Low-calcium peritoneal dialysis solution is effective in bringing PTH levels to the range recommended by current guidelines in patients with PTH levels < 150 pg/dL

Adinamic bone disease (ABD) is a common finding in peritoneal dialysis (PD) and is associated with higher risk of developing cardiovascular and bone disease. Data from BRAZPD indicates that 3.5 mEq/L calcium PD solutions represents the majority of PD prescriptions in the country. A positive calcium balance can contribute to ABD development. Currently guidelines suggest that PTH-i levels in end stage renal disease should be kept from 150-300 pg/mL. The purpose of this study is to evaluate 6 month PTH-i response after conversion to 2.5 mEq/L calcium PD solution in patients with baseline PTH-i levels < 150 pg/mL.

Prospective, observational study of all prevalent patients (at least 90 days on therapy) on PD of a single Brazilian center from January 2008 to May 2009. Inclusion criteria (1) be in use of a PD solution with 3.5 mEq/L of calcium; (2) baseline PTH levels < 150 pg/ mL. According to clinical practice patients could be switched to PD solutions with 2.5 mEq/L of calcium.

35 patients (age 62 ± 17 years) were included. Of these 22 were converted to 2.5 mEq/L calcium solutions. Diabetic nephropathy (36%) was the main cause of renal disease followed by nephrosclerosis (25%) and glomerulonephritis (14%). Converted group presented a greater increase in PTH levels when compared with the control group (Δ194 pg/dL versus Δ 92/dL; p < 0,05). Among patients switched to low calcium solution, 41% reached the target values (PTH 150-300 pg/mL) compared to 14% whose remain with normal calcium solutions (p < 0.05). There were no differences between groups regarding calcium, phosphorus and alkaline phosphatase.

In patients with PTH < 150 pg/mL conversion to low calcium solutions (2.5 mEq/L) appears to be a simple and effective strategy to bring PTH levels to the range determined by current guidelines when compared with 3.5 mEq/L calcium PD solutions.