RESUMEN
BACKGROUND: Heart failure (HF) patients develop important changes in body composition, but only a small number of studies have evaluated the associations between these changes and functional class deterioration in a prospective manner. OBJECTIVE: The aim of this study was to evaluate whether changes in bioimpedance parameters were associated with NYHA functional class deterioration over six months. METHODS: A total of 275 chronic stable HF patients confirmed by echocardiography were recruited. Body composition measurements were obtained by whole body bioelectrical impedance with multiple frequency equipment (BodyStat QuadScan 4000). We evaluated functional class using the New York Heart Association (NYHA) classification at baseline and after six months. RESULTS: According to our results, 66 (24%) subjects exhibited functional class deterioration, while 209 improved or exhibited no change. A greater proportion of patients exhibited higher extracellular water (> 5%), and these patients developed hypervolemia, according to location on the resistance/reactance graph. A 5% decrease in resistance/height was associated with functional class deterioration with an OR of 1.42 (95% CI 1.01-2.0, p = 0.04). CONCLUSIONS: Body composition assessment through bioelectrical impedance exhibited a valuable performance as a marker of functional class deterioration in stable HF patients.
Asunto(s)
Composición Corporal , Impedancia Eléctrica , Insuficiencia Cardíaca/patología , Anciano , Anciano de 80 o más Años , Progresión de la Enfermedad , Agua Pulmonar Extravascular/metabolismo , Femenino , Insuficiencia Cardíaca/clasificación , Insuficiencia Cardíaca/diagnóstico por imagen , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
Short-term mechanical ventilation with high tidal volume (HVT) causes mild to moderate lung injury and impairs active Na+ transport and lung liquid clearance in rats. Dopamine (DA) enhances active Na+ transport in normal rat lungs by increasing Na+-K+-ATPase activity in the alveolar epithelium. We examined whether DA would increase alveolar fluid reabsorption in rats ventilated with HVT for 40 min compared with those ventilated with low tidal volume (LVT) and with nonventilated rats. Similar to previous reports, HVT ventilation decreased alveolar fluid reabsorption by ~50% (P < 0.001). DA increased alveolar fluid reabsorption in nonventilated control rats (by ~60%), LVT ventilated rats (by approximately 55%), and HVT ventilated rats (by ~200%). In parallel studies, DA increased Na+-K+-ATPase activity in cultured rat alveolar epithelial type II cells (ATII). Depolymerization of cellular microtubules by colchicine inhibited the effect of DA on HVT ventilated rats as well as on Na+-K+-ATPase activity in ATII cells. Neither DA nor colchicine affected the short-term Na+-K+-ATPase alpha1- and beta1-subunit mRNA steady-state levels or total alpha1- and beta1-subunit protein abundance in ATII cells. Thus we reason that DA improved alveolar fluid reabsorption in rats ventilated with HVT by upregulating the Na+-K+-ATPase function in alveolar epithelial cells.