Circulating Adiponectin Levels Vary in Clinical phenotypes of Women with Polycystic Ovary Syndrome

Adiponectin is an insulin‐sensitizing hormone secreted by adipose tissue. Adiponectin circulates in oligomeric forms and little is known about how adiponectin might influence glucose regulation in persons at risk for diabetes. The objective of this study was to characterize serum adiponectin profiles in women with clinical phenotypes of polycystic ovary syndrome (PCOS). Levels of total, low (LMW), medium (MMW) and high (HMW) molecular weight adiponectin were quantified by western blot analysis in women with three phenotypes of PCOS (Frank, n=30; Ovulatory, n=7; and Mild, n=6) and healthy controls (n=21). Native proteins were separated in gradient 4 – 15% SDS‐PAGE under non‐reducing non‐denaturing conditions and quantified using near‐infrared fluorescence. LMW and MMW adiponectin levels were similar among all clinical phenotypes of PCOS and did not differ from controls. By contrast, levels of HMW were lower in women with Frank PCOS (p<0.001), but not Ovulatory (p=0.58) or Mild (p=0.42), compared to controls. HMW adiponectin negatively correlated to fasting insulin (p<0.02) and measures of insulin sensitivity (p< 0.02) in women with Frank PCOS. In summary, the ratios of oligomeric forms of adiponectin vary in clinical phenotypes of PCOS. Lower levels of HMW adiponectin may contribute to abnormal glucose regulation in women with more severe forms of PCOS. Study sponsored by Cornell University.