Serum phosphate may interfere with the anti-proteinuric response to a very low protein diet (VLPD) in patients with chronic kidney disease (CKD), according to researchers.
In a study of 99 CKD patients with proteinuria who sequentially followed a low-protein diet (LPD) and a VLPD, 24-hour proteinuria decreased modestly in those who maintained relatively higher serum phosphate levels or relatively higher phosphaturia, investigators reported online ahead of print in Nephrology Dialysis Transplantation. Reducing phosphate burden may decrease proteinuria and slow progression of renal disease, Biagio R. Di Iorio, MD, of A. Landolfi’ Hospital, Solofra, Avellino, Italy, and colleagues concluded.
The patients supplemented the diets with keto-analogues and followed each diet for periods longer than one year. The daily protein intake was 0.6 g/kg during LPD and 0.3 g/kg during VLPD.
Serum phosphate levels decreased to a significantly lower level during VLPD compared with LPD (3.2 vs. 3.7 mg/dL), an effect paralleled by a significant decline in phosphate excretion (649 mg/day with LPD and 462 mg/day with VLPD).
The median proteinuria during LPD was 1,910 mg/24 hour; this declined significantly to 987 mg/24 hour during VLPD. The investigators observed no significant change in estimated glomerular filtration rate (eGFR) during the two diet periods.