Abstract Introduction: severe obesity has had a greater increase than non-severe obesity in Chilean schoolchildren during the last years. We do not know whether the cut-off point currently used to define severe obesity in children (BMI ≥ + 3 DE, WHO-2007 curves) is associated with a greater biological risk in our population. Objective: to describe and compare cardiometabolic risk in schoolchildren with severe vs. non-severe obesity. Methods: a secondary analysis of a sample of 3,325 schoolchildren was performed, in which cardiometabolic risk factors were studied. The prevalence of these was compared in the subsample of 589 schoolchildren with obesity according to whether it was severe or not, and the respective ORs were calculated. Results: mean age was 11.4 ± 0.98 years, 46 % were girls, and 11.5 % of the sample had severe obesity, with a higher prevalence of most of the factors studied and no differences in chronic disease, obesity or education in parents, or physical activity of the child. The risk of those with severe obesity for central obesity, insulin resistance, high blood pressure, and metabolic syndrome reached an OR of 12.9, 3.2, 2.67, and 1.92, respectively, as compared to those with non-severe obesity. Conclusion: this definition of severe obesity in childhood favors the identification of children with higher cardiometabolic comorbidity, which allows to focus the efforts of secondary prevention and its most timely treatment.

Resumen Introducción: la obesidad grave ha tenido un mayor aumento que la obesidad no grave en los escolares chilenos durante los últimos años. Desconocemos si el punto de corte actualmente utilizado para definir la obesidad grave (IMC ≥ + 3 DE, curvas OMS-2007) se asocia a un mayor daño biológico en nuestra población pediátrica. Objetivo: describir y comparar el riesgo cardiometabólico en escolares con obesidad grave y no grave. Método: se realizó un análisis secundario de una muestra de 3325 escolares en los que se estudiaron los factores de riesgo cardiometabólico. Se comparó la prevalencia de estos factores en los que presentaban obesidad según fuera esta grave o no, calculándose los OR respectivos. Resultados: de los 589 sujetos con obesidad, con una media de edad de 11,4 ± 0,98 años, el 46 % eran de género femenino y el 11,5 % presentaban obesidad grave, con mayor prevalencia de la mayoría de los factores estudiados y sin diferencias en cuanto a antecedentes parentales de enfermedad crónica u obesidad, educación de los padres y actividad física del niño. Los niños con obesidad grave tenían un mayor riesgo de obesidad central (OR: 12,9), resistencia insulínica (OR: 3,2), HTA (OR: 2,67) y síndrome metabólico (OR:1,92). Conclusión: esta definición de obesidad grave en la niñez favorece la identificación de los niños con mayor comorbilidad cardiometabólica, lo cual permite focalizar los esfuerzos de prevención secundaria y su tratamiento más oportuno.

Background: The statistical significance α = 0.05 is the cut-off point used to decide whether a hypothesis is statistically significant. When p-value is less than 0.05, we reject the null hypothesis. Although this criterion has been used for almost a century to generate new knowledge, there is currently an international discussion about the need to decrease the significance to α = 0.005. Aim: To determine the effects that changing the p value would have on the sample size of different types of studies. Material and Methods: A series of formulas for calculating the sample size of cross-sectional and comparative studies were used to create case scenarios. Results: By changing α = 0.05 to α = 0.005, the sample sizes in cross-sectional studies would double and in comparative studies would increase between 60% and 70%, depending on the statistical power chosen. Conclusions: Considering the sample size implications, the change in the level of significance would have important effects on the Chilean science. The cost of a randomized clinical trial could increase by at least 27% to 32%. This increase could be similar for cross-sectional studies. With an investment of less than 0.4% of gross domestic product in science and technology, national scientific research would become more expensive, distributing the few available resources among fewer projects. This effect should be considered in any discussion about national budget for science and technology.

