Impaired growth hormone secretion after glucose loading in non-obese women with polycystic ovary syndrome, possibly related to androgen but not insulin and free fatty acids

Abstract

Background. Secretion of growth hormone (GH) is known to be suppressed in women with polycystic ovary syndrome (PCOS). The suppression may be implicated in the pathogenesis of PCOS.

Objective. To investigate the cause of suppressive GH secretion in PCOS.

Methods. In order to eliminate the influence of obesity on the variables, all subjects were non-obese. Standard oral glucose tolerance tests (OGTT) were performed in 13 normal women and 15 patients with PCOS.

Results. The serum GH level decreased progressively during the OGTT, and the mean area under the curve (AUC) for the GH response was significantly smaller in the PCOS group than in the normal group. A reduction in the level of serum free fatty acids (FFAs) was observed during OGTT, but only the fasting level of FFAs was significantly higher in the PCOS group than in the normal group. The mean AUCs for glucose, insulin and FFA responses in the PCOS group were significantly greater than those in the normal group. There was a significant negative correlation only between AUC(GH) and testosterone (r = −0.4557, p = 0.012).

Conclusion. Our findings suggest that the cause of susceptibility for GH secretion to be suppressed after glucose loading in non-obese PCOS patients may be hyperandrogenemia.

Keywords:

• Polycystic ovary syndrome
• growth hormone
• insulin
• glucose
• free fatty acids
• oral glucose tolerance test