Importancia actual de la vitamina D: déficit prevalente y asociación a diversas patologías / Current importance of vitamin D

En los últimos años se ha detectado una epidemia mundial de bajos niveles de vitamina D en la población general, la que ha alertado sobre su correlación con diversas enfermedades. Hay muchas razones que pueden ser las causales de este importante problema, siendo la baja exposición a luz solar uno de los principales. Nuestra especialidad juega un rol central en promover una foto exposición más saludable o suplementando a pacientes de alto riesgo para lograr niveles adecuados de esta vitamina. En nuestra revisión analizamos brevemente las causas de bajos niveles de vitamina D, sus funciones y las recientes correlaciones de su déficit con varias condiciones, entre ellas; el cáncer de piel, atopia y enfermedades autoinmunes. Finalmente recomendamos búsqueda activa y suplementación cuando sea necesario.

In the last few years, a worldwide epidemic of low levels of vitamin D in general population has been discovered, raising an alert about its correlation with health problems. Many reasons may be responsible for this important problem, and insufficient exposure to sunlight may be the main one. Our specialty has a key role in promoting a healthy sun exposure or supplementing high risk patients, to keep adequate levels of this vitamin. In our review, we analyze briefly the causes for low levels of vitamin D, its functions and newly discovered correlations with diseases, including skin cancer, atopy and autoimmune conditions. Finally we recommend screening and supplementation, when necessary.

Índice glcémico e insulinemico de dos tipos de pasta de presentación larga y corta en individuos sanos / Glycemic and insulinemic index of two types pasta of short and long presentation in healthy subjects

AIM: To measure the glucose and insulin responses of a standard dry pasta and a dry pasta enriched with egg in their long and short presentation. MATERIAL AND METHODS: The glycemic index (GI) and the insulin index (II) were determined in a randomized, cross over protocol in 10 healthy volunteers between 26 and 58 years of age. Each subject underwent ten tests: six with the standard meal (bread) and four with the study pastas. Every study pasta was evaluated 10 times. Blood glucose and insulin levels were measured in the fasted state and over the 180 min following commencement of consumption of the foods. The Area Under the Curve (AUC) was calculated for the values above baseline for the 3-hour period following the meal. GI and II were calculated as the ratio of glucose and insulin Auks for a given test meal and the AUCs for the standard meal. RESULTS: Both type of pasta in their long and short presentation had lower GI than the standard meal (long pasta A: 47.8+/-54.4 percent, pasta B: 58.6+/-95.4 percent; short pasta A:71.4+/-32.8, pasta B: 79.9+/-47.6 percent percent p<.001). The II was lower with the two type of large pasta compare to the standard meal and to the two type of short pasta (p<.005). CONCLUSIONS: This study has shown that dry pasta with or without addition of egg put in the mass, is low Gl food. Long dry pasta has lower insulin response.

Introducción: Las pastas secas (industrializadas) se caracterizan por ser manufacturadas a base de harina dura de trigo y otros cereales, llamado semolina, a diferencia del pan que se prepara con harina fina, lo que supone que la respuesta insulinémica y glicémica debiera ser menor que la del pan. Objetivo: Medir la respuesta glicémica e insulinsulinémica de una pasta seca estándar y una pasta seca enriquecida con huevo, de presentación larga (espagueti) y corta (corbata). Material y Métodos: El índice glicémico (IG) e índice insulinémico (II) se determinaron en 10 sujetos sanos entre 26 y 58 años de edad. En forma aleatoria a cada sujeto se le midió la glicemia e insulina en ayuno y después de ingerir en forma isoglucídica alimento estándar (pan marraqueta) o los 2 tipos de pasta en presentación larga o corta a los 15,45,60,90,120,150 y 180 minutos. Posteriormente se calculó el área bajo la curva (ABC) de glucosa e insulina en cada sujeto. Los IG e II fueron calculados como la razón entre el ABC para un alimento de prueba dado y el ABC del alimento estándar (considerado el 100 por ciento). RESULTADOS : Ambos tipos de pasta en presentación larga y corta presentaron menor IG que el alimento estándar (marraqueta) ( pasta larga A: 47,8+/-54,4, pasta larga B: 58,6+/-95,4 por ciento; pasta corta A:71,4+/-32,8 por ciento, pasta corta B: 79,9+/-4,.6 por ciento p<001). El II de los dos tipos de pasta larga fue menor que el alimento estándar y los mismos tipos de pasta, pero cortas (p<.005). El II de las pastas cortas no se diferenció del alimento estándar. Conclusión: Este estudio demostró que las pastas secas con o sin adición de huevo tienen una menor respuesta glicémica que el alimento estándar, por lo tanto, se pueden clasificar como alimento de bajo IG. Además las pastas de presentación larga tienen una menor respuesta insulinémica.

