Failure of somatostatin to diagnose organic hyperinsulinism

In four patients with organic hyperinsulinism (two with surgically proven beta-cell adenomas of the body of the pancreas) a standard tolbutamide test during continuous somatostatin infusion (5 microgram/min) was carried out. Tolbutamide induced insulin release was completely inhibited by somatostatin as in normal subjects. These results suggest that the inhibition test with somatostatin does not seem to be a better or safer way of diagnosing insulin producing tumours.