Prominent role of low HDL-cholesterol in explaining the high prevalence of the metabolic syndrome in polycystic ovary syndrome

Background and aimsThe main objective was to evaluate the prevalence of the metabolic syndrome in Caucasian women with PCOS, using either of the currently proposed definitions (NCEP/ATPIII, IDF and AHA/NHLBI) and, therefore, to estimate the concordance between these three classifications. Secondary objectives were to evaluate: i) which individual criterion of the metabolic syndrome is most strongly associated with PCOS; and ii) whether the severity of hyperandrogenemia, hyperinsulinemia and insulin resistance may influence the presence of the metabolic syndrome in PCOS women.Methods and resultsThe metabolic syndrome was assessed in 200 Caucasian women with PCOS and in 200 Caucasian controls, matched for age and BMI, considering the NCEP/ATPIII, IDF and AHA/NHLBI definitions. PCOS women had an increased prevalence of the metabolic syndrome compared with controls: 32 versus 23% with the NCEP/ATPIII, 39 versus 25% with the IDF and 37 versus 24% with the AHA/NHLBI, respectively (Cohen's Kappa index between the three classifications, P < 0.001). Multivariate logistic regressions revealed that among the individual criteria of the metabolic syndrome, only low HDL-cholesterol levels were significantly associated with PCOS (P < 0.001) which, in turn, are related to insulinAUC (P = 0.029) but not to androgens.ConclusionThis case-control study indicates a high prevalence of the metabolic syndrome in Caucasian PCOS women that is independent of the diagnostic classification used. Furthermore, it shows that low HDL-cholesterol is the criterion which best explains the high prevalence of the metabolic syndrome in PCOS subjects which, in turn, is influenced by hyperinsulinemia, rather than by hyperandrogenemia.