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.