Assuntos
Determinação da Pressão Arterial , Monitorização Ambulatorial da Pressão Arterial , Hipertensão , Humanos , Brasil , Hipertensão/diagnóstico , Determinação da Pressão Arterial/normas , Determinação da Pressão Arterial/métodos , Monitorização Ambulatorial da Pressão Arterial/normas , Monitorização Ambulatorial da Pressão Arterial/métodos , Visita a Consultório Médico , Pressão Sanguínea/fisiologia , FemininoRESUMO
The acute decrease in blood pressure (BP) observed after a session of exercise (called post-exercise hypotension) has been proposed as a tool to predict the chronic reduction in BP induced by aerobic training. Therefore, this study investigated whether post-exercise hypotension observed after a maximal exercise test is associated to the BP-lowering effect of aerobic training in treated hypertensives. Thirty hypertensive men (50 ± 8 years) who were under consistent anti-hypertensive treatment underwent a maximal exercise test (15 watts/min until exhaustion), and post-exercise hypotension was determined by the difference between BP measured before and at 30 min after the test. Subsequently, the patients underwent 10 weeks of aerobic training (3 times/week, 45 min/session at moderate intensity), and the BP-lowering effect of training was assessed by the difference in BP measured before and after the training period. Pearson correlations were employed to evaluate the associations. Post-maximal exercise test hypotension was observed for systolic and mean BPs (-8 ± 6 and -2 ± 4 mmHg, all P < 0.05). Aerobic training reduced clinic systolic/diastolic BPs (-5 ± 6/-2 ± 3 mmHg, both P < 0.05) as well as awake and 24 h mean BPs (-2 ± 6 and -2 ± 5 mmHg, all P < 0.05). No significant correlation was detected between post-exercise hypotension and the BP-lowering effect of training either for clinic or ambulatory BPs (r values ranging from 0.00 to 0.32, all p > 0.05). Post-exercise hypotension assessed 30 min after a maximal exercise test cannot be used to predict the BP-lowering effect of aerobic training in treated hypertensive men.
Assuntos
Hipertensão , Hipotensão Pós-Exercício , Masculino , Humanos , Pressão Sanguínea/fisiologia , Hipotensão Pós-Exercício/diagnóstico , Hipotensão Pós-Exercício/terapia , Teste de Esforço , Hipertensão/terapia , Anti-Hipertensivos/uso terapêuticoAssuntos
Hipertensão , Brasil , Humanos , Hipertensão/diagnóstico , Hipertensão/prevenção & controleRESUMO
A anormalidade da pressão arterial durante o período de sono identificada como médias ≥ 120 x 70 mm Hg, por meio de registros da Monitorização Ambulatorial da Pressão Arterial de 24 horas (MAPA), está relacionada a pior prognóstico e maior risco de eventos. Essa alteração pode ser decorrência de vários fatores, mas, geralmente, independentemente da causa está fortemente relacionada a maior probabilidade de eventos e mortalidade cardiovasculares. Ainda restam dúvidas, embora evidências começam a ser oferecidas, se o tratamento medicamentoso desse estado de comportamento peculiar da pressão arterial nas 24 horas deva ser instituído. Nessa revisão esses aspectos são amplamente discutidos com base nas melhores evidências disponíveis
The abnormality of blood pressure during the sleep period identified as means ≥ 120 x 70 mm Hg, through 24-hour Ambulatory Blood Pressure Monitoring (ABPM) records, is related to a worse prognosis and greater risk of events. This change can be due to several factors, but, generally, regardless of the cause, it is strongly related to a higher probability of cardiovascular events and mortality. Doubts remain, although evidence is beginning to be offered, whether drug treatment of this peculiar behavioral state of blood pressure within 24 hours should be instituted. In this review, these aspects are widely discussed based on the best available evidence
Assuntos
