To Örebro University

Introduction: Diagnosing growth hormone (GH) deficiency (GHD) is challenging due to the low specificity of diagnostic tests, particularly in children during the prepubertal and early pubertal stages. Although sex steroid priming increases stimulated GH peak levels, its impact on spontaneous nocturnal GH values has not yet been reported. Priming may reduce discrepancies between spontaneous and stimulated GH testing, potentially improving diagnostic accuracy. We aimed to assess the impact of priming on combined spontaneous and stimulated GH testing and the occurence of divergent test results, as well as to evaluate short-term adverse events associated with priming.

Methods: This was a retrospective chart review of all 132 short children who underwent a nocturnal spontaneous GH secretion test followed by an arginine-insulin stimulation test over 30 years at the Department of Pediatrics, & Ouml;rebro University Hospital, Sweden.

Results: Among the 132 children tested, 25 (19%) received priming prior to GH testing. Compared with nonprimed children, primed children presented higher peak and mean spontaneous GH values (14.2 mu g/L [0.6-22.5] vs. 10.8 mu g/L [0.2-27.0], p = 0.042 and 3.0 mu g/L [0.3-6.9] vs. 2.3 mu g/L [0.1-6.9], p = 0.007, respectively). Divergent results between the two GH tests were less common in primed children (4%) than in nonprimed children (23%, p = 0.027). Mild adverse events occured in three (12%) of the primed children.

Conclusion: Sex steroid priming prior to GH testing is well tolerated, enhances spontaneous nocturnal GH secretion, and reduces the frequency of divergent results between spontaneous and stimulated values. We recommend incorporating priming when evaluating children in prepuberty or early puberty for suspected GHD.