Growth hormone secretory status in patients with Turner syndrome

The growth hormone (GH) secretory capacities in patients with Turner syndrome aged 5.1-15.9 years and those with constitutional short stature (CSS) aged 5.2-14.2 years were evaluated by pharmacological and physiological means. The GH response to hypoglycemia in the patients with Turner syndrome was lower than that in the patients with CSS. However, the GH response to arginine was not significantly different between the two patient groups. For the physiological test, the integrated concentration of GH (ICGH), the number of episodic peaks and their mean height were evaluated using blood obtained from the patients every 20 minutes for a period of 24 hours. The ICGH and the mean height of the episodic peaks in the patients with Turner syndrome were significantly lower than those in the CSS patients during the night but not during the day. Negative correlation between the bone age and the night-time values of ICGH was observed in the patients with Turner syndrome. Such correlation was not observed in the CSS patients. The patients with CSS showed a significant day-night difference in the ICGH and the mean height of the episodic peaks, but the patients with Turner syndrome did not show any significant day-night difference in either the ICGH or the mean height of episodic peaks. In conclusion, the GH secretory capacity in patients with Turner syndrome is lower than that in CSS patients.