Tabaco y peso corporal / Smoking and body weight

Resumen En esta revisión, se analiza la literatura existente en relación al tabaco y el peso corporal, su rol en el cambio de peso corporal según el consumo de tabaco o cesación de este y las diferentes alternativas farmacológicas validadas para el manejo de este problema, cada vez más prevalente.

This review analyses the existing literature regarding tobacco and body weight, its role in the change of body weight according to smoking consumption or cessation and the different pharmacological alternatives validated used to address this issue, which is everyday more prevalent

Nutrición para el entrenamiento y la competición / Nutrition for training and competition

La nutrición es un factor relevante en el rendimiento deportivo. El objetivo de la nutrición deportiva es aportar la cantidad de energía apropiada, otorgar nutrientes para la mantención y reparación de los tejidos y, mantener y regular el metabolismo corporal. Entre los macronutrientes más relevantes para el deportista están los Hidratos de Carbono, cuyo aporte se ajusta de acuerdo al entrenamiento, semana previa a la competencia, día de la competición y recuperación. Otro aspecto central, es asegurar una hidratación adecuada, para lo cual es fundamental implementar planes adaptados a los requerimientos individuales como parte del programa de entrenamiento. Finalmente, es importante considerar el uso de suplementos en los deportistas basados en la evidencia de la medicina actual, de manera de obtener beneficios a partir de ellos, evitar riesgo de salud y de dopaje.

Nutrition is an important factor in sports performance. The goal of sports nutrition is to provide the proper amount of energy, nutrients for maintenance and repair of tissues and, preserve and regulate body metabolism. Among the most important macronutrient for the athlete are carbohydrate, whose intake is adjusted according to the training a week before the competition, the day of the competition, and the recovery after it. Another focus is to ensure an adequate hydration, which is essential for implementing specifics plans to individual requirements as part of the training program. Finally, it is important to consider the use of supplements in athletes based on current medical evidence, to obtain benefits from them, and to avoid health risks and doping.

Hipercolesterolemia familiar heterocigota: diagnóstico molecular y terapia combinada. Caso clínico / Molecular diagnosis and combined lipid lowering therapy of heterozygous familial hypercholesterolemia: Report of one case

Heterozygous familial hypercholesterolemia affects one every 400 individuals, is caused by mutations in the LDL receptor gene and is associated with premature coronary artery disease. Nowadays, LDL cholesterol can be efficiently reduced with the new therapies to reduce blood lipids. We report a female patient who consulted in 1975, when she was 46 years old, for severe hypercholesterolemia. In 2003, a sample of leukocyte DNA was obtained and the uncommon 1705 + 1G >A mutation of the LDL receptor gene was detected. No mutations in the apolipoprotein B gene were found. The patient was treated successfully with simvastatin 80 mg/day and ezetimibe 10 mg/day and LDL cholesterol levels were reduced below 200 mg/dl.

El colesterol HDL: ¿un nuevo objetivo terapéutico en el manejo de las dislipidemias y la ateroesclerosis? / HDL cholesterol: A new target in the treatment of lipid disorders and atherosclerosis?

Low plasma HDL cholesterol levels are an independent risk factor for atherosclerotic cardiovascular disease. During the past years, the study of HDL has been stimulated by the discovery of novel genes and proteins, which have provided new insights into the molecular and cellular mechanisms involved in HDL metabolism. In addition, recent clinical studies focused on treating low HDL as primary objective in high cardiovascular risk patients have been very encouraging. Furthermore, new drugs for raising HDL cholesterol are under development. This article reviews the recent progress in the HDL field and its important implications for the pathophysiology and treatment of atherosclerosis. In the near future, we expect that new drugs with specific and beneficial effects on HDL metabolism and the associated cardiovascular risk should improve the current approach to this disease with high burden on health systems and society.

Lo último en diagnóstico y tratamiento de la obesidad: ¿Hay lugar aún para la terapia conservadora? / Is there still place for conservative treatment of obesity?

In Chile and other countries the actual prevalence of obesity is reaching 30% in selected populations (low income women). Nowadays bariatric surgery appears to be the treatment of choice. However, it is only indicated in selected patients and is not the first line treatment, since it does not prevent or reduce the appearance of this condition, a crucial challenge in its clinical management. The contemporary medical management of obesity should include changes in lifestyle habits and diet together with a behavioral therapy. However, this optimal management requires a multidisciplinary team. A challenge for contemporary medicine is to design efficient interventional strategies to change lifestyles among the obese. These interventions are the only way to reduce the adverse health consequences of obesity.

