Conventional versus ultrapure dialysate for lowering serum lipoprotein(a) levels in patients on long-term hemodialysis: A randomized trial

Purpose: In patients on long-term hemodialysis, high lipoprotein(a) [Lp(a)] levels are difficult to lower with medications, although they remain a risk factor for cardiovascular disease. We investigated whether ultrapure dialysate (UPD) could lower Lp(a). Methods: We randomly assigned patients stabilized on long-term dialysis to either a low-flux synthetic polysulphone membrane (the UPD group; n=14) or to a conventional dialysate (the CD group; n=13). Blood samples were collected 1 week before dialysis and 1 week, 1 month, 6 months and 12 months after dialysis; Lp(a) was measured by the immunotur- bidimetry method. Hemoglobin, interleukin-6, hypersensitive C-reactive protein, (β 2 microglobulin and albumin were also measured. The erythropoietin dosage, Kt/V, and normalized protein catabolic rate were recorded monthly. Results: At 12 months, mean (SD) serum levels of Lp(a) in the CD patients increased from 143.46 (125.11) to 283.89 (145.81) mg/L (p<0.01), whereas levels in the UPD group remained unchanged: 131.38 (201.45) to 120.90 (122.11) mg/L. Endotoxin levels in the 10 CD patients who completed the study ranged from 0.116 to 0.349 EU/mL and were undetectable in the 11 UPD patients who completed the study. The cultures were less than 200 CFU/mL in CD patients and negative all the time for all UPD patients. Changes in Lp(a) from baseline values were lower in the UPD group than in the CD group (p<0.05). However, changes in other variables did not differ between groups. Conclusions: Ultrapure dialysate can prevent the rise of Lp(a), potentially decreasing the risk of cardiovascular disease in hemodialysis patients.