Abstract
Because the secretion of PTH is controlled when the serum magnesium level is high, generally a dialysate magnesium concentration of 1.5mEq/l is prescribed. However, since hypermagnesemia is also a cause of peripheral nerve damage, pruritus etc., as far as possible magnesium at normal levels is advisable. Recently a preparation of 1α(OH)D3 was used and with an easy compensation for hypocalcemia in dialysis patients the efficacy of low dialysate magnesium (magnesium concentration 0.5mEq/l) was examined.
Low dialysate magnesium was used for a period of 3 months for 40 regular hemodialysis patients and studies were carried out on the changes in serum magnesium, calcium, phosphate, and c-PTH levels. With the use of low dialysate magnesium the serum magnesium level fell significantly from 2.59±0.53mEq/l to 2.00±0.33mEq/l (p<0.01). There was no significant difference in the serum calcium and phosphate levels before and after the use of low dialysate magnesium. However, with the use of low dialysate magnesium the serum c-PTH level rose significantly from 2.06±1.16ng/ml to 2.75±1.86ng/ml (p<0.02). In addition, with the use of low dialysate magnesium, a negative correlation was obtained between the serum magnesium level and the serum c-PTH level.
In the future, in order to use low dialysate magnesium concentration over a long term, it will be necessary to examine the fluctuation of serum c-PTH levels obtained from the closely corrected serum calcium level, and to suppress PTH secretion by some other method.
