DIAGNOSIS OF SEVERE GROWTH-HORMONE (GH) DEFICIENCY IN YOUNG-ADULTS WHO RECEIVED GH REPLACEMENT THERAPY DURING CHILDHOOD

Between 20% and 87% of young adults who had completed growth hormone ( GH) therapy in childhood for a putative diagnosis of GH deficiency (GH D) had normal GH responses to provocative tests when they were reteste d. Patients with isolated idiopathic GHD were more likely to exhibit n ormal GH responses at retest in young adult life than were patients wi th multiple pituitary hormone deficits. When determining which patient s should receive GH therapy in adult life, those who have isolated GHD should undergo two tests of GH status, while those with multiple ante rior pituitary hormone deficits require only one test. Most informatio n is available for the insulin tolerance test, the arginine stimulatio n test and the glucagon stimulation test, but more recent methods, suc h as GH-releasing hormone in combination with pyridostigmine, are show ing promise in the investigation of GHD. In young adults with childhoo d-onset GHD, the serum concentration of insulin-like growth factor I i s a useful marker of GH status, and can be used in conjunction with a GH provocative test. The choice of GH provocative test should ultimate ly depend on the experience and policy developed at the centre perform ing the assessment. Whichever tests are chosen, each should be validat ed in subjects known to have hypothalamic-pituitary disease as well as in normal individuals.