Abstract: Introduction: Good physical fitness (PF) is related, among many benefits, to functional and structu ral brain changes that favor learning. Objective: To analyze the association between PF and academic performance (AP) in Chilean schoolchildren according to sex, and to determine if the kind of school dependency influences this association. Subjects and Method: Cross-sectional study analyzing po pulation data of 8th-grade students evaluated by the SIMCE-2011 test. The sample included only 13 and 14 years old students, of both sexes, with all PF and AP tests taken. The results of PF and AP tests were categorized as poor, regular, and good. A binary logistic regression was performed explaining a good AP from the PF categories according to sex, and kind of school dependency, adjusting for age, nutritional status, parents’ educational level, and school socioeconomic level. Results: Out of 19,929 records, 12,338 schoolchildren were considered, where 47.9% were female. 33.4% of girls and 49.5% of boys presented good PF, and 16.9% and 21.5% presented good AP respectively. Schoolchildren with good PF had more chances of achieving good AP than those with poor PF (girls 84% and boys 78%, both p < 0.001). Considering the kind of school dependency, good PF in girls attending public schools increased the chances of achieving good AP by 334% (p < 0.001) and in boys attending sub sidized private schools by 91% (p = 0.01). Conclusion: Both girls and boys with good PF have more chances of achieving a good AP. By including the kind of school dependency, the association persists in girls attending public schools and boys attending subsidized private schools.

Resumen: Introducción: Una buena condición física (CF) se relaciona, entre muchos beneficios, a modifica ciones funcionales y estructurales cerebrales que favorecen el aprendizaje. Objetivo: Analizar la aso ciación entre CF y rendimiento académico (RA) en escolares chilenos según sexo y determinar si la dependencia administrativa de la escuela influye en dicha asociación. Sujetos y Método: Estudio transversal sobre datos poblacionales de escolares de 8° básico evaluados por SIMCE-2011. La mues tra incluyó solo escolares de 13 y 14 años, de ambos sexos, con todas las pruebas de CF y RA rendidas. Los resultados de CF y RA fueron categorizados en malo, regular y bueno. Se realizó una regresión logística binaria explicando un buen RA a partir de las categorías de CF según sexo y dependencia administrativa, ajustando por edad, estado nutricional, nivel educacional de los padres y nivel so cioeconómico de la escuela. Resultados: De 19.929 registros se consideraron 12.338 escolares donde 47,9% fueron mujeres. Presentaron buena CF 33,4% de las mujeres y 49,5% de los hombres, y buen RA 16,9% y 21,5%, respectivamente. Escolares con buena CF presentaron más chances de alcanzar buen RA que escolares con mala CF (mujeres: 84% y hombres 78% más; p < 0,001). Considerando la dependencia administrativa, buena CF en mujeres de colegios municipales aumentó las posibilidades en 334% (p < 0,001) y en hombres de colegios particulares subvencionados, en 91% (p = 0,01). Con clusión: Tanto mujeres como hombres con buena CF tienen más posibilidades de alcanzar un buen RA. Al incluir la dependencia administrativa la asociación persiste en mujeres de colegios municipa les y en hombres de colegios particulares subvencionados.

Abstract: Introduction: Spirometry is the most commonly used test to evaluate lung function. Foreign refe rence standards are currently available for preschool children. Objectives: 1. To measure spirometric variables in healthy Chilean preschool children, 2. To compare these results with predictive ones according to GLI (Global Lung Initiative), Eigen (USA) and França (Brazil), and 3. If there is a sig nificant difference with these, to develop reference equations. Subjects and Method: Questionnaires were distributed to parents in several schools and kindergartens in Santiago. Children with a history of prematurity, asthmatic symptoms, chronic lung disease (including asthma), and chronic non respiratory disease were excluded. Spirometry was performed according to ATS/ERS 2007 guideli nes, with MedGraphics equipment, USA. Family and environmental background, weight and height were recorded, as well as values obtained in forced vital capacity (FVC), forced expiratory volume in 0.5, 0.75 and 1 second (FEV0.5, FEV0.75, and FEV1, respectively). Results: 276 spirometries were performed, 202 met acceptability criteria, 112 girls, average age 5.01 ± 0.57 years, height 108.7 ± 5.6 cm. When comparing by gender, there was only a significant difference in FVC, which was higher in boys. The average values obtained in the total group were: FVC 1.22 ± 0.22 liters, FEV1 1.16 ± 0.18 liters, FEV0.75 1.07 ± 0.17 liters. These parameters were higher in percentage than the predictive ones according to GLI, Eigen, and França, except FVC with Eigen, therefore, predictive equations were de veloped. Conclusions: Spirometric values of preschoolers living in Santiago were higher than foreign reference values. We proposed these reference standards to be used in our country.

