GROWTH-HORMONE RESPONSE TO L-DOPA AND PYRIDOSTIGMINE IN WOMEN WITH POLYCYSTIC OVARIAN SYNDROME

Objective: To evaluate the GH secretion and clarify the factors influe ncing the GH secretion in women with polycystic ovarian syndrome (PCOS ). Design: Comparison of the GH response to L-dopa with or without pyr idostigmine (inhibitor of acetylcholinesterase) pretreatment and insul in response to oral glucose tolerance test in patients with PCOS and m atched controls. Setting: Outpatients and healthy volunteers studied a t a clinical research unit of a university hospital. Patients, Partici pants: Ten women with PCOS and 9 controls with regular cycles were rec ruited. Interventions: After an overnight fast, each subject underwent a GH stimulation test with L-dopa with or without pyridostigmine pret reatment. Plasma insulin and glucose levels were measured after a 75-g glucose load. Main Outcome Measures: Plasma GH, insulin-like growth f actor I (IGF-I), insulin, and nonesterified fatty acids. Results: Grow th hormone responses and GH area under the response curve (AUC) to L-d opa were significantly lower in PCOS than those in controls. Pyridosti gmine enhanced the GH response to L-dopa significantly in PCOS. Insuli n responses and insulin AUC to oral glucose load were significantly hi gher in PCOS than those in controls. Plasma IGF-I levels of PCOS were significantly higher than controls. Insulin AUC had a positive correla tion with plasma IGF-I levels but an inverse correlation with GH AUC i n PCOS and controls. Conclusion: Our result indicated that decreased G H secretion of PCOS may be associated with a high somatostatin activit y and a high plasma IGF-I level.