Mecanismos de hipo e hiper alfalipoproteinemia en individuos adultos chilenos / Mechanisms of hypo and hyper alphalipoproteinemia in Chilean adults

Background: High density lipoprotein (HDL) cholesterol is inversely associated to atherosclerotic cardiovascular risk. Disturbances in HDL cholesterol plasma leves are frecuent in the Chilean population, however the pathophysiological mechanisms are unknown. Aim: To evaluate the mechanisms involved in the hypo and hyper alfalipoproteinemias in Chilean subjects. Materials and Methods: Twenty three subjects with hyperalphalipoproteinemia and 12 with hypoalphalipoproteinemia, paired with control subjects (col-HDL between 35 and 55 mg/dl) were studied. We measured plasma lipids, subfractions and sizing of HDL particles and enzymatic activity of cholesteryl ester transfer protein (CETP), lecithin: cholesterol acyltransferase (LCAT), lipoprotein lipase (LPL) and hepatic lipase (LH). Results: Subjects with hyperalphalipoproteinemia showed significantly higher levels of total HDL-cholesterol (70±2 vs 44±1 mg/dl), HDL 2 (30±3 vs 5±1 mg/dl), Apo A I (175±3 vs 146±4 mg/dl), lower HL activity (23,7±0,8 vs 32,4±1,8 mmol/h/l) and HDL particles of greater size, compared to their controls. Subjects with hypoalphalipoproteinemia, showed significantly lower levels of total HDL-cholesterol (26±1 vs 48±2 mg/dl), HDL 3 (21±1 vs 40±2 mg/dl), Apo A I (107±5 vs 145±7 mg/dl), lower LCAT activity (18,6±1,9 vs 26,2±1,6 nmol/h/ml) and smaller HDL particles, compared to their controls. Conclusion: Changes in hepatic lipase and lecithin cholesterol acyltransferase activities may explain the hyper and hypo alphalipoproteinemia respectively, in Chilean subjects.

Evaluación ultrasonográfica de la función endotelial en niños y adultos chilenos / Ultrasound assessment of endothelial function in Chilean children and adults

Background: Endothelial dysfunction is an important pathogenetic mechanism in the development of atherosclerosis. Aim: To evaluate endothelial function in Chilean children and adult subjects and to provide normal values of flow mediated dilatation (FMD) in the Chilean population. Subjects and Methods: Flow mediated dilation of the brachial artery was measured by high resolution ultrasonography in healthy children (n=32) and adults (n=69) of both gender, in a group of 8 healthy women during 4 periods of pregnancy and late postpartum, and in 22 men and women with a history of stroke or coronary heart disease. Results: FMD in boys and girls was 9.9±3.6 and 10.0±4.2% respectively (NS). The figures for young women and young men were 11.3±3.8 and 8.6±3.9, respectively (p=0.02); for postmenopausal women and older men, 5.5±6.6 and 7.6±6.7 respectively (NS). During normal pregnancy and postpartum there were no significant changes in FMD. Patients with cardiovascular disease had a FMD of 0.3±5.2%, (p <0.001, with other groups). Conclusions: The present study provides values of FMD in healthy Chilean subjects of different ages, and in patients with coronary heart disease.

Función endotelial: evaluación ultrasonográfica e implicancias fisiopatológicas / Endothelial function: ultrasonographic evaluation and physiopathological implications

Durante las últimas décadas se ha establecidoel rol del endotelio sobre el control del tono vascular, coagulación, fibrinolisis y crecimiento celular estudios experimentales han demostrado que la integridad funcional del endotelio ejerce efectos antiaterogénicos y antitrombóticos. La alteración de este equilibrio es considerada como un evento precoz y determinante en el desarrollo de aterogénesis y de riesgo cardiovascular. El síndrome de disfución endotelial es propuesto como un predictor independiente de progresión de la enfermedad coronoaria y de eventos cardiovasculares. Su evaluación puede ser realizada por diversos métodos invasivos como la administración intra-arterial de vasodilatadores. Sin embargo, la naturaleza de dichos estudios limita su utilización seriada y aplicación clínica. La medición no invasiva de la dilatación mediada por flujo a través de ultrasonografía de alta resolución en arteria braquial es una técnica que ha emergido como una herramienta de utilidad en el diagnóstico y valoración de riesgo cardiovascular. En esta revisión se abordarán las implicancias fisiopatológicas del síndrome de disfunción endotelial y su determinación con ultrasonografía de alta resolución en arteria braquial. Se describirán los aspectos técnicos, aplicaciones clínicas, ventajas y limitaciones en la identificación de pacientes en riesgo cardiovascular, incluidos grupos aún poco conocidos, como mujeres con falla reproductiva de origen isquémico y en la postmenopausia.

