Premium
Dysfunction of the growth hormone/insulin‐like growth factor‐I axis in women with polycystic ovarian syndrome
Author(s) -
Piaditis G. P.,
Kounadi T. G.,
Rangou D. B.,
Trovas G. P.,
Kaklas N. A.,
Tzonou A. J.,
Chlouverakis C. S.
Publication year - 1995
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/j.1365-2265.1995.tb02691.x
Subject(s) - endocrinology , medicine , polycystic ovary , basal (medicine) , hirsutism , luteinizing hormone , hormone , insulin , insulin resistance
Summary OBJECTIVE Although a defect In G H regulation has been suggested In women with polycystic ovarian syndrome (PCOS), the data are limited and mechanism obscure. We have assessed the function of the GH/IGF‐I axis In women with PCOS by measuring basal IGF‐I levels and the ability of the pituitary to secrete GH following dopamine and GHRH. DESIGN For each woman the complete study lasted 3 days. On the 1st and 2nd days, saline (0.9%, 5 ml/h for 3 h) and dopamine (4μg/kg min for 3h) Infusion tests were performed, respectively, In all PCOS and control women. Blood samples for G H measurement were obtained before and at 20‐mlnute Intervals for 3 hours. On the 3rd day a GHRH test (100μg, i.v.bolus) was performed In 9 of the women with PCOS and In 9 controls. Blood samples for G H measurements were obtained before and at 20‐minute Intervals for 3 hours. Basal IGF‐I levels were measured In the basal blood samples from the saline infusion test in all patients studied. SUBJECTS Thirteen women with PCOS and 11 normally menstruating women (control group), aged 18‐35 years, were studied. All women with PCOS had hirsutism and oligomenorrhoea since menarche, elevated serum values of at least one ovarian androgen and the typical ultrasound appearances of PCOS. RESULTS Growth hormone releasing hormone (GHRH) induced a significant increase In GH secretion In both control and PCOS groups. However, the GH response to GHRH was found to be significantly lower In women with PCOS. The 3‐hour infusion of dopamine induced a significant increase in GH levels only in the control group, while it failed to stimulate G H release in the women with PCOS. Although both dopamine and GHRH failed to induce a normal GH response in women with PCOS, their IGF‐I levels did not differ significantly from those observed In control women. CONCLUSIONS The diminished G H responses to both GHRH and dopamine In women with PCOS, in the presence of normal circulating IGF‐I levels, suggests a dysregulation in GH secretion. Although the data are suggestive of a hypothalamic defect, further studies are required to clarify the underlying mechanism and the role, if any, of GH In the pathogenesis of polycyctic ovarian syndrome.