Low-dose estrogen therapy does not change postexercise hypotension, sympathetic nerve activity reduction, and vasodilation in healthy postmenopausal women

Author(s)

Oneda, Bruna ^[1] ; Forjaz, Claudia L. M. ^[2] ; Bernardo, Fernanda R. ^[1] ; Araujo, Tatiana G. ^[1] ; Gusmao, Josiane L. ^[1] ; Labes, Eliana ^[3] ; Abrahao, Sandra B. ^[1] ; Mion, Jr., Decio ^[1] ; Fonseca, Angela M. ^[3] ; Tinucci, Tais ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Gen Hosp, Hypertens Unit, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Sch Phys Educ & Sport, Exercise Hemodynam Lab, Sao Paulo - Brazil

^[3] Univ Sao Paulo, Gen Hosp, Gynecol & Climacter Serv, Sao Paulo - Brazil

• Document type: Journal article
• Source: AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY; v. 295, n. 4, p. H1802-H1808, OCT 2008.
• Web of Science Citations: 8

Abstract

The aim of this study was to determine whether estrogen therapy enhances postexercise muscle sympathetic nerve activity (MSNA) decrease and vasodilation, resulting in a greater postexercise hypotension. Eighteen postmenopausal women received oral estrogen therapy (ET; n = 9, 1 mg/day) or placebo (n = 9) for 6 mo. They then participated in one 45-min exercise session (cycle ergometer at 50% of oxygen uptake peak) and one 45-min control session (seated rest) in random order. Blood pressure (BP, oscillometry), heart rate (HR), MSNA (microneurography), forearm blood flow (FBF, plethysmography), and forearm vascular resistance (FVR) were measured 60 min later. FVR was calculated. Data were analyzed using a two-way ANOVA. Although postexercise physiological responses were unaltered, HR was significantly lower in the ET group than in the placebo group (59 +/- 2 vs. 71 +/- 2 beats/min, P < 0.01). In both groups, exercise produced significant decreases in systolic BP (145 +/- 3 vs. 154 +/- 3 mmHg, P = 0.01), diastolic BP (71 +/- 3 vs. 75 +/- 2 mmHg, P = 0.04), mean BP (89 +/- 2 vs. 93 +/- 2 mmHg, P = 0.02), MSNA (29 +/- 2 vs. 35 +/- 1 bursts/min, P < 0.01), and FVR (33 +/- 4 vs. 55 +/- 10 units, P = 0.01), whereas it increased FBF (2.7 +/- 0.4 vs. 1.6 +/- 0.2 ml (.) min(-1) (.) 100 ml(-1), P = 0.02) and did not change HR (64 +/- 2 vs. 65 +/- 2 beats/min, P = 0.3). Although ET did not change postexercise BP, HR, MSNA, FBF, or FVR responses, it reduced absolute HR values at baseline and after exercise. (AU)

• FAPESP's process: 01/14989-7 - Sympathetic nervous sistem, hypertension and fitness in post menopausal women submited to hormon replacement therapy
• Grantee: Angela Maggio da Fonseca
• Support Opportunities: Research Projects - Thematic Grants