Relationship Between Serum Magnesium and Parathyroid Hormone Levels in Hemodialysis Patients / 대한신장학회잡지

ABSTRACT

The important factors involved in the regulation of PTH are calcium, vitamin D, and phosphorus. However, recent studies have suggested that magnesium may also play a significant role in the modulation of PTH. The aims of this study was to analyze the relationship between serum magnesium and PTH levels in the hemodialysis patients. We studied 66 stable patients under maintenance hemodialysis for more than 6 months. Calcium carbonate was used as a phosphate binder in all patients. No patient had been previously treated with vitamin D and aluminum hydroxide. Biochemical parameters were evaluated 3 times during 7 months, and the mean values were computed. The mean serum magnesium level was 2.7+/-0.4 mEq/L. Hypermagnesemia(defined as serum Mg>2.2 mEq/L) was found in 60 patients(90.1%). Serum magnesium levels were inversely correlated with serum iPTH levels(r=-0.579; p<0.001). Serum total and ionized calcium levels were inversely correlated with serum iPTH levels(r=-0.743; p<0.001, r=-0.699; p<0.001, respectively). Serum alkaline phosphatase levels positively correlated with serum iPTH levels (r=0.364; p=0.003). In lower iPTH group(serum iPTHserum magnesium, total calcium, and ionized calcium levels were significantly higher. Alkaline phosphatase level was significantly lower in lower PTH group. After controlling for the effect of the other variables, serum magnesium and iPTH levels were inversely correlated(r=-0.53; p<0.001). A stepwise multiple regression analysis showed that serum magnesium level was the most predictive variable(R2=0.72; p<0.001). Hypermagnesemia is frequent in hemodialysis patients. There is a significant inverse relationship between serum magnesium and PTH levels. In addition, serum magnesium concentration has an important influence on PTH regulation. These results suggest that hypermagnesemia may have a suppressive effect on PTH regulation in hemodialysis patients.