Omental fat expression of adiponectin and adiponectin receptors in non-obese women with PCOS: a preliminary study

Adiponectin is regarded as a possible link between adiposity and insulin resistance. The aim of the study was to determine adipose levels of mRNA for adiponectin and adiponectin receptors (AdipoR) in non-obese women with polycystic ovary syndrome (PCOS), and to assess whether the cytokine and receptors are related to insulin resistance in PCOS. Adipose tissue obtained from eight non-obese women with PCOS [body mass index (BMI) <27 kg/m2 as cut-off point] was analysed. Levels of mRNA for adiponectin, AdipoR1 and 2 were quantified using the semi-quantitative reverse transcriptase–polymerase chain reaction. Eight non-obese, age- and BMI-matched healthy women served as controls. The level of adiponectin mRNA in non-obese women with PCOS were lower than in controls, but the difference was not statistically significant. However, AdipoR1 and 2 mRNA levels in non-obese women with PCOS were significantly lower than in controls. There was a significant negative correlation between 2 h insulin levels and AdipoR1 or AdipoR2 mRNA levels in non-obese women with PCOS (r = 0.45 and 0.52 respectively, P < 0.05). The present study demonstrates that adiponectin receptor expression is down-regulated by hyperinsulinaemia in non-obese women with PCOS, resulting in adiponectin resistance.