Total cholesterol, cyclosporin trough level, serum creatinine, time after-transplant and the ratio of ionized calcium to ionized magnesium were also measured in renal transplant recipients and the relationships between these variables and ionized and total magnesium were evaluated. Values for ionized and total calcium did not differ. By stepwise linear multiple regression analysis, ionized magnesium was significantly related to cyclosporin trough level and total cholesterol but not to serum creatinine, time after transplant or the dose of cyclosporin. Ionized magnesium correlated positivly with the cyclosporin trough level. Ionized magnesium may be a more sensitive clinical parameter than total magnesium in this population, in whom total magnesium may be only mildy decreased in the setting a severe deficit in the setting of a severe deficit in ionized magnesium.
Ionized magnesium correlates with the cyclosporin level.
Renal transplant recipients with high cyclosporin levels demonstrate the most severe deficits in ionized magnesium, and this finding could contribute to cyclosporin-induced hypertension and nephrotoxicity. The direct correlation betweeen ionized magnesium and total cholesterol may result from a 'masked magnesium deficiency', as has been suggested in animal models, and requires further study. Accelerated atherosclerosis observed after renal transplantation may relate to alterations in ionized magnesium and elevated ratios of ionized calcium to ionized magnesium, which are associated with artherogenesis in other models.