Ingesta de alimentos de origen animal versus origen vegetal y riesgo cardiovascular / Intake of animal versus vegetable food and cardiovascular risk

Cardiovascular mortality has been associated with changes in lifestyle and food habits. The occidental diet has been characterized by high intake of animal fat and meat, and it is associated whit increased risk of type 2 diabetes and high blood pressure, an increase in levels of markers of endothelial dysfunction, and presence of pro-thrombotic risk factors. We search the Pubmed database and other review references. Inclusion criteria were: papers published after 1999, randomized controled clinical studies, case-control studies, systematic reviews and methanalyses. Vegetarians groups show less cardiovascular morbidity and mortality than non-vegetarians. The evidence indicated that a decreasing intake of red meat, saturate fat, trans fat, and mainly processed meat, and an increase in the intake of whole grain cereals, fruits, vegetables and fish, are associated with a better overall cardiovascular health and survival.

El aumento de la mortalidad cardiovascular en el último tiempo está fuertemente asociado a cambios en los hábitos de alimentación. La dieta occidental caracterizada por una alta ingesta de alimentos de origen animal, presenta mayor riesgo de diabetes tipo 2 (DM 2), hipertensión arterial (HTA), aumento de marcadores de disfunción endotelial y factores protrombóticos. La búsqueda se realizó en la biblioteca online Pubmed y en referencias de otras revisiones. Los criterios de inclusión fueron: artículos de 1999 en adelante, ensayos clínicos aleatorizados-controlados, estudios caso-control, revisiones sistemáticas y meta análisis. En grupos con alto consumo de alimentos de origen vegetal se ha evidenciado una menor morbi-mortalidad cardiovascular, comparado con los grupos con alta ingesta de alimentos de origen animal. La evidencia apoya que la disminución en el consumo de carnes rojas, grasas saturadas y grasas trans, así como el aumento en el consumo de cereales integrales, frutas, vegetales y pescado, disminuye la morbi-mortalidad global y cardiovascular.

¿Es efectiva la consejería para aumentar el consumo de frutas y verduras y disminuir el riesgo cardiovascular en prevención secundaria?: una revisión / Is counseling an effective strategy to increase fruits and vegetables consumption and decrease the cardiovascular risk in secondary prevention?: a review

Introducción: El consumo de frutas y verduras, dado su alto contenido de fibra y antioxidantes, se ha asociado a una mejoría de algunos de los parámetros biológicos que modifican el riesgo cardiovascular, como el colesterol total, colesterol LDL y la presión arterial. Dentro de las estrategias dirigidas a aumentar la ingesta de vegetales, la consejería es una de las más estudiadas. Métodos: se realizó una búsqueda en la base de datos MEDLINE, y en referencias de otras revisiones. Resultados: se revisaron 42 resúmenes (36 de MEDLINE y 6 de la revisión del United States Preventive Service Task Forcé) de los cuales se seleccionaron 30. De estos 30, 8 cumplieron con los criterios de inclusión. Se encontró evidencia epidemiológica sólida que asoció el consumo de frutas y verduras a una disminución del riesgo cardiovascular (RCV). No encontramos evidencia suficiente respecto a la efectividad de la consejería para modificar el perfil de riesgo en prevención secundaria. Conclusiones: la consejería produce cambios modestos en la dieta y el perfil de riesgo en pacientes sanos, sin embargo se necesita más información respecto su efectividad en pacientes con enfermedad CV y a sus efectos a largo plazo.

