Effect of metformin on the growth hormone response to growth hormone-releasing hormone in obese women with polycystic ovary syndrome.
OBJECTIVE
Obese women with polycystic ovary syndrome (PCOS) show a marked growth hormone (GH) hyporesponsiveness to several stimuli. We aimed to evaluate the impact of insulin metabolism on the GH secretion impairment in these subjects in relation to food ingestion.


METHODS
Prospective clinical study.


METHODS
Academic research center.


METHODS
Nine obese women with PCOS.


METHODS
Metformin (1,500 mg/daily) was administered for three months. The study protocol, which was performed before and after therapy, included hormonal and lipid assays, oral glucose tolerance test (75 g), euglycemic hyperinsulinemic clamp, and growth hormone-releasing hormone (GHRH) test (50 microg/ev), both on fasting and after a standard meal.


METHODS
Growth hormone response to GHRH (expressed as the area under the curve) in different experimental conditions.


RESULTS
The preprandial GH response to GHRH was not modified by the therapy, whereas a significant increase (P<.05) occurred in the postprandial GH secretion, thus resembling the response of obese normal persons. This change was accompanied by a trend towards improvement, though not statistically significant, of all the evaluated glycoinsulinemic parameters. A significant reduction in cholesterol (P<.01) and androstenedione (P<.05) and an increase in sex hormone-binding globulin (P<.05) were also achieved.


CONCLUSIONS
These data suggest that metformin is able to affect GH secretion in obese women with PCOS, even with minimal metabolic modifications.
Guido
Maurizio
M
Department of Obstetrics and Gynaecology, Università Cattolica del Sacro Cuore, Rome, Italy. maurizioguido@libero.it
Romualdi
Daniela
D
Giuliani
Maddalena
M
Suriano
Rosanna
R
Tienforti
Daniele
D
Costantini
Barbara
B
Lanzone
Antonio
A
D000293:Adolescent; D000328:Adult; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D006801:Humans; D008687:Metformin / Q000627:therapeutic use*; D009765:Obesity / Q000097:blood* / Q000188:drug therapy; D011085:Polycystic Ovary Syndrome / Q000097:blood* / Q000188:drug therapy; D011446:Prospective Studies; D018709:Statistics, Nonparametric
D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D008687:Metformin