Effects of long term device-guided slow breathing on sympathetic nervous activity in hypertensive patients: a randomized open-label clinical trial.

PURPOSE: Device-guided slow breathing (DGB) is indicated as nonpharmacological treatment for hypertension. The sympathetic nerve activity (SNA) reduction may be one of the mechanisms involved in blood pressure (BP) decrease. The aim of this study is to evaluate the long-term use of DGB in BP and SNA. SUBJECTS AND METHODS: Hypertensive patients were randomized to listen music (Control Group-CG) or DGB (aim to reduce respiratory rate to less than 10 breaths/minute during 15 minutes/day for 8 weeks). Before and after intervention ambulatory blood pressure monitoring (ABPM), catecholamines and muscle sympathetic nerve activity (MSNA) by microneurography were performed. RESULTS: 17 volunteers in the DGB and 15 in the CG completed the study. There was no change in office BP before and after intervention in both groups. There was a reduction in systolic and diastolic BP in the awake period by ABPM only in the CG (131 ± 10/92 ± 9 vs 128 ± 10/88 ± 8mmHg, p < 0.05). In relation to SNA, no difference in catecholamines was observed. In the volunteers who had a microneurography record, there was no change the MSNA (bursts/minute): DGB (17(15-28) vs 19(13-22), p = 0.08) and CG (22(17-23) vs 22(18-24), p = 0.52). CONCLUSION: Long-term DGB did not reduce BP, catecholamines levels or MSNA in hypertensive patients. ClinicalTrials.gov identifier: NCT01390727.

Post-Exercise Hypotension Is Mediated by a Decrease in Sympathetic Nerve Activity in Stages 2-3 CKD.

BACKGROUND: This study aimed at evaluating the after effects of a single bout of aerobic exercise on muscle sympathetic nerve activity (MSNA), peripheral vascular resistance and blood pressure (BP) in stages 2-3 chronic kidney disease (CKD) patients. We hypothesized that CKD patients present a greater decline in these variables after the exercise than healthy individuals. METHODS: Nine patients with stages 2-3 CKD (50 ± 8 years) and 12 healthy volunteers (50 ± 5 years) underwent 2 sessions, conducted in a random order: exercise (45 min, cycle ergometer, 50% of peak oxygen uptake) and rest (seated, 45 min). Sixty minutes after either intervention, MSNA (by microneurography), BP (by oscillometry), and forearm vascular resistance (FVR) were measured. A 2-way analysis of variance with group (between) and session (within) as main factors was employed, accepting p < 0.05 as significant. RESULTS: Diastolic BP and MSNA were higher in the CKD than the control group in both sessions. Responses after exercise were similar in both groups. Systolic BP, diastolic BP, MSNA and FVR were significantly lower after the exercise than after the rest session in both the CKD and the control groups (162 ± 15 vs. 152 ± 23 and 155 ± 11 vs. 145 ± 16 mm Hg, 91 ± 11 vs. 85 ± 14 and 77 ± 5 vs. 71 ± 10 mm Hg, 38 ± 4 vs. 31 ± 4 and 34 ± 2 vs. 27 ± 4 burst/min, 59 ± 29 vs. 41 ± 29 and 45 ± 20 vs. 31 ± 8 U, respectively, all p < 0.05). CONCLUSION: These results showed that aerobic exercise may produce hemodynamic and neural responses that can be beneficial to these patients in spite of CKD.

Oral estrogen therapy may mitigate the effects of aerobic training on cardiorespiratory fitness in postmenopausal women: a double-blind, randomized clinical pilot study.

