Linear growth response to exogenous growth hormone in children with short stature
I. D. Schwartz, C. S. Hu, D. I. Shulman, A. W. Root and B. B. Bercu
Section of Pediatric Endocrinology, University of South Florida College of Medicine, St Petersburg.
Response to growth hormone (GH) therapy was evaluated in 38 short children
(28 males and 10 females; less than 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 micrograms/L; mean 24-hour GH, 1.7 +/-
0.6 micrograms/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 micrograms/L; mean
24-hour GH, 1.7 +/- 0.5 micrograms/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
micrograms/L; mean 24-hour GH, 3.8 +/- 1.1 micrograms/L; and insulinlike
growth factor-I, 1.07 +/- 0.69 U/mL. Following administration of
somatropin, an increase (delta) in HV of 2.0 cm/y or greater occurred in
94% (16/17) of the group I subjects (delta HV of 5.1 +/- 2.6 cm/y), in 90%
(9/10) of the group 2 subjects (delta HV of 4.3 +/- 2.2 cm/y), and in 73%
(8/11) of group 3 subjects (delta HV 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 delta HV and pretreatment HV (r = -.67), delta HV and GH
concentration expressed as a 24-hour area under the curve (r = -.33), and
delta HV and peak GH (r = -.34).(ABSTRACT TRUNCATED AT 400 WORDS)