Introduction: Consumption of fruits and vegetables, due to their high fiber and antioxidant contain, has been associated with an improvement in some biological parameters that modify cardiovascular risk, such as total cholesterol, LDL cholesterol and blood pressure. One of the most investigated strategies to increase the consumption of vegetables is counselling. Method: We searched the MEDLINE database and other review references. Results: 42 abstraéis were reviewed (36from MEDLINE and 6 of United States Preventive Service Task Force Review) and 30 were selected. Of the 30, 8 match with the inclusion criteria. We found solid epidemiological evidence that showed the association between the intake of fruits and vegetables and cardiovascular risk factors. We did not find enough evidence to demonstrate that counselling is effective in modifying the risk profile in secondary prevention. Conclusion: counselling produces modest changes in the diet and the risk profile in healthy patients, but there is still a need for more information about its effectiveness in long term changes in patients with high cardiovascular risk.

La mantención de peso en humanos podría ser equivalente a la restricción calórica de los modelos animales? / Weight maintenance in humans. Could it mimic calorie restriction of animal models?

BACKGROUND: Energy restriction (ER) extends life span in animals, by decreasing oxidative stress. AIM: To compare adiposity, metabolic variables and DNA oxidative damage, among adults, reporting a constant body weight (weight maintainers), versus those reporting a progressive increase (weight gainers). SUBJECTS AND METHODS: Clinical history, dietary recall, anthropometric measures, abdominal CT scan and fasting blood samples (to measure lipoproteins, glucose and insulin), were obtained in 44 males. These subjects were classified as weight maintainers if they had a change in weight of 3 kg or less in the last 10 years, or weight gainers, if they had a weight increment of more than 6 kg, in the same lapse. Oxidative damage was assessed by 8-hydroxydeoxyguanosine (8-OHdG), in DNA extracted from circulating lymphocytes, in 5 weight maintainers, 8 weight gainers and 5 healthy elders. RESULTS: Energy Intake was 18% higher in weight gainers (p <0.01). Adiposity and central fat were higher among weight gainers (p <0.01). Abdominal fat correlated with serum lipoproteins, glucose and insulin sensitivity, assessed by the Homeostasis Model Assessment (HOMA). 8-OHdG levels did not differ between groups. CONCLUSIONS: The analysis of weight change based on the clinical history correlates with actual body composition, thus it may be a reliable indicator of long term energy Intake. This method could be comparable to weight clamp models employed in animals to study aging.

Pacientes con limitación crónica al flujo aéreo: efectos del entrenamiento muscular respiratorio con válvula de carga umbral construída con tecnología apropiada, asociado a apoyo nutricional / Patients with chronic airflow limitation: effects of muscular respiratory training with threshold load valve constructed according to appropriate technology, associated to nutritional support

To assess prospectively the effects of a controlled program of inspiratory muscle program and nutritional support in patients with chronic obstructive lung disease (COPD). 23 patients with COPD were randomly assigned into 4 groups. Group I received a 1000 kcal/day nutritional supplement, given as a casein based enteral nutritional formula; group III was subjected to inspiratory muscle training, using an inexpensive pressure threshold load valve constructed according to appropriate technology principles of the WHO, adjusted at 30 percent of Maximal Inspiratory Mouth Pressure and received also the nutritional supplement; group IV was trained but did not receive the nutritional supplement and group II was not trained nor supplemented. Patients were studied during 3 months and monthly, inspiratory muscle function, exercise capacity and antropometry were measured. A significant improvement in exercise capacity, maximal inspiratory pressure and inspiratory muscle endurance was observed in the 4 groups throughout the study. Trained subjects had greater improvement in their inspiratory muscle endurance, compared to untrained subjects. Nutritional support had no effect in inspiratory muscle function or exercise capacity. No changes in antropometric measures were observed. The pressure threshold load valve used in this study, improved inspiratory muscle endurance and nutritional support had no effect in patients with COPD