Endogenous growth hormone secretion does not correlate with growth in patients with Turner's syndrome

We investigated in Turner's syndrome patients whether the decrease in growt h hormone (GH) secretion is frequent or sporadic, whether or not reduced GH secretion contributes to insufficient growth, and whether age, spontaneous presence of telarche and/or pubarche, karyotype and weight influence GH se cretion decrease. We evaluated GH reserve in 301 patients by classical stim ulation tests and in 68 of these patients mean nocturnal spontaneous secret ion was also measured. Spontaneous telarche and/or pubarche were present in 33% of girls aged >9 years, In 11% of patients, weight was more than 20% a bove levels appropriate for height. In 36.2% of patients (low-responders), we observed a reduction of the GH reserve (peak less than or equal to 10 mu g/l during two stimulation tests), Moreover, we noted reduced mean nocturn al spontaneous secretion (less than or equal to 3.3 mu g/l) in 61.8% of pat ients. Karyotype and the presence/absence of spontaneous telarche and/or pu barche did not influence either GH reserve or mean nocturnal spontaneous se cretion. GH secretion (both GH reserve and mean nocturnal spontaneous secre tion) did not influence height, yet low-responders had a significantly high er chronological age than normal-responders. Obese Turner's girls were low- responders and showed reduced mean nocturnal spontaneous secretion more fre quently than normal weight girls; body mass index was significantly higher in patients with reduced GH secretion when compared to patients with normal GH secretion. We conclude that impairment of GH secretion is frequent in T urner's syndrome patients, especially if obese; that GH secretion impairmen t is not related to karyotype or spontaneous telarche and/or pubarche; that GH secretion is irrelevant to growth in these patients and, therefore, its evaluation is unnecessary.