ABSTRACT Obesity is a multifactorial disease defined by a pathological accumulation of body fat. Its prevalence has increased greatly across the world. Chile has one of the highest prevalence of obesity among OCDE countries. It is caused by a sustained difference between energy expenditure and intake, keeping a positive delta, which drives fat accumulation. However, its etiology is comprised several factors: psychological, genetics, environmental, etc. The environment plays a key role in the predisposition towards food consumption, the adoption of exercise, and genetic susceptibility, increasing or decreasing the genetic load towards obesity. This modification of susceptibility is known as epigenetics, which refers to modifications “over” genetics, which are highly modifiable by environmental factors. Some of these modifications can be inherited from one generation to another, granting a higher complexity level regarding designing novel complementary therapies against obesity. Thus, the present review described which epigenetic modifications are related to obesity and different dietary patterns, and finally how epigenetic modifications can be related to transgenerational transmission of obesity.

RESUMEN La obesidad es una enfermedad multifactorial definida como acumulación patológica de grasa. Su prevalencia ha aumentado enormemente en el mundo. Chile presenta una de las mayores prevalencias de obesidad de la OCDE. Su casuística simplificada comprende una diferencia sostenida entre gasto e ingesta de energía, manteniendo un delta positivo traducido en mayor acumulación de grasa. No obstante, la etiología completa de esta enfermedad comprende también factores psicológicos, genéticos, ambientales, etc. El ambiente juega un papel clave en la predisposición al consumo de alimentos, a la realización de ejercicio físico, incluso afectando la susceptibilidad genómica, exacerbando o disminuyendo la carga genética. Esta modificación de susceptibilidad genética por el ambiente se conoce como epigenética, que se refiere a una serie de modificaciones por “sobre” la genética que son altamente modificables por factores ambientales. Se ha descrito que algunas de estas modificaciones pueden heredarse de una generación a otra, lo que otorga otro nivel de complejidad al estudio de nuevas terapias complementarias para frenar la tendencia al sobrepeso. En la presente revisión se describe cuales son las modificaciones epigenéticas más frecuentes encontradas, su relación con obesidad y dieta, y finalmente como se relaciona con la transmisión transgeneracional de esta patología.

This review analyzes the effects of high intensity interval training (HIIT) on muscle and cardiovascular fitness and body composition in teenagers. A search was carried out in international databases, finding 145 papers and selecting five for analysis. In all the reviewed manuscripts, peak oxygen uptake improved after HIIT. In the three manuscripts that measured muscle strength, it also increased. We conclude that HIIT improves muscle strength and cardiovascular fitness in school age children. A 12 weeks protocol with three 12-minute sessions per week would be ideal.

ABSTRACT Objective The aim of this research was to analyze the expression profile of miR-155, miR-146a, and miR-326 in peripheral blood mononuclear cells (PBMC) of 47 patients with type 1 diabetes mellitus (T1D) and 39 control subjects, as well as the possible association with autoimmune or inflammatory markers. Subjects and methods Expression profile of miRs by means of qPCR using TaqMan probes. Autoantibodies and inflammatory markers by ELISA. Statistical analysis using bivariate correlation. Results The analysis of the results shows an increase in the expression of miR-155 in T1D patients in basal conditions compared to the controls (p < 0.001) and a decreased expression level of miR-326 (p < 0.01) and miR-146a (p < 0.05) compared T1D patients to the controls. miR-155 was the only miRs associated with autoinmmunity (ZnT8) and inflammatory status (vCAM). Conclusion Our data show a possible role of miR-155 related to autoimmunity and inflammation in Chilean patients with T1D.

Obesity has a high prevalence among children. On the other hand, acute respiratory infections especially of viral origin, are an important cause of morbidity and mortality in this age group. During the recent pandemic of influenza A (H1N1) virus, obesity was identified as a novel independent risk factor for severity multiple markers of the disease. We reviewed the evidence associating obesity with a worse course of respiratory diseases in children. Nine out of 40 retrieved articles, were chosen to be reviewed. We concluded that there is evidence suggesting that immunomodulatory effects of obesity could be considered as a novel risk factor. Thus, bearing in mind the drastic rise in obesity prevalence around the world and in Chile, and the latent possibility of new respiratory pandemics caused by viruses, studying the possible effect of obesity aggravating viral respiratory infections will become important.

