C-peptide and Glucose Values in the Peritransplant Period After Intraportal Islet Infusions in Type 1 Diabetes

Transplant Proc. 2005 Oct;37(8):3433-4. doi: 10.1016/j.transproceed.2005.09.090.


Background: Successful islet allograft transplantation has been achieved worldwide. This study aimed at evaluating the relationship between peritransplant C-peptide (CP) values and long-term allograft function.

Methods: We measured CP-to-glucose ratio (CPGR) in intraportal samples pre- and postinfusion, and in peripheral circulation at baseline pretransplant and at 1, 3, 6, 12, 72 hours, 1 week, and 15 and 30 days after first and second infusion in 13 islet allograft recipients. Peritransplant treatment included intravenous (IV) 5% dextrose in saline in all patients. We compared portal CPGR to insulin reduction (%) at 30 days after each infusion, and at 1 year after second infusion.

Results: CPGR peaked between the immediate postinfusion and 3 hours and decreased at 12 hours. At 1 week, CPGR was 0.76 +/- 0.45 and 1.44 +/- 0.37 after first and second infusion, respectively. CPGR at 30 days after second infusion doubled compared to first infusion (P < .001). There was no correlation between peak CPGR and insulin reduction percent at any time point. One patient experienced hypoglycemia (47 mg/dL) 1 hour after second infusion.

Conclusions: There was no relationship between the CP values in the peritransplant period and long-term graft function or success rate. The early peak in the C-peptide levels is indicative of a significant insulin release after each islet infusion. For this reason, it is important to carefully monitor serum glucose levels in the peritransplant period (hourly for the first 6 hours) and to maintain an IV glucose infusion to avoid hypoglycemia.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Glucose / metabolism
  • C-Peptide / blood*
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / surgery*
  • Humans
  • Islets of Langerhans Transplantation / methods*
  • Islets of Langerhans Transplantation / physiology*
  • Portal System*
  • Transplantation, Homologous
  • Treatment Outcome


  • Blood Glucose
  • C-Peptide