Juliane Léger, Damir Mohamed, Sophie Dos Santos, Myriam Ben Azoun, Delphine Zénaty, Dominique Simon, Anne Paulsen, Laetitia Martinerie, Didier Chevenne, Corinne Alberti, Jean-Claude Carel and Sophie Guilmin-Crepon
Regular monitoring of serum IGF-I levels during growth hormone (GH) therapy has been recommended, for assessing treatment compliance and safety.
To investigate serum IGF-I SDS levels during GH treatment in children with GH deficiency, and to identify potential determinants of these levels.
Design, patients and methods
This observational cohort study included all patients (n = 308) with childhood-onset non-acquired or acquired GH deficiency (GHD) included in the database of a single academic pediatric care center over a period of 10 years for whom at least one serum IGF-I SDS determination during GH treatment was available. These determinations had to have been carried out centrally, with the same immunoradiometric assay. Serum IGF-I SDS levels were determined as a function of sex, age and pubertal stage, according to our published normative data.
Over a median of 4.0 (2–5.8) years of GH treatment per patient, 995 serum IGF-I SDS determinations were recorded. In addition to BMI SDS, height SDS and GH dose (P < 0.01), etiological group (P < 0.01) had a significant effect on serum IGF-I SDS levels, with patients suffering from acquired GHD having higher serum IGF-I SDS levels than those with non-acquired GHD, whereas sex, age, pubertal stage, treatment duration, hormonal status (isolated GHD (IGHD) vs multiple pituitary hormone deficiency (MPHD)) and initial severity of GHD, had no effect.
These original findings have important clinical implications for long-term management and highlight the need for careful and appropriate monitoring of serum IGF-I SDS and GH dose, particularly in patients with acquired GHD, to prevent the unnecessary impact of potential comorbid conditions.
Julie Harvengt, Priscilla Boizeau, Didier Chevenne, Delphine Zenaty, Anne Paulsen, Dominique Simon, Sophie Guilmin Crepon, Corinne Alberti, Jean-Claude Carel and Juliane Léger
To assess in a pediatric population, the clinical characteristics and management of triiodothyronine-predominant Graves' disease (T3-P-GD), a rare condition well known in adults, but not previously described in children.
We conducted a university hospital-based observational study.
All patients with GD followed for more than 1 year between 2003 and 2013 (n=60) were included. T3-P-GD (group I) was defined as high free T3 (fT3) concentration (>8.0 pmol/l) associated with a normal free thyroxine (fT4) concentration and undetectable TSH more than 1 month after the initiation of antithyroid drug (ATD) treatment. Group II contained patients with classical GD without T3-P-GD.
Eight (13%) of the patients were found to have T3-P-GD, a median of 6.3 (3.0–10.5) months after initial diagnosis (n=4) or 2.8 (2.0–11.9) months after the first relapse after treatment discontinuation (n=4). At GD diagnosis, group I patients were more likely to be younger (6.8 (4.3–11.0) vs 10.7 (7.2–13.7) years) and had more severe disease than group II patients, with higher serum TSH receptor autoantibodies (TRAb) levels: 40 (31–69) vs 17 (8–25) IU/l, P<0.04, and with slightly higher serum fT4 (92 (64–99) vs 63 (44–83) pmol/l) and fT3 (31 (30–46) vs 25 (17–31) pmol/l) concentrations. During the 3 years following T3-P-GD diagnosis, a double dose of ATD was required and median serum fT4:fT3 ratio remained lower in group I than in group II.
Severe hyperthyroidism, with particularly high TRAb concentrations at diagnosis, may facilitate the identification of patients requiring regular serum fT3 determinations and potentially needing higher doses of ATD dosage during follow-up.