Diagnosis and growth hormone (GH) therapy in children with GH deficiency: experience in King Chulalongkorn Memorial Hospital, Thailand.

ABSTRACT

BACKGROUND: Diagnosis of growth hormone deficiency (GHD) needs both clinical and biological aspects such as auxological data and GHprovocative tests, and active metabolites of GH including IGF-I and IGFBP-3. In GHD children, rhGH has been used worldwide with minimal serious side effects. The aims of the present study were to describe the experience in King Chulalongkorn Memorial Hospital regarding diagnosis and treatment with rhGH in GHD children. MATERIAL AND METHOD: Clinical data of 173 short children was retrospectively reviewed. Two GH provocative tests used in the present study were insulin tolerance test (ITT) and clonidine test. To make the diagnosis of GHD, the children had to fail both GH provocative tests (peak GH < 10 ng/ml). Baseline clinical data, IGF-I, and IGFBP-3 were compared between the group with true positive test and the group with false positive test. Thirty-five children with GHD, who had been treated with rhGH, were evaluated in terms of growth response, changes of IGF-I SDS and the relationship between these parameters. RESULTS: From the present study, ITT could diagnose GHD with true positive 57% and false positive 43% and clonidine could diagnose with true positive 67% and false positive 33%. Clinical data including chronological age, bone age, HtSDS, WtSDS, IGF-I SDS, and IGFBP-3 SDS were not different between the true positive and false positive group. rhGH with a mean dose of 29.3 +/- 4.6 microg/kg/day increased height velocity (HV) from 3.9 +/- 2.5 to 9.3 +/- 2.5, 8.1 +/- 1.5, 7.2 +/- 2.2, 6.8 +/- 2.2, 7.6 +/- 2.4, and 6.5 +/- 1.8 cm/yr after 6 months, 1, 2, 3, 4, and 5 years after treatment, respectively. This also improved HtSDS during treatment and brought the HtSDS into the target range after 3 years of treatment. At the end of the first year of treatment, the difference of IGF-I SDS (DeltaIGF-I SDS) > or = 1 could predict a good response (DeltaHtSDS > or = 0.5) with sensitivity of 88.9% and specificity of 60% respectively. At the end of the second year, DeltaIGF-I SDS > or = 1 could predict a good response with sensitivity and specificity of 100% and 29%, respectively. CONCLUSION: From the present study, the authors demonstrated the investigation and treatment practices of short children with GHD. The growth response is satisfactory even with a lower dose than suggested. In addition, measurement of IGF-I and IGFBP-3 cannot be used in diagnosing GHD but can predict the height outcome at least by the first 2 years of the treatment. However long-term outcome need to be clarified.