|
|
Ultimate Height of Growth Hormone Deficient Patients who Normalized Growth Hormone Secretion in Puberty« Back to Volume 23, Issue 2, June 2007 - Table of Contents The objectives of the study by Zucchini et al were to establish the percentage and the characteristics of subjects diagnosed with isolated growth hormone deficiency (GHD) in childhood who normalized their GH secretion in puberty and discontinued treatment at that time. The final height attained by this group was compared with that of subjects with persistent GHD who continued on GH therapy after retesting. Sixty-nine subjects (40 males, 29 females) with a diagnosis of isolated GHD before puberty were evaluated by means of arginine and l-dopa testing and were reevaluated after at least 2 years of GH therapy and after the onset of puberty. If peak GH levels were >10 µg/L therapy was withdrawn. At retesting, 44 subjects (63.7%; 24 males, 20 females) had a peak GH <10 µg/L. Patients with confirmed GHD were not different from subjects with normalized GH secretion regarding: height deficit at diagnosis, first year growth response to GH, age and height at onset of puberty, or height and insulin-like growth factor (IGF)-I at retesting. Males who continued treatment achieved an adult height of 165.1 ± 4.5 cm, while those who suspended therapy after retesting had an adult height of 164.0 ± 3.4 cm. Final height of females who continued treatment was 153.2 ± 4.1 cm, whereas those who suspended therapy after retesting were 152.9 ± 5.2 cm. Duration of therapy and GH levels at diagnosis and at retesting were found to be unrelated to achieved adult height or to height increments obtained during the period of observation. First Editor’s CommentA significant number of children diagnosed with GHD before entering puberty, particularly those with non-severe GHD not associated with multiple pituitary hormone deficiencies or with alterations of the pituitary anatomy, display normal GH secretion when retested after the completion of puberty. This discrepancy in GH testing before and after puberty could be the result of a transient deficiency which tends to normalize with the secretion of gonadal steroids or could be due to the unreliability of pharmacological tests when repeated over time. Zucchini et al suggested that GH retesting should take place at midpuberty when GH secretion rises and not after the attainment of final height and completion of puberty, thus avoiding unnecessary treatment of subjects who have normal GH secretion when retested at puberty. The final height attainted by subjects with normal GH secretion at retesting, who discontinued therapy, was similar to that of individuals with confirmed GHD who continued treatment. Therefore, the withdrawal of GH therapy after retesting did not lead to a reduction in ultimate height. There were no clinical or laboratory parameters that allowed for the differentiation of patients with or without persistent GHD after puberty. In subjects with non-severe GHD it seems advisable to retest GH secretion during puberty and to discontinue treatment in those individuals that are no longer deficient, thus avoiding unnecessary treatment during and beyond puberty in these subjects. Roberto Lanes, MD Second Editor’s CommentSeveral years ago we described the recovery of patients with isolated suboptimal GH secretion after a short trial of GH releasing hormone (GHRH).1 Why wait until puberty? Fima Lifshitz, MD Reference - (linked to
|
Volume 24 Number 1
May 2008
www.GGHjournal.com
ISSN 1932-9032
)