Long-term beneficial effect of islet transplantation on diabetic macro-/microangiopathy in type 1 diabetic kidney-transplanted patients

OBJECTIVE - Our aim was to evaluate the long-term effects of transplanted islets on diabetic macro-/microangiopathy in type 1 diabetic kidney-transplanted patients. RESEARCH DESIGN AND METHODS - A total of 34 type I diabetic kidney-transplanted patients underwent islet transplantation and were divided into two groups: successful islet-kidney transplantation (SI-K; 21 patients, fasting C-peptide serum concentration >0.5 ng/ml for >1 year) and unsuccessful islet-kidney transplantation (UI-K; patients, fasting C-peptide serum concentration <0.5 ng/ml). Patients cumulative survival, cardiovascular death rate, and atherosclerosis progression were compared in the two groups. Skin biopsies, endothelial dependent dilation (EDD), nitric oxide (NO) levels, and atherothrombotic risk factors [von Willebrand factor (vWF) and D-dimer fragment (DDF)] were studied cross-sectionally. RESULTS - The SI-K group showed a significant better patient survival rate (SI-K 100, 100, and 90% vs. UI-K 84, 74, and 51% at 1, 4, and 7 years, respectively, P = 0.04), lower cardio`andlower intima-media vascular death rate (Sl-K 1/21 vs. Ul-K 4/13, chi(2) = 3.9 P = 0.04), and lower intima-media. thickness progression than the Ul-K group (Sl-K group: Delta 1-3 years-13 +/- 30 mu m vs. UI-K group: Delta 1-3 years 245 +/- 20 mu m, P = 0.03) with decreased signs of endothelial injuring at skin biopsy. Furthermore, the SI-K group showed a higher EDD than the Ul-K group (EDD: SI-K 7.8 +/- 4.5% vs. Ul-K 0.5 +/- 2.7%, P = 0.02), higher basal NO (Sl-K 42.9 +/- 6.5 vs. UI-K 20.2 +/- 6.8 mu mol/l, P = 0.02), and lower levels of vWF (SI-K 138.6 +/- 15.3 vs. UI-K 180.6 +/- 7.0%, P = 0.02) and DDF (SI-K 0.61 +/- 0.22 vs. UI-K 3.07 +/- 0.68 mu g/ml, P < 0.01). C-peptide-to-creatinine ratio correlated positively with EDD and NO and negatively with vWF and DDF. CONCLUSIONS - Successful islet transplantation improves survival, cardiovascular, and endothelial function in type I diabetic kidney-transplanted patients.