Response of pancreatic polypeptide to hypoglycaemia in insulin-dependent diabetics with and without residual...

To investigate a possible association between the beta-cells and the cells secreting pancreatic polypeptide (PP), the response of PP to insulin-induced hypoglycaemia was investigated in seven insulin-dependent diabetics with and seven without residual beta-cell function, all without signs of autonomic neuropathy. The mean concentrations of PP was significantly greater from 15 to 60 min after symptoms of hypoglycaemia in patients with residual beta-cell function than in patients without (P less than 0.05) despite similar blood glucose concentrations in the two groups. Also the total integrated areas beneath the response curves as well as the incremental integrated areas were significantly greater in patients with beta-cell function (216 +/- 36 pmol/l x min and 188 +/- 34 pmol/l x min, respectively) than in patients without beta-cell function (125 +/- 26 pmol/l x min and 102 +/- 26 pmol/l x min) (P less than 0.05 for both). The mean maximal concentrations of adrenaline (1.53 +/- 0.28 ng/ml v. 1.29 +/- 0.12 ng/ml) and noradrenaline (0.56 +/- 0.16 ng/ml v. 0.45 +/- 0.04 ng/ml) were not statistically different in the two groups. No well established explanation for an association between residual insulin secretion and capacity for PP-response to hypoglycaemia in type 1 diabetics exists.