A Martinez

Nocturnal TSH Surge and TRH Test Response in the Evaluation of Thyroid Axis in Hypothalamic Pituitary Disorders in Childhood

We studied, by means of TSH nocturnal secretion and TRH test, 42 children (4.2–19.9 years) with hypothalamic pituitary disorders and 24 healthy euthyroid children (5.7–15.4 years) as control group. Patients were divided according to their serum values of FT4 in group 1 (n = 27) with FT4 ≥10.3 pmol/l and group 2 (n = 15) with FT4 <10.3 pmol/l. TSH was measured by immunoradiometric assay. TSH nadir, TSH peak and TSH surge were calculated. Both groups differed significantly from control group in TSH surge values: group 1 (p < 0.05), group 2 (p < 0.01). TRH test was abnormal in 11/27 patients of group 1 and 10/15 patients of group 2. In group 1, 7 patients had normal tests, 2 had abnormalities in both tests, 9 had only TSH nocturnal surge altered and 9 showed only TRH alterations. All patients of group 2 presented thyroid axis abnormalities. In conclusion, in patients with hypothalamic pituitary disorders with low FT4, no further investigation is required to demonstrate thyroid axis alterations, however in patients with normal FT4, nocturnal TSH secretion and TRH test may be required to evidence thyroid abnormalities.

Long-term endocrine sequelae after surgery, radiotherapy, and chemotherapy in children with medulloblastoma

Thirteen children with medulloblastoma, were studied after 2 to 62 months off radiotherapy and chemotherapy with methotrexate and BCNU. Ages at time of study ranged from 2.3 to 15.7 years. Eleven patients, followed for a mean of 22 months, showed a significant decrease of height score, whereas nine patients had deficient growth hormone (GH) response to provocative tests. Clinical pubertal progression was normal in all patients, and three of five girls with advanced pubertal development had menarche. No evidences of gonadotropin disturbances were found in five patients whereas seven had raised basal folliclestimulating hormone (FSH) level or FSH response to luteinizing hormone‐releasing hormone (LH‐RH). Abnormalities in thyrotrophin (TSH) secretion were found in 9 of 13 patients. This study shows that poor growth and GH deficiency were frequent in our patients. The high frequency of thyroid disturbances observed point out the need of evaluating thyroid function for adequate replacement therapy. Perhaps modification of adjuvant chemotherapy in the future can diminish drug‐induced gonadal damage. Cancer 59:801‐806, 1987.

Normal Growth Spurt and Final Height despite Low Levels of All Forms of Circulating Insulin-Like Growth Factor-I in a Patient with Acid-Labile Subunit Deficiency

Background: In a recently described patient with acid-labile subunit (ALS) deficiency, the inability to form ternary complexes resulted in a marked reduction in circulating total insulin-like growth factor (IGF)-I, whereas skeletal growth was only marginally affected. To further study the role of circulating versus locally produced IGF-I in skeletal growth in this patient, we now describe in detail growth changes and their relationship with several components of the circulating IGF system. Design and Methods: We followed growth and development up to the final height in a patient with complete ALS deficiency and determined both spontaneous and growth hormone (GH)-stimulated changes in the IGF system, including measurements of total, free and bioactive IGF-I, total IGF-II and insulin-like growth factor binding protein (IGFBP)-1, IGFBP-2 and IGFBP-3. Results: The patient had a delayed growth and pubertal onset. Six months of GH treatment had no effect on growth. At the age of 19.3 years, he spontaneously completed puberty and had a normal growth spurt for a late adolescent (peak height velocity of 8.4 cm/year). A normal final height was attained at 21.3 years (167.5 cm; –0.78 SDS). During as well as after puberty, basal levels of total, free and bioactive IGF-I were low, as were total IGF-II, IGFBP-1, IGFBP-2 and IGFBP-3. GH treatment for 6 months normalized free IGF-I and increased bioactive IGF-I, but had no effect on growth velocity. Conclusions: This case story shows that in the presence of complete ALS deficiency, a height within normal limits can be obtained despite low levels of all forms of circulating IGF-I. Furthermore, the patient presented a delayed but normal growth spurt without any marked increment of circulating IGF-I.

Long-term effects of insulin-like growth factor (IGF)-I treatment on serum IGFs and IGF binding proteins in adolescent patients with growth hormone receptor deficiency

OBJECTIVE The aim of this investigation was to study the effect of relatively high dose IGF‐I therapy given for several months, on serum levels of IGF‐I, IGF‐II and IGFBP‐3, and on IGF‐I pharmacokinetics In patients with growth hormone insensitivity due to GH receptor dysfunction.

