RESUMEN
OBJECTIVE: The aim of this study was to assess the dynamical interaction between the cardiovascular autonomic control and sex hormones in perimenopausal women under menopausal hormone therapy (MHT). PATIENTS AND METHODS: Seventy women (age: 51.6±2.1 years) were treated with MHT. Standard time and frequency domain measures of heart rate variability (HRV) and index S of synchronization between the slow oscillations in HRV and photoplethysmographic waveform variability were studied during a 6-week treatment with MHT. We assessed also the dynamics of the following sex hormones: estradiol, follicle-stimulating hormone, dehydroepiandrosterone sulfate, and testosterone. RESULTS: MHT increased estradiol and decreased follicle-stimulating hormone. Hot flashes and index S were significantly decreased under MHT (P<0.05). Other autonomic indices were not significantly changed (P>0.05). Changes of index S did not correlate with changes of sex hormones and hot flushes (P>0.05). CONCLUSION: The obtained results may indicate the independence of heart autonomic control (assessed by HRV measures) from women's hormonal status. However, any changes in sex hormones contribute to changes in the systemic control of circulation, which is assessed by index S.
RESUMEN
OBJECTIVE: The aim of this cross-sectional study was to assess the features of autonomic control of the cardiovascular system in pre- and postmenopausal women. MATERIAL AND METHODS: We studied 185 postmenopausal women aged 59.3±8.5 years (mean±SD) and 104 premenopausal women aged 45.1±5.8 years. Standard indices of heart rate variability (HRV) (mean heart rate, coefficient of variation, standard deviation of the NN interval (the time elapsing between two consecutive R waves in the electrocardiogram with normal sinus rhythm) (SDNN), square root of the mean squared differences of successive NN intervals (RMSSD), proportion derived by dividing RR50, the number of interval differences of successive NN intervals greater than 50 ms, by the total number of NN intervals (PNN50), and power of low frequency (LF) and high frequency (HF) bands in absolute values and percentages of total spectral power) and index S of synchronization between the 0.1-Hz rhythms in heart rate and photoplethysmogram were compared between these two groups at rest. We assessed the following sex hormones: estradiol, follicle stimulating hormone, dehydroepiandrosterone sulfate, and testosterone. RESULTS: Mean heart rate and power of LF and HF bands were significantly different (p<0.05) in pre- and postmenopausal women. The autonomic indices were similar in women with natural and surgical menopause. Some indices (coefficient of variation, SDNN, RMSSD, PNN50, and power of LF and HF bands) showed weak correlation with menopause time in women with natural menopause. In women with surgical menopause, a moderate statistically significant correlation was observed only between menopause time and S index (r=-0.41, p=0.039). In premenopausal women, only testosterone correlated weakly with coefficient of variation, SDNN, PNN50, RMSSD, and power of HF band. In postmenopausal women, no correlations were found. We did not find any significant relationship between autonomic indices and hot flashes, assessed by hot flash diary. CONCLUSION: We did not find a clinically important relationship between cardiovascular autonomic control and menopausal status in women.
