A feasibility study of avoiding positive calcium balance and parathyroid hormone increase in patients on peritoneal...

Area of Science:

• Nephrology
• Mineral and Bone Metabolism
• Peritoneal Dialysis

Background:

• Dialysate calcium concentration (D[Ca])'s role in mineral and bone metabolism for peritoneal dialysis (PD) patients is under-researched.
• A D[Ca] of 1.75 mmol/L is still widely used, despite previous studies predating calcimimetic use.
• The safety of reducing D[Ca] without increasing parathyroid hormone (PTH) requires further investigation.

Purpose of the Study:

• To evaluate the safety and efficacy of reducing D[Ca] from 1.75 mmol/L to 1.25 mmol/L in prevalent PD patients.
• To determine the impact of reduced D[Ca] on serum PTH levels and other CKD-MBD biomarkers.
• To assess the need for medication adjustments (e.g., calcitriol, sevelamer) during D[Ca] reduction.

Main Methods:

• A non-randomized clinical trial involving prevalent PD patients.
• D[Ca] was reduced from 1.75 mmol/L to 1.25 mmol/L over a one-year period.
• Demographic, clinical, and CKD-MBD biomarkers were monitored at baseline and at 3, 6, and 12 months.

Main Results:

• Twenty patients completed the 1-year follow-up; mean age 56 ± 16 years, 50% male, 25% diabetic, 55% with baseline PTH >300 pg/mL.
• No significant changes were observed in calcium, phosphate, total alkaline phosphatase, 25(OH)-vitamin D, or PTH levels over the study period.
• Medication adjustments for calcitriol and sevelamer were necessary; PTH levels showed a median change of 20% (-28, 45), and the proportion of patients with PTH >300 pg/mL remained unchanged (p=0.173).

Conclusions:

• Reducing D[Ca] in PD patients is a safe and beneficial strategy for managing mineral and bone disorders.
• While reducing D[Ca] is safe, careful medication management is essential to prevent PTH elevation.
• This approach offers a valuable option for PD patients, considering the risks associated with positive calcium balance.