Safety of the insulin tolerance test

Concerns have been raised about the hazards of the insulin tolerance test (ITT), used to measure growth hormone secretion. In Glasgow, we continue to use this test, adhering to a strict protocol. A review of outcome over a 10 year period (1989-99), during which 550 ITTs were performed, was undertaken. No serious adverse events occurred; in particular, no child fitted or required intravenous glucose. Fewer tests were done during the latter five years, with a higher yield of growth hormone (GH) deficiency, reflecting our increasingly conservative approach to paediatric GH therapy during this period. We conclude that the ITT is safe and reliable in a paediatric setting provided that a strict procedure is followed.