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Published on: August 13, 2019
Effect of hormonal replacement therapy on autonomic regulation of the heart
Tomasz Banach1, Lukasz Dobrek, Tomasz Milewicz
1Department of Pathophysiology, Medical College of Jagiellonian University, Cracow. tombanach@poczta.onet.pl
Insights
Continuous combined hormonal replacement therapy (ccHRT) in postmenopausal women enhances cardiac autonomic nervous system (cANS) activity. This therapy restores premenopausal reactivity to vagal stimulation, as indicated by heart rate variability (HRV) parameters.
Area of Science:
- Cardiology
- Endocrinology
- Physiology
Background:
- Postmenopausal women exhibit increased cardiovascular disease risk, potentially linked to altered cardiac autonomic nervous system (cANS) function.
- Heart rate variability (HRV) is a key indicator of cANS activity.
- Continuous combined hormonal replacement therapy (ccHRT) is a common treatment for menopausal symptoms.
Purpose of the Study:
- To investigate the impact of ccHRT on cANS activity in postmenopausal women.
- To assess changes in HRV parameters before and after specific autonomic stimulation tests.
Main Methods:
- A study involving 34 healthy postmenopausal women divided into ccHRT and control groups.
- ECG recordings were taken at rest, during deep breathing (DB), and after sham feeding (SF).
- HRV parameters, including LF, HF, and RR intervals, were analyzed.
Main Results:
- No significant differences in resting HRV were observed between groups.
- Both DB and SF significantly increased HRV parameters in the ccHRT group, indicating enhanced vagal response.
- The ccHRT group showed increased LF and LF/HF ratio during DB, and increased RR, SDNN, LF, and HF during SF.
Conclusions:
- ccHRT enhances the reactivity of HRV parameters to vagal stimulation (DB and SF) in postmenopausal women.
- This suggests that ccHRT increases cANS activity.
- ccHRT appears to restore premenopausal levels of cANS reactivity.
Background:
Increased incidence of cardiovascular diseases frequently reported in postmenopausal women may follow disturbed activity of cardiac autonomic nervous system (cANS). Our purpose was to evaluate the influence of continuous combined hormonal replacement therapy (ccHRT) on cANS reflected by parameters of heart rate variability (HRV).
Method:
Thirty four healthy postmenopausal women aged 56+/-6 years (7+/-4 years after last menorrhoea) were divided into 2 equal groups--women receiving ccHRT (serum estradiol--81+/-75 ng/l, FSH--45+/-27 IU/l) and control group (serum estradiol--31+/-45 ng/l, FSH--74+/-32 IU/l). The ccHRT women have been receiving daily 50 mg of 17beta-estradiol (Oesclim 50, Fournier) in transcutaneous depot and 5 mg of oral progesterone (Duphaston, Solway Pharma) for recent 1.4+/-0.6 years. All recordings began at 8.00 a.m. and were carried out in supine position and resting conditions (room temperature 24 degrees C). The protocol applied consisted of 5 min. of resting ECG recording, 5 min. of deep breathing (DB) test, 6 min of sham feeding (SF) and 5 min. of ECG recording after SF.
Results:
Analysis of the resting HRV didn't reveal any significant differences between the compared groups. In the control group during DB increases of mean LF (455+/-500 vs. 1381+/-1540; p<0.001) and LF/HF (1.5+/-1.1 vs. 5.4+/-4.3; p=0.002) ratio were observed. No influence of SF on HRV was noticed in this group. In the ccHRT women significant increases of mean LF (189+/-125 vs. 728+/-929; p=0.02) and LF/HF ratio (3.1+/-4.8 vs. 9+/-7.3; p=0.002) were observed during DB. SF revealed significant increases of mean RR (841+/-92 vs. 918+/-82; p<0.001), SDNN (35+/-14 vs. 43+/-20; p=0.02), LF (189+/-125 vs. 372+/-434; p=0.03) and HF (150+/-133 vs. 300+/-332; p=0.01).
Conclusions:
Our results revealed increased reactivity of the HRV parameters to vagal stimulation by DB and SF in the postmenopausal women receiving ccHRT that suggests increased activity of cANS in the analysed group. Application of ccHRT restores the premenopausal reactivity of cANS.
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