Total serum and intraerythrocyte magnesium concentrations in hemodialysis patients using different dialysate solutions.

Beside routinely used 0.5 mmol/L dialysate-magnesium, higher dialysate-magnesium (1.0 mmol/L) was recently introduced. The aim of this study was to evaluate the impact of different dialysate-magnesium on serum and intraerythrocyte levels of magnesium (Mg) before and after dialysis. The study included 43 patients receiving chronic hemodialysis, divided into two groups based on dialysate-magnesium (0.5 or 1.0 mmol/L) used prior to study initiation and during 12 months of follow-up. Blood samples were taken at the mid-week dialysis; total serum Mg was measured colorimetrically and intraerythrocyte Mg by atomic absorption spectrophotometry. Hypermagnesiemia-associated complications were observed for 12 months. Total serum Mg was 1.14 ± 0.19 mmol/L before and 0.95 ± 0.16 mmol/L after dialysis in patients using lower dialysate-Mg (p < 0.001), whereas it was 1.47 ± 0.25 mmol/L before and 1.49 ± 0.18 mmol/L after dialysis in patients using higher dialysate-Mg (p = 0.926). Intraerythrocyte Mg was 1.98 ± 0.34 mmol/L before and 1.97 ± 0.28 mmol/L after dialysis in the lower dialysate-Mg group (p = 0.939), while it was 2.09 ± 0.37 mmol/L before and 2.19 ± 0.48 mmol/L after dialysis in the higher dialysate group (p = 0.067). After 12 months total serum Mg decreased in both the groups, remaining lower in 0.5 mmol/L dialysate-Mg group. No hypermagnesiemia-related symptoms occur during 12 months of follow-up in both the groups. In patients using lower dialysate-Mg total serum Mg remains within the reference range and shows postdialytic decline, while in higher dialysate-Mg group it exceeded reference range before and after dialysis without significant intradialytic change. The intraerythrocyte values remain within reference range with both dialysates used. No clinical signs and symptoms of hypermagnesiemia occur during longer administration of higher dialysate-magnesium despite high total serum Mg level.