Control of serum phosphate without any phosphate binders in patients treated with nocturnal hemodialysis

Abstract

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.

Left Ventricular Hypertrophy

“…Nocturnal hemodialysis, which increases both dialysis frequency and total weekly dialysis time, will induce negative phosphorus balance, to the point that phosphorus supplementation becomes necessary. This modality has been shown to achieve excellent control of serum phosphorus without the use of phosphate-binding medications (47). However, daily hemodialysis had mixed effects on serum phosphorus in previous studies (32-34).…”

Did 20 Years of Technological Innovations in Hemodialysis Contribute to Better Patient Outcomes?

“…Urea kinetics significantly differ from the kinetic behavior of other molecules, such as middle molecules, proteinbound solutes, and even other small and water-soluble compounds (21,22). The factor time plays an even more important role in the removal of middle molecules or other solutes that are difficult to remove by standard HD, such as ␤ 2 microglobulin and phosphorus (22)(23)(24)(25)(26)(27)(28)(29)(30)(31). This is most likely due to a different multicompartmental behavior of these substances (12).…”

Utility and Limitations of a Multicenter Nocturnal Home Hemodialysis Cohort

“…The study model is usually a before-and-after paradigm; frequently, a comparator group (an external control) that does not undergo the conversion to the alternative modality is added to enhance the internal validity of the study. Some relevant health parameter, such as LVM, phosphate binder use, hemoglobin concentration, or sleep pattern, is then studied while a patient is undergoing CHD and assessed again after some time interval while on NHD (19)(20)(21)(22). The presumption is that any change observed between measurements is due to the nocturnal dialysis.…”