Diferencias en antioxidantes plasmáticos según nivel socioeconómico en mujeres chilenas / Differences in plasma antioxidants according to socioeconomic level in chilean women

Background: Free radical-mediated oxidative damage is a known initial event in atherogenesis. Cardiovascular disease is frequent in the Chilean population showing differences in the prevalence of risk factors of the disease according to socioeconomic level (SEL). Aim: To determine levels of antioxidants and lipid peroxides in Chilean women from different SEL. Patients and methods: Blood samples were taken from 81 women for measurements of plasma ascorbic acid, ß-carotene, a-tocopherol, licopene, ubiquinol, glutathione, total plasma antioxidant capacity, and lipid peroxides (TBARS). Results:Individuals in the lower SEL showed reduced levels of plasma ß-carotene, ascorbic acid, a-tocopherol, and ubiquinol compared to women in the higher SEL. There were no differences between groups in the plasma levels of glutathione, total antioxidant capacity, or TBARS. Conclusions: The results could be explained in part by the higher consumption of fruits and vegetables in women from the upper SEL

Disfunción endotelial como alteración primaria en las patologías vasculares / Endothelial dysfunction as a primary alteration in vascular diseases

Endothelium controls vascular smooth muscle tone by secreting relaxing and contracting factors. There is a constant release of endothelium derived relaxing factors, mainly nitric oxide, a potent vasodilator, inhibitor of platelet aggregation, monocyte adhesion and smooth muscle proliferation. In addition, the endothelium may increase the release of NO in response to humoral stimulation by vasoactive substances such as acetylcholine, bradikinin or substance P. Although the endothelium releases a number of products, no single blood test has yet proved useful to determine normal endothelial function or as early abnormalities. The most useful test of endothelial function relies on the meassurement of endothelium-dependent dilatation in response to pharmacological or physiologic stimuli. The alteration of this response is known as endothelial dysfunction and has been observed in a variety of circumstances related to cardiovascular risk. This review summarizes the evidence that sustains this association and emphasizes the clinical utility of assessing endothelial function presenting two clinical cases of hypercholesterolemia in which a high-resolution vascular ultrasound in the braquial artery was used

Ingesta de nutrientes en vegetarianos chilenos / Nutrient intake in chilean vegetarians

El consumo de alimentos en vegetarianos ha sido estudiado en forma muy limitada en Chile. En este estudio se midió la ingesta alimentaria en 27 vegetarianos (VT) comparándola con 27 omnívoros (OM), pareados por índice de masa corporal, sexo y edad. El consumo diario fue determinado con encuestas por recordatorio de 24 horas tomando el promedio de 3 días. La ingesta promedio de calorías en VT fue de 1.613 cal/día, que no fue significativamente diferente de OM. El consumo de grasas en VT fue significativamente menor que en OM (37,7 ñ 13.2 g en VT y 46,6 ñ 22,0 g en OM, p<0,01), al igual que el consumo de colesterol (72,5 ñ 52,0 y 192 ñ 111, p<0,001). La ingesta de fibra fue significativamente mayor en VT que en OM (26,7 ñ 12,7 g y 14,4 ñ 6,6 g, p<0,01). Los VT consumen significativamente más caroteno y vitamina C y menos vitamina B12 que los OM. El consumo promedio de calcio fue similar y muy bajo en VT y OM (635 y 655 mg, respectivamente)

Dislipidemias en enfermedades renales: etiopatogenia y tratamiento / Dyslipidemias in renal diseases: pathogenesis and treatment

Patients with renal diseases like nephorotic syndrome, chronic renal failure (uremia) and renal transplantation frequently present disturbances of lipid metabolisms, howerer their pathogenesis is partially understood. Moreover, cardiovascular diseases are responsible for many deaths in these patients. Although the effect of the dyslipidemias in the development of atherosclerosis in renal diseases is not clear, they probably play a role. Since actually the survival of these patients is substantial, it is important to manage them appropriately with regard to their dyslipidemias. this review will examine the pathogenesis and treatment of dyslipidemias in patients with nephrotic syndrome, chronic renal failure and renal transplantation