OBJECTIVE: The aim of this study was to evaluate the isolated and associated effects of oral estrogen therapy and aerobic training on cardiorespiratory fitness in postmenopausal women. METHODS: Forty-two hysterectomized healthy postmenopausal women were randomly divided (in a double-blind manner) into four groups: placebo-control (n = 9), estrogen therapy-control (n = 12), placebo-aerobic training (PLA-AT; n = 11), and estrogen therapy-aerobic training (ET-AT; n = 10). The estrogen therapy groups received estradiol valerate (1 mg/day) and the aerobic training groups trained on a cycle ergometer three times per week at moderate intensity. Before and 6 months after the interventions, all women underwent a maximal cardiopulmonary exercise test on a cycle ergometer. RESULTS: Regardless of hormone therapy, aerobic training increased oxygen uptake at anaerobic threshold (P = 0.001), oxygen uptake at respiratory compensation point (P = 0.043), and oxygen uptake at peak exercise (P = 0.020). The increases at respiratory compensation point and peak exercise were significantly greater in the groups receiving placebo than in the groups receiving estrogen (oxygen uptake at respiratory compensation point: PLA-AT +5.3 [2.8] vs ET-AT +3.0 [2.5] mL kg(-1) min(-1), P = 0.04; oxygen uptake at peak exercise: PLA-AT +5.8 [3.4] vs ET-AT +2.8 [1.4] mL kg(-1) min(-1), P = 0.02). CONCLUSIONS: Oral estrogen therapy may mitigate the cardiorespiratory fitness increase induced by aerobic training in hysterectomized healthy postmenopausal women.

Effects of estrogen therapy and aerobic training on sympathetic activity and hemodynamics in healthy postmenopausal women: a double-blind randomized trial.

OBJECTIVE: The aim of this study was to evaluate the isolated and associated effects of aerobic training and estrogen therapy on sympathetic nerve activity and hemodynamics in healthy postmenopausal women. METHODS: Forty-five postmenopausal women (mean [SD] age, 51 [3] y) were randomly divided into four groups: sedentary-placebo (SED-PLA; n = 11), sedentary-estrogen therapy (SED-ET; n = 14), aerobic training-placebo (AT-PLA; n = 12), and aerobic training-estrogen therapy (AT-ET; n = 8). The ET groups received oral estradiol valerate (1 mg/d), whereas the PLA groups received placebo. The AT groups performed aerobic exercise three times a week on a cycle ergometer for 50 minutes, whereas the SED groups remained sedentary. All participants were evaluated before and after 6 months. Muscle sympathetic nerve activity (MSNA; microneurography), forearm blood flow (plethysmography), blood pressure (oscillometry), and heart rate (HR) were measured at rest for 10 minutes. Data were analyzed by three-way analysis of variance. RESULTS: Estrogen administration itself did not change any of the studied parameters. AT improved forearm blood flow (AT-PLA, 2.02 [0.85] vs 2.92 [1.65] mL min(-1) 100 mL(-1), P = 0.03; AT-ET, 1.68 [1.11] vs 2.27 [0.76] mL min(-1) 100 mL(-1), P = 0.03), reduced MSNA in the AT-PLA group (39 [6] vs 34 [5] bursts/min(-1), P = 0.01), and decreased HR in the AT-ET group (65 [8] vs 62 [7] beats/min, P = 0.01). CONCLUSIONS: AT reduces sympathetic nerve activity and improves muscle blood flow in healthy hysterectomized postmenopausal women. Moreover, AT decreases HR when combined with ET. However, ET abolishes the reducing effect of AT on MSNA.

Aerobic training abolishes ambulatory blood pressure increase induced by estrogen therapy: a double blind randomized clinical trial.

