Relationship between estrogen, vasomotor symptoms, and heart rate variability in climacteric women

The present study investigated resting cardiac autonomic function in Japanese climacteric women using heart rate variability (HRV) power spectral analysis to evaluate the relationship between HRV indices and estrogen, as well as the ability of each HRV index to predict vasomotor symptoms. Forty-five peri- and postmenopausal women completed a questionnaire about the presence of vasomotor symptoms (hot flashes, sweating). To analyze the relationship between HRV and hot flashes or sweating, we classified subjects into groups based on symptoms and combinations of symptoms: no hot flashes (H1), hot flashes (H2), non-sweating (S1), sweating (S2), neither hot flashes nor sweating (V1), either hot flashes or sweating (V2), and both hot flashes and sweating (V3). Values for total power and the low-frequency component of HRV were significantly lower in the H2 group than in H1 (p < 0.05); values for total power and the high-frequency and low-frequency components of HRV were significantly lower in group S2 than S1 (p < 0.05); and values for total power and the high-frequency and low-frequency component of HRV were significantly lower in groups V2 and V3 compared to V1 (p < 0.05). Clinical diagnosis of climacterium relies upon subjective complaints of patients. Our findings suggest that HRV indices may help to evaluate vasomotor symptoms.