MicroRNAs as Biomarkers for Metabolic Disorders in Polycystic Ovary Syndrome (PCOS): A Review

Polycystic ovary syndrome (PCOS) is associated with several mild metabolic disorders, including insulin resistance (IR), obesity, and dyslipidemia, as well as with some more severe ones, including type 2 diabetes mellitus, non-alcoholic fatty liver disease (NAFLD), and cardiovascular disease. Clinically, mild metabolic complications of PCOS such as IR or lipid metabolism disorders are the predictors of these more severe ones. So far, there is no reliable single marker that enables defining metabolic risk in patients with PCOS. Therefore, novel independent markers of metabolic disturbances are needed. Most reports have focused on microRNA (miRNA, miR) assessment in blood serum or granulosa cells, suggesting the high potential clinical utility of such management. The greatest number of studies focused on the association between miRNAs and IR, obesity, or lipid disorders, and some miRNAs were characteristics of all these processes concomitantly. The altered expression of miR-222, miR-223, miR-320, and miR-122 has been most commonly mentioned as the regulator of these metabolic distortions and seems to result from common regulation pathways of metabolic disturbances. In turn, the current literature lacked the miRNA which could be identified as a reliable marker of type 2 diabetes mellitus or NAFLD accompanying PCOS. Therefore, the main objective of future studies should be determining miRNA markers of these most serious metabolic complications. This article aims to review the role of microRNAs as biomarkers for metabolic disorders in PCOS.