Objective: The purpose of this study was to determine the plasma, erythrocyte, and mononuclear blood cell (MBC) magnesium concentrations in patients with chronic, severe hypomagnesemia due to a chronic magnesium-wasting tubulopathy.
Methodology: Six patients with Bartter's syndrome and five patients with magnesium-wasting tubulopathy were compared with normal subjects. We determined magnesium in plasma, erythrocytes, and MBCs.
Results: Patients with chronic magnesium-wasting tubulopathy had a significantly lower plasma magnesium concentration than controls, but erythrocyte magnesium concentration and MBC magnesium concentration and content did not differ significantly between patients and controls.
Conclusion: Two disorders with chronic magnesium-wasting tubulopathies are associated with a low plasma magnesium concentration but normal erythrocyte and MBC magnesium.