Associations of calcium, phosphate and intact parathyroid hormone levels with mortality, residual kidney function and technical failure among patients on peritoneal dialysis.

Background: Associations of calcium, phosphate and intact parathyroid hormone (iPTH) levels with outcomes may be different between patients on peritoneal dialysis (PD) and hemodialysis (HD). The aim of the study is to evaluate these associations among PD patients.
Methods: In this prospective cohort study on the Japan Renal Data Registry, adults on PD at the end of 2009 were included. The observation period was until the end of 2018 and the data were censored at the time of transplantation or transition to HD. Exposures were time-averaged or time-dependent albumin-corrected calcium (cCa), phosphate and iPTH levels. Outcomes were all-cause and cardiovascular mortality, transition to HD and urine output. Data were analyzed using Cox regression models or linear mixed-effects models and the results were shown as cubic spline curves.
Results: Among 7393 patients, 590 deaths and 211 cardiovascular deaths were observed during a median follow-up of 3.0 years. Higher cCa and phosphate levels were associated with higher mortality. Lower cCa levels were associated with a faster decline, whereas lower phosphate was associated with a slower decline in urine output. Lower phosphate and iPTH levels were associated with a lower incidence of transition to HD.
Conclusions: Among PD patients, the observed associations of cCa, phosphate and iPTH with mortality, residual kidney function and technical failure suggest that avoiding high cCa, phosphate and iPTH levels might improve outcomes.
Competing Interests: M.M. receives honoraria from Kyowa Kirin Co., Ltd, and Torii Pharmaceutical Co., Ltd. N.F. receives honoraria from Astellas Pharm Inc., Bayer Yakuhin Ltd, Kissei Pharmaceutical Co., Ltd, Kyowa Kirin Co., Ltd, Ono Pharmaceutical Co., Ltd, Sanwa Kagaku Kenkyusho Co., Ltd, and Torii Pharmaceutical Co., Ltd. S.G. receives research funds from Kyowa Kirin Co., Ltd, Bayer Yakuhin, Ltd, and Chugai Pharmaceutical Co., Ltd, and honoraria from Kyowa Kirin Co., Ltd, Sanwa Kagaku Kenkyusho Co., Ltd, Kissei Pharmaceutical Co., Ltd, and Astellas Pharm Inc. T.Hasegawa receives honoraria from Kyowa Kirin Co., Ltd, Baxter and Termo. M.F. receives research funds from Kyowa Kirin Co., Ltd, and honoraria from Kyowa Kirin Co., Ltd, Kissei Pharmaceutical Co., Ltd, Bayer Yakuhin, Ltd, Ono Pharmaceutical Co., Ltd, and Sanwa Kagaku Kenkyusho Co., Ltd. M.A. receives research funds from Torii Pharmaceutical Co., Ltd, and Kyowa Kirin Co., Ltd, and honoraria from Kyowa Kirin Co., Ltd, Torii Pharmaceutical Co., Ltd, Ono Pharmaceutical Co., Ltd, and Bayer Yakuhin Ltd. T.Hamano receives research funds from Chugai Pharmaceutical Co., Ltd, Torii Pharmaceutical Co., Ltd, Kyowa Kirin Co., Ltd, Sanwa Kagaku Kenkyusho Co., Ltd, Kissei Pharmaceutical Co., Ltd, and Astellas Pharm Inc., and honoraria from Astellas Pharm Inc., Kissei Pharmaceutical Co., Ltd, Kyowa Kirin Co., Ltd, Torii Pharmaceutical Co., Ltd, Sanwa Kagaku Kenkyusho. Co., Ltd, Ono Pharmaceutical Co., Ltd, and Bayer Yakuhin Ltd.
(© The Author(s) 2023. Published by Oxford University Press on behalf of the ERA.)