Children: Growth retardation due to growth hormone deficiency (GHD), growth retardation in girls due to gonadal dysgenesis (Turner syndrome), growth retardation in prepubertal children due to chronic renal disease and short children born small for gestational age (SGA) who failed to show catch-up growth by 2 years of age.
Adults: Childhood onset growth hormone deficiency: Patients with childhood onset GHD should be re-evaluated for growth hormone secretory capacity after growth completion. Testing is not required for those with more than three pituitary hormone deficits, with severe GHD due to a defined genetic cause, due to structural hypothalamic pituitary abnormalities, due to central nervous system tumours or due to high-dose cranial irradiation, or with GHD secondary to a pituitary/hypothalamic disease or insult if measurements of insulin-like growth factor (IGF-I) is < -2 SDS after at least four weeks off growth hormone treatment.
In all other patients an IGF-I measurement and one growth hormone stimulation test is required.
Adult onset growth hormone deficiency: Pronounced GHD in known hypothalamic-pituitary disease, cranial irradiation and traumatic brain injury. GHD should be associated with one other deficient axis, other than prolactin. GHD should be demonstrated by one provocative test after institution of adequate replacement therapy for any other deficient axis.
In adults, the insulin tolerance test is the provocative test of choice. When the insulin tolerance test is contraindicated, alternative provocative tests must be used. The combined arginine-growth hormone releasing hormone is recommended. An arginine or glucagon test may also be considered; however, these tests have less established diagnostic value than the insulin tolerance test.