Lack of von Willebrand factor, factor VIII related antigen and factor VIII coagulant response to human growth hormone infusion in type 2 diabetes mellitus.

Excessive growth hormone (GH) secretion and platelet hyperaggregation have been considered to be involved in the development of the vascular complications of diabetes mellitus (DM). Trying to find a common link between GH and platelet hyperaggregation, we measured von Willebrand or ristocetin cofactor activity (VIII R:Rcof), factor VIII-related antigen (VIII R:Ag) and factor VIII coagulant activity (VIII:C) in ten type 2 DM (NIDDM) and seven normal control (C) human subjects. These three parameters were measured before (time 0), and after a one-hour intravenous infusion of 0.1 U/kg bw of GH, (times 1, 4, 6, and 24 hours). The NIDDM subjects were nonobese and without clinical evidence of diabetic vascular complications. Despite remarkably high levels of GH reached during the infusion (average 280 ng/ml), there were no significant changes in the measured parameters in either NIDDM or C group. The baseline levels of factors VIII R:Rcof, VIII R:Ag and VIII:C were also not significantly different in the two groups. Changes in GH serum levels seem to have no effect on the factors VIII:C, VIII R:Ag or VIII R:Rcof levels in normals (C) or in NIDDM subjects without evidence of vascular complications. These results do not preclude the possibility that there may be a different response to GH in DM patients with advanced vascular complications and probable endothelial cell abnormalities.