Permanently reduced plasma ionized magnesium among renal transplant recipients on cyclosporine

Hypomagnesemia is common after kidney transplantation. Until recently, only the determination of total plasma magnesium was possible, whereas the asse ssment of ionized magnesium has since become practicable. One hundred and n ine renal transplant patients on cyclosporine with allografts functioning s tably for more than 6 months and plasma creatinine levels of less than 200 mu mol/l entered the study. Total and ionized circulating magnesium were as sessed among these 109 patients, as well as among 15 renal transplant patie nts not on cyclosporine and 21 healthy volunteers. Cyclosporine patients sh owed significantly Lower total and ionized circulating magnesium values tha n the two control groups. Plasma total and ionized magnesium levels were al so significantly lower among cyclosporine patients treated concurrently wit h insulin or oral hypoglycemic agents than among those who were not. No cor relation was noted between time after transplantation and plasma magnesium with respect to patients on cyclosporine; In conclusion, the study demonstr ates that a large subset of renal transplant patients treated with cyclospo rine have permanent deficiencies of ionized and total magnesium. The tenden cy towards hypomagnesemia is also more pronounced among patients with diabe tes mellitus.