Endocannabinoid system activation may be associated with insulin resistance in women with polycystic ovary syndrome

Objective To assess the levels of endocannabinoids and cannabinoid receptors (CB) 1 and 2 in women with polycystic ovary syndrome (PCOS). Design Case-control study. Setting University teaching hospital. Patient(s) In total, 20 women with PCOS and 20 healthy women in a control group, who were matched for body mass index and age, were enrolled in this study. Intervention(s) The homeostasis model index was used to assess insulin resistance. Main Outcome Measure(s) Omental adipose tissue and human peripheral blood mononuclear cells (PBMCs) from PCOS and the controls were analyzed using real-time polymerase chain reactions for the expressions of CB1 and CB2. The levels of endocannabinoids were analyzed using high-performance liquid chromatography. Result(s) The levels of anandamide and 2-arachidonoylglycerol, and the expression of CB1 and CB2 mRNA (messenger ribonucleic acid) in the PBMCs were significantly higher in the women with PCOS than in the women serving as controls. We found that expression of CB1, but not CB2, in adipose tissue was significantly higher in the women with, vs. without, PCOS. The expressions of CB1 mRNA and endocannabinoids showed a significant positive correlation with 2-hour glucose and insulin levels 2 hours after glucose loading in the PBMCs and adipose tissue. Conclusion(s) Activation of endocannabinoids and overexpression of cannabinoid receptors, especially CB1, may be associated with insulin resistance in women with PCOS.