Quantitative growth hormone secretion and final adult height

OBJECTIVE The relationship of quantitative GH secretion to height, growth v elocity and puberty is complex and has been the subject of extensive study in children. This study was designed to relate quantitative GH secretion to final height, SUBJECTS Twenty tall (>183cm, 90th centile for adult height) and 20 short ( <166cm, 10th centile) postpubertal men who had recently completed linear gr owth (age range 18-27 years). MEASUREMENTS GH dynamics were studied on four occasions; insulin (0.15 unit s/kg, iv)-induced hypoglycaemia and GHRH (100 mg, iv) with and without the anticholinesterase, pyridostigmine (120 mg orally). Spontaneous nocturnal G H secretion was assessed by 20 minute sampling from 2100h until 0600h, GH w as measured by IRMA. Analysis was by comparison of peak GH response and are a under the curve (AUC), GH profiles were further analysed using the 'pulsa r' programme. RESULTS The mean height in the tall group was 187.7cm (range 183-197) compa red to 163.5cm (range 160-166) for the short group. No difference existed b etween groups in the GH response to hypoglycaemia or GHRH with and without pyridostigmine, Area under the curve, pulse number, length and amplitude fo r spontaneous nocturnal GH secretion showed no significant difference betwe en the tall and short subjects. Serum IGF-1 (mean 230.5 +/- 15.4 vs. 230.6 +/- 18.9 mu g/l) did not differ between the groups. CONCLUSIONS Quantitative GH secretion does not appear to be an important de terminant of final height in healthy individuals.