Early Changes in Body Composition After Cessation of Growth Hormone Therapy in Childhood-Onset Growth Hormone Deficiency

At final height, somatic maturity has not been reached yet. We investigated bone and body composition in patients, who completed pediatric growth hormone (GH) treatment at final height. After a mean period of 0.55 +/- 0.17 yr off GH treatment 90 (66 m/24 f) childhood-onset growth hormone deficiency (GHD) patients were reinvestigated for GHD by insulin tolerance testing at a mean age of 17.52 +/- 1.50 yr. Thirty-seven (25 m/12 0 patients remained GH deficient (persistent GHD). Bone and body composition were measured using peripheral quantitative computed tomography of the nondominant forearm. Bone mineral density (BMD) was within normal limits. Total cross-sectional bone area Z-score (0.64 +/- 1.3) was significantly higher as a result of an enlarged medullary cavity Z-score (1.12 +/- 1.2) leading to reduction of cortical thickness Z-score (-1.21 +/- 1.0). Patients with persistent GHD had a significantly higher fat mass (13.3 +/- 8.7 and 6.8 +/- 4.6 cm(2), p < 0.05), which was more pronounced in multiple pituitary hormone deficiency patients. Shortly after cessation of GH treatment in patients treated for childhood-onset GHD age adequate normal BMD and enlarged diaphysis was detectable. Patients with persistent GHD status had a significant higher fat mass.