Humanos , Sono , Monitorização Ambulatorial da Pressão Arterial , Pressão Arterial/fisiologia , Hipertensão/fisiopatologiaRESUMO
Hypertensives present cardiac autonomic dysfunction. Reduction in sleep quality increases blood pressure (BP) and favors hypertension development. Previous studies suggested a relationship between cardiovascular autonomic dysfunction and sleep quality, but it is unclear whether this association is present in hypertensives. Thus, this study evaluated the relationship between sleep quality and cardiac autonomic modulation in hypertensives. Forty-seven middle-aged hypertensive men under consistent anti-hypertensive treatment were assessed for sleep quality by the Pittsburgh Sleep Quality Index (PSQI-higher score means worse sleep quality). Additionally, their beat-by-beat BP and heart rate (HR) were recorded, and cardiac autonomic modulation was assessed by their variabilities. Mann-Whitney and t tests were used to compare different sleep quality groups: poor (PSQI > 5, n = 24) vs good (PSQI ≤ 5, n = 23), and Spearman's correlations to investigate associations between sleep quality and autonomic markers. Patients with poor sleep quality presented lower cardiac parasympathetic modulation (HR high-frequency band = 26 ± 13 vs 36 ± 15 nu, P = .03; HR total variance = 951 ± 1373 vs 1608 ± 2272 ms2 , P = .05) and cardiac baroreflex sensitivity (4.5 ± 2.3 vs 7.1 ± 3.7 ms/mm Hg, P = .01). Additionally, sleep quality score presented significant positive correlation with HR (r = +0.34, P = .02) and negative correlations with HR high-frequency band (r = -0.34, P = .03), HR total variance (r = -0.35, P = .02), and cardiac baroreflex sensitivity (r = -0.42, P = .01), showing that poor sleep quality is associated with higher HR and lower cardiac parasympathetic modulation and baroreflex sensitivity. In conclusion, in treated hypertensive men, poor sleep quality is associated with cardiac autonomic dysfunction.
Assuntos
Hipertensão , Sistema Nervoso Autônomo , Barorreflexo , Pressão Sanguínea , Frequência Cardíaca , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , SonoRESUMO
BACKGROUND: Postexercise heart rate recovery (HRR) is determined by cardiac autonomic restoration after exercise and is reduced in hypertension. Postexercise cooling accelerates HRR in healthy subjects, but its effects in a population with cardiac autonomic dysfunction, such as hypertensives (HT), may be blunted. This study assessed and compared the effects of postexercise cooling on HRR and cardiac autonomic regulation in HT and normotensive (NT) subjects. METHODS: Twenty-three never-treated HT (43 ± 8 years) and 25 NT (45 ± 8 years) men randomly underwent two exercise sessions (30 min of cycling at 70% VO2peak ) followed by 15 min of recovery. In one randomly allocated session, a fan was turned on in front of the subject during the recovery (cooling), while in the other session, no cooling was performed (control). HRR was assessed by heart rate reductions after 60 s (HRR60s) and 300 s (HRR300s) of recovery, short-term time constant of HRR (T30) and the time constant of the HRR after exponential fitting (HRRτ). HRV was assessed using time- and frequency-domain indices. RESULTS: HRR and HRV responses in the cooling and control sessions were similar between the HT and NT. Thus, in both groups, postexercise cooling equally accelerated HRR (HRR300s = 39±12 versus 36 ± 10 bpm, P≤0·05) and increased postexercise HRV (lnRMSSD = 1·8 ± 0·7 versus 1·6 ± 0·7 ms, P≤0·05). CONCLUSION: Differently from the hypothesis, postexercise cooling produced similar improvements in HRR in HT and NT men, likely by an acceleration of cardiac parasympathetic reactivation and sympathetic withdrawal. These results suggest that postexercise cooling equally accelerates HRR in hypertensive and normotensive subjects.
