Backgrounds. Calcium (Ca) and bone metabolism in continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD) patients show a remarkable difference depending on dialysis modalities. The levels of serum Ca and phosphate (P) in HD patients fluctuate contributing to the intermittent and rapid removal of plasma solute unlike in CAPD. Characteristics of plasma solute transport in automated peritoneal dialysis (APD) patients are resembled with that in HD. The purpose of the present study was to examine the difference of transperitoneal Ca removal between APD and CAPD anuric patients. Subjects and Methods. Twenty-three APD anuric patients were enrolled in this study. Biochemical parameters responsible for transperitoneal Ca removal in 24-hour and 4-hour peritoneal effluents were analyzed on CAPD and APD. Results. Transperitoneal Ca removal on APD was smaller compared with that on CAPD. The Ca removal was related to the ultrafiltration during short-time dwell. Decrease of the Ca removal during NPD induced by short-time dialysate dwell caused negative or small Ca removal in APD patients. The levels of intact PTH were increased at the end of PET. Conclusion. It appears that short-time dwell and frequent dialysate exchanging might suppress the transperitoneal Ca removal in anuric APD patients. 1. Introduction Bone disease is one of the serious complications in chronic dialysis patients. Adynamic bone disease and secondary hyperparathyroidism are associated with not only viability and quality of life (QOL) but also mortality in long-term dialysis patients. It is generally considered that Ca and bone metabolism between peritoneal dialysis (PD) and hemodialysis (HD) patients provided remarkable differences according to dialysis modalities. Hemodialysis patients undergo rapid and intermittent removal of phosphate, uremic toxins and excess body fluid from sera, and influx or efflux of Ca influent in such metabolism [1–3]. Higher serum Ca levels and continuous glucose loading occur, which may lead to a higher incidence of adynamic bone in CAPD patients compared with that in HD patients [4, 5]. Patients with very low parathyroid hormone (PTH) level had a higher mortality rate after adjustment for age, gender, diabetes, and dialysis vintage [6]. The turnover of bone remodeling in PD patients is lower than that in HD patients [4, 5]. Using 3.5？mEq/L Ca dialysate in HD, Ca removal demonstrated a negative balance [7, 8]. It is recognized that Ca mass transport in CAPD patients depends on the following factors: Ca concentration in the dialysis fluid, starting plasma
References
[1]
F. Malberti, B. Corradi, and E. Imbasciati, “Effect of CAPD and hemodialysis on parathyroid function,” Advances in Peritoneal Dialysis, vol. 12, pp. 239–244, 1996.
[2]
J. W. Coburn, “Mineral metabolism and renal bone disease: effects of CAPD versus hemodialysis,” Kidney International, Supplement, no. 40, pp. S92–S100, 1993.
[3]
J. Cunningham, “Renal bone disease in peritoneal dialysis,” Peritoneal Dialysis International, vol. 19, supplement 2, pp. S397–S401, 1999.
[4]
J. B. Cannata Andía, “Adynamic bone and chronic renal failure: an overview,” American Journal of the Medical Sciences, vol. 320, no. 2, pp. 81–84, 2000.
[5]
T. Weinreich, “Prevention of renal osteodystrophy in peritoneal dialysis,” Kidney International, vol. 54, no. 6, pp. 2226–2233, 1998.
[6]
G. Jean, D. Lataillade, L. Genet et al., “Association between very low PTH levels and poor survival rates in haemodialysis patients: results from the French ARNOS cohort,” Nephron, vol. 118, no. 2, pp. c211–c216, 2011.
[7]
J. M. Bone, A. M. Davison, and J. S. Robson, “Role of dialysate calcium concenration in osteoporosis in patients on haemodialysis,” The Lancet, vol. 1, no. 7759, pp. 1047–1049, 1972.
[8]
A. Raman, Y. K. Chong, and G. A. Sreenevasan, “Effects of varying dialysate calcium concentrations on the plasma calcium fractions in patients on dialysis,” Nephron, vol. 16, no. 3, pp. 181–187, 1976.
[9]
P. Kurz, P. Roth, E. Werner, J. Vlachojannis, and P. Grützmacher, “Factors influencing transperitoneal calcium balance during CAPD,” ASAIO Journal, vol. 38, no. 3, pp. M589–M592, 1992.
[10]
E. Ritz, J. Passlick-Deetjen, and J. Lippert, “What is the appropriate dialysate calcium concentration for the dialysis patient?” Nephrology Dialysis Transplantation, vol. 11, supplement 3, pp. 91–95, 1996.
[11]
J. Montenegro, R. Saracho, R. Aguirre, and I. Martinez, “Calcium mass transfer in CAPD: the role of convective transport,” Nephrology Dialysis Transplantation, vol. 8, no. 11, pp. 1234–1236, 1993.
[12]
C. G. M. Buijsen, D. G. Struijk, H. J. Huijgen, E. W. Boeschoten, and J. M. Wilmink, “Can low-calcium peritoneal dialysis solution safely replace the standard calcium solution in the majority of chronic peritoneal dialysis patients?” Peritoneal Dialysis International, vol. 16, no. 5, pp. 497–504, 1996.
[13]
W. M. Michels, M. Verduijn, D. C. Grootendorst et al., “Decline in residual renal function in automated compared with continuous ambulatory peritoneal dialysis,” Clinical Journal of the American Society of Nephrology, vol. 6, no. 3, pp. 537–542, 2011.
[14]
C. Hamada, S. Osada, S. Inoue et al., “Effects of automated peritoneal dialysis on residual urinary volume,” Peritoneal Dialysis International, vol. 20, no. 2, pp. 239–241, 2000.
[15]
B. Rippe and L. Levin, “Should dialysate calcium be varied in proportion to the amount of ultrafiltration in peritoneal dialysis dwells? Directions from a computer simulation,” Peritoneal Dialysis International, vol. 18, no. 5, pp. 474–477, 1998.
[16]
J. A. Delmez, E. Slatopolsky, and K. J. Martin, “Minerals, vitamin D, and parathyroid hormone in continuous ambulatory peritoneal dialysis,” Kidney International, vol. 21, no. 6, pp. 862–867, 1982.
[17]
R. S. Goldsmith, J. Furszyfer, W. J. Johnson, G. W. Beeler Jr., and W. F. Taylor, “Calcium flux during hemodialysis,” Nephron, vol. 20, no. 3, pp. 132–140, 1978.
[18]
E. E. Banalagay, J. Bernardini, and B. Piraino, “Calcium mass transfer with 10-hour dwell time using 1.25 versus 1.75？mmol/L calcium dialysate,” Advances in Peritoneal Dialysis, vol. 9, pp. 271–273, 1993.
[19]
S. Bro, L. Brandi, and K. Olgaard, “High-normal calcium (1.35？mmol/l) dialysate in patients on CAPD: efficient and safe long-term control of plasma calcium, phosphate, and parathyroid hormone,” Nephrology Dialysis Transplantation, vol. 11, no. 8, pp. 1586–1591, 1996.
