Growth hormone response to clonidine in anovulatory infertile women resistant to clomiphene citrate stimulation

Objective: To evaluate the GK response to the clonidine test in a group of infertile women and to determine their ovulatory response to clomiphene cit rate (CC) stimulation. Design: Prospective study. Setting: Reproductive endocrinology unit. Patient(s): Thirty-three anovulatory infertile women (age range, 25-36 year s) and 9 healthy controls with normal ovulation. Intervention(s): In the early follicular phase, 0.3 mg of clonidine was adm inistered between 8:30 and 9:00 A.M. and blood samples were collected for 1 20 minutes thereafter for measurement of serum CH levels. Plasma levels of insulin and glucose were measured after a 75-g glucose load, and CC was giv en at a dosage of 50-250 mg/d for ovulation induction. Main Outcome Measure(s): Serum concentrations of GH, insulin-like growth fa ctor I, insulin, and insulinlike growth factor binding protein-1. Result(s): On the basis of their ovulatory response to CC, 15 patients were considered nonresponsive (group 1) and 18 patients were considered respons ive (group 2). Baseline levels of GH, insulin-like growth factor I, and ins ulin-like growth factor binding protein-1 were similar in the two groups of patients and the controls. The GH response to clonidine was significantly greater in group 2 and in the controls than in group 1. Concentrations of i nsulin and glucose after the glucose load were not different among the thre e groups. Conclusion(s): Women who were resistant to CC had a reduced GH response to clonidine. These data suggest that adequate GH secretory capacity is import ant for CC action. (Fertil Steril(R) 2000;73:78 - 84. (C) 1999 by American Society for Reproductive Medicine.)