Heterozygous IGFALS Gene Variants in Idiopathic Short Stature and Normal Children: Impact on Height and the IGF System

Background: In acid-labile subunit (ALS)-deficient families, heterozygous carriers of IGFALS gene mutations are frequently shorter than their wild-type relatives, suggesting that IGFALS haploinsufficiency could result in short stature. We have characterized IGFALS gene variants in idiopathic short stature (ISS) and in normal children, determining their impact on height and the IGF system. Patients and Methods: In 188 normal and 79 ISS children levels of IGF-1, IGFBP-3, ALS, ternary complex formation (TCF) and IGFALS gene sequence were determined. Results: In sum, 9 nonsynonymous or frameshift IGFALS variants (E35Gfs*17, G83S, L97F, R277H, P287L, A330D, R493H, A546V and R548W) were found in 10 ISS children and 6 variants (G170S, V239M, N276S, R277H, G506R and R548W) were found in 7 normal children. If ISS children were classified according to the ability for TCF enhanced by the addition of rhIGFBP-3 (TCF+), carriers of pathogenic IGFALS gene variants were shorter and presented lower levels of IGF-1, IGFBP-3 and ALS in comparison to carriers of benign variants. In ISS families, subjects carrying pathogenic variants were shorter and presented lower IGF-1, IGFBP-3 and ALS levels than noncarriers. Conclusions: These findings suggest that heterozygous IGFALS gene variants could be responsible for short stature in a subset of ISS children with diminished levels of IGF-1, IGFBP-3 and ALS.

Basal Follicle-Stimulating Hormone and Peak Gonadotropin Levels after Gonadotropin-Releasing Hormone Infusion Show High Diagnostic Accuracy in Boys with Suspicion of Hypogonadotropic Hypogonadism

CONTEXT Differential diagnosis between hypogonadotropic hypogonadism (HH) and constitutional delay of puberty in boys is challenging. Most tests use an acute GnRH stimulus, allowing only the release of previously synthesized gonadotropins. A constant GnRH infusion, inducing de novo gonadotropin synthesis, may allow a better discrimination. OBJECTIVE We evaluated the diagnostic accuracy of basal and peak gonadotropins after GnRH infusion, measured by ultrasensitive assays, to confirm the diagnosis in boys with suspected HH. DESIGN AND SETTING We conducted a validation study following Standards for Reporting of Diagnostic Accuracy criteria at a tertiary public hospital. PATIENTS AND METHODS A GnRH i.v. infusion test was performed in 32 boys. LH and FSH were determined by immunofluorometric assay at 0-120 min. DIAGNOSIS ASCERTAINMENT: The following diagnoses were ascertained: complete HH (n = 19; testes < 4 ml at 18 yr), partial HH (n = 6; testes enlargement remained arrested for > or = 1 yr or did not reach 15 ml), and constitutional delay of puberty (n = 7; testes > or = 15 ml at 18 yr). MAIN OUTCOME MEASURES Sensitivity, specificity, positive and negative predictive values, and diagnostic efficiency were assessed. RESULTS Basal FSH less than 1.2 IU/liter confirmed HH with specificity of 1.00 (95% confidence interval = 0.59-1.00), rendering GnRH infusion unnecessary. In patients with basal FSH of at least 1.2 IU/liter, the coexistence of peak FSH less than 4.6 IU/liter and peak LH less than 5.8 IU/liter after GnRH infusion had high specificity (1.00; 95% confidence interval = 0.59-1.00) and diagnostic efficiency (76.9%) for HH. CONCLUSIONS Basal FSH less than 1.2 IU/liter confirms HH, which precludes from further testing, reducing patient discomfort and healthcare system costs. In patients with basal FSH of at least 1.2 IU/liter, a GnRH infusion test has a high diagnostic efficiency.

Psychosocial outcome in growth hormone deficient patients diagnosed during childhood.

Social disabilities have been described in GHD patients. The aim of this study was to evaluate the social outcome of a group of adult hypopituitary patients diagnosed and treated during childhood. Seventy patients were interviewed at a mean age of 25.6 years (range 18-50 yr). They answered a semistructured questionnaire and the Beck Depression Inventory test. Patients were compared for academic achievement, marital status and employment with the nearest age sibling. We found high levels of school repeaters, school was often not completed, and around 50% were overprotected by teachers and teased by peers. 32% were unemployed, while 58% of those employed work with their families. 80% still live with their parents; only 16% are married and 9% have children. 44% had no dating experience and 52% had never had sexual intercourse. Depression was common, especially in hypogonadic subjects. Juvenilization was the most common complaint. We did not found differences in maximal educational achievements and levels of employment between patients and siblings, but significantly more married siblings were found. Depression, social isolation and dependent life style were found in GHD patients. Appropriate medical and psychological counseling should be included for patients and their families as part of treatment.

