RESUMEN
Systemic arterial hypertension is accompanied by autonomic impairments that, if not contained, promotes cardiac functional and morphological damages. Pyridostigmine bromide (PYR) treatment results in positive effects on autonomic control and beneficial cardiac remodeling. These findings were also observed after aerobic physical training (APT). However, little is known about PYR effects on left ventricular contractility, mainly when it is combined with APT. We aimed to investigate the effects of chronic acetylcholinesterase inhibition on cardiac autonomic tone balance, coronary bed reactivity, and left ventricular contractility in spontaneously hypertensive rats (SHR) submitted to APT. Male SHR (18 weeks) were divided into two groups (N = 16): untrained and submitted to APT for 14 weeks (18th to 32nd week). Half of each group was treated with PYR (15 mg/kg/day) for two weeks (31st to 32nd week). The experimental protocol consisted of recording hemodynamic parameters, double autonomic blockade with atropine and propranolol, and assessment of coronary bed reactivity and ventricular contractility in isolated hearts using the Langendorff technique. PYR and APT reduced blood pressure, heart rate, and sympathetic influence on the heart. The Langendorff technique showed that APT increased coronary perfusion pressure and left ventricle contractility in response to coronary flow and ß-agonist administration. However, treatment with PYR annulled the effects of APT. In conclusion, although chronic treatment with PYR reduces cardiac sympathetic tonic influence, it does not favor coronary bed reactivity and cardiac contractility gains. PYR treatment in the trained SHR group nullified the coronary vascular reactivity and cardiac contractility gains.
Asunto(s)
Inhibidores de la Colinesterasa , Hipertensión , Contracción Miocárdica , Condicionamiento Físico Animal , Bromuro de Piridostigmina , Ratas Endogámicas SHR , Animales , Inhibidores de la Colinesterasa/farmacología , Masculino , Ratas , Contracción Miocárdica/efectos de los fármacos , Hipertensión/tratamiento farmacológico , Hipertensión/fisiopatología , Bromuro de Piridostigmina/farmacología , Presión Sanguínea/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Vasos Coronarios/efectos de los fármacos , Vasos Coronarios/fisiopatología , Función Ventricular Izquierda/efectos de los fármacos , Acetilcolinesterasa/metabolismoRESUMEN
The treatment of hypertensive patients with losartan is very common. Despite the reduction in blood pressure, its effects on cardiac contractility and sympathetic autonomic drive are still controversial. In turn, aerobic physical training (APT) also presents an important therapeutic option, providing significant improvements in cardiovascular autonomic control, however little is known about its effects on cardiac contractility, especially when associated with losartan. Therefore, we investigated in spontaneously hypertensive rats (SHR) the effects of losartan and APT on cardiac hemodynamics and functionality, with emphasis on autonomic tonic balance and cardiac contractility. Sixty-four SHR (18 weeks old) were divided into four groups (N = 16): vehicle; vehicle submitted to APT through swimming for 12 weeks; treated with losartan (5 mg·kg-1·d-1) for 12 weeks; and treated with losartan associated with APT. The groups were submitted to cardiac morphological and functional analysis by echocardiography; double blockade of cardiac autonomic receptors with atropine and propranolol; and coronary bed reactivity and left ventricular contractility analyses by the Langendorff technique. APT improved functional parameters and autonomic balance by reducing sympathetic drive and/or increasing vagal drive. In contrast, it promoted a concentric remodeling of the left ventricle (LV). Treatment with losartan reduced sympathetic autonomic drive and cardiac morphological parameters, but there were no significant gains in cardiac functionality and contractility. When combined, the concentric remodeling of the LV to APT was abolished and gains in cardiac functionality and contractility were observed. Our findings suggest that the effects of losartan and APT are complementary and should be applied together in the treatment of hypertension. In spontaneously hypertensive rats, the combination of aerobic physical training with losartan treatment was crucial to greater blood pressure reductions and an increase in left ventricular contractility. Furthermore, losartan treatment prevented the concentric left ventricular remodeling caused by aerobic physical training.
Asunto(s)
Antihipertensivos , Hipertensión , Losartán , Contracción Miocárdica , Condicionamiento Físico Animal , Ratas Endogámicas SHR , Animales , Losartán/farmacología , Losartán/uso terapéutico , Contracción Miocárdica/efectos de los fármacos , Hipertensión/tratamiento farmacológico , Hipertensión/fisiopatología , Masculino , Condicionamiento Físico Animal/fisiología , Ratas , Antihipertensivos/farmacología , Antihipertensivos/uso terapéutico , Presión Sanguínea/efectos de los fármacosRESUMEN
BACKGROUND: Hypertension treatment with renin-angiotensin system inhibitors (RASi) presents contradictions about the recovery of damage in cardiovascular autonomic modulation characterized by reduced heart rate variability (HRV) and increased blood pressure variability (BPV). Conversely, the association of RASi with physical training can influence achievements in cardiovascular autonomic modulation. OBJECTIVE: To investigate the effects of aerobic physical training on hemodynamics and cardiovascular autonomic modulation in hypertensive volunteers untreated and treated with RASi. METHODS: A non-randomized controlled trial in which 54 men (â 40-60 years old) with a history of hypertension for >2 years were allocated in accordance with their characteristics into three groups: untreated (Control; n=16), treated with type 1 angiotensin II (AT1) receptor blocker (losartan; n=21), and treated with angiotensin-converting enzyme inhibitor (enalapril; n=17). All participants underwent hemodynamic, metabolic, and cardiovascular autonomic evaluation using baroreflex sensitivity (BRS) and spectral analysis of HRV and BPV, before and after 16 weeks of supervised aerobic physical training. RESULTS: The volunteers treated with RASi had lower BPV and HRV, both in the supine position and in the tilt test, with the losartan group having the lowest values. Aerobic physical training increased HRV and BRS in all groups. However, the association of enalapril with physical training appears to be more prominent. CONCLUSION: Long-term treatment with enalapril and losartan may harm the autonomic modulation of HRV and BRS. Aerobic physical training is essential to promote positive adjustments in the autonomic modulation of HRV and BRS in hypertensive patients treated with RASi, especially with enalapril.