The prevalence of obesity in Chilean children has been increasing steadily for the last two decades. The first study to determine nutritional status and food intake in a representative sample of this population was carried out in 1960. Recently the National Food Consumption Survey (ENCA) carried out in 2012 was released by the Ministry of Health. However, this study did not include biochemical determinations of micronutrients which would allow a better diagnosis of nutritional status in children. Objective: to review the literature available from 2004 to 2014 in food intake and nutritional status in Chilean children aged 4 to 14 years. Method: a total of 362 references published between 2004 and 2014 were obtained through searches in the databases PubMed, Lilacs, Embase and Scielo. From these, 40 articles were selected for a thorough review. Results: food intake by children is characterized by a high-energy intake, a low consumption of fruits and vegetables and a high consumption of bread. The ENCA showed that 95% of the Chilean population has a deficient diet. A high prevalence of obesity is observed from very early in life. There is a dearth of data available on plasma indicators of vitamin and mineral status since 1960, which would provide more reliable information on nutritional assessment. Conclusion: It is imperative to implement a representative nutrition survey of children in Chile that includes biochemical indicators to get reliable information in order to develop strategies aimed to correct micronutrient malnutrition from excess or deficiency.

La prevalencia de obesidad en niños chilenos ha aumentado consistentemente en las últimas dos décadas. El primer estudio que determinó el estado nutricional y la ingesta de alimentos efectuado en una muestra representativa de la población fue llevado a cabo en 1960. Recientemente el Ministerio de Salud publicó la Encuesta Nacional de Consumo Alimentario (ENCA), efectuada en el año 2012. Sin embargo, este estudio no incluyó mediciones bioquímicas de nutrientes que permitan un diagnóstico integral y representativo de la condición nutricional del niño en Chile. Objetivos: revisar la literatura disponible entre los años 2004 y 2014 sobre ingesta de alimentos y estado nutricional en niños chilenos de 4 a 14 años de edad. Método: un total de 362 referencias publicadas en ese período se obtuvieron de las bases de datos PubMed, Lilacs, Embase y Scielo. De estos, 40 artículos fueron seleccionados para una revisión completa. Resultados: la ingesta de alimentos se caracteriza por una ingesta calórica alta; un bajo consumo de frutas, verduras y productos lácteos y un alto consumo de pan. La ENCA concluyó que un 95% de los chilenos presenta una dieta deficiente. Se observa una alta prevalencia de obesidad desde edades tempranas. Desde 1960 no ha habido un estudio representativo de la población que incluya niveles plasmáticos de micronutrientes, que proveerían información más confiable sobre el estado nutricional de los niños, además de encuestas de consumo de alimentos. Conclusión: los niños chilenos presentan un estado nutricional y una alimentación deficientes; sin embargo, no hay evidencia representativa de los niveles plasmáticos de nutrientes, por lo que es imperativo desarrollar un estudio representativo que incluya indicadores bioquímicos de micronutrientes con objeto de desarrollar estrategias para mejorar el estado nutricional de los niños.

Background: The worldwide rise in the incidence of Type 1 Diabetes (T1D), and the concordance rate between monozygotic twins (50%), indicate a strong effect of the environment as an underlying factor of this disease. This process can occur throughout epigenetic modifications of gene expression such as DNA methylation, in which several nutrients participate as cofactors. Aim: To determine DNA methylation status in T1D patients and if it is related to plasma levels of folates and homocysteine (Hcy). Material and Methods: We obtained blood samples from 25 T1D patients aged 13.7 ± 5.9 years (11 males) and 25 healthy subjects aged 31.1 ± 7.8 years (16 males). DNA methylation was measured using a colorimetric kit in extracted DNA. Results are expressed as median (interquartile range). Results: Compared with healthy controls, T1D patients had lower global DNA methylation (0.85 (0.91) % and 1.25 (1.16) % respectively, p < 0.02) and Hcy levels (4.8 (1.1) µmol/L and 7.3 (1.4) µmol/L respectively p < 0.01). There were no differences in folate levels between groups. A significant association between folates and global DNA methylation status was observed in T1D patients (r = -0.564, p < 0.01) and healthy subjects (r = 0.440, p = 0.03). Conclusions: TD1 patients had lower levels of Hcy and global DNA methylation. It is relevant to further investigate if this imbalance also induces epigenetic changes in a gene-specific manner, especially in key genes involved in T1D pathogenesis.