GROWTH-HORMONE STATUS IN ADULTS TREATED FOR ACUTE LYMPHOBLASTIC-LEUKEMIA IN CHILDHOOD

OBJECTIVE Growth hormone status was assessed in a cohort of 32 (16 mal e) adults who had received cranial irradiation (XRT) in childhood as p art of their treatment for acute lymphoblastic leukaemia (ALL) and com pared with 35 age matched young adults (18 mate). DESIGN Height and we ight were measured in all subjects and the heights of the patients at XRT were obtained from their case notes. Each patient and control unde rwent two provocative tests of growth hormone (GH) secretion using ins ulin (0.2 IU/kg body weight) and arginine (20g/m(2)). Basal serum insu lin like growth factor-1 (IGF-1) and IGFBP-3 (binding protein-3) conce ntrations were also measured. RESULTS The patient group had a signific antly lower peak GH response to both provocative tests (P<0.01), and l ower IGF-1 and IGFBP-3 levels compared with the normal controls (P<0.0 1). Nine of the patient group were severely GH deficient (peak GH resp onse <9 mU/l to both provocative agents) and a further 12 patients wer e GH insufficient (peak GH response <20 mU/l to both tests with at lea st one peak GH response >9 mU/l), Overall a significant median change in height from XRT to final height of -0.5 SDS was found which was eve n greater in the severely GH deficient group (median change in height of -2.1 SDS), CONCLUSION These data suggest that a significant proport ion of adults treated with cranial XRT in childhood with irradiation d oses between 18-25 Gy, as part of their treatment for ALL, are severel y GH deficient now and should be considered for GH replacement, Change s in GH secretion evolve with time following irradiation-induced damag e to the hypothalamic-pituitary axis; therefore long-term surveillance will be required in those remaining patients, in whom GH status is co nsidered currently to be insufficient or even normal.