Resumen: Introducción: La espirometría es el examen más utilizado para evaluar función pulmonar. Para niños pre-escolares actualmente se cuenta con patrones de referencia extranjeros. Objetivos: 1. Medir va riables espirométricas en pre-escolares chilenos sanos, 2. Comparar estos resultados con predictivos según GLI (Global Lung Initiative), Eigen (USA) y França (Brasil) y 3. De haber diferencia signifi cativa con éstos, elaborar ecuaciones de referencia. Sujetos y Método: Se distribuyeron encuestas a apoderados de colegios y jardines infantiles de Santiago. Se excluyeron niños con antecedente de prematurez, síntomas asmáticos, enfermedad pulmonar crónica (incluida asma) y enfermedad cró nica no respiratoria. La espirometría se realizó según guías ATS/ERS 2007, con equipo MedGraphics, USA. Se registraron antecedentes familiares, ambientales, peso y talla y los valores obtenidos en ca pacidad vital forzada (CVF), volumen espirado forzado en 0,5, 0,75 y 1 segundo (VEF 05, VEF0 75 y VEFj, respectivamente). Resultados: Se realizaron 276 espirometrías, de las cuales 202 cumplieron criterios de aceptabilidad, 112 mujeres, edad promedio 5,01 ± 0,57 años, talla 108,7 ± 5,6 cm. Al comparar por género, solo hubo diferencia significativa en CVF, siendo superior en hombres. Los valores promedio obtenidos en el grupo total fueron: CVF 1,22 ± 0,22 litros, VEF1 1,16 ± 0,18 litros, VEF075 1,07 ± 0,17 litros. Nuestros parámetros fueron porcentualmente mayores que los predictivos según GLI, Eigen y França, excepto CVF con Eigen, motivo por el cual se construyeron ecuaciones predictivas. Conclusiones: Los valores espirométricos de pre-escolares residentes en Santiago fueron superiores a los valores de referencia extranjeros. Se proponen patrones de referencia que podrían ser utilizados en nuestro medio.

Background: during recent years consistent studies have characterized the relationship between moderate and severe protein-calorie malnutrition and the appearance of non-communicable diseases in adulthood like metabolic syndrome (MS). Aim: to analyze the relationship between moderate and severe protein-calorie malnutrition during the first 1 000 days of life and the MS in a cohort of adults from Curicó, Chile. Material and methods: we studied 49 young adults who had suffered moderate to severe protein-calorie malnutrition during their first two years of life. Anthropometry, blood pressure measurement and laboratory tests were performed, and the burden of MS attributes was determined. Results: the prevalence of MS was 14.3% with no significant differences by gender, showing a direct and significant association between burden of MS and body mass index, waist / height index, blood pressure, plasma levels of glucose and triglyceride, and an inverse association with HDL. Conclusion: systolic blood pressure and plasma level of triglyceride represented the most important risk factors for SM in this cohort. We found no association between the presence of protein-calorie malnutrition and MS.

Introducción: estudios consistentes durante los últimos años han caracterizado la relación entre la desnutrición calórico-proteica (DCP) y el desarrollo de enfermedades no transmisibles en la adultez, como el Síndrome Metabólico (SM). Objetivo: analizar la relación entre SM en la adultez y la DCP durante los primeros 1.000 días de vida en una cohorte de adultos recientemente generada en Curicó, Chile. Material y métodos: se analizaron 49 sujetos adultos jóvenes que durante sus primeros dos años de vida sufrieron desnutrición calórico-proteica moderada a severa mediante la realización de antropometría, medición de la presión arterial y exámenes de laboratorio. Se determinó la prevalencia del SM y la carga de sus atributos. Resultados: se obtuvo una prevalencia de SM del 14,3% sin diferencias significativas por género, con una asociación directa y notable entre la carga de SM, el índice de masa corporal (IMC), el índice cintura/talla, presión arterial y niveles plasmáticos de glicemia y triglicéridos (TG), y una asociación inversa con colesterol HDL. Conclusión: la presión arterial sistólica y el valor plasmático de TG representaron los factores de riesgo más importantes del SM en esta cohorte. No se encontró asociación entre la DCP en los 1.000 primeros días de vida y el SM en la adultez.

