Aims: To compare ghrelin levels in women with polycystic ovary syndrome (PCOS) and healthy subjects and to evaluate the relationships between circulating ghrelin and the heterogeneity of clinical and biochemical manifestations of PCOS women.
Methods: Forty-five women with PCOS and 20 controls were included in the study. Serum levels of ghrelin, leptin, testosterone, immune-reactive insulin (IRI), sex hormone-binding globulin, dehydroepiandrosterone sulfate, cortisol, luteinizing hormone and follicle-stimulating hormone were measured. Free androgen index and homeostasis model assessment of insulin resistance (HOMA-IR) were calculated. Body mass index (BMI) and waist-to-hip ratio (WHR) were calculated.
Results: Serum ghrelin levels in PCOS patients were lower than in the control group (mean+/-standard error of the mean: 21.78+/-2.12 vs. 34.67+/-3.57 ng/ml; p = 0.04). In women with PCOS, a strong negative correlation was observed between ghrelin values and the clinical (BMI, WHR, waist circumference) and hormonal indices of insulin resistance (IRI and HOMA-IR). The negative correlative relationship between ghrelin and HOMA-IR disappeared after partial correlation analysis when controlling for WHR and BMI. Negative correlation existed between ghrelin and testosterone (r = -0.315; p<0.05) and between ghrelin and leptin levels (r = -0.306; p<0.05). The latter correlation disappeared after partial correlation analysis controlling for BMI, WHR and HOMA-IR.
Conclusion: The ghrelin level in women with PCOS reflects the metabolic and hormonal changes which are characteristics of the syndrome. The inverse correlation between ghrelin and leptin in these women is mediated through metabolic factors.