OBJECTIVE -In response to hyperglycemia, -cells release insulin and C-peptide, as well as islet amyloid pancreatic polypeptide, which is involved in glucose homeostasis. After successful pancreas-kidney transplantation (PKT), type 1 diabetic patients may revert to a nondiabetic metabolism without exogenous insulin therapy and re-secrete all -cell hormones.
RESEARCH DESIGN AND METHODS-Using mathematical models, we investigated hormone (amylin, insulin, C-peptide) and metabolite (glucose, free fatty acids) kinetics, -cell sensitivity to glucose, and oral glucose insulin sensitivity index (OGIS) in 11 nondiabetic type 1 diabetic patients after PKT (BMI 25 Ϯ 1 kg/m 2 , 47 Ϯ 2 years of age, 4 women/7 men, glucocorticoid-free), 6 matching nondiabetic patients after kidney transplantation (25 Ϯ 1 kg/m 2 , 50 Ϯ 5 years, 3 women/3 men, on glucocorticoids), and 9 matching nondiabetic control subjects (24 Ϯ 1 kg/m 2 , 47 Ϯ 2 years, 4 women/5 men) during a 3-h 75-g oral glucose tolerance test (OGTT).RESULTS -PKT patients had higher fasting amylin (19 Ϯ 3 vs. control subjects: 7 Ϯ 1 pmol/l) and insulin (20 Ϯ 2 vs. control subjects: 10 Ϯ 1 U/ml; each P Ͻ 0.01) levels. Kidney transplant subjects showed increased OGTT plasma insulin at 90 min and C-peptide levels (each P Ͻ 0.05). In PKT patients, plasma glucose from 90 to 150 min was 9 -31% higher (P Ͻ 0.05 vs. control subjects). Amylin clearance was comparable in all groups. Amylin's plasma concentrations and area under the concentration curve were up to twofold higher in PKT patients during OGTT (P Ͻ 0.05). OGIS was not significantly different between groups. -Cell sensitivity to glucose was reduced in PKT patients (Ϫ64%, P Ͻ 0.009). Fasting plasma amylin was inversely associated with -cell sensitivity to glucose (r ϭ Ϫ0.543, P Ͻ 0.004).CONCLUSIONS -After successful PKT, type 1 diabetic patients with nondiabetic glycemia exhibit increased fasting and post-glucose load plasma amylin, which appears to be linked to impaired -cell function. Thus, higher amylin release in proportion to insulin might also reflect impaired -cell function in type 1 diabetic patients after PKT.