ESPE Abstracts

Background/aims: Primary IGF1 deficiency (IGFD)’ is defined by low levels of IGF1 without a concomitant impairment in GH secretion in the absence of secondary cause. The aims of this study were to evaluate the prevalence of non-GH deficient IGFD in prepubertal children with isolated short stature (SS) and to describe their response to GH therapy.

Methods: This retrospective study included all children with isolated SS seen in our Pediatric Endocrinology Unit from January 2017 to December 2017. Children were included based on the following criteria: i) SS with current height SDS < -2, ii) age > 2 years, and iii) prepubertal status. Exclusion criteria were: i) identified cause of SS and ii) current or past therapy with GH. IGF1-deficient children were defined as children without GH deficiency and with IGF1 levels below or equal to -1.5 SDS for age and sex.

Results: Among 38 children with isolated SS, 10 (26%) had low IGF1 levels, consistent with a diagnosis of primary IGFD. All were born appropriate for gestational age. When compared with non-IGFD children, IGFD children were shorter (p = 0.02) and their parents were shorter (p = 0.05) compared to SS with normal IGF1. Bone age and BMI SDS did not differ between the two groups. 40% of SS children with low IGF1 had low BMI SDS (< -1.7). After 1 year of treatment with GH (0.05 mg/kg/d), HtSDS, BMI SDS and bone age did not differ between SS treated with GH versus the non-treated group.

Conclusion: The prevalence of primary IGFD was 26% in children with isolated SS. Concerning the pathophysiology, our study emphasizes that IGFD in some children may be secondary to undernutrition.