Background: Ghrelin is a novel peptide associated with energy balance, obesity, and perhaps gonadal function. The present study was designed in order: (i) to compare plasma ghrelin levels between women with PCOS, women who presented only with hyperandrogenaemia and healthy controls; and (ii) to investigate the relationship between circulating ghrelin and the heterogeneity of clinical and biochemical manifestations of PCOS.
Methods: Two hundred and fifty-nine women with PCOS, 25 women who had only hyperandrogenaemia and 46 controls, were studied. Women with PCOS were further divided, based on the presence of chronic anovulation, biochemical hyperandrogenaemia, clinical hyperandrogenism, and polycystic ovary morphology on ultrasound evaluation. In all women, the basal levels of gonadotrophins, androgens, 17-OH-progesterone, sex hormone-binding globulin, glucose, insulin and ghrelin were measured.
Results: Women with PCOS had lower ghrelin levels, compared to both women with hyperandrogenaemia and controls; women with hyperandrogenaemia had lower ghrelin levels, compared to controls, but not significantly so. While PCOS-associated hyperandrogenaemia was inversely related to ghrelin levels, anovulation and polycystic ovary morphology were associated with higher concentrations. Ghrelin levels were negatively correlated with 17-OH-progesterone levels.
Conclusions: In PCOS, circulating ghrelin and androgens are inversely related and it is possible that this peptide is involved in steroidal synthesis and/or action. It is also likely that different clinical and biochemical manifestations of the syndrome are also associated with different ghrelin concentrations.