We have used the technique of deconvolution analysis to determine if abnormalities in growth hormone (GH) secretion or metabolic clearance underlie the observed alterations in circulating hormone concentrations in a group of seven prepubertal males with constitutional delay of growth (SHORT-DBA). The results were compared with data obtained from 13 healthy, short prepubertal males (SHORT) and 11 healthy prepubertal male subjects of normal stature (NORMAL). Although the mean 12-h overnight GH production rates were invariant among the groups (8.0 ±1.0 versus 7.3 ± 0.7 versus 6.7 ±1.2 μg/L, NORMAL versus SHORT versus SHORT-DBA for all comparisons), different secretory mechanisms were operative. The secretory burst half-duration (time interval of the secretory event at half-maximal amplitude) of the SHORT-DBA subjects (26 ± 1 min) was greater (p = 0.02) than that of the SHORT group (20 ± 1 min); values for both the SHORT and SHORT-DBA subjects were indistinguishable from that of NORMAL controls (22 ± 2). Both the mass of GH released per secretory episode and the maximal rate of hormone secretion were less (p < 0.02 and p < 0.01, respectively) for the SHORT-DBA subjects [16 ± 2 μg/unit of body distribution volume (Lv) and 0.6 ± 0.1 μg/Lv/min, respectively] compared with those of the NORMAL (26 ± 2μg/L, and 1.1 ± 0.1 μg/Lv/min, respectively) and SHORT (28 ± 4 μg/Lv and 1.3 ± 0.2 μg/Lv/min, respectively) groups; values for the latter two groups were indistinguishable. Given the dominant association of GH pulse amplitude with normal childhood growth, the present findings suggest a possible GH secretory mechanism underlying the suboptimal growth in a subset of prepubertal males with constitutional delayed growth.
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health