Integrative physiological study of adaptations induced by aerobic physical training in hypertensive hearts.

Aerobic physical training reduces arterial pressure in patients with hypertension owing to integrative systemic adaptations. One of the key factors is the decrease in cardiac sympathetic influence. Thus, we hypothesized that among other causes, cardiac sympathetic influence reduction might be associated with intrinsic cardiac adaptations that provide greater efficiency. Therefore, 14 spontaneously hypertensive rats (SHR group) and 14 normotensive Wistar Kyoto rats (WKY group) were used in this study. Half of the rats in each group were trained to swim for 12 weeks. All animals underwent the following experimental protocols: double blockade of cardiac autonomic receptors with atropine and propranolol; echocardiography; and analysis of coronary bed reactivity and left ventricle contractility using the Langendorff technique. The untrained SHR group had a higher sympathetic tone, cardiac hypertrophy, and reduced ejection fraction compared with the untrained WKY group. In addition, reduced coronary bed reactivity due to increased flow, and less ventricular contractile response to dobutamine and salbutamol administration were observed. The trained SHR group showed fewer differences in echocardiographic parameters as the untrained SHR group. However, the trained SHR group showed a reduction in the cardiac sympathetic influence, greater coronary bed reactivity, and increased left intraventricular pressure. In conclusion, aerobic physical training seems to reduce cardiac sympathetic influence and increase contractile strength in SHR rats, besides the minimal effects on cardiac morphology. This reduction suggests intrinsic cardiac adaptations resulting in beneficial adjustments of coronary bed reactivity associated with greater left ventricular contraction.

Effects of chronic cholinergic stimulation associated with aerobic physical training on cardiac morphofunctional and autonomic parameters in spontaneously hypertensive rats.

We investigated hemodynamic, cardiac morphofunctional, and cardiovascular autonomic adaptations in spontaneously hypertensive rats (SHRs) after aerobic physical training associated with chronic cholinergic stimulation. Fifty-four SHRs were divided into two groups: trained and untrained. Each group was further subdivided into three smaller groups: vehicle, treated with pyridostigmine bromide at 5 mg/kg/day, and treated with pyridostigmine bromide at 15 mg/kg/day. The following protocols were assessed: echocardiography, autonomic double pharmacological blockade, heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS). Physical training and pyridostigmine bromide reduced BP and HR and increased vagal participation in cardiac autonomic tonic balance. The associated responses were then potentialized. Treatment with pyridostigmine bromide increased HRV oscillation of both low frequency (LF: 0.2-0.75 Hz) and high frequency (HF: 0.75-3 Hz). However, the association with physical training attenuated HF oscillations. Additionally, treatment with pyridostigmine bromide also increased LF oscillations of BPV. Both treatment groups promoted morphofunctional adaptations, and associated increased ejection volume, ejection fraction, cardiac output, and cardiac index. In conclusion, the association of pyridostigmine bromide and physical training promoted greater benefits in hemodynamic parameters and increased vagal influence on cardiac autonomic tonic balance. Nonetheless, treatment with pyridostigmine bromide alone seems to negatively affect BPV and the association of treatment negatively influences HRV.

Frequency of osteopenia and osteoporosis in men and women living with HIV/Aids: an observational study / Frequência de osteopenia e osteoporose em homens e mulheres vivendo com HIV/Aids: um estudo observacional

ABSTRACT: Aims: To identify the frequency in changes of bone metabolism, including below the average value for age, osteopenia, and osteoporosis, in people living with HIV/AIDS (PLWHA) and to compare the frequency of factors associated with bone mineral density (BMD) and body composition between sex. Methods: This observational study assessed 106 PLWHA (65 male) recruited from the University Hospital of Ribeirão Preto Medical School from 2013 to 2014. BMD was measured using Dual Energy X-ray Absorptiometry (DXA). Standard deviation values for Z- and T-score proposed by the International Society for Clinical Densitometry were adopted to classify participants below the average value for age, osteopenia, and osteoporosis. Qui-square and Fischer's exact tests were employed to compare males and females based on their factors associated with BMD reduction. Results: Fifty-two (49%) PLWHA presented at least one diagnosis for below the average value for age, osteopenia, and osteoporosis, being 37 (57%) and 15 (37%) male and female, respec-tively. Frequency of alcohol consumption was higher in males (n=20; 30.8%) than females (n=05; 12.2%) (p=0.028).Conclusions: A high rate of PLWHA showed changes in bone metabolism, with a higher frequency in males. The fre-quency of alcohol consumption was higher in males, and it may partially explain the possible causes of the increased rates of bone metabolism changes observed in this group. This information may help develop strategies for reducing the frequency of diagnosis for below the average value for age, osteopenia, osteoporosis improving quality of life in PLWHA. (AU)

RESUMO: Objetivos: Identificar a frequência de alterações no metabolismo ósseo, incluindo valores abaixo do estimado para idade, osteopenia e osteoporose, em pessoas vivendo com HIV/Aids (PVHA) e comparar a frequência de fatores associados à redução da densidade mineral óssea (DMO) e composição corporal entre sexos. Métodos: Estudo observacional que ava-liou 106 PVHA (65 do sexo masculino) recrutadas do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo entre os anos 2013 e 2014. A DMO foi medida utilizando a Absorciometria Radiológica de Dupla Energia (DXA). Valores de desvio padrão Z- e T- scores propostos pela Sociedade Internacional para Densitometria Clí-nica foram adotados para classificar os participantes em abaixo do valor estimado para idade, osteopenia e osteoporose. Os testes do qui-quadrado e exato de Fischer foram empregados na comparação entre os sexos baseado em seus respec-tivos fatores associados à redução da densidade mineral óssea. Resultados: Cinquenta e dois (49%) PVHA apresentaram ao menos um diagnóstico para abaixo do valor estimado para idade, osteopenia e osteoporose, sendo 37 (57%) do sexo masculino e 15 (37%) feminino. A frequência de consumo de álcool foi maior no sexo masculino (n=20; 30,8%) compara-do ao feminino (n=5; 12,2%) (p=0,028). Conclusões: Uma alta taxa de PVHA apresentaram alterações no metabolismo ósseo, com maior frequência no sexo masculino. A frequência no consumo de álcool foi maior no sexo masculino, podendo explicar parcialmente as possíveis causas para taxa aumentada de alterações no metabolismo ósseo observada nesse grupo. Essa informação pode contribuir no desenvolvimento de estratégias para redução da frequência do diagnóstico para valores abaixo do estimado para idade, osteopenia e osteoporose, melhorando a qualidade de vida em PVHA