Reduced erythrocyte and leukocyte magnesium is associated with cyclosporin treatment and hypertension in renal transplant patients.

Plasma, urine, erythrocyte and leukocyte magnesium were measured in normotensive and hypertensive renal transplant patients who were being treated with either azathioprine or cyclosporin. These were compared with essential hypertensive patients and normal subjects. Erythrocyte and leukocyte magnesium were reduced in renal transplant patients in independent association (ANOVA) with both cyclosporin treatment (P = 0.03, P = 0.016 respectively) and hypertension (P less than 0.001 for both). Therefore, hypertensive transplant patients on cyclosporin had the lowest magnesium content of both erythrocytes (1.22 +/- 0.09 mmol/l cells) and leukocytes (2.68 +/- 0.2 nmol/10(6) cells) compared to normal subjects (1.96 +/- 0.17 and 4.11 +/- 0.58 respectively) whereas normotensive transplant patients on azathioprine had normal values (2.12 +/- 0.16 and 5.13 +/- 1.0 respectively). Plasma magnesium was also reduced with cyclosporin treatment. Urine magnesium was not significantly different between any of the groups. Therefore, magnesium depletion may have a role in hypertension in renal transplant patients. Since cyclosporin treatment is also associated with magnesium depletion, this could explain the increased occurrence of hypertension in these patients.