We compared the efficacy and the long-term effects of nocturnal hemodialysis (NHD) versus conventional hemodialysis (CHD) in controlling serum phosphate levels in patients with end-stage renal disease (ESRD). Patients underwent thrice weekly CHD and were subsequently switched to NHD six nights weekly. In the "acute" study serum and dialysate phosphate were measured during and after dialysis, and the total dialysate was collected to calculate mass solute removal. Although pre-dialysis (1.7 +/- 0.6 vs. 1.5 +/- 0.8 mM) serum phosphate levels were similar in CHD and NHD, respectively, post-dialysis levels were slightly lower with CHD (0.7 +/- 0.2 vs. 0.8 +/- 0.2 mM, P < 0.05). The measured phosphate removed per session of CHD or NHD was comparable, 25.3 +/- 7.5 versus 26.9 +/- 9.8 mumol/session, respectively. On the other hand, the cumulative weekly phosphate removal was significantly higher with NHD as compared to CHD, 75.8 +/- 22.5 versus 161.6 +/- 59.0 mumol/week (P < 0.01). In the "chronic" study serum phosphate levels were measured monthly for five months on CHD and for five months after the patients were switched to NHD. Dietary phosphate intake and the dosage of phosphate binders were tabulated. Serum phosphate levels fell during NHD: 2.1 +/- 0.5 mM at the beginning of the study and 1.3 +/- 0.2 mM five months after being switched to NHD (P < 0.001). At the same time dietary phosphate intake increased by 50%. By the fourth month of NHD therapy none of the patients was taking any phosphate binders. In conclusion, NHD is more effective in controlling serum phosphate levels than CHD, allowing patients to discontinue their phosphate binders completely and to ingest a more liberal diet.

NHD provides a much higher clearance of beta(2)m than CHD, leading to a long-term decrease in the pre-dialysis concentration of beta(2)m.

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Background/Aims: The purpose of this study was to examine the effect of nocturnal hemodialysis (NHD) on serum amino acid (AA) profile. Methods: In a cross-over trial, we studied the AA profile in 11 patients who were switched from conventional hemodialysis to NHD. Plasma levels of AA were measured at monthly intervals for a period of 1 year. Results: Concentrations of AA isoleucine, threonine, phenylalanine, valine, glycine, glutamine and taurine increased on switch to NHD. Total AA (2,907.2 ± 542.2 vs. 3,870.2 ± 715.2 μmol/l, p = 0.03), essential AA (EAA, 842.2 ± 259.4 vs. 1,125.8 ± 235.3 μmol/l, p = 0.03), nonessential AA (NEAA, 2,307.2 ± 399.1 vs. 2,879.5 ± 581.2 μmol/l, p = 0.03), and branched chain AA (315.5 ± 90.8 vs. 386.0 ± 114.3 μmol/l, p = 0.05) concentrations were significantly higher on NHD. However, abnormalities in the ratios of EAA/NEAA, valine/glycine and tyrosine/phenylalanine persisted during NHD. Conclusions: NHD alleviated some abnormalities in the aminogram of uremia, but other metabolic derangements lingered.