Relationship between Serum Magnesium, Parathyroid Hormone, and Vascular Calcification in Patients on Dialysis: A Literature Review

Abstract

Secondary hyperparathyroidism is present in most patients with end-stage renal disease and has been linked to uremic bone disease, vascular calcification, and mortality. Current literature suggests an association between hypomagnesemia and cardiovascular disease in the general population. We reviewed all published studies on the relationship between serum magnesium and parathyroid hormone and the relationship between serum Mg and vascular calcification in dialysis patients. Of these, 10 of 12 studies of patients on hemodialysis and 4 of 5 studies of patients on peritoneal dialysis showed a significant inverse relationship between serum Mg and serum intact parathyroid hormone. Hyperparathyroidism develops in peritoneal dialysis patients dialyzed with a solution containing normal calcium (1.25 mmol/L) and low Mg (0.25 mmol/L), even though serum calcium is maintained at a normal level. Four of the hemodialysis studies and one of the peritoneal dialysis studies indicated that there is an inverse relationship between serum Mg and vascular calcification in these patients. Potential benefits have been attributed to magnesium carbonate as a phosphate binder and it may possibly be an effective, less toxic, less expensive phosphate binder. We believe that the role of Mg in secondary hyperparathyroidism and vascular calcification merits further investigation.

Influence of serum magnesium on markers of calcium-phosphorus metabolism in patients on regular haemodialysis

“…A definite negative correlation between serum Mg and iPTH was observed, as well. Serum Mg in relation to iPTH levels investigated so far by other scientists show similar results (10). The study of Gonda et al in 86 hemodialysis patients established the negative correlation between serum iPTH and Mg and the authors conclude that serum Mg can be used to predict expected levels of PTH (11).…”

Biomarkers Associated with Vascular Calcification in Peritoneal Dialysis

“…Osteogenic markers that play an important role in mineralization of ectopic sites have recently been identified and linked to vascular calcification (9), including osteoprotegerin (OPG) (10), osteopontin (OPN) (11), osteocalcin (OCN) (12), and fibroblast growth factor 23 (FGF-23) (13). These complement previously-known factors such as hypomagnesemia (14) or diminished peritoneal and renal phosphate clearance (15), which have been poorly studied in PD patients in clinical settings. Phosphate clearance represents a modifiable determinant of serum phosphate control (16) which is strongly linked to arteriolar calcification and mortality.…”

Assessment of calcium balance in patients on hemodialysis, based on ionized calcium and parathyroid hormone responses

“…Although the magnitude of the PTH response is primarily determined by the change in pCa 2+ and the overall calcium balance, other factors are also involved. Hyperphosphatemia is known to stimulate PTH secretion (17,18), whereas hypermagnesemia and 1,25(OH) 2 D 3 suppress PTH secretion (19,20). Alkalinization stimulates PTH release by decreasing pCa 2+ (12).…”