The polycystic ovary syndrome phenotype modulates prevalence of the metabolic syndrome

Abstract

Polycystic ovary syndrome (PCOS) affects about 6% of women of fertile age. Its main charasteristics are hyperandrogenism (HA) and chronic anovulation (CA). Many PCOS-patients also suffer from obesity and insulin resistance. The prevalence of the metabolic syndrome (MBS), possibly reflecting an elevated cardiovascular risk, is found to be elevated in PCOS. The phenotype of PCOS is heterogenous and its definition still controversial. We have now evaluated the prevalence of the MBS in different phenotypes of PCOS, as defined by the Rotterdam criteria. 206 PCOS-patients (mean age: 28.4±6.3 years, mean BMI: 30.8±9.2kg/m2) were recruited by the Rotterdam criteria and were subdivided according to their phenotype into three groups (I: HA, CA and polycystic ovaries (PCO), n=146; II: HA, CA but without PCO, n=30; III PCO with only one of either HA or CA, n=30). The groups did not differ significantly in age or BMI. Cardiovascular risk factors were evaluated by personal interview, physical examination and blood testing. The MBS was defined according to the ATP III criteria. An age-matched control group was derived from the PROCAM-study. Multivariate analysis were used for statistical testing. Prevalence of MBS differed significantly between the three groups (I: 32.2%, II: 36.7%, III: 10.0%; Chi2=6.7, p<0.05). The relative risk for MBS is 3.2 (95%CI 1.1–9.7) for I vs. III and 3.7 (95%CI 1.1–11.8) for II vs. III, respectively. In comparison to age-matched controls derived from the PROCAM study (6.5%) prevalence of MBS was 5-fold increased in PCOS-patients with the combination of CA and HA. Patients of group III had a 50% increase in comparison to the controls. Among the patients with the combination of CA and HA there was no difference in the prevalence of MBS. Thus, their MBS prevalence was independent of the presence of PCO. In conclusion, the prevalence of the MBS depends on PCOS phenotype. Patients with the combination of HA and CA seem to be at higher risk to develop a MBS than patients defined as PCOS by PCO and one of the two other features.