Growth hormone secretion after baclofen administration in different phases of the menstrual cycle in healthy women.

AIM: The aim of this study was to investigate the effect of baclofen administration on growth hormone (GH) secretion during different phases of the menstrual cycle. METHODS: Twelve healthy women (33.6 +/- (SD) 2.8 years; range 23-40 years) with regular menstrual cycles were enrolled. The phases of the menstrual cycle were determined using transvaginal ultrasonography (TV-US) and detecting hormonal serum levels. Plasma GH levels were evaluated during the early follicular, periovulatory and luteal phases of the cycle before and after the baclofen challenge test. RESULTS: After acute baclofen administration, GH levels increased significantly (p < 0.001) compared to basal values during the periovulatory and luteal phases, while no significant variation was detected during the early follicular phase. In addition, plasma GH levels resulted significantly (p < 0.001) higher during the luteal phase than during the periovulatory phase. CONCLUSION: Acute baclofen administration induces a significant increase in plasma GH levels in healthy females during the periovulatory and luteal phases, but not during the early follicular phase. These data suggest a modulator role of plasma sex steroids levels on GH release induced by baclofen.

GH release after GHRH plus arginine administration in obese and overweight women with polycystic ovary syndrome.

Few and unclear data are available in the literature about the relationship between impairment of GH/IGF-I axis and polycystic ovary syndrome (PCOS). This study was aimed to evaluate the basal GH and IGF- levels, and GH release after challenge test in obese and overweight women with PCOS. Thirty patients with PCOS and other 30 healthy women matched for age, body mass index (BMI) and waist-hip ratio (WHR) were studied. Serum follicle-stimulating hormone (FSH), LH, PRL, E2, P, 17OH-progesterone (17OH-P), total T, delta4, DHEA-S, SHBG, GH and IGF-I levels were evaluated in each subject. A GHRH plus arginine challenge test was performed in all subjects. After provocative test, in PCOS and control women the GH levels were significantly (p<0.05) higher in comparison to basal values from 30 min to 120 min. At the same times, a significant (p<0.05) difference was observed between women with PCOS in comparison to healthy women. The mean peak value of GH resulted significantly (p<0.05) lower in PCOS women in comparison to healthy women. The total GH response (area under curve, AUC) to GHRH plus arginine test resulted significantly (p<0.05) lower in PCOS than in healthy women. These findings were statistically significant (p<0.05) also considering the distinction in obese and overweight women. The AUC for GH secretion was significantly lower (p<0.05) in obese in comparison to overweight subjects in the control group, whereas no significant difference was detected between obese and overweight women in the PCOS group. In conclusion, in PCOS women there is a BMI-independent alteration of the GH levels. Further investigations will be necessary to establish the real cause of these data.