Abstract
Purpose
We evaluated the diagnostic accuracy of insulin-like growth factor-1 (IGF-1) for screening growth hormone deficiency (GHD) to determine the usefulness of IGF-1 as a screening test.
Methods
On 298 consecutive children who had short stature or decreased height velocity, we measured IGF-1 levels and performed growth hormone (GH) secretion test using clonidine, arginine, and, in cases with different results of the two tests, L-dopa. Patients with congenital abnormalities were excluded. GHD was defined as peak GH ≤ 6.0 ng/mL in the two tests.
Results
We identified 60 and 238 patients with and without GHD, respectively. The mean IGF-1 (SD) was not significantly different between the GHD and non-GHD groups (p = 0.23). Receiver operating characteristic curve analysis demonstrated the best diagnostic accuracy at an IGF-1 cutoff of −1.493 SD, with sensitivity of 0.685, specificity of 0.417, positive predictive value of 0.25, negative predictive value of 0.823, and area under the curve of 0.517. Spearman’s rank correlation coefficient showed that IGF-1 (SD) was weakly correlated with age, bone age, height velocity before examination, weight (SD), and BMI (SD) and very weakly correlated with height (SD), target height (SD), and maximum GH peak.
Conclusion
IGF-1 level had poor diagnostic accuracy as a screening test for GHD. Correlation analysis revealed that none of the items increased the diagnostic power of IGF-1. Therefore, IGF-1 should not be used alone in the screening of GHD. A predictive biomarker for GHD should be developed in the future.
Efficacy of growth hormone replacement on anthropometric outcomes, obesity, and lipids in children with optic nerve hypoplasia and growth hormone deficiency
