Islet Transplantation Is Associated With an Improvement of Cardiovascular Function in Type 1 Diabetic Kidney Transplant Patients

Abstract

OBJECTIVE—Cardiovascular mortality and morbidity are major problems in type 1 diabetic patients with end-stage renal disease (ESRD). The aim of this study was to determine whether islet transplantation can improve cardiovascular function in these patients. RESEARCH DESIGN AND METHODS—We assessed various markers of cardiac function at baseline and 3 years later in a population of 42 type 1 diabetic patients with ESRD who received a kidney transplant. Seventeen patients then received an islet transplant that had persistent function as defined by long-term C-peptide secretion (kidney-islet group). Twenty-five patients did not receive a functioning islet transplant (kidney-only group). RESULTS—GHb levels were similar in the two groups, whereas the exogenous insulin requirement was lower in the kidney-islet group with persistent C-peptide secretion. Overall, cardiovascular parameters improved in the kidney-islet group, but not in the kidney-only group, with an improvement of ejection fraction (from 68.2 ± 3.5% at baseline to 74.9 ± 2.1% at 3 years posttransplantation, P < 0.05) and peak filling rate in end-diastolic volume (EDV) per second (from 3.87 ± 0.25 to 4.20 ± 0.37 EDV/s, P < 0.05). Time to peak filling rate remained stable in the kidney-islet group but worsened in the kidney-only group (P < 0.05). The kidney-islet group also showed a reduction of both QT dispersion (53.5 ± 4.9 to 44.6 ± 2.9 ms, P < 0.05) and corrected QT (QTc) dispersion (67.3 ± 8.3 to 57.2 ± 4.6 ms, P < 0.05) with higher erythrocytes Na+-K+-ATPase activity. In the kidney-islet group only, both atrial natriuretic peptide and brain natriuretic peptide levels decreased during the follow-up, with a stabilization of intima-media thickness. CONCLUSIONS—Our study showed that type 1 diabetic ESRD patients receiving a kidney transplant and a functioning islet transplant showed an improvement of cardiovascular function for up to 3 years of follow-up compared with the kidney-only group, who experienced an early failure of the islet graft or did not receive an islet graft.