ESPE Abstracts

Background: The correct diagnosis of growth hormone deficiency (GHD) and the definition of growth response in the management of growth hormone (GH)-treated children is controversial.

Objective and hypotheses: To evaluate: i) short-term and long-term efficacy of GH treatment; ii) various criteria commonly used to define poor response to GH therapy and compare them in the same cohort of GHD patients.

Method: Our study includes 94 children (66 boys and 28 girls), affected by GHD and treated with GH until final or near-final height. We assessed data recorded at the start, at 1 year, at 2 years and at the end of GH therapy. The criteria used for detecting poor responders after the first year were: ΔHt SDS (gain in height) <0.5, <0.3 for less severe or <0.4 SDS for severe GHD, a height velocity (HV) <mean −1 SDS. The final height was considered satisfactory if ΔHt ≧ 1 SDS.

Results: After one year of treatment we could define “poor responders” 55.3% of patients (ΔHt SDS <0.5), 40.9% (HV < mean −1 SDS) and 23.4% (ΔHt SDS <0.3 for less severe GHD or <0.4 SDS). At the end of the treatment poor responders were 22.3%, even if 97.9% of our population achieved midparental target height. The median final height was −1.11 SDS, with a total height gain of +1.5±0.6 SDS. Our analysis revealed also a negative association between height gain (after 1 year and at the end of treatment) and chronological age at diagnosis, and a statistically significant positive correlation between final ΔHt and duration of therapy.

Conclusion: A clear definition of satisfactory growth response after replacement therapy is still lacking. We suggest to evaluate the individual patient and not only a statistic parameter. Most of patients have pubertal delay and a potential for spontaneous catch up growth, which must be taken into account when measuring the effect and cost-effectiveness of treatment.