| Journal: | Brazilian journal of medical and biological research |
| Database: | PERIÓDICA |
| System number: | 000349883 |
| ISSN: | 0100-879X |
| Authors: | Neves, V.F.C1 Silva de Sa, M.F2 Gallo-Junior, L2 Catai, A.M1 Martins, L.E.B3 Crescencio, J.C2 Perpetuo, N.M4 Silva, E1 |
| Institutions: | 1Universidade Federal de Sao Carlos, Nucleo de Pesquisa em Exercicio Fisico, Sao Carlos, Sao Paulo. Brasil 2Universidade de Sao Paulo, Faculdade de Medicina de Ribeirao Preto, Ribeirao Preto, Sao Paulo. Brasil 3Universidade Estadual de Campinas, Faculdade de Educacao Fisica, Campinas, Sao Paulo. Brasil 4Universidade Metodista de Piracicaba, Faculdade de Ciencias da Saude, Piracicaba, Sao Paulo. Brasil |
| Year: | 2007 |
| Season: | Abr |
| Volumen: | 40 |
| Number: | 4 |
| Pages: | 491-499 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Experimental, aplicado |
| English abstract | 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 |
| Disciplines: | Medicina |
| Keyword: | Endocrinología, Sistema cardiovascular, Ginecología, Menopausia, Terapia hormonal, Estrógenos, Ritmo cardiaco |
| Keyword: | Medicine, Cardiovascular system, Endocrinology, Gynecology, Menopause, Hormonal therapy, Estrogens, Heart rate |
| Full text: | Texto completo (Ver HTML) |
