Abstract
BackgroundThe diagnosis of growth hormone (GH) deficiency (GHD) in short children seems unquestionable when both GH peak in stimulating tests (GHST) and IGF-I concentration are decreased. However, the discrepancies between the results of GHST and IGF-I secretion are observed. It seems purposeful to determine the significance of GHST and IGF-I assessment in diagnosing GHD. The relationship between GH secretion and thyroid function, as well as GH influence on the peripheral thyroxine (T4) to triiodothyronine (T3) deiodination, mediated by IGF-I, were identified. Thus, clear differences in thyroid function between GH-deficient and non-GH-deficient subjects should exist.MethodsAnalysis comprised 800 children (541 boys), age 11.6 ± 3.1 years (mean ± SD), with short stature, in whom two (2) standard GHST (with clonidine and with glucagon) were performed and IGF-I, free T4 (FT4), free T3 (FT3) and TSH serum concentrations were assessed. The patients were qualified to the following groups: GHD - decreased GH peak in GHST and IGF-I SDS (n = 81), ISS - normal GH peak and IGF-I SDS (n = 347), low GH - normal IGF-I SDS, and decreased GH peak (n = 212), low IGF - decreased IGF-I SDS, and normal GH peak (n = 160). The relationships among the results of particular tests were evaluated.ResultsIn the groups with decreased IGF-I concentrations (GHD Group and low IGF Group), the more severe deficit of height was observed, together with higher TSH and FT4 but lower FT3 levels than in groups with normal IGF-I concentrations (ISS Group and low GH Group), independently of the results of GHST. TSH, FT4 and FT3 concentrations were - respectively - similar in two groups with decreased IGF-I secretion, as well as in two groups with normal IGF-I levels. Significant correlations were found between patients' height SDS and IGF-I SDS, between FT3 and IGF-I SDS (positive), and between FT4 and IGF-I SDS (negative), with no correlation between GH peak and any of the parameters analyzed.ConclusionThe assessment of thyroid function in children with short stature provides the evidence that measurement of IGF-I concentration may be a procedure reliable at least to the some degree in diagnosing GHD as the results of GHST.
Highlights
The diagnosis of growth hormone (GH) deficiency (GHD) in short children seems unquestionable when both GH peak in stimulating tests (GHST) and Insulin-like growth factorI (IGF-I) concentration are decreased
In order to avoid the possible influence of disorders of thyroid function on GH and/or IGF-I secretion and action, only the children with values of thyroid stimulating hormone (TSH), free T4 (FT4), and free T3 (FT3) concentrations within the reference range were included into the analysis
The deficit of height proved to be the most expressed in low IGF Group, being significantly lower than that in both idiopathic short stature (ISS) Group (p < 0.001) and low GH Group (p < 0.001), as well as than that in GH deficiency (GHD) Group (p = 0.031)
Summary
The diagnosis of growth hormone (GH) deficiency (GHD) in short children seems unquestionable when both GH peak in stimulating tests (GHST) and IGF-I concentration are decreased. The diagnosis of GH deficiency (GHD) seems unquestionable when both GH peak in GHST and IGF-I concentration are decreased. GHD may be excluded in the patients, in whom both GH and IGF-I secretion are normal In such cases, the diagnosis of idiopathic short stature (ISS) seems to be the most adequate after careful exclusion of other possible causes of short stature (including geneticallydetermined syndromes, chronic diseases, malnutrition, etc.). The relationships between GH secretion, more presently - between the results of GHST and IGF-I levels were assessed in numerous studies. In one of our previous studies [19], the stability of IGF-I concentration was proved, despite divergent results of the repeated GHST
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
