The utility of a random growth hormone level in determining neonatal growth hormone sufficiency

Background Random growth hormone (GH) levels have been used in the neonate to investigate congenital growth hormone deficiency (GHD). The cut-off value for use in this diagnosis is yet to be established. Methods This is a retrospective chart review of all random GH levels obtained in neonates ≤28 days of age. Neonates were divided into three groups: those diagnosed with congenital GHD, those at risk for GHD (ARF-GHD) and a non-growth hormone deficient (non-GHD) group. Mean GH levels for each group were compared, and ROC analysis was used to identify a cut-off for the diagnosis of GHD. Results The study included 138 neonates with the mean age of 9.07 ± 6.6 days, and 65% of these were born at term gestation. Mean GH levels were lower in the GHD group (2.73 ± 1.19 ng/ml) as compared to the ARF-GHD (9.4 ± 7.96 ng/ml, p = .002) and non-GHD groups (14.86 ± 14.42 ng/ml, p = .027). GH values were not significantly different between non-GHD and ARF-GHD groups. ROC analysis identified a cut-off of serum random GH level of 4.5 ng/ml that achieved 100% sensitivity and 83% specificity for the diagnosis of congenital GHD. Conclusion This study demonstrates that random GH levels obtained in the first 28 days of life can be useful in diagnosing congenital GHD. Moreover, a diagnostic cut-off for congenital GHD using random GH levels was identified.