MAGnesium in Chronic HemoDialysis

INTERVENTION: Stepwise increase of magnesium concentration in the dialysate: ‐ Week 0: continuation of standard 0.50 mmol/L dialysate magnesium ‐ Week 1, 2, 3, 4: dialysate magnesium 0.75 mmol/L ‐ Week 5, 6, 7, 8: dialysate magnesium 1.00 mmol/L if pre‐dialysis plasma Mg <1.15 mmol/L in week 4; dialysate magnesium 0.75 mmol/L if pre‐dialysis plasma Mg 1.15 or above in week 4 ‐ Week 9: dialysate magnesium concentration reduction of 0.25 mmol/L (to either 0.75 mmol/L or 0.50 mmol/L) ‐ Week 10, 11: dialysate magnesium 0.50 mmol/L CONDITION: Chronic kidney disease, End‐stage renal disease ; ; PRIMARY OUTCOME: ‐ The difference between plasma magnesium concentration after the long interdialytic interval in the intervention group with incremental dialysate magnesium concentration and plasma magnesium concentration in the control group with standard dialysate magnesium concentration at the end of week 8.; ; ‐ The difference in change of plasma magnesium concentration after the long interdialytic interval from baseline to the end of week 8 between the intervention group and the control group.; SECONDARY OUTCOME: ‐ The cumulative incidence of magnesium concentration 1.25 mmol/L or above in the intervention group and in the control group. ; ; ‐ The cumulative incidence of prolonged duration of QTc (defined as >450ms in male and >460ms in female) in the intervention group and in the control group. ; ; ‐ The cumulative incidence of bradycardia (defined as heart rate below 60 beats per minute) in the intervention group and in the control group. ; ; ; ; ‐ The effect of dialysate magnesium concentration on pre‐dialysis and post‐dialysis plasma magnesium concentration at the dialysis after the long interdialytic interval. ; ; ‐ Predictive factors for the effect of dialysate magnesium concentration on pre‐dialysis and post‐dialysis plasma magnesium concentration at the dialysis after the long interdialytic interval. ; ; ‐ The difference in carotid‐femoral pulse wave velocity in the intervention group and the control group in week 8, and the difference in change of pulse wave velocity from baseline to week 8 between the intervention group and the control group. ; INCLUSION CRITERIA: ‐ Age 18 years or above ‐ Hemodialysis with regular three times weekly dialysis schedule ‐ Hemodialysis since at least 3 months ‐ Standard dialysate Mg2+ 0.50 mmol/L ‐ Providing informed consent ‐ Pre‐dialysis plasma magnesium concentration not higher than 1.00 mmol/L