Assuntos
Exercício Físico/fisiologia , Frequência Cardíaca/fisiologia , Hipertensão/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Adulto , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
INTRODUCTION: The acute blood pressure (BP) decrease is greater after evening than morning exercise, suggesting that evening training (ET) may have a greater hypotensive effect. OBJECTIVE: This study aimed to compare the hypotensive effect of aerobic training performed in the morning versus evening in treated hypertensives. METHODS: Fifty treated hypertensive men were randomly allocated to three groups: morning training (MT), ET, and control (C). Training groups cycled for 45 min at moderate intensity (progressing from the heart rate of the anaerobic threshold to 10% below the heart rate of the respiratory compensation point), while C stretched for 30 min. Interventions were conducted 3 times per week for 10 wk. Clinic and ambulatory BP and hemodynamic and autonomic mechanisms were evaluated before and after the interventions. Clinic assessments were performed in the morning (7:00-9:00 AM) and evening (6:00-8:00 PM). Between-within ANOVA was used (P ≤ 0.05). RESULTS: Only ET decreased clinic systolic BP differently from C and MT (morning assessment -5 ± 6 mm Hg and evening assessment -8 ± 7 mm Hg, P < 0.05). Only ET reduced 24 h and asleep diastolic BP differently from C and MT (-3 ± 5 and -3 ± 4 mm Hg, respectively, P < 0.05). Systemic vascular resistance decreased from C only in ET (P = 0.03). Vasomotor sympathetic modulation decreased (P = 0.001) and baroreflex sensitivity (P < 0.02) increased from C in both training groups with greater changes in ET than MT. CONCLUSIONS: In treated hypertensive men, aerobic training performed in the evening decreased clinic and ambulatory BP due to reductions in systemic vascular resistance and vasomotor sympathetic modulation. Aerobic training conducted at both times of day increases baroreflex sensitivity, but with greater after ET.
Assuntos
Pressão Sanguínea/fisiologia , Exercício Físico/fisiologia , Hipertensão/fisiopatologia , Condicionamento Físico Humano , Adulto , Anti-Hipertensivos/uso terapêutico , Barorreflexo/fisiologia , Humanos , Hipertensão/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resistência Vascular/fisiologia , Sistema Vasomotor/fisiologiaRESUMO
KEY POINTS: Recent evidence indicates that metaboreflex regulates heart rate recovery after exercise (HRR). An increased metaboreflex activity during the post-exercise period might help to explain the reduced HRR observed in hypertensive subjects. Using lower limb circulatory occlusion, the present study showed that metaboreflex activation during the post-exercise period delayed HRR in never-treated hypertensive men compared to normotensives. These findings may be relevant for understanding the physiological mechanisms associated with autonomic dysfunction in hypertensive men. ABSTRACT: Muscle metaboreflex influences heart rate (HR) regulation after aerobic exercise. Therefore, increased metaboreflex sensitivity may help to explain the delayed HR recovery (HRR) reported in hypertension. The present study assessed and compared the effect of metaboreflex activation after exercise on HRR, cardiac baroreflex sensitivity (cBRS) and heart rate variability (HRV) in normotensive (NT) and hypertensive (HT) men. Twenty-three never-treated HT and 25 NT men randomly underwent two-cycle ergometer exercise sessions (30 min, 70% VÌO2 peak ) followed by 5 min of inactive recovery performed with (occlusion) or without (control) leg circulatory occlusion (bilateral thigh cuffs inflated to a suprasystolic pressure). HRR was assessed via HR reduction after 30, 60 and 300 s of recovery (HRR30s, HRR60s and HRR300s), as well as by the analysis of short- and long-term time constants of HRR. cBRS was assessed by sequence technique and HRV by the root mean square residual and the root mean square of successive differences between adjacent RR intervals on subsequent 30 s segments. Data were analysed using two- and three-way ANOVA. HRR60s and cBRS were significant and similarly reduced in both groups in the occlusion compared to the control session (combined values: 20 ± 10 vs. 26 ± 9 beats min-1 and 2.1 ± 1.2 vs. 3.2 ± 2.4 ms mmHg-1 , respectively, P < 0.05). HRR300s and HRV were also reduced in the occlusion session, although these reductions were significantly greater in HT compared to NT (-16 ± 11 vs. -8 ± 15 beats min-1 for HRR300s, P < 0.05). The results support the role of metaboreflex in HRR and suggest that increased metaboreflex sensitivity may partially explain the delayed HRR observed in HT men.