Table 3.

Studies on Simultaneous pancreas and kidney transplant outcomes of C-peptide positive vs C-peptide negative recipients

First author, yr	Country	No. patients	Study period	C-peptide positive (%)	BMI (kg/m2) Mean (SD)	Follow-up (yr)	Outcomes	Conclusion
Chakkera et al[61], 2010	United States	80	2003-2008	a15	T1DM 24.8 (4.2); T2DM 27 (3)	1	No difference in graft (kidney and pancreas) or patient survival.	SPK should be considered in selected patients with T2DM and ESRD. C-peptide measurements for ESRD patients can be misleading.
Light et al[64], 2013	United States	173	1989-2008	c33.5	T2DM 26.1 (ns)d; T1DM 22.5 (ns)d (P < 0.0001)	20	T2DM were older at diabetes diagnosis, older at transplant, and heavier pre- and post-transplant, and had better graft survival. T1DM had better patient survival	There was a difference in patient but not graft survival in 20 yr follow-up.
Stratta et al[62], 2015	United States	162	2001-2013	b18.5	T2DM 26.1 (3.3); T1DM 24.4 (3.2)	5.6 (median)	No difference in patient and graft survival or surgical complications, rejections, serum creatinine, HbA1c, eGFR, C-peptide and weight gain were higher in the C-peptide positive group.	C-peptide “positive” patients appear to have a T2DM phenotype. Outcomes were similar between the two groups, suggesting that C-peptide should not be used exclusively when assessing for SPK transplant candidacy.
Shin et al[65], 2017	Republic of Korea	217	2004-2015	ens	T2DM 38 (9); T1DM 18 (7)	5	Similar post-operative HbA1c (< 6%), fasting insulin, HOMA of insulin resistance, and insulinogenic index. Higher post-transplant C-peptide in T2DM recipients.	No significant difference in insulin resistance or β-cell function in 5 yr.

^aT2DM definition: C-peptide presence, negative glutamic acid decarboxylase antibody, no diabetic ketoacidosis, use of oral hypoglycemics;

^bC-peptide “positive” (T2DM) = C-peptide ≥ 2.0 ng/mL; C-peptide “negative” = C-peptide < 2.0 ng/mL;

^cPatients with undetectable C-peptide (< 0.8 ng/mL) were considered T1DM; patients with detectable C-peptide (> 0.8 ng/mL) were considered T2DM;

^dSD not stated;

^ePatients were classified as T1DM and T2DM, based upon the American Diabetes Association and the World Health Organization definitions of T2DM. As such, there were 151 T1DM [C-peptide 0.92 (SD = 0.58) ng/mL] and 42 T2DM [C-peptide 3.49 (SD = 3.95) ng/mL] patients. T1DM: Type 1 diabetes mellitus; T2DM: Type 2 diabetes mellitus; ESRD: End-stage renal disease; eGFR: Estimated glomerular filtration rate; HbA1c: Glycosylated hemoglobin A1; SPK: Simultaneous kidney-pancreas transplant; ns: Not stated; HOMA: Homeostasis model assessment.