Observaciones sobre la patogénesis de la anorexia asociada a cáncery su regulación por el sistema nervioso central / Neural pathophysiology of cancer anorexia

Introducción: Se estima que dos terceras partes de los pacientes con cáncer sufren de anorexia o pérdida significativa de apetito, lo que conduce a la disminución acentuada de peso y desnutrición, con repercusiones significativas en la calidad de vida y morbimortalidad de los afectados. Aún se desconocen los mecanismos precisos que originan la pérdida de apetito; diversas hipótesis proponen que la patogénesis es multifactorial, destacándose las características biológicas del tumor, del huésped y las relacionadas al tratamiento. Existen nuevas teorías que señalan diversas substancias con efectos antimetabólicos en el sistema nervioso central y que parecen asociarse con resistencia a señales periféricas que informan al hipotálamo sobre el estado de consumo y gasto energético corporal. El objetivo de la revisión es describir conceptos actuales sobre la patogénesis de la anorexia asociada al cáncer, con particular interés en alteraciones del sistema nervioso central. Conclusiones: Es necesario continuar investigando los mecanismos participantes a nivel neural involucrados en la regulación alimentaria, con la finalidad de implementar mejores medidas de alimentación y tratamiento de los pacientes oncológicos con pérdida de apetito, mejorar su estado nutricio, su calidad de vida y sobre todo, reducir la morbimortalidad asociada a desnutrición (AU)

Introduction: Approximately two thirds of cancer patients at advanced stages of the disease suffer from anorexia. Defined as the loss of the desire to eat, anorexia lower the energy intake which further exacerbates a progressive deterioration of the patient nutritional status. Malnutrition has a large impact on morbidity and mortality affecting the quality of life. Cancer anorexia etiologyis multifactorial including complex interactions among the tumor, host metabolism and antineoplastic treatment. New related theories include peripheral and brain mechanisms affecting hypothalamic pathways; inducing behavioral and metabolic failure of responses to energy balance. The aim of this review is to describe actual concepts involved in the pathogenesis of cancer anorexia with special interest in brain mechanisms. Conclusions: Anorexia and reduced food in take are important issues in the management of cancer patients, more knowledge about pathogenic mechanism is needed to improve therapeutic options, prognosis and quality of life in cancer patients (AU)

[Neural pathophysiology of cancer anorexia]. / Observaciones sobre la patogénesis de la anorexia asociada a cáncer y su regulación por el sistema nervioso central.

INTRODUCTION: Approximately two thirds of cancer patients at advanced stages of the disease suffer from anorexia. Defined as the loss of the desire to eat, anorexia lower the energy intake which further exacerbates a progressive deterioration of the patient nutritional status. Malnutrition has a large impact on morbidity and mortality affecting the quality of life. Cancer anorexia etiology is multifactorial including complex interactions among the tumor, host metabolism and antineoplastic treatment. New related theories include peripheral and brain mechanisms affecting hypothalamic pathways; inducing behavioral and metabolic failure of responses to energy balance. The aim of this review is to describe actual concepts involved in the pathogenesis of cancer anorexia with special interest in brain mechanisms. CONCLUSIONS: Anorexia and reduced food intake are important issues in the management of cancer patients, more knowledge about pathogenic mechanism is needed to improve therapeutic options, prognosis and quality of life in cancer patients.

Chronic renal failure, cachexia, and ghrelin.

Protein energy wasting is frequently observed in patients with advanced chronic renal failure and end-stage renal disease. Anorexia and reduced food intake are critical contributing factors and negatively impact on patients' survival. Ghrelin is a prophagic peptide produced by the stomach and acting at the hypothalamic level to increase the activity of orexigenic neurons. In patients with chronic renal disease, plasma levels are increased as a likely effect of reduced renal clearance. Nevertheless, patients' food intake is significantly reduced, suggesting inflammation-mediated resistance of hypothalamic nuclei to peripheral signals. A number of forms of evidence show that ghrelin resistance could be overcome by the administration of exogenous ghrelin. Therefore, ghrelin has been proposed as a potential strategy to improve food intake in chronic renal failure patients with protein energy wasting. Preliminary data are encouraging although larger prospective clinical trials are needed to confirm the results and to identify those patients who are likely to benefit most from the administration of exogenous ghrelin.