Circulating Zinc-α₂-Glycoprotein Levels And Insulin Resistance In Polycystic Ovary Syndrome

Context:Polycystic ovary syndrome (PCOS) is a multifaceted metabolic disease linked with insulin resistance. Recent studies have shown that circulating levels of the insulin-mimetic adipokine zinc-a2-glycoprotein (ZAG) decrease with type 2 diabetes mellitus (T2DM). Currently, no report has demonstrated a relationship between ZAG and insulin resistance in PCOS women.Objective:The aim of this cross-sectional study was to assess the associations between ZAG and androgen excess with insulin resistance in PCOS women.Design and Patients:99 PCOS women and 100 healthy age-matched controls were recruited. Euglycemic- hyperinsulinemic clamps (EHCs) were preformed to assess their insulin sensitivity, which was expressed as M value. Circulating ZAG was determined with ELISA kit.Results:Circulating ZAG levels and M-value were much lower in PCOS women than in controls (35.3±18.3 vs.53.9±15.3 mg/L for ZAG; 5.9±＋2.9 vs.10.1±2.6 mg/kg/min for M-value, both P<0.01). Pearson correlations showed that in PCOS women, ZAG correlated positively with SHBG, M-value, and ADI and negatively correlated with BMI, FAT%, TG, FIns, HbAlc, HOMA-IR, HOMA-β, AUCglucose and AUCinsulin. Multiple linear regression analysis revealed that only M-value and AUCglucose were independently related factors to circulating ZAG in PCOS women. Binary logistic regression analysis showed that circulating ZAG was significantly associated with PCOS even after controlling for anthropometric variables, blood pressure, lipid profile and hormone.Conclusions:Circulating ZAG levels are reduced in women with PCOS and are associated with insulin resistance. ZAG may play a role in the pathogenesis of insulin resistance in PCOS women.