Elevated circulating levels of YKL-40 are a marker of abnormal glucose tolerance in women with polycystic ovary syndrome

Abstract

This study investigates human cartilage glycoprotein-39 (YKL-40) levels in patients with polycystic ovary syndrome (PCOS) and controls, and tests their relationship with metabolic and hormonal parameters. Clinical study carried out in a university hospital in Tekirdag, Turkey. Eighty-five women with PCOS and normal glucose tolerance (NGT) and twenty-five women with PCOS and abnormal glucose tolerance (AGT), diagnosed according to Rotterdam criteria, and fifty-nine healthy women. YKL-40 levels, fasting hormone levels and metabolic parameters were investigated in all subjects. We showed increased YKL-40 levels in women with PCOS compared to controls. (152·57 ± 3·96 μg/l vs 98·16 ± 1·6 μg/l, P < 0·000). YKL significantly correlated with BMI (r = 0·344; P < 0·000), 2-h glucose (r = 0·193; P = 0·012), HOMA-IR (r = 0·268; P < 0·000) and fasting insulin (r = 0·310; P < 0·000), but not with waist/hip ratio (r = 0·016; P = 0·832) and fasting glucose (r = 0·108; P = 0·832). When ROC curve analysis was used to analyse the suitability of YKL-40 to identify glucose intolerance in women with PCOS, area under curve for YKL-40 was found to be significant (AGT-PCOS: AUC 0·632, P = 0·046). Plasma YKL-40 levels increased in patients with PCOS compared to healthy subjects. Moreover, there was a significant difference in YKL-40 levels between AGT-PCOS and NGT-PCOS subjects. Subsequently, we also found that YKL-40 levels above the cut-off point may help the clinician to predict abnormal glucose tolerance in patients with PCOS.