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.
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.
Authors: F Orio; S Palomba; A Colao; T Russo; C Dentico; L Tauchmanovà; S Savastano; C Nappi; C Sultan; F Zullo; G Lombardi Journal: J Endocrinol Invest Date: 2003-02 Impact factor: 4.256
Authors: P Villa; A Rossodivita; A M Fulghesu; F Cucinelli; A Barini; R Apa; C Belosi; A Lanzone Journal: J Endocrinol Invest Date: 2003-04 Impact factor: 4.256
Authors: D Micić; M Sumarac-Dumanović; Dj Macut; A Kendereski; S Zoric; V Popović; G Cvijović; C Dieguez; F F Casanueva Journal: J Endocrinol Invest Date: 2003-04 Impact factor: 4.256
Authors: A Fusco; A Bianchi; A Mancini; D Milardi; A Giampietro; V Cimino; T Porcelli; D Romualdi; M Guido; A Lanzone; A Pontecorvi; L De Marinis Journal: J Endocrinol Invest Date: 2007-12 Impact factor: 4.256