Clinical aspects of magnesium physiology in patients on dialysis

Abstract

Magnesium balance is infrequently discussed in the dialysis population, and the clinical consequences of derangements in magnesium homeostasis are incompletely understood. There is an association between hypomagnesemia and adverse outcomes including increases in cardiovascular disease and mortality, while elevated magnesium levels have also been linked with complications such as osteomalacia. In this review, we discuss the features of magnesium physiology relevant to dialysis patients and provide an updated summary of the literature linking magnesium derangements with bone disease, cardiovascular disease, sudden cardiac death, and mortality.

Hypomagnesemia is not an independent risk factor for mortality in Japanese maintenance hemodialysis patients

“…Recently, interest has grown in the relationships between serum magnesium (Mg) levels and vascular calcification or mortality in HD patients [ 2 ]. Extracellular magnesium accounts for only 1% of the total body content [ 3 , 4 ]. Serum contains a much smaller amount (0.3% of total body stores), of which one-third is bound to protein, and nonprotein bound magnesium is the fraction that is ultrafilterable in HD and consists of complexed and free magnesium (5.5% and 61% of total serum levels, respectively) [ 4 ].…”

“…Extracellular magnesium accounts for only 1% of the total body content [ 3 , 4 ]. Serum contains a much smaller amount (0.3% of total body stores), of which one-third is bound to protein, and nonprotein bound magnesium is the fraction that is ultrafilterable in HD and consists of complexed and free magnesium (5.5% and 61% of total serum levels, respectively) [ 4 ]. Normal Mg concentration is 1.7–2.4 mg/dl, and magnesium homeostasis is determined by the balance between absorption and excretion (intestinal and renal) [ 3 , 4 ].…”

“…Serum contains a much smaller amount (0.3% of total body stores), of which one-third is bound to protein, and nonprotein bound magnesium is the fraction that is ultrafilterable in HD and consists of complexed and free magnesium (5.5% and 61% of total serum levels, respectively) [ 4 ]. Normal Mg concentration is 1.7–2.4 mg/dl, and magnesium homeostasis is determined by the balance between absorption and excretion (intestinal and renal) [ 3 , 4 ]. In experimental studies, magnesium inhibited vascular calcification and osteogenic differentiation in vitro [ 5 ], prevented calciprotein particle maturation, which can induce calcification in vitro [ 6 ], and bound to phosphate in the intestines, which reduced vascular calcification in rats [ 7 ].…”

Relationship of serum magnesium level with body composition and survival in hemodialysis patients

“…4,5 Extracellular Mg accounts for only 1% of the total body content; in serum, which contains only 0.3% of the total body stores of Mg, one-third of Mg content is protein bound. 6 Only unbound Mg is ultrafiltrable in hemodialysis. While normal serum Mg levels in the general population were reported at 1.7 to 2.4 mg/dL, 6 the optimal serum Mg levels and dialysate Mg concentrations for hemodialysis patients remain unclear.…”

“…6 Only unbound Mg is ultrafiltrable in hemodialysis. While normal serum Mg levels in the general population were reported at 1.7 to 2.4 mg/dL, 6 the optimal serum Mg levels and dialysate Mg concentrations for hemodialysis patients remain unclear.…”