Heart rate variability in normal-weight patients with polycystic ovary syndrome

Among the different methods for evaluating autonomic activity, the analysis of heart rate variability (HRV), a noninvasive approach by which quantitative information on the cardiac vagal and sympathetic control of heart rate (HR) can be obtained in various physiological and pathological conditions, has gained high popularity (1, 2). The analysis of HRV has been shown to have clinical utility in testing autonomic function and as a valuable predictor for various diseases (3). Polycystic ovary syndrome (PCOS) is characterized by the association of endocrine disturbances and other disorders, including obesity, insulin resistance, metabolic syndrome, and hypertension, most of which are accompanied by enhanced sympathetic tone (4). The analysis of HRV has revealed that the autonomic control of HR in women with typical PCOS is altered, with significantly increased sympatho-vagal interaction, as estimated using the ratio of the LF and HF components of the HRV power spectra (5).