gms | German Medical Science

Objectives: Sympathetic overactivity is present in renal failure and contributes to hypertension and high cardiovascular morbidity in these patients. Correction of uremia by renal transplantation (RTX) does not have a short-term effect on sympathetic overactivity. However, the long-term effect of RTX on muscle sympathetic nerve activity (MSNA) and a possible effect of the type of immunosuppression has not been studied. We investigated sympathetic nerve activity 3 and 18 months after RTX in stable transplant patients treated with cyclosporine A (Rx-CYA) or tacrolimus (Rx-FK) and in normal controls.

Methods: 21 patients with stable graft function (9 Rx-CYA, 12 Rx-FK, serum creatinine 1.2+/-0.4 and 1.2+/-0.7 mg/dl, age 44+/-7 and 46+/-6, resp.) were included. MSNA was measured by microneurography at the peroneal nerve 3 and 18 months after RTX. Plasma norepinephrine (NE) levels were also studied. 22 sex- and age-matched healthy volunteers were studied as control group (serum creatinine 0.92+/-0.12 mg/dl).

Results: Data are mean+/-SD. MSNA was significantly higher in both patient groups compared to controls (19+/-11 burst/min, p<0.01 vs. Rx-CyA and Rx-FK). However, in patients elevated MSNA did not change during follow up after RTX. Neither were there significant between group- or trend-differences between Rx-CYA and Rx-FK.

Conclusions: Our data show significant and persistent sympathetic overactivity for up to 18 months after renal transplantation in patients with stable graft function independent of the type of calcineurin-inhibitor used. Moreover, our data show a good longitudinal reproducibilty of microneurographic measurements of sympathetic nerve activity, confirming the good reproducibility of this method in other patient collectives and in healthy volunteers.

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