Emerging data reveal that oral estrogen therapy can increase clinic blood pressure (BP) in post-menopausal women; however, it is important to establish its effects on ambulatory BP, which is a better predictor for target-organ damage. Besides estrogen therapy, aerobic training is widely recommended for post-menopausal women, and it can decrease ambulatory BP levels. This study was designed to evaluate the effect of aerobic training and estrogen therapy on the ambulatory BP of post-menopausal women. Forty seven healthy hysterectomized women were randomly divided (in a double-blind manner) into 4 groups: placebo-control (PLA-CO=12), estrogen therapy-control (ET-CO=14), placebo-aerobic training (PLA-AT=12), and estrogen therapy-aerobic training (ET-AT=09). The ET groups received estradiol valerate (1 mg/day) and the AT groups performed cycle ergometer, 3×/week at moderate intensity. Hormonal status (blood analysis), maximal cardiopulmonary exercise test (VO(2) peak) and ambulatory BP (24-h, daytime and nighttime) was evaluated before and 6 months after interventions. A significant increase in VO(2) peak was observed only in women who participated in aerobic training groups (+4.6±1.0 ml kg(-1) min(-1), P=0.00). Follicle-stimulating hormone was a significant decreased in the ET groups (-18.65±5.19 pg/ml, P=0.00), and it was accompanied by an increase in circulating estrogen (56.1±6.6 pg/ml). A significant increase was observed in the ET groups for daytime (P=0.01) and nighttime systolic BP (P=0.01), as well as nighttime diastolic BP (P=0.02). However, daytime diastolic BP was increased only in the ET-CO group (+3.4±1.2 mmHg, P=0.04), and did not change in any other groups. No significant effect was found in ambulatory heart rate. In conclusion, aerobic training abolished the increase of daytime ambulatory BP induced by estrogen therapy in hysterectomized, healthy, normotensive and postmenopausal women.

Sympathetic nerve activity is decreased during device-guided slow breathing.

It is known that slow breathing (<10 breaths min(-1)) reduces blood pressure (BP), but the mechanisms involved in this phenomenon are not completely clear. The aim of this study was to evaluate the acute responses of the muscle sympathetic nerve activity, BP and heart rate (HR), using device-guided slow breathing (breathe with interactive music (BIM)) or calm music. In all, 27 treated mild hypertensives were enrolled. Muscle sympathetic nerve activity, BP and HR were measured for 5 min before the use of the device (n=14) or while subjects listened to calm music (n=13), it was measured again for 15 min while in use and finally, 5 min after the interventions. BIM device reduced respiratory rate from 16+/-3 beats per minute (b.p.m) to 5.5+/-1.8 b.p.m (P<0.05), calm music did not affect this variable. Both interventions reduced systolic (-6 and -4 mm Hg for both) and diastolic BPs (-4 mm Hg and -3 mm Hg, respectively) and did not affect the HR (-1 and -2 b.p.m respectively). Only the BIM device reduced the sympathetic nerve activity of the sample (-8 bursts min(-1)). In conclusion, both device-guided slow breathing and listening to calm music have decreased BP but only the device-guided slow breathing was able to reduce the peripheral sympathetic nerve activity.

Efeitos da terapia de reposição estrogênica nas respostas hemodinâmicas e neurais ao exercício físico agudo em mulheres no período pós-menopausa / Effects of estrogen replacement therapy in hemodinamic and neural responses to acute aerobic exercise in post-menopausal women

A pós-menopausa é marcada por alterações fisiológicas hemodinâmicas e metabólicas. A terapia de reposição estrogênica é uma forma de amenizar as conseqüências da deficiência hormonal e o exercício físico contribui significativamente para a redução do risco cardiovascular. O objetivo desse estudo foi avaliar em mulheres pós-menopausadas os efeitos isolados e associados da terapia oral estrogênica (TRH) e do treinamento físico aeróbio (TF) nas respostas hemodinâmicas e neurais basais e durante os exercícios com handgrip. Quarenta e cinco mulheres (51±3 anos), histerectomizadas, com e sem ovários, saudáveis, realizaram uma sessão experimental e, posteriormente foram divididas em 4 grupos SED-PLA (n=11), SED-TRH (n=14), TF-PLA (n=12) e TF-TRH (n=8). Os grupos TRH e receberam valerato de estradiol 1mg/dia; PLA receberam placebo; TF, realizaram exercício aeróbio em cicloergômetro por 50 minutos, 3 vezes por semana e SED permaneceram sedentárias. Todas as voluntárias participaram de uma segunda sessão experimental após 6 meses de acompanhamento. Nas sessões experimentais foram avaliadas a atividade nervosa simpática periférica (ANSP - microneurografia), pressão arterial, freqüência cardíaca (FC - método oscilométrico Dixtal no membro inferior), fluxo sangüíneo do antebraço (FSA - pletismografia) em um período basal e durante exercícios estático e dinâmico com handgrip a 30% da força de contração máxima. Para análise estatística foi utilizada ANOVA. O TF isoladamente diminuiu ANSP de 40±7 a 34±4 impulsos/min, (P=0,01) e aumentou FSA de 1,92±0,96 a 2,65±1,34 ml(min.100ml), P=0,03 no período basal. TRH e TF associados reduziram a FC no período basal de 65±8 para 62±7 bpm (P=0,01) e durante o exercício estático e dinâmico com handgrip. A TRH de maneira isolada ou associada ao TF diminuiu as respostas de FC durante os exercícios estático e dinâmico com handgrip. Em conclusão, as intervenções de maneira isolada ou associada promovem alterações hemodinâmicas e neurais...