Introduction: Dyslipidemias are a key cardiovascular risk factor, and are increased since early childhood. The objective of this study was to describe the prevalence, characteristics of dyslipidemias and associated factors in a population of Chilean children. Methods: Cross-sectional study done in school-age children from Santiago, Chile (2009-2011). Parents answered questions about family medical history and children answered questions about physical activity. Anthropometry was performed and in a blood sample (12 hours fast) lipid profile, glycemia and insulinemia were measured. Results: We recruited 2900 euglycemic children, 11.4±0.97 years old, 52% girls. According to BMI, 22.5% were overweight and 15,3% had obesity. Considering recommended cut-off points for lipids, 69.3% were in acceptable range, 19.2% at risk and 11.5% at high cardiovascular risk. In total, 32% of the population had any clinical form of dyslipidemia: Isolated hypertriglyceridemia (9.4%), low HDL-C (7.6%), isolated hypercholesterolemia (4.9%), atherogenic dyslipidemia (6.24%) and mixed dyslipidemia (3.9%). Except for isolated hypercholesterolemia, dyslipidemias were more frequent in girls (globally 36.2% vs. 27.4%, p<0.0001). Low HDL-C was associated with sedentary lifestyle. In multiple logistic regression analysis, nutritional status was the most important associated factor, with less influence of age, sex, central obesity, insulin resistance and history of parental cardiovascular risk factors. Conclusions: In this population of Chilean school-age children, we found a high prevalence of dyslipidemia, and the principal determinant was weight excess.

Introducción: Las dislipidemias son un factor de riesgo cardiovascular clave, en aumento ya desde la niñez. El objetivo de este estudio fue describir la prevalencia, tipo de dislipidemias y factores asociados, en una población de niños chilenos. Métodos: Estudio transversal en escolares de Santiago de Chile (2009-2011). Se realizó antropometría, encuesta de antecedentes familiares a los padres y de actividad física a los niños. En muestra sanguínea de ayunas se midió perfil lipídico, glicemia e insulinemia. Resultados: Se reclutaron 2900 escolares de 11,42±0,97 años de edad, 52% mujeres, todos euglicémicos. Según IMC, 22,5% tenía sobrepeso y 15,3% obesidad. Al considerar los límites recomendados para cada lípido, 69,3% se encontraba en rango aceptable, 19,2% en riesgo y 11,5% en alto riesgo cardiovascular. En total, 32% de la población presentó alguna forma clínica de dislipidemia: Hipertrigliceridemia aislada (9,4%), Bajo C-HDL (7,6%), Hipercolesterolemia aislada (4,9%), Dislipidemia aterogénica (6,24%) y Dislipidemia mixta (3,9%). Excepto la hipercolesterolemia aislada, las demás dislipidemias fueron más frecuentes en las niñas (36,2% vs. 27,4%, p<0,0001). El menor C-HDL se asoció al sedentarismo y a la menor frecuencia de actividad física. En regresión logística múltiple, el estado nutricional fue el factor asociado más gravitante, con menor influencia de: edad, sexo, obesidad central, resistencia insulínica y antecedente de factores de riesgo parental cardiovascular. Conclusiones: En esta muestra poblacional de escolares chilenos se encontró una alta prevalencia de dislipidemias asociadas principalmente al exceso de peso.

