Observed and predicted total pubertal growth during treatment with growth hormone in adolescents with idiopathic growth hormone deficiency, Turner syndrome, short stature, born small for gestational age and idiopathic short stature: KIGS analysis and review.

BACKGROUND/AIMS: The aim was to describe the factors determining total pubertal growth (TPG) in adolescents with growth hormone deficiency (GHD), Turner syndrome (TS), who were small for gestational age (SGA) or had idiopathic short stature (ISS).
METHODS: The patients were documented within KIGS (Pfizer International Growth Database). TPG was defined as growth from puberty onset - spontaneous (>B1 or testes >3 ml) or induced with sex steroids to adult height in idiopathic GHD (n = 639; males 399), TS (n = 463), SGA (n = 59; males 35), and ISS (n = 130; males 87). Algorithms to predict TPG at puberty onset were developed by multiple linear regression analysis.
RESULTS: In GHD (males, females) and TS TPG could be explained with the same four predictors: (1) age (years) at puberty onset (neg.), (2) age - bone age at puberty onset (pos.), (3) height - midparental height (SDS) at puberty onset (neg.), and (4) mean dose of growth hormone (GH) during puberty (pos.). The algorithms explained 66, 65 and 68%, respectively, of the variability with total errors of 4.5, 3.8 and 2.9 cm, in spontaneous and induced TPG.
CONCLUSIONS: TPG is determined by the same factors at puberty onset in adolescents with GHD, TS, SGA or ISS treated with GH. Thus, TPG depends mostly on the outcomes achieved at the end of prepubertal growth and less so on the dose of GH.