Metabolic syndrome and its components in different phenotypes of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting reproductive-age women. Important factors in its pathogenesis are hyperinsulinaemia and insulin resistance, which lead to higher risk of metabolic syndrome (MetS) and its complications. With the implementation of the Rotterdam diagnostic criteria in 2003, the group of PCOS patients became highly heterogeneous, with varying metabolic risk reported for different phenotypes of the syndrome. The aim of the present review is to assess the prevalence and severity of MetS and its components in patients with the four phenotypes of PCOS. A comprehensive search of Pubmed database was performed to identify studies comparing metabolic characteristics between PCOS patients with different phenotypes of the syndrome. The results of 60 studies published between 2004 and 2020 were retrieved and analysed. More adverse metabolic profile was observed in PCOS patients with hyperandrogenic phenotypes in comparison to normoandrogenic patients, as well as in classic phenotypes, defined by National Institutes of Health criteria, in comparison to newer phenotypes introduced by the Rotterdam criteria. In the majority of observations, normoandrogenic PCOS patients did not differ significantly from controls in terms of metabolic characteristics, although some East Asian studies reported more adverse metabolic profile in normoandrogenic phenotype in comparison to healthy women. In conclusion, metabolic abnormalities in PCOS seem to be associated with joint effects of hyperandrogenism, insulin resistance and visceral obesity. The differences observed between the four phenotypes of PCOS underline the need for individualised diagnostic and therapeutic approach.