Effect of -202 A/C IGFBP-3 polymorphisms on growth responses in children with idiopathic short stature

Investigating whether serum IGF-1 and IGFBP-3 levels reflect the height outcome in prepubertal children upon rhGH therapy: LG growth study database

Serum insulin-like growth factor-1 (IGF-I) and IGF binding protein-3 (IGFBP-3) levels can be used to monitor the safety of recombinant human growth hormone (rhGH) therapy. In this study, we evaluated the changes in serum IGF-I and IGFBP-3 levels during rhGH therapy as a marker of height outcome in prepubertal children. Totally, 705 prepubertal children with short stature were enrolled from the LG Growth Study Database. Data for three groups of subjects were obtained as follows: Idiopathic GH deficiency (IGHD; n = 486); idiopathic short stature (n = 66); small for gestational age (n = 153). Serum IGF-I and IGFBP-3 levels at the baseline and after the 1st and 2nd year of rhGH therapy, as well as the Δheight standard deviation score (SDS), were obtained. Δheight SDS after the 1st and 2nd year of rhGH therapy had notably increased compared to that at the baseline for all three groups. IGF-I and IGFBP-3 levels in all three groups were significantly increased compared to those at the baseline (p <0.001). Δheight SDS was positively correlated with ΔIGF-1 SDS after the 1st year of therapy, ΔIGFBP-3 SDS after the 2nd year of therapy in the IGHD group, and ΔIGF-I SDS and ΔIGFBP-3 SDS after the 2nd year of therapy (p < 0.05), regardless of whether the height at the baseline was a covariate. The increase in IGF-I and IGFBP-3 levels during rhGH therapy was related to the growth response in children with IGHD. Therefore, it may be valuable to measure the change in serum IGF-I and IGFBP-3 levels, especially the latter, during rhGH treatment to predict the growth response upon long-term treatment.

Gene polymorphisms in leptin and its receptor and the response to growth hormone treatment in patients with idiopathic growth hormone deficiency

This study aimed to investigate the relationships between genetic polymorphisms of leptin/receptor genes and clinical/biochemical characteristics in children with growth hormone deficiency (GHD). Ninety-three GHD children and 69 age-matched normal controls were enrolled. Anthropometric measurements, bone age, and laboratory test results were obtained. Polymorphisms in the LEP gene promoter locus (LEP-2548, rs7799039) and LEPR genes (K109R, rs1137100 and Q223R, rs1137101) were analyzed using PCR-RFLP. The serum leptin levels were measured using an ELISA kit. The median height and BMI z-scores of all GHD subjects were -2.20 and -0.26, respectively, and those of normal controls were -0.30 and -0.13, respectively. The serum leptin levels were similar between GHD subjects and normal controls (p = 0.537), but those were different between the complete GHD (6.97 ng/mL) and partial GHD (4.22 ng/mL) groups (p = 0.047). There were no differences in the genotypic distributions of LEP-2548, LEPR K109R, and Q223R between GHD subjects and normal controls. However, GHD subjects with the G allele at LEP-2548 showed higher IGF-1 (p = 0.047) and IGFBP-3 SDSs (p = 0.027) than GHD subjects with the A allele. GHD subjects with the G allele at LEPR Q223R showed lower stimulated GH levels (p = 0.023) and greater height gain after 1 year of GH treatment (p = 0.034) than GHD subjects with the A allele. In conclusion, leptin/leptin receptor genes are suggested to have the role of growth-related factors, which can affect various growth responses in children who share the same disease entity.