Ionized serum magnesium in type 2 diabetes mellitus: its correlation with total serum magnesium and hemoglobin A1c levels

South Med J. 1999 Dec;92(12):1162-6. doi: 10.1097/00007611-199912000-00005.


Background: Hypomagnesemia has been described in diabetes mellitus. We sought to compare serum total and ionized magnesium (Mg) levels in patients with type 2 diabetes with control subjects and to determine the relationship between diabetes control, as assessed by hemoglobin A1c (Hb A1c) and Mg (total and ionized).

Methods: Serum ionized Mg was measured by ion-selective electrode (ISE) method using the NOVA electrode.

Results: Serum ionized Mg was significantly higher in diabetics than in control subjects, whereas no difference was found in total Mg. Serum ionized Mg correlated with total Mg in diabetics and in control subjects. There was an inverse correlation between total Mg and Hb A1c; the correlation was not statistically significant between ionized Mg and Hb A1c.

Conclusions: Our data do not support routine Mg supplementation or monitoring in type 2 diabetes.

MeSH terms

  • Adult
  • Aged
  • Case-Control Studies
  • Cations, Divalent / blood
  • Diabetes Mellitus, Type 2 / blood*
  • Female
  • Glycated Hemoglobin A / metabolism*
  • Humans
  • Magnesium / blood*
  • Male
  • Middle Aged


  • Cations, Divalent
  • Glycated Hemoglobin A
  • Magnesium