Kristen Sparrow • June 08, 2014
The study was conducted to assess the sympathovagal balance in patients with polycystic ovary syndrome (PCOS) using short-term heart rate variability (HRV) analysis and conventional autonomic function tests (CAFT).
Thirty-one newly diagnosed patients with PCOS and 30 age-matched controls were recruited. Body mass index (BMI), waist : hip ratio (WHR), cardiovascular parameters such as basal heart rate (BHR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and rate-pressure product (RPP), and fasting blood glucose (FBG) were measured in both groups. Cardiovascular autonomic functions assessed were spectral analysis of HRV, heart rate and blood pressure response to standing (30:15 ratio), deep breathing (E:I ratio) and isometric handgrip (ΔDBP(ihg)).
The cases had significantly increased BMI, WHR, BHR, SBP, DBP and RPP. Ratio of low-frequency to high-frequency power of HRV (LF-HF ratio), the marker of sympathovagal balance was significantly increased in cases compared to controls. Time-domain indices of HRV and E:I ratio were decreased, and 30:15 ratio, ΔDBP(ihg) and FBG were increased in cases. Though there was a significant correlation of LF-HF ratio with BMI, WHR, BHR, RPP and FBG, only BHR and RPP had independent contribution to LF-HF ratio.
We conclude that PCOS patients have altered autonomic modulation in the form of increased sympathetic and decreased parasympathetic reactivity and HRV. The sympathovagal imbalance exposes them to cardiovascular morbidities.