Association of plasma GDF-9 or GDF-15 levels with bone parameters in polycystic ovary syndrome.

We aimed to determine plasma levels of growth and differentiation factor (GDF)-9 and GDF-15, and their possible association with bone turnover parameters and bone mineral density (BMD), in patients with polycystic ovary syndrome (PCOS). Forty-two obese PCOS women aged 25–35 years, 23 women with idiopathic hirsutism (IH) and 20 healthy controls matched for age and body mass index were enrolled. Anthropometric, metabolic and hormonal patterns, plasma GDF-9 and GDF-15 concentrations, bone turnover markers and BMD were measured. No significant differences were observed in bone turnover markers, BMD measurements, plasma GDF-9 and GDF-15 levels in subjects with PCOS compared with the other two groups. In the combined population of all three groups, GDF-15 concentrations were negatively correlated with osteocalcin (r = −0.317, p < 0.01). Analysis of PCOS patients showed a significant correlation of GDF-15 concentrations with age and homeostasis model assessment index (r = 0.319, p < 0.05, and r = 0.312, p < 0.05, respectively). In addition, GDF-15 concentrations were negatively correlated with osteocalcin (r = −0.395, p < 0.01) and positively correlated with urine deoxypyridinoline (r = 0.353, p < 0.05). GDF-9 did not correlate with bone markers and BMD measurements. In conclusion, plasma GDF-9 and GDF-15 levels as well as bone turnover markers and BMD measurements in subjects with PCOS (25–35 years of age) were comparable with those either in subjects with IH or in healthy controls with similar anthropometric and metabolic profiles. GDF-15 might be a marker of a crossregulation between bone and energy metabolism.