Acute insulin responses to glucose and arginine as predictors of beta-cell secretory capacity in human islet transplantation.
Islet transplantation for type 1 diabetes can enable the achievement of near-normal glycemic control without severe hypoglycemic episodes. How much an islet (beta-cell) graft may be contributing to glycemic control can be quantified by stimulatory tests of insulin (or C-peptide) secretion. Glucose-potentiation of arginine-induced insulin secretion provides a measure of functional beta-cell mass, the beta-cell secretory capacity, as either AIR(pot) or AIR(max), but requires conduct of a hyperglycemic clamp. We sought to determine whether acute insulin responses to intravenous glucose (AIR(glu)) or arginine (AIR(arg)) could predict beta-cell secretory capacity in islet recipients. AIR(arg) was a better predictor of both AIR(pot) and AIR(max) (n=10, r2=0.98, P<0.0001 and n=7, r2=0.97, P<0.0001) than was AIR(glu) (n=9, r2=0.78, P=0.002 and n=6, r2=0.76, P=0.02). Also, the measures of beta-cell secretory capacity were highly correlated (n=7, r2=0.98, P<0.0001). These results support the use of AIR(arg) as a surrogate indicator of beta-cell secretory capacity in islet transplantation.
Rickels
Michael R
MR
Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6149, USA. rickels@mail.med.upenn.edu
Naji
Ali
A
Teff
Karen L
KL
D001120:Arginine / Q000494:pharmacology*; D003922:Diabetes Mellitus, Type 1 / Q000601:surgery; D005947:Glucose / Q000494:pharmacology*; D015309:Glucose Clamp Technique; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism*; D016381:Islets of Langerhans Transplantation / Q000502:physiology*
D007328:Insulin; D001120:Arginine; D005947:Glucose