Intranasal GHRP-2 Boosts GH but Fails to Spur Growth in GHD Children
Background
Growth hormone deficiency (GHD) in children leads to short stature and developmental issues, often requiring daily growth hormone injections. While GH-releasing peptides like GHRP-2 are known to stimulate endogenous growth hormone (GH) secretion, their efficacy in promoting actual linear growth in GHD patients via non-invasive routes remains unclear. This study specifically investigated whether an intranasal GHRP-2 spray could improve growth velocity in short children diagnosed with GHD.
Results
Treatment with intranasal GHRP-2 significantly increased endogenous GH secretion, with peak GH levels rising from 10.2 ± 5.8 ng/mL at baseline to 22.4 ± 10.9 ng/mL after 1 month (p<0.01). Similarly, serum IGF-I and IGFBP-3 levels showed significant increases, indicating a robust hormonal response. However, despite these hormonal changes, the study found no significant improvement in growth parameters. > The mean height velocity (HV) remained statistically unchanged, measuring 4.6 ± 1.0 cm/year before treatment and 4.9 ± 1.3 cm/year after 6 months of therapy (p=0.42). The height velocity SDS also showed no significant change, moving from -1.9 ± 0.6 to -1.7 ± 0.7 (p=0.48), demonstrating that the increased GH secretion did not translate into accelerated growth.
Why It Matters
This study highlights a critical distinction: while GHRP-2 effectively stimulates GH release, this alone may not be sufficient to induce linear growth in children with established GHD. The findings suggest that the underlying pathology in GHD might involve more than just a lack of GH secretion, or that the pulsatile, endogenous GH release stimulated by GHRP-2 might not mimic the therapeutic effects of exogenous GH administration. This implies that intranasal GHRP-2 is unlikely to be a viable standalone treatment for GHD-related short stature, necessitating continued exploration of other non-invasive delivery methods or combination therapies, potentially moving towards larger Phase II or III human trials if alternative mechanisms are identified.