Reproducibility and comparison of growth hormone secretion tests.

To assess the degree of reproducibility of spontaneous GH secretion and pharmacological tests we studied 15 prepubertal children with short stature and abnormal growth rate. In all children, spontaneous overnight GH secretion was measured followed by a clonidine test in 8 children and an arginine test in the remaining 7. The same protocol was repeated a week later. Intra-individual variability of GH secretion in both physiological and pharmacological tests was expressed as the coefficient of variation (CV%). No significant difference was found between the first and second value of parameters of spontaneous GH secretion. Maximum spontaneous GH peak (MS) and mean 12-h GH concentration (MGH) correlated significantly (r = 0.78, p < 0.001). Mean CV% of all parameters of repeated GH profiles (around 30%) were lower than those of provocative tests (around 70%) (p < 0.05). No significant difference was found between CV% of clonidine and arginine tests. There was no correlation between MGH or MS and GH response to provocative test in the same child. We found a significant correlation between the log transformed maximum provocative GH response to the arginine test and the length of the time interval (in min) from the end of the last GH peak in the previous profile to the time zero of the provocative test (r = 0.60, p < 0.05). This relationship was not found for the clonidine test. We conclude that spontaneous GH secretion in children with short stature is more reproducible than stimulated GH response with a weeks difference. Perhaps the higher variability of provocative GH secretion may be related to the state of the endogenous hypothalamic rhythm of both GHRH and somatostatin release at the time of the test.

Circulating IGF-I, IGFBP-3 and the IGF-I/IGFBP-3 Molar Ratio Concentration and Height Outcome in Prepubertal Short Children on rhGH Treatment over Two Years of Therapy

Objective: To investigate the occurrence of abnormally elevated values of biomarkers of growth hormone (GH) action in short children on recombinant human GH (rhGH) therapy. Methods: Sixty-three prepubertal short children were examined: 31 with GH deficiency (GHD), 25 small for gestational age (SGA), and 9 with Turner syndrome (TS). The main outcomes were the following: standard deviation score (SDS) values of IGF-I, IGFBP-3, and IGF-I/IGFBP-3 molar ratio before, at the 1st and at the 2nd year on rhGH and Δheight (Ht)-SDS to evaluate GH treatment efficacy (adequate 1st-year ΔHt SDS: >0.4 SDS for GHD and >0.3 SDS for non-GHD). Results: Seventy-eight percent of GHD, 78% of SGA and 55% of TS children had adequate 1st-year ΔHt SDS. In GHD, 88% of IGF-I SDS and IGFBP-3 SDS that were ≤–2.0 SDS at baseline normalized on treatment. Abnormal IGF-I values >+2.0 SDS were observed in 52% of SGA and in 55% of TS patients on rhGH. Within each group, the IGF-I/IGFBP-3 molar ratio increased significantly from pretreatment and throughout therapy, remaining within normal range for most patients. ΔIGF-I/IGFBP-3 molar ratio SDS were significantly higher in children with an adequate response (p < 0.01). Conclusion: Non-GHD groups presented markedly elevated concentrations of GH biomarkers on rhGH and normal IGF-I/IGFBP-3 molar ratio in most patients. Since there is a lack of consensus regarding the molar ratio usefulness, we think that interventions towards a more physiological IGF-I serum profile should be implemented.

Bone age at discontinuation of medroxyprogesterone acetate therapy in girls with precocious puberty: effect on final height.

To determine the final height of patients with precocious puberty treated with medroxyprogesterone acetate (MPA; 150 mg every week) for a period > 1 year (mean +/- SD = 3.24 +/- 1.85 years), data from a group of 26 girls were analyzed. The attained final height was 155.6 +/- 8.06 cm (-1.1 SD of the normal population). In a group of 8 untreated girls with precocious puberty, adult height was 149.2 +/- 5.07 (-2.16 SD, p < 0.02). In 9 patients in whom treatment was stopped at a bone age < or = 12 years, final height was 159.2 +/- 10.05 cm, while in 16 girls who had a bone age > 12 years at the end of treatment, the final height was 153.03 +/- 6.28 cm. Our data demonstrate the effectiveness of MPA treatment on ultimate height. The better height observed in those patients who stopped treatment with a bone age < 12 years suggests the advantage of discontinuing therapy before reaching a more advanced degree of skeletal maturation.