Metabolic syndrome in polycystic ovary syndrome (PCOS): lower prevalence in Southern Italy than in USA and the influence of criteria for the diagnosis of PCOS

OBJECTIVE: Metabolic syndrome (MBS) is a common disorder and is thought to be extremely prevalent in polycystic ovary syndrome (PCOS). In the USA the prevalence of MBS in PCOS has been reported to be as high as 43-46% using Adult Treatment Panel III (ATP-III) criteria. Because of differences in diet, lifestyle and genetic factors, we postulated that the prevalence of MBS might not be as high in Italian women. This study sought to determine the prevalence of MBS in Italian women using both the ATP-III and the World Health Organization (WHO) criteria and to determine whether the prevalence is influenced by the way in which PCOS is diagnosed. DESIGN: Assessment of the prevalence of MBS in 282 women with PCOS, aged 18-40 years, living in western Sicily. Eighty-five age- and weight-matched normal women served as controls. METHODS: Patients were divided into those with chronic anovulation and hyperandrogenism (classic PCOS; n = 225) and others with hyperandrogenism and polycystic ovaries but who were ovulatory (ovulatory PCOS; n = 57). A 75 g oral glucose tolerance test was carried out, as were lipid determinations; insulin resistance was assessed by the Quantitative Insulin-Sensitivity Check Index (QUICKI). We used ATP-III and WHO criteria to diagnose MBS. RESULTS: Using ATP-III criteria, the prevalence of MBS was 8.2% and using WHO criteria it was 16% in Italian women with PCOS. In controls, the prevalence was 2.4% using both methods. In classic PCOS patients, MBS was higher (8.9% by ATP-III, 17.3% by WHO) than in ovulatory PCOS (5% and 10.6% respectively). Body weight significantly modified prevalence rates. CONCLUSION: MBS is substantially higher in women with PCOS than in the general population, and the prevalence is higher in those women diagnosed by classic criteria. However, the prevalence of MBS in PCOS appears to be much lower in Italy than in the USA.