RT Journal A1 Lanes R T1 DIagnostic limitations of spontaneous growth hormone measurements in normally growing prepubertal children JF American Journal of Diseases of Children JO American Journal of Diseases of Children YR 1989 FD November 1 VO 143 IS 11 SP 1284 OP 1286 DO 10.1001/archpedi.1989.02150230042020 UL http://dx.doi.org/10.1001/archpedi.1989.02150230042020 AB • To evaluate whether the measurement of the spontaneous overnight growth hormone secretion in prepubertal children clearly separated normal children from subjects with growth hormone deficiency, we studied 45 prepubertal normally growing children (10 with normal height and 35 with constitutional growth delay) and compared their overnight growth hormone secretion with that of a group of subjects with either isolated growth hormone deficiency or neurosecretory dysfunction. Peak growth hormone levels ≥10 ng/mL) following oral clonidine administration were normal in individuals with normal height, constitutional growth delay, and neurosecretory dysfunction, as was the basal somatomedin C concentration; subjects with growth hormone deficiency had low peak growth hormone levels (<10 ng/mL) following oral clonidine administration as well as low basal somatomedin C values. The mean 9-hour overnight growth hormone concentration, total growth hormone output, total number of nocturnal pulses, and the mean peak growth hormone response during nocturnal sampling were similar in the normal height and constitutional growth delay groups and significantly greater than those seen in subjects with either growth hormone deficiency or neurosecretory dysfunction. Twelve (26.6%) of 45 normally growing children (4 of 10 normal height and 8 of 35 constitutional growth delay), however, had low overnight growth hormone levels (3 ng/mL), which overlapped results obtained in the growth hormone—deficient or neurosecretory dysfunction groups. Frequent overnight growth hormone (GH) sampling does not always separate normal-growing children from those with partial or complete GH deficiency. In our this study over one quarter of the normally growing children had overnight GH levels in the range of children with either GH deficiency or neurosecretory dysfunction. These findings, in addition to the cost and difficulty in performing this test, do not support the measurement of spontaneous GH as a routine test in short but normally growing prepubertal children.AJDC.1989;143:1284-1286)