title: Postdialytic rebound of serum phosphorus: pathogenetic and clinical insights.
abstract: To gain insights into postdialytic rebound of serum phosphate (PDR-P), serum phosphate (P), calcium (Ca), and parathyroid hormone (PTH), levels were compared from the end of treatment (T0) to the subsequent 30 to 120 min and up to 68 hr in uremic patients who underwent with crossover modality a single session of two dialytic treatments characterized by different convective removal: standard hemodialysis (HD) and hemodiafiltration (HDF). In HDF, versus HD, P removal was greater (1171 +/- 90 versus 814 +/- 79 mg; P < 0.05) in the presence of similar predialytic P levels (6.0 +/- 0.2 and 5.9 +/- 0.4 mg/dl) and Kt/V (1.35 +/- 0.06 and 1.34 +/- 0.05); however, the serum P values at T0 did not differ (3.0 +/- 0.2 versus 3.3 +/- 0.2 mg/dl). In HDF, PDR-P was more rapid (30 min versus 90 min) and of a greater extent (at T120: +69 +/- 6% versus +31 +/- 4%; P < 0.0001). The higher P levels were maintained throughout the interdialytic period. Ca x P and PTH changed in parallel. Thereafter, patients were randomized to receive either HD or HDF for 3 mo. During this period, in the presence of similar Kt/V, protein intake, and dose of phospate binder, predialytic serum P levels diminished in HDF (from 5.8 +/- 0.2 to 4.4 +/- 0.3 mg/dl; P < 0.05), but they remained unchanged in HD. A similar pattern of changes was detected in Ca x P. Therefore, PDR-P is likely dependent on the mobilization of phosphate from a deep compartment induced by the intradialytic removal of this solute. Enhancement of convective removal acutely amplifies the entity of the phenomenon but allows a better control of Ca-P homeostasis in the medium term.
authors.affiliation: *Division of Nephrology, School of Medicine, Second University of Naples, Naples, Italy; University "Federico II" of Naples, Naples, Italy; and Division of Nephrology-Country Hospital in Lauria, Polla, and Ariano Irpino, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Minutolo
authors.affiliation: *Division of Nephrology, School of Medicine, Second University of Naples, Naples, Italy; University "Federico II" of Naples, Naples, Italy; and Division of Nephrology-Country Hospital in Lauria, Polla, and Ariano Irpino, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Bellizzi
authors.affiliation: *Division of Nephrology, School of Medicine, Second University of Naples, Naples, Italy; University "Federico II" of Naples, Naples, Italy; and Division of Nephrology-Country Hospital in Lauria, Polla, and Ariano Irpino, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Cioffi
authors.affiliation: *Division of Nephrology, School of Medicine, Second University of Naples, Naples, Italy; University "Federico II" of Naples, Naples, Italy; and Division of Nephrology-Country Hospital in Lauria, Polla, and Ariano Irpino, Italy.
authors.forename: Carmela
authors.initials: C
authors.lastname: Iodice
authors.affiliation: *Division of Nephrology, School of Medicine, Second University of Naples, Naples, Italy; University "Federico II" of Naples, Naples, Italy; and Division of Nephrology-Country Hospital in Lauria, Polla, and Ariano Irpino, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Giannattasio
authors.affiliation: *Division of Nephrology, School of Medicine, Second University of Naples, Naples, Italy; University "Federico II" of Naples, Naples, Italy; and Division of Nephrology-Country Hospital in Lauria, Polla, and Ariano Irpino, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Andreucci
authors.affiliation: *Division of Nephrology, School of Medicine, Second University of Naples, Naples, Italy; University "Federico II" of Naples, Naples, Italy; and Division of Nephrology-Country Hospital in Lauria, Polla, and Ariano Irpino, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Terracciano
authors.affiliation: *Division of Nephrology, School of Medicine, Second University of Naples, Naples, Italy; University "Federico II" of Naples, Naples, Italy; and Division of Nephrology-Country Hospital in Lauria, Polla, and Ariano Irpino, Italy.
authors.forename: Biagio R
authors.initials: BR
authors.lastname: Di Iorio
authors.affiliation: *Division of Nephrology, School of Medicine, Second University of Naples, Naples, Italy; University "Federico II" of Naples, Naples, Italy; and Division of Nephrology-Country Hospital in Lauria, Polla, and Ariano Irpino, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Conte
authors.affiliation: *Division of Nephrology, School of Medicine, Second University of Naples, Naples, Italy; University "Federico II" of Naples, Naples, Italy; and Division of Nephrology-Country Hospital in Lauria, Polla, and Ariano Irpino, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: De Nicola
mesh_terms: D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood; D018592:Cross-Over Studies; D005260:Female; D017583:Hemodiafiltration; D006801:Humans; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood; D010758:Phosphorus / Q000097:blood*; D006435:Renal Dialysis; D016037:Single-Blind Method; D013997:Time Factors; D014511:Uremia / Q000628:therapy*
chemical_list: D010281:Parathyroid Hormone; D010710:Phosphates; D010758:Phosphorus; D002118:Calcium