Acute hyperinsulinemia is associated with increased circulating levels of adrenomedullin in patients with type 2 diabetes mellitus.

Abstract

To investigate the effect of acute hyperinsulinemia on the plasma levels of adrenomedullin (AM) in patients with type 2 diabetes mellitus. We measured the plasma levels of AM in 18 patients with type 2 diabetes mellitus and in 19 normal subjects before and during a euglycemic hyperinsulinemic clamp study (the goal was for blood sugar levels of 5.24 mmol/l and insulin levels of 1200 pmol/l). Both plasma AM and serum insulin were measured by immunoradiometric assays. Before the glucose clamp study there was no significant difference in the plasma levels of AM between patients with type 2 diabetes mellitus and normal subjects. During the glucose clamp study, the serum levels of insulin significantly increased (from 33.0+/-3.6 to 1344.6+/-67.8 pmol/ml, P<0.001), as did the plasma levels of AM (from 12.8+/-0.7 to 14.2+/-0.9 fmol/ml, P<0.03) only in patients with type 2 diabetes mellitus. There was a significant correlation between the change in circulating levels of insulin and AM (r=0.755, P<0.01). Acute hyperinsulinemia induced a significant increase in the plasma levels of AM in patients with type 2 diabetes mellitus. Increased insulin may regulate circulating levels of AM in patients with type 2 diabetes mellitus.