Does glucagon stimulation predict oral glucose tolerance in patients aftersimultaneous pancreas-kidney transplantation?

Background. Exogenous glucagon rapidly stimulates insulin secretion. This t est has been used to estimate insulin secretory capacity, which may predict oral glucose tolerance in patients after pancreas transplantation. Methods. In 32 pancreas-kidney transplant recipients, in 10 nondiabetic kid ney transplant recipients, and in 9 healthy control subjects, a glucagon st imulation test (1 mg i.v.) and a 75-g oral glucose tolerance test were perf ormed with determination of glucose, insulin, and C-peptide profiles, Results. Of 16 pancreas transplant recipients with the lowest insulin respo nses after glucagon, 7 had an impaired oral glucose tolerance, in contrast to 1 of 16 with high insulin responses (P=0.037). A low insulin response af ter glucagon was associated with significantly lower 120-min glucose concen trations (P=0.043) and a lower integrated incremental insulin response afte r oral glucose (P=0.006). Conclusions. In pancreas-kidney transplant recipients, a low insulin respon se after intravenous glucagon predicts a reduced insulin response after ora l glucose and an impaired oral glucose tolerance, This simple test may be h elpful in the follow-up of pancreas transplant recipients.