Asunto(s)
Hipertensión , Renina , Masculino , Humanos , Adulto , Persona de Mediana Edad , Frecuencia Cardíaca , Losartán/efectos adversos , Presión Sanguínea , Antihipertensivos/efectos adversos , Hipertensión/diagnóstico , Hipertensión/tratamiento farmacológico , Enalapril/efectos adversos , Ejercicio Físico/fisiología , Angiotensinas/farmacologíaRESUMEN
BACKGROUND: The cardioprotective effect of physical exercise has been demonstrated in several studies. However, no systematic or updated analysis has described the effects of physical exercise on cardiovascular autonomic modulation in postmenopausal women. AIM: to describe the effects of physical exercise on cardiovascular autonomic modulation in postmenopausal women. METHODS: The Scopus, PubMed, and Embase databases were searched for randomized clinical trials published between January 2011 and December 2021, and regarding the effects of physical exercise on cardiovascular autonomic modulation in postmenopausal women. Two independent authors processed the citations. The methodological quality was evaluated using the PEDRo scale. RESULTS: Of the 91 studies identified, only 8 met the inclusion criteria, of which 7 had fair or poor methodological quality. The analyzed studies investigated the effects of functional training, whole-body vibration, muscular resistance, stretching, and aerobic exercises performed at home or at the gym. The majority of these exercise modalities showed improvements in heart-rate variability (HRV) indices and in the low-frequency band of blood pressure variability. The meta-analysis shows that exercise increased the standard deviation of instantaneous beat-to-beat variability (SD1) (mean difference (MD) = 3.99; 95% confidence interval (CI) = 1.22 to 6.77, n = 46; I2: 0%) and the standard deviation of long-term variability (SD2) (MD = 11.37; 95% CI = 2.99 to 19.75; n = 46; I2: 0%). CONCLUSIONS: Aerobic exercise and some nonconventional training modalities may have beneficial effects on cardiovascular autonomic modulation in postmenopausal women. More high-quality studies are still needed to further confirm their efficacy and safety.
Asunto(s)
Ejercicio Físico , Posmenopausia , Humanos , Femenino , Corazón , Presión Sanguínea , Sistema Nervioso Autónomo/fisiologíaRESUMEN
People living with HIV (PWH) experience an accelerated reduction in bone mineral content (BMC), and a high risk of osteopenia and osteoporosis. Anthropometry is an accurate and low-cost method that can be used to monitor changes in body composition in PWH. To date, no studies have used anthropometry to estimate BMC in PWH. To propose and validate sex-specific anthropometric models to predict BMC in PWH. This cross-sectional study enrolled 104 PWH (64 males) aged >18 years at a local university hospital. BMC was measured using dual energy X-ray absorptiometry (DXA). Anthropometric measures were collected. We used linear regression analysis to generate the models. Cross-validations were conducted using the "leave one out", from the predicted residual error sum of squares (PRESS) method. Bland-Altman plots were used to explore distributions of errors. We proposed models with high coefficient of determination and reduced standard error of estimate for males (r2 = 0.70; SEE = 199.97 g; Q2PRESS = 0.67; SEEPRESS = 208.65 g) and females (r2 = 0.65; SEE = 220.96 g; Q2PRESS = 0.62; SEEPRESS = 221.90 g). Our anthropometric predictive models for BMC are valid, practical, and a low-cost alternative to monitoring bone health in PWH.
Asunto(s)
Densidad Ósea , Infecciones por VIH , Absorciometría de Fotón/métodos , Antropometría/métodos , Composición Corporal , Estudios Transversales , Femenino , Humanos , MasculinoRESUMEN
Fluctuation analysis in intervals between heartbeats provides important indices related to autonomic modulation of heart rate variability (HRV). These indices are considered predictors of morbidity and mortality as they are frequently altered in patients with chronic degenerative diseases, especially in those with cardiovascular and metabolic diseases. Similarly, a reduction in HRV is common with aging. In all cases, cardiovascular fitness is often reduced to below the predicted values. In turn, increases in cardiovascular fitness through regular physical exercise, especially aerobic exercise, represent an important therapeutic tool capable of promoting positive adjustments in cardiac autonomic modulation. These adjustments are characterized by reduced sympathetic modulatory influence and/or increased vagal modulatory influence on the heart, increasing the HRV. Therefore, several methodological tools have been used to assess the degree of impairment of autonomic modulation and the therapeutic effects of physical exercise. In contrast, establishment of strict protocols in experimental design is a main challenge in establishing HRV analysis as a robust parameter for evaluating cardiovascular homeostasis. Thus, this review aimed to contribute to the understanding of autonomic modulation of HRV and its relationship with cardiovascular fitness, highlighting the advances made thus far, the applicability of analysis tools, and the confounding factors observed frequently.