The potential diagnostic use of clinical characteristics and mitochondrial DNA copy numbers of peripheral blood and ovarian tissue in polycystic ovary syndrome (PCOS) patient

Polycystic ovary syndrome (PCOS) is a complex, heterogeneous syndrome of uncertain etiology characterized by hyperandrogenemia, hyperinsulinemia, chronic anovulation, and polycystic ovaries. Recent studies showed that the abnormalities of mitochondrial metabolism are related to PCOS. We hypothesized that mtDNA copy number is an important marker that can reflect mitochondrial function. In this study, 135 PCOS patients and 57 age-matched healthy participants were studied. Mitochondrial DNA copy number in peripheral blood and PCOS ovarian tissues, and some clinical parameters were assessed. From the single factor analysis, we can find some clinical parameters are different between PCOS and healthy women and the mitochondrial DNA copy numbers in peripheral blood in PCOS women were significantly lower than in healthy women. We also found that there was no correlation between mtDNA copy numbers in peripheral blood and in ovarian tissue. After multiple logistic regressions, we identified the occurrence of PCOS was significantly positively correlated with BMI and pulse, and negatively correlated with mitochondrial DNA copy numbers in peripheral blood. We also found the decreased mtDNA copy numbers in PCOS patients are independent of these clinical parameters. We constructed the ROC curve based on these risk factors and found if they have potential to predict the patient’s outcome. In conclusion, the changes in mtDNA copy number and some clinical parameters may provide new ideas for PCOS diagnosis. More studies are necessary for further validation of their use in PCOS diagnosis.