• Response to growth hormone (GH) therapy was evaluated in 38 short children (28 males and 10 females; <1% in height for chronologic age [CA]) who were clinically categorized into three groups based on their endogenous mean 24-hour GH concentration (mean 24-hour GH) and peak GH response to two or more provocative agents (peak GH). All patients were treated with biosynthetic somatropin (human growth hormone) (0.15 to 0.30 mg/kg per week) injected subcutaneously three to seven times per week for a mean duration of 12.5 months. Group 1 consisted of 17 subjects (CA, 12.5 ± 2.9 years [mean ± SD]; bone age, 9.4± 2.9 years; height velocity [HV], 3.4 ± 1.8 cm/y; peak GH, 5.8± 2.6 μg/L; mean 24-hour GH, 1.7 ± 0.6 μg/L; and insulinlike growth factor–I, 0.40 ± 0.24 U/mL. Group 2 consisted of 10 subjects (CA, 11.7± 2.7 years; bone age, 9.2 ± 3.0 years; HV, 3.4 ± 1.6 cm/y; peak GH, 16.4 ± 5.2 μg/L; mean 24-hour GH, 1.7 ± 0.5 μg/L; and insulinlike growth factor–I, 0.49 ± 0.27 U/mL. Group 3 consisted of 11 subjects (CA, 12.7 ± 2.2 years; bone age, 10.2 ± 2.4 years; HV, 3.5 ± 1.5 cm/y; peak GH, 22.5 ± 8.6 μg/L; mean 24-hour GH, 3.8 ± 1.1 μg/L; and insulin-like growth factor–I, 1.07 ± 0.69 U/mL. Following administration of somatropin, an increase (Δ) in HV of 2.0 cm/y or greater occurred in 94% (16/17) of the group 1 subjects (ΔHV of 5.1 ± 2.6 cm/y), in 90% (9/10) of the group 2 subjects (ΔHV of 4.3 ± 2.2 cm/y), and in 73% (8/11) of group 3 subjects (AHV of 3.7 ± 2.3 cm/y). However, regardless of provoked and/or endogenous GH secretory dynamics, 88% of the children whose pretreatment HV was 2.0 cm/y or less, 94% whose pretreatment HV was between 2.0 and 4.0 cm/y, and 79% whose pretreatment HV was greater than 4.0 cm/y increased their HVs to 2.0 cm/y or greater while they were receiving somatropin. Significant negative correlations were observed between ΔHV and pretreatment HV (r= −.67), ΔHV and GH concentration expressed as a 24-hour area under the curve (r = −.33), and ΔHV and peak GH (r= −.34). In conclusion, 87% (33/38) of children with stature less than the first percentile, mean HV of 4.0 cm/y or less, and mean bone age of 2.7 years less than CA responded to 1 year of somatropin treatment with acceleration in HV regardless of their endogenous and/or provoked GH values.
(AJDC. 1990;144:1092-1097)