RESUMEN
OBJECTIVE: To evaluate the effect of a single bout of power exercise training (PT) on office and ambulatory blood pressure (BP). METHODS: Twenty-four older adults with essential hypertension participated in two experimental sessions in a randomized order: the PT composed of 3 sets of 8-10 repetitions in 5 power training exercises and the non-exercise control at seated rest (Con). Both experimental sessions lasted 40 min. Office BP was measured continuously for 1 h in the laboratory and 24 h BP through ambulatory blood pressure monitoring. RESULTS: Compared with Con, office systolic/diastolic BP decreased after PT (Systolic BP: 10 mmHg, p < 0.001; Diastolic BP: 4 mmHg, p = 0.015). A trend toward decrease (p = 0.06) was found in diastolic ambulatory BP during daytime (2 mmHg; p = 0.062) and nighttime (3 mmHg; p = 0.063) after PT. No differences were found between PT and Con sessions for systolic and mean ambulatory BP. CONCLUSION: A single bout of PT decreases office BP but this hypotensive effect is not sustained under ambulatory conditions in older patients with essential hypertension.
Asunto(s)
Presión Sanguínea/fisiología , Hipertensión Esencial/terapia , Ejercicio Físico/fisiología , Anciano , Monitoreo Ambulatorio de la Presión Arterial , Estudios Cruzados , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Patients with hypertension have altered autonomic nervous system function, which are increased sympathetic activity. Transcutaneous Electrical Nerve Stimulation (TENS) is a useful modality for pain control and has also been shown to be effective in the reduction of sympathetic activity in healthy subjects and individuals with cardiovascular diseases. OBJECTIVE: The aim of this study was to verify the effects of transcutaneous electrical nerve stimulation by the evaluation of heart rate variability (HRV) in patients with essential hypertension. METHOD: Twenty-eight patients received an application of low-frequency TENS(4 Hz) n=8, highfrequency TENS (100 Hz) n=10 or placebo TENS n=10 in paravertebral ganglionar region during thirty minutes. RESULTS: After 4 Hz TENS, there was a decrease in the low-frequency (LFn.u.) component (57.71±9.46 vs 45.58±13.51, p<0.026) and an increase in the high-frequency (HFn.u.) component (33.03±13.83 vs 45.83±20.19, p <0.05) of HRV. After 100 Hz TENS and placebo, there were no changes in the LF and HF components. No significant differences were found in systolic blood pressure with low-frequency TENS (129.37± 15.48 vs 126.69 ± 15.21, p<0.490). There was an increase, although not significant, with high-frequency TENS (131.00 ± 15.97 vs 138.75 ± 25.79, p<0.121) and placebo (133.80 ± 29.85 vs 134.80 ± 29.72, p< 0.800). No differences were found in the diastolic blood pressure with low-frequency TENS and placebo, but there was a significant increase in high-frequency TENS (81.00 ± 11.78 vs 85.65 ± 13.68, p< 0.018). CONCLUSION: Low-frequency TENS decreases sympathetic nervous system activity and increases parasympathetic nervous system activity and high-frequency TENS increases diastolic blood pressure, when applied on the paravertebral ganglionar region in the hypertensive patients.
Asunto(s)
Presión Arterial , Sistema Nervioso Autónomo/fisiopatología , Sistema Cardiovascular/inervación , Hipertensión Esencial/terapia , Frecuencia Cardíaca , Estimulación Eléctrica Transcutánea del Nervio , Anciano , Brasil , Método Doble Ciego , Hipertensión Esencial/diagnóstico , Hipertensión Esencial/fisiopatología , Femenino , Ganglios Autónomos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Tiempo , Estimulación Eléctrica Transcutánea del Nervio/efectos adversos , Resultado del TratamientoRESUMEN
BACKGROUND: Hypertension is a complex chronic condition characterized by elevated arterial blood pressure. Management of hypertension includes non-pharmacologic strategies, which may include techniques that effectively reduce autonomic sympathetic activity. Respiratory exercises improve autonomic control over cardiovascular system and attenuate muscle metaboreflex. Because of these effects, respiratory exercises may be useful to lower blood pressure in subjects with hypertension. METHODS/DESIGN: This randomized, double-blind clinical trial will test the efficacy of inspiratory muscle training in reducing blood pressure in adults with essential hypertension. Subjects are randomly allocated to intervention or control groups. Intervention consists of inspiratory muscle training loaded with 40 % of maximum inspiratory pressure, readjusted weekly. Control sham intervention consists of unloaded exercises. Systolic and diastolic blood pressures are co-primary endpoint measures assessed with 24 h ambulatory blood pressure monitoring. Secondary outcome measures include cardiovascular autonomic control, inspiratory muscle metaboreflex, cardiopulmonary capacity, and inspiratory muscle strength and endurance. DISCUSSION: Previously published work suggests that inspiratory muscle training reduces blood pressure in persons with hypertension, but the effectiveness of this intervention is yet to be established. We propose an adequately sized randomized clinical trial to test this hypothesis rigorously. If an effect is found, this study will allow for the investigation of putative mechanisms to mediate this effect, including autonomic cardiovascular control and metaboreflex. TRIAL REGISTRATION: ClinicalTrials.gov NCT02275377 . Registered on 30 September 2014.