RESUMEN
Cocoa flavanols protect humans against vascular disease, as evidenced by improvements in peripheral endothelial function, likely through nitric oxide signalling. Emerging evidence also suggests that flavanol-rich diets protect against cognitive aging, but mechanisms remain elusive. In a randomized double-blind within-subject acute study in healthy young adults, we link these two lines of research by showing, for the first time, that flavanol intake leads to faster and greater brain oxygenation responses to hypercapnia, as well as higher performance only when cognitive demand is high. Individual difference analyses further show that participants who benefit from flavanols intake during hypercapnia are also those who do so in the cognitive challenge. These data support the hypothesis that similar vascular mechanisms underlie both the peripheral and cerebral effects of flavanols. They further show the importance of studies combining physiological and graded cognitive challenges in young adults to investigate the actions of dietary flavanols on brain function.
Asunto(s)
Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Cognición/efectos de los fármacos , Flavonoles/administración & dosificación , Oxígeno/metabolismo , Adulto , Cacao , Corteza Cerebral/irrigación sanguínea , Circulación Cerebrovascular/efectos de los fármacos , Suplementos Dietéticos , Método Doble Ciego , Voluntarios Sanos , Humanos , Hipercapnia/dietoterapia , Hipercapnia/fisiopatología , Hipercapnia/psicología , Masculino , Persona de Mediana Edad , Consumo de Oxígeno/efectos de los fármacos , Oxihemoglobinas/metabolismo , Adulto JovenRESUMEN
Obesity compounds the metabolic response to critical illness and augments the consequences of overfeeding. Effective monitoring is essential for the prevention of, or to avoid, worsening of preexistent morbidities associated with obesity during the implementation of specialized nutrition support. This monitoring should guide the clinician toward the selection of appropriate therapeutic options to reduce complications from significant hyperglycemia, dyslipidemia, hypercapnia, fluid overload, and worsening of hepatic steatosis. Conventional nutrition outcome markers should be employed, with their limitations understood, when used for the critically ill obese patient.
Asunto(s)
Enfermedad Crítica/terapia , Apoyo Nutricional/métodos , Obesidad/dietoterapia , Peso Corporal , Cardiomegalia/complicaciones , Cardiomegalia/dietoterapia , Hígado Graso/complicaciones , Hígado Graso/dietoterapia , Índice Glucémico/efectos de los fármacos , Humanos , Hipercapnia/complicaciones , Hipercapnia/dietoterapia , Hiperglucemia/complicaciones , Hiperglucemia/dietoterapia , Hipertrigliceridemia/complicaciones , Hipertrigliceridemia/dietoterapia , Nitrógeno/análisis , Enfermedad del Hígado Graso no Alcohólico , Obesidad/complicaciones , Proteínas/análisis , Resultado del TratamientoRESUMEN
To explore the effects of low calorie, low carbohydrate intake on abnormal pulmonary physiology in chronic hypercapneic respiratory failure, spirometric, arterial blood gas tension, oximetric, and electrocardiographic studies were carried out before and after weight reduction in eight patients. During a single night of monitoring, the mean basal oxygen saturation was 68.4 +/- 20.7 percent with 38 hypoxemic "dips" (a fall in oxygen saturation of more than 10 percent for one minute or longer); six patients had resting tachycardia, four had a prolonged QTc interval, three showed multiple episodes of ST-T depression, and six patients had multiple atrial and ventricular premature contractions. After a low calorie (600 kcal per day) intake for 4.4 +/- 2.3 weeks, there was a mean weight loss of 8.5 +/- 3.6 kg, the mean arterial oxygen tension increased significantly (p less than 0.005) from 55.6 +/- 9.2 to 69.1 +/- 7.9 torr, the mean arterial carbon dioxide tension fell from 59.9 +/- 9.6 to 52.4 +/- 5.4 torr (p less than 0.01), the mean oxygen saturation increased significantly (p less than 0.05) to 85.0 +/- 9.0 percent with only two hypoxemic "dips," the resting heart rate decreased from a mean of 100 +/- 19 to 90 +/- 18 beats/per minute (p less than 0.05), there was a marked reduction in ectopic activity, the ST-T depression disappeared, and the QTc interval fell in two subjects. Follow-up data in four patients suggest that the improvements achieved in arterial blood gas values can be maintained with a low calorie intake. These studies show that a low calorie, low carbohydrate intake improves all the unfavorable physiologic abnormalities in chronic hypercapneic respiratory failure.