A função neurocardiovascular e a associação com diferentes componentes da capacidade física na exacerbação da Doença Pulmonar Obstrutiva Crônica

Abstract

Introduction: Patients with Chronic Obstructive Pulmonary Disease (COPD) present impairment of the neuro-cardiovascular system with a high risk for cardiovascular events, in addition to impairments in physical-functional capacity, both of which are potentially aggravated by periods of exacerbation of the disease (AECOPD). However, there is still no broad knowledge about the association of neuro-cardiovascular function with different parameters of physical capacity, which can be valuable and a precursor to strategies aimed at improving physical capacity with consequent potential for cardiovascular health. Objective: to investigate neuro-cardiovascular function and its association with different components of patients' physical capacity during acute COPD exacerbation. Methodology: Observational and cross-sectional study with the study population consisting of 50 patients with a diagnosis of COPD in exacerbation. The assessment of neuro-cardiovascular function included 1. Evaluation of endothelial function by brachial artery flow-mediated vasodilation (FMD), 2. Hemodynamic evaluation by analysis of pulse wave and carotid-femoral pulse wave velocity (cfPWV) and 3. Evaluation of cardiac neuroautonomic modulation by frequency variability heart rate (HRV). The assessment of physical capacity included: 1. Walking capacity by the six-minute walk test (6MCW), 2. Handgrip strength and 3. Quadriceps peripheral muscle strength. Results: All parameters of physical capacity (walking ability, quadriceps strength and handgrip) showed a positive association with endothelial function (FMD%) (r=0.37, p=0.01; r=0.44, p<0.01 and r=0.31, p=0.03 respectively) and with the LF sympathetic index of HRV (r=0.31, p=0.05; r=0.37, p=0.31 and r=0,55, p<0.01 respectively). Arterial stiffness (cfPWV) was negatively associated with walking (r=-0.50, p<0.01) and peripheral muscle strength (r=-0.57, p<0.01). In addition, multiple regression analysis revealed peripheral quadriceps muscle strength and age as independent predictors of endothelial function (adjusted R2=0.19; F=4.47; p=0.008) and arterial stiffness (adjusted R2 = 0,35; F=5.86, p=0.004). Conclusion: Physical capacity through its different parameters (walking ability, quadriceps muscle strength and handgrip strength) is associated with endothelial, cardiac neuro-autonomic function and arterial stiffness in patients during severe COPD exacerbation. The greater peripheral muscle strength of the quadriceps is an independent predictor of better endothelial function and arterial stiffness. This study reinforces the need for integrative care in the management of patients with COPD exacerbated with a view to cardiovascular health and physical-functional capacity.