ABSTRACT Objectives To describe the findings of thyroid ultrasonography (T-US), its contribution to diagnose congenital hypothyroidism (CH) and the best time to perform it. Subjects and methods Forty-four patients with CH were invited to undergo T-US and 41 accepted. Age ranged from 2 months to 45 years; 23 patients were females. All were treated with L-thyroxine; 16 had previously undergone scintigraphy and 30 had previous T-US, which were compared to current ones. Results At the current T-US, the thyroid gland was not visualized in its normal topography in 10 patients (24.5%); 31 T-US showed topic thyroid, 17 with normal or increased volume due to probable dyshormonogenesis, 13 cases of hypoplasia and one case of left-lobe hemiagenesis. One patient had decreased volume due to central hypothyroidism. Scintigraphy scans performed 3-4 years earlier showed 100% agreement with current results. Comparisons with previous T-US showed concordant results regarding thyroid location, but a decrease in current volume was observed in eight due to the use of L-thyroxine, calling the diagnosis of hypoplasia into question. Conclusions The role of T-US goes beyond complementing scintigraphy results. It allows inferring the etiology of CH, but it must be performed in the first months of life. An accurate diagnosis of CH will be attained with molecular study and the T-US can guide this early assessment, without therapy withdrawal.

OBJECTIVES: To establish cut-off values for growth hormone concentrations using clonidine as a secretagogue and an immunochemiluminescent assay as the method of measurement and to analyze the response time as well as the influence of gender, nutritional status and pubertal stage. METHODS: A total of 225 tests were performed in 3 patient groups, categorized as group 1 (normal), group 2 (idiopathic short stature) and group 3 (growth hormone deficiency). Among the 199 disease-free individuals, 138 were prepubertal, and 61 were pubertal. Clonidine (0.1 mg/m2) was orally administered, and the growth hormone level was measured by immunochemiluminescent assay. The growth hormone peak and the difference between the growth hormone peak and the baseline level were then analyzed. Statistical analyses were performed using Student’s t-test or the Mann-Whitney test and Kruskal-Wallis test followed by Dunn’s post hoc test. Cut-off values were determined using a receiver operating characteristic curve. RESULTS: Group 1 and group 2 had no difference in growth hormone peak, gender, body mass index standard deviation score, or pubertal stage. Group 3 exhibited a significantly lower growth hormone peak than the other groups did. The receiver operating characteristic curve demonstrated that growth hormone concentrations ≥ 3.0 ng/mL defined responsiveness to clonidine. In total, 3.02% of individuals in group 1 and group 2 were considered false positive, i.e., these children lacked growth hormone deficiency and had a peak below 3.0 ng/mL. CONCLUSION: Clonidine-stimulated growth hormone concentrations ≥3 ng/mL, as measured by immunochemiluminescent assay, suggest responsiveness to the stimulus regardless of gender, body mass index standard deviation score or pubertal stage.

Objective To report our experience of treating central precocious puberty (CPP) with a GnRH analogue with respect to the final heights (FH) attained in patients who completed treatment. Subjects and methods Among 105 records of children diagnosed with precocious puberty, 62 cases (54 girls and 8 boys), who were treated with leuprolide acetate/3.75 mg/monthly, were selected, and divided into 4 groups: group 1 (G1), 25 girls who attained FH; group 2 (G2), 18 girls who completed treatment but did not reach FH; group 3 (G3), 11 girls still under treatment; and group 4 (G4), 8 boys, 5 of which attained FH. Treatment was concluded at a bone age of 12 years, and follow-up continued until FH was achieved. Results In both G1 and G2 groups, height standard deviation score (SDS), weight-SDS and percentile of body mass index (PBMI) did not show intra/intergroup differences at the beginning and at interruption of treatment, but when added, G1+G2, height-SDS and weight-SDS differed significantly (p = 0.002 and 0.0001, respectively). In G1, 19 of 25 cases attained TH, and average height gain was 16.7 cm (7.7- 27.1); there was significant difference between FH and prediction of FH at the start (PFH at start) (p = 0.0001), as well as between PFH at interruption vs TH and vs FH (p = 0.007) with FH higher than TH (p = 0.004). Significant correlation was identified between FH and height gain after treatment. Conclusion As shown by some studies, GnRH analogue treatment was effective in children with CPP reaching FH near the genetic target.