Serum Magnesium Concentration and Its Clinical Significance in Hemodialysis Patients

Cho, Jong Tae

Abstract

BACKGROUND
Hypermagnesemia may be implicated to have both harmful and beneficial effects in dialysis patients. It may contribute to osteomalacic renal osteodystrophy and suppression of parathyroid hormone. The purposes of this study were to analyze the serum magnesium concentration in hemodialysis patients, and to clarify the relationship between serum magnesium and intact parathyroid hormone concentration (iPTH) independently of other clinical parameters. METHODS: Eighty-one patients (38 males and 43 females) with end-stage renal failure undergoing maintenance hemodialysis in Dankook University Hospital were included in this study. The mean age was 53+/-12 years and the duration of dialysis was 36+/-35 months. The underlying kidney disease was diabetic nephropathy in 24 patients (30%). The patients used a dialysate magnesium concentration of 1.5 mEq/L. The serum magnesium, iPTH and other clinical parameters were evaluated and analyzed. RESULTS: The mean serum magnesium concentration was 2.78+/-0.45 mEq/L (range 1.50-3.95 mEq/ L). Hypermagnesemia (defined as serum Mg >2.1 mEq/L) was found in 72 patients (89%). The mean iPTH was 128+/-224 pg/mL (range 3-1, 344 pg/mL). The iPTH was significantly low, and the serum aluminum concentration was significantly high in patients (n=28) with more severe hypermagnesemia (defined as serum Mg >3.0 mEq/L). The serum magnesium, aluminum and calcium concentration have significant negative correlations with iPTH respectively (r=-0.27, -0.31, -0.28, p<0.05) in patients (n=55) with relative hypoparathyroidism (defined as iPTH <120 pg/mL). CONCLUSION: Hypermagnesemia was common in hemodialysis patients. High serum aluminum concentration should be considered in patients with moderate to severe hypermagnesemia. Furthermore, hypermagnesemia as well as high serum aluminum and calcium concentration may have a suppressive effect on PTH in patients with relative hypoparathyroidism or adynamic bone disease.