To the Editor,We thank the author for the great interest in our study entitled “Heart rate variability and heart rate turbulence in patients with polycystic ovary syndrome” published in the Anatol J Cardiol 2016; 16: 323-7 (1).There are few studies evaluating cardiac autonomic activity in patients with polycystic ovary syndrome (PCOS) (2–5). We believe that the very small sample size of study populations is the main reason for the difference in study results. Obesity, dyslipidemia, high blood pressure, insulin resistance, and serum androgen level are additional risk factors for cardiovascular disease. In some studies, body mass index was higher in PCOS group, whereas it was similar in other studies (2, 4). Similar results were also true for insulin resistance, serum lipid level, and blood pressure variability. In light of these data, it is not clearly known whether or not cardiac autonomic activity is detoriated in PCOS. If so, the underlying mechanism or mechanisms have not yet been identified.In conclusion, we have the same opinions and concerns you expressed. We believe that these contradictions could be resolved with multi-center, large-scale, comprehensive studies.