Dysfunction of the growth hormone/insulin-like growth factor-I axis in women with polycystic ovarian syndrome

Clin Endocrinol (Oxf). 1995 Jun;42(6):635-40. doi: 10.1111/j.1365-2265.1995.tb02691.x.


Objective: Although a defect in GH 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 (4 micrograms/kg/min for 3 h) infusion tests were performed, respectively, in all PCOS and control women. Blood samples for GH measurement were obtained before and at 20-minute intervals for 3 hours. On the 3rd day a GHRH test (100 micrograms, i.v. bolus) was performed in 9 of the women with PCOS and in 9 controls. Blood samples for GH 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 appearance 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 GH 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 GH 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.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Dopamine*
  • Female
  • Growth Hormone / blood
  • Growth Hormone / metabolism*
  • Growth Hormone-Releasing Hormone
  • Humans
  • Insulin-Like Growth Factor I / metabolism*
  • Pituitary Gland / metabolism*
  • Polycystic Ovary Syndrome / blood
  • Polycystic Ovary Syndrome / metabolism*
  • Stimulation, Chemical


  • Insulin-Like Growth Factor I
  • Growth Hormone
  • Growth Hormone-Releasing Hormone
  • Dopamine