Do pretransplant C-peptide levels influence outcomes in simultaneous kidney-pancreas transplantation?

Objective. To analyze outcomes in simultaneous kidney-pancreas transplantation (SKPT) recipients who retain C-peptide production at the time of SKPT. Methods. This retrospective analysis of SKPTs from January 2002 through January 2007 compared outcomes between patients with absent or low C-peptide levels (<2.0 ng/mL, group A) with those having levels >= 2.0 ng/mL (group B). Results. Among 74 SKPTs, 67 were in group A and seven in group B (mean C-peptide level 5.7 ng/mL). During transplantation, group B subjects were older (mean age 51 vs 41 years, P = .006); showed a later age of onset of diabetes (median 35 vs 1.3 years, P = .0001); weighed more (median 77 vs 66 kg, P = .24); had a greater proportion of African-Americans (57% vs 13%, P = .004); and had a longer pretransplant duration of dialysis (median 40 vs 14 months, P = .14). With similar median follow-up of 40 months, death-censored kidney (95% group A vs 100% group B, P = NS) and pancreas (87% group A vs 100% group B, P = NS) graft survival rates were similar, but patient survival (94% group A vs 71% group B, P = .03) was greater in group A. At 1-year follow-up, there were no significant differences in rejection episodes, surgical complications, infections, readmissions, hemoglobin A1C or C-peptide levels, serum creatinine, or MDRD GFR levels. Conclusions. Diabetic patients with measurable C-peptide levels before transplant were older, overweight, more frequently African-American and had a later age of onset of diabetes, longer duration of pretransplant dialysis, and reduced patient survival compared to insulinopenic patients undergoing SKPT. The other outcomes were similar.