RESUMEN
AIM: Children treated with a growth hormone (GH) for idiopathic growth hormone deficiency (IGHD) may be monitored with the first-year prediction model from the Pfizer International Growth Database (KIGS) using auxology, age, GH dose and the maximum GH concentration from a stimulation test (GHmax stim). We tested the hypothesis that using a 12-hour spontaneous profile (GHmax 12h) would be as accurate. METHODS: We studied 98 prepubertal Swedish children (78 boys) aged 2-12 years enrolled in KIGS. The first-year growth was predicted using the GHmax from the GH profile and a stimulation test, and both of these were compared separately with the observed growth response. RESULTS: The increased height observed in the first year was 0.74 standard deviation scores (SDS), and the studentised residuals for the predicted and observed growth with GHmax stim (-0.16 SDS) and GHmax 12h (-0.22) were similar. Individual predictions calculated with stimulated or spontaneous GHmax showed a significant correlation (r = 0.80). CONCLUSION: We validated the KIGS IGHD prediction model and found that the stimulated GHmax peak can be reliably replaced by the GHmax 12h with similar accuracy. This makes the model more accessible for clinicians, who can then provide realistic expectations for the growth response during the first year of treatment.