Hemodialysis (HD) with dialysis adequacy could increase the excretion of B vitamins (folate, vitamin B-6, and B-12) and raise the plasma level of homocysteine. Here we determined the associations of plasma homocysteine with B vitamins in patients with HD adequacy or inadequacy. Methods: We recruited 68 patients who had received HD treatments (three times a week, 4 h each). Based on the individual's hemogram and quarterly urea reduction rate (Kt/V), patients were pooled into one of the following two groups: the first group with dialysis adequacy (Kt/V > 1.2, n = 48) and the second with dialysis inadequacy (Kt/V <= 1.2, n = 20). We also recorded the anthropometric date of each patient and their biochemical data and dietary intakes. Plasma levels of homocysteine, cysteine, folate, pyridoxal 5'-phosphate (PLP), and vitamin B-12 were measured twice, once before and once after HD. Results: The plasma levels of homocysteine, cysteine, folate, PLP, and vitamin B-12 dropped significantly at the end of HD. The plasma levels of vitamin B-12 were negatively correlated with the plasma levels of homocysteine, both pre- and post-HD, and in both groups regardless of dialysis adequacy or inadequacy. In contrast, plasma levels of folate and PLP were not correlated with homocysteine at both pre- or post-HD in both groups. Conclusions: The plasma level of vitamin B-12, but not folate or vitamin B-6, was negatively correlated with that of homocysteine both before and after HD treatment, and regardless of dialysis adequacy or inadequacy. (C) 2018 Elsevier Inc. All rights reserved.