On the effect of magnesium on the PTH secretion in uremic patients on maintenance hemodialysis.

The Mg, Ca and immunoreactive parathyroid hormone (PTH) serum levels were determined in 22 uremic patients on chronic hemodialysis with different Mg concentrations in the dialysate. Baseline levels of PTH, Ca and Mg were obtained over a 4-month-period whilst on Mg dialysis of 1.5 mEq/l. Patients were then divided into three groups: 10 patients were dialyzed for 6 months with 0.5 mEq/l of Mg, 7 patients with 1.5 mEq/l, and 5 patients wih 2.5 mEq/l Mg. At the end of the 6-month period with differentiated Mg dialysis the three groups were characterized by significantly different Mg serum levels. On the contrary, no significant changes were observed in the PTH or the Ca serum levels. The results of this study indicate that PTH secretion in uremic patients on regular hemodialysis is not appreciably influenced by the Mg serum levels.