Linear growth and final height after treatment for Cushing's disease in childhood

Cushing's disease is associated with growth failure in childhood and adolescence. Growth and final height were analyzed in 10 patients who were cured or in remission after treatment of Cushing's disease. Seven males and 3 females, aged 6.8-17.6 yr (bone age, 3.3-15.4 yr), had transsphenoidal surgery, which was combined with pituitary irradiation (4,500 cGy in 25 fractions) in 5 patients. At presentation, 5 patients were prepubertal (males), and 5 were pubertal (2 males and 3 females). The mean height SD score was -2.15 +/-1.26 (range, -0.21 to -4.32) compared with mean target height SD score of -0.43 +/- 0.58. Height velocity in 6 patients was subnormal (0.9-3.8 cm/yr). After treatment, short-term height velocity, over a mean interval of 0.57 yr, in 8 patients not receiving human GH (hGH) therapy, was variable (range, 0.8-7.6 cm/yr). GH stimulation tests (insulin tolerance test/glucagon) in 9 subjects showed peak GH levels of 0.5-20.9 mU/L. Eight were treated with hGH (14 IU/m2 wk), combined in 2 girls and 1 boy with a GnRH analog. After 1 yr of hGH, the mean height SD score had increased from -2.45 +/- 1.0 at initiation of hGH to -2.07 +/- 1.2 (P = 0.01). GH therapy was continued until final height or latest assessment. The mean final height SD score (n = 6) was - 1.24 +/- 1.38, and at the latest assessment the mean height SD score (n = 4) was - 1.52 +/- 1.33. Combining these 2 groups, the mean height so score was -1.36 +/- 1.29. The difference between final or latest height SD score and target height SD score was 0.93 +/- 1.13, i.e. less (P = 0.005) than the difference between height and target height SD score of 1.72 +/- 1.26 at presentation. In conclusion, catch-up and favorable long-term growth was seen after treatment for Cushing's disease. Posttreatment GH deficiency was frequent, and early hGH replacement may have contributed to the encouraging outcome.