Abstract
Introduction
Growth hormone deficiency (GHD) is a rare but important cause of short stature in children. Although GH stimulation tests remain the gold standard for diagnosis, establishing a definitive diagnosis continues to be challenging. In this study, we aimed to evaluate the diagnostic performance of the peak-to-basal ratio and difference for identifying GHD in children.
Materials-Methods
We retrospectively analyzed 265 patients with short stature who were evaluated for GHD with growth hormone stimulation tests. ΔGH was defined as the difference between peak and basal GH levels. The GH ratio was calculated as the ratio of peak to basal GH levels.
Results
Data were collected from 265 patients (182 prepubertal) with a median age at presentation of 10.6 years (IQR: 6.13-12.42), of whom 46.7% were female. In total, 146 patients met the diagnostic criteria for GHD. ΔGH and GH ratio during the L-Dopa and Clonidine stimulation tests were significantly lower in the GHD group (p<0.001). A ΔGH cutoff of ≤7.08 in the clonidine test demonstrated excellent discriminative ability, with both sensitivity and specificity above 80%, and an AUC close to 0.9, suggesting that this parameter may may provide supportive diagnostic information for GHD.
Conclusion
To the best of our knowledge, ΔGH has been explored only in a limited number of studies. This study investigated diagnostic accuracy of difference (ΔGH) or ratio of peak-to-basal GH on a large cohort of children with short stature. The supportive diagnostic performance observed in our cohort suggests that ΔGH is clinically useful in routine practice.
What is already known on this topic?
Growth hormone deficiency (GHD) is a relatively rare but important cause of short stature in children, and its diagnosis remains challenging due to the limitations of GH stimulation tests.
What this study adds?
In this study, we evaluated the diagnostic performance of basal-to-peak ratio and basal-to-peak difference derived from L-Dopa and clonidine stimulation tests. Our findings indicate that ΔGH (peak-to-basal difference), particularly in the clonidine test, demonstrated excellent diagnostic performance and may serve as a reliable adjunct to conventional peak GH cut-offs in clinical practice.


