[Measurement of the spontaneous growth hormone increase in short children. Diagnostic significance and neuroendocrine implications].

The assessment of growth hormone deficiency (GHD) in children with growth retardation is frequently difficult. The diagnostic reliability of standard pharmacological GH provocative tests has been questioned and several investigators have focussed on measurement of spontaneous GH secretion at frequent intervals over periods of 12-24 hours, with mathematical analysis of resulting secretory patterns. The aim of our study was to assess GH secretion in children with growth retardation, either in prepuberal and puberal ages, in order 1) to evaluate the diagnostic relevance of spontaneous GH secretion in comparison to tests, and 2) to gain neuroendocrine interpretations of GH secretion. We investigated 58 short children (height < 5th centile), 35 males, aged 6.4-15 years, without chronic diseases or dysmorphic syndromes. All subjects were divided into 3 groups, either in prepubertal and pubertal ages: normal (normal growth rate, within -0.80 HVSDS; normal GH peak after standard clonidine test > 7 ng/ml; 15 prepubertal, 8 pubertal); slow-growing (growth rate lower than -0.80 SDS; normal GH peak to test; 13 prepubertal, 13 pubertal); GH deficit (growth rate lower than -0.80 SDS; GH peak to test < 7 ng/ml; 6 prepubertal, 3 pubertal). In all children spontaneous GH secretion was evaluated for 24-hrs, 12-hrs daily and 12-hrs overnight, sampling every 30 minutes. The results were analyzed by the PULSAR computer program to determine number, height, area and amplitude of pulses and the baseline and GH secretory areas under and over baseline.(ABSTRACT TRUNCATED AT 250 WORDS)