The post-menopause is marked by physiological hemodynamic and metabolic changes. The estrogen replacement therapy is a way to reduce the consequences of hormone deficiency and physical exercise contributes significantly to the reduction of cardiovascular risk. The aim of this study was to evaluate in post-menopausal women the isolated and associated effects of oral estrogen therapy (TRH) and physical training (TF) in the neural and hemodynamic responses during baseline and "handgrip" exercises. Forty-five women (51 ± 3 years), hysterectomized, with or without ovaries, healthy, participated of an initial session and then they were divided into 4 groups SEDPLA (n = 11), SED-TRH (n = 14), TF-PLA (n = 12) and TF-TRH (n = 8). The TRH groups received estradiol valerate 1 mg / day; PLA placebo; TF, performed aerobic exercise on a cycle ergometer for 50 minutes, 3 times a week and SED remained sedentary. All subjects participated in a second experimental session after 6 months of follow-up. In the experimental sessions peripheral sympathetic nerve activity (ANSP - microneurography), blood pressure, heart rate (FC - oscillometry - Dixtal lower limb), forearm blood flow (FSA - plethysmography) were evaluated at the baseline period and during static and dynamic "handgrip" exercises at 30% of the maximum force. ANOVA was used for the statistica analysis. The TF alone decreased ANSP from 40 ± 7 to 34 ± 4 bursts/min, P = 0.01 and increased FSA 1.92 ± 0.96 to 2.65 ± 1.34 ml (min.100ml), P = 0.03 at the baseline. The association of TRH and TF reduced HR at the baseline from 65 ± 8 to 62 ± 7 bpm (P=0.01) and during exercise with static and dynamic "handgrip". HRT alone or associated with TF decreased the HR responses during static and dynamic "handgrip exercises. In conclusion, the interventions alone or in an associated way promote neural and hemodynamic changes that may contribute to cardiovascular risk reduction in healthy postmenopausal women.

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

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 x min(-1) x 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.

A randomized, placebo-controlled trial of the effects of physical exercises and estrogen therapy on health-related quality of life in postmenopausal women.

OBJECTIVE: The purpose of this study was to evaluate the isolated and associated effects of estrogen therapy (estradiol valerate 1 mg/d orally) and physical exercise (moderate aerobic exercise, 3 h/wk) on health-related quality of life (HRQOL) and menopausal symptoms among women who had undergone hysterectomy. DESIGN: A 6-month, randomized, double-blind, placebo-controlled clinical trial with 44 postmenopausal women who had undergone hysterectomy. The interventions were physical exercise and hormone therapy (n = 9), being sedentary and hormone therapy (n = 14), physical exercise and placebo (n = 11), and being sedentary and placebo (n = 10). HRQOL was assessed by a Brazilian standard version of the Medical Outcome Study Short-Form Health Survey and symptoms by Kupperman Index at baseline and after 6 months. RESULTS: There was a decrease in symptoms in all groups, but only groups who performed physical exercise showed an increase in quality of life. Analysis of variance showed that changes in physical functioning (P = 0.001) and bodily pain (P = 0.012) scores over the 6-month period differed significantly between women who exercised and women who were sedentary, regardless of hormone therapy. Hormone therapy had no effect, and there was also no significant association between physical exercise and hormone therapy in HRQOL. CONCLUSIONS: Physical exercises can reduce menopausal symptoms and enhance HRQOL, independent of whether hormone therapy is taken.