Autonomic modulation of heart rate of young and postmenopausal women undergoing estrogen therapy
| Autor: | N.M. Perpétuo, Ester da Silva, Leb Martins, M.F. Silva de Sá, A. M. Catai, Júlio César Crescêncio, V.F.C. Neves, Lourenço Gallo |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: |
Adult
medicine.medical_specialty Aging Supine position medicine.drug_class Posture Hypoestrogenism Estrogen therapy Ocean Engineering Sitting Autonomic Nervous System Heart Rate Internal medicine Heart rate medicine Heart rate variability Humans lcsh:QH301-705.5 lcsh:R5-920 Estrogens Conjugated (USP) business.industry Estrogen Replacement Therapy Heart Middle Aged medicine.disease Menopause Postmenopause Endocrinology Cross-Sectional Studies lcsh:Biology (General) Estrogen Cardiovascular Diseases Cardiology Female lcsh:Medicine (General) business |
| Zdroj: | Brazilian Journal of Medical and Biological Research, Volume: 40, Issue: 4, Pages: 491-499, Published: 07 FEB 2007 Brazilian Journal of Medical and Biological Research v.40 n.4 2007 Brazilian Journal of Medical and Biological Research Associação Brasileira de Divulgação Científica (ABDC) instacron:ABDC Brazilian Journal of Medical and Biological Research, Vol 40, Iss 4, Pp 491-499 (2007) |
| Popis: | The aim of the present study was to determine whether estrogen therapy (ET) reduces alterations of the autonomic control of heart rate (HR) due to hypoestrogenism and aging. Thirteen young (24 ± 2.6 years), 10 postmenopausal (53 ± 4.6 years) undergoing ET (PM-ET), and 14 postmenopausal (56 ± 2.6 years) women not undergoing ET (PM) were studied. ET consisted of 0.625 mg/day conjugated equine estrogen. HR was recorded continuously for 8 min at rest in the supine and sitting positions. HR variability (HRV) was analyzed by time (SDNN and rMSSD indices) and frequency domain methods. Power spectral components are reported as normalized units (nu) at low (LF) and high (HF) frequencies, and as LF/HF ratio. Intergroup comparisons: SDNN index was higher in young (median: supine, 47 ms; sitting, 42 ms) than in PM-ET (33; 29 ms) and PM (31; 29 ms) women (P < 0.05). PM showed lower HFnu, higher LFnu and higher LF/HF ratio (supine: 44, 56, 1.29; sitting: 38, 62, 1.60) than the young group in the supine position (61, 39, 0.63) and the PM-ET group in the sitting position (57, 43, 0.75; P < 0.05). Intragroup comparisons: HR was lower in the supine than in the sitting position for all groups (P < 0.05). The HRV decrease from the supine to the sitting position was significant only in the young group. These results suggest that HRV decreases during aging. ET seems to attenuate this process, promoting a reduction in sympathetic activity on the heart and contributing to the cardioprotective effect of estrogen hormones. |
| Databáze: | OpenAIRE |
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