Serum magnesium levels in patients undergoing chronic ambulatory peritoneal dialysis

We retrospectively examined the magnesium status of our chronic ambulatory peritoneal dialysis (CAPD) patients dialyzed with a 0.75 mmol/l magnesium peritoneal dialysis solution, using the total serum magnesium concentration corrected for hypoalbuminemia according to Kroll proposed equation. A total of 37 patients on CAPD for at least 3 months (age: 32 - 71 years, mean 56 +/- 15 years; duration of CAPD: 6 - 71 months, mean 29 +/- 22 months) were studied. The corrected serum magnesium concentration was 1.17 +/- 0.15 mmol/l and significantly higher compared to that observed in 62 age- and sex-matched controls (0.92 +/- 0.1 mmol/l, p < 0.01). Serum magnesium levels were only weakly correlated with serum prealbumin levels (r = 0.18, p = 0.07). Twenty patients had hypermagnesemia (total corrected serum magnesium concentration > 1.1 mmol/l). There were no significant differences between the hypermagnesemic and normomagnesemic groups with respect to age, sex, body weight, BMI, dialysis duration, PTH, serum albumin, calcium and phosphorus levels, nPCR, and Kt/V. However, serum prealbumin levels were somewhat increased in hypermagnesemic patients. We conclude that in CAPD patients dialyzed with a 0.75 mmol/l magnesium peritoneal dialysis solution mild hypermagnesemia is frequently found relating at least in part to nutritional status. It is suggested that patients dialyzed with a 0.75 mmol/l magnesium peritoneal dialysis solution should have regular routine estimation of the corrected total serum magnesium concentration. This is absolutely imperative in well-nourished CAPD patients exhibiting higher serum prealbumin levels.