Büyüme Hormonu Tedavisi Kullanan Çocukların Kalıcı Büyüme Hormonu Eksikliği Açısından Yeniden Değerlendirilmesi ve Bunu Öngören Parametrelerin Belirlenmesi

Abstract

Some cases are diagnosed as growth hormone deficiency (GHD) mistakenly and unnecessary growth hormone (GH) replacement therapy is implemented in these cases due to low reliability of auxological and biochemical criteria that are used for the diagnosis of GHD. The purpose of this study is to determine the patients who are not actually growth hormone deficient but diagnosed by mistake due to the fact that diagnostic procedures are not distinctive enough. To achieve the goal we perfomed retesting to all of the cases who are diagnosed as GHD and receiving GH replacement therapy in the early stage and by the help of these retests we tried to specify the differences between permanent cases from the cases mistakenly diagnosed as GHD in regard to auxological and laboratory parameters and to set the parameters to foresee which patients should be reevaluated with the retests. Within this framework, retests are performed at 1,22 ± 0,42 years of the treatment on the cases diagnosed as GHD and receiving GH replacement therapy at the Hacettepe University Pediatric Endocrinology Unit between 2000 and 2012. Auxological data and the stage of puberty, results of GH stimulation tests both at the diagnosis and at retesting, levels of IGF-1 and IGFBP-3 at the diagnosis, and pituitary gland MRI results were recorded. For all cases, height at the first year of the treatment; for cases that continued GH treatment due to low retest response, height at the second and third years of the treatment; for cases that stopped using GH treatment as a response to normal retest results, height at the first and second year after discontinuing the treatment and for both groups, adult height data were evaluated. Isolated growth hormone deficiency (IGHD) was present in 64% (170/265) of the cases and multiple pituitary hormone deficiency (MPHD) was observed in 36% (95/265). It was seen that the GH levels were normal in %26 (69/265) of all cases retested. The cases that had normal retest results all had IGHD and no one in the MPHD group had normal GH responses at the retest. As the probability of having normal GH responses is high in IGHD cases with pituitary scans reported as normal or having only adenohypophyseal hypoplasia, it is believed that these cases should be retested. Due to the low probability of having normal GH levels in MPHD cases or in IGHD cases with structural pituitary defects, it is considered that retesting these cases is not necessary. It was observed that being pubertal or having sex steroid priming in prepubertal cases increase the probability of having normal peak GH level in the retests. The most determinative factors to distinguish the cases with normal GH response in the retest are the peak GH level and the height gain in the first year of the treatment. It is shown that cases with a peak GH level below 5 ng/ml at the diagnosis and a height gain higher than 0.61 SDS in the first year of the treatment are more likely to have permenant GHD. GH replacement treatment was continued for the cases that showed permanent deficiency in the retests, while the treatment of the cases which had normal GH levels in the retests was discontinued. Temporary GHD cases reached their target heights after the discontinuation of the growth hormone treatment, height gain after the diagnosis and adult heights were similar to the permenant GHD cases that continued to have the growth hormone replacement therapy. For this reason, it is thought that it is safe to discontinue GH treatment in the cases who are proven to have temporary GHD in the retests.