Background: A tight glycemic control of hospitalized patients increases the risk of hypoglycemia, whose management is not always optimal. Aim: To assess the hypoglycemia management competences of a multidisciplinary team in a clinical hospital. Material and Methods: An anonymous questionnaire about hypoglycemia management was answered by 11 staff physicians, 42 residents and 28 nurses of the department of medicine and critical care unit ofa university hospital. Results: Respondents had a mean of 60% of correct answers, without significant differences between groups. The capillary blood glucose level that defines hypoglycemia was known by most of the respondents, but the value that defines severe episodes was known only by 60%. The initial management and follow up was well known only for severe episodes. Less than 50%o knew the blood glucose value that required continuing with treatment. Conclusions: Although most professionals are able to recognize hypoglycemia, the knowledge about is management if insufficient.

Background: The health associated costs of obesity can represent between 2% and 9% of the total health costs of a given country. Aim: To assess the impact of obesity on health care costs and absenteeism in a cohort of mine workers. Patients and wethods: Prospective study of 4.673 men, employees of a mining company, aged 49 ± 7 years that were followed for 24 ± 11 months. Total health care cost and days of sick leave were recordedfor each individual. The association between obesity and these variables was analyzed by logistic regression adjusting for co-morbidities, age and other variables. Results: Mean annual health care costs for obese workers were 17% higher (p <0.001) compared to workers with normal weight and 58% higher (p <0.001) for workers with severe and morbid obesity. Mean annual days of sick leave increased by 25%o in the obese (p =0.002) and by 57%o in subjects with severe and morbid obesity (p <0.001). For health care costs the most significant predictors were: presence of diabetes mellitus (Odds ratio (OR) 6.21, 95%o confidence intervals (95% CI) 4.9 to 7.9), hypertension (OR 3-99; 95% CI3-4 to 4.6) and severe and morbid obesity (OR 2.55, 95%o CI 1.9 to 3-4). For absenteeism the most significant predictors were: presence of diabetes mellitus (OR 1.58, 95%> CI 1.2 to 2.0), hypertension (OR 1,34, 95%> CI 1.2 to 1.6) and severe and morbid obesity (OR 1.50, 95%o CI 1.1 to 2.1). Conclusions: Obesity increases significantly health care costs and absenteeism.

OBJECTIVE: For Chilean teenage mothers under 15 years old and from 15 to 19 years old, to evaluate the trends in birth rates and reproductive risk for the period of 19901999. METHODS: A database was constructed using data from the Demography Yearbook (Anuario de demografía) volumes published by Chile's National Institute of Statistics (Instituto Nacional de Estadísticas) for 19901999. From that database we calculated the trends in the number of live births and in the rates of maternal mortality, late fetal mortality, neonatal mortality, and infant mortality among the teenage mothers under 15 and from 15 to 19 years old. We calculated the risk odds ratio (OR) for both of those age groups in comparison with women from 20 to 34 years old. The groups were compared using Fisher's exact test or the chi-square test, and the analysis of trends in the period studied was carried out with Pearson's correlation, with an alpha level of 0.05. RESULTS: In the period studied, for the teenage mothers under age 15, the respective rates for maternal mortality, late fetal mortality, neonatal mortality, and infant mortality were 41.9 per 100 000 live births, 5.1 per 1 000 live births, 15.2 per 1 000 live births, and 27.4 per 1 000 live births. For the adolescents from 15 to 19 years, the corresponding rates were 19.3, 4.1, 8.1, and 16.6; for the women 2034 years old, they were 26.8, 5.0, 6.7, and 12.1. The adolescents under 15 had higher risks of maternal mortality (OR = 1.56; 95% confidence interval (CI): 0.50 to 4.31; P = 0.372) and of fetal mortality (OR = 1.02; 95% CI: 0.76 to 1.36; P = 0.890), but those differences were not statistically significant. However, the younger adolescents did have significantly higher risks of neonatal mortality (OR = 2.27; 95% CI: 1.922.68; P < 0.0001) and of infant mortality (OR = 2.39; 95% CI: 2.04 to 2.62; P < 0.0001). In comparison to the women 2034 years old, the teenage mothers from 15 to 19 years old had significantly lower risks of maternal mortality (OR = 0.72; 95% CI: 0.56 to 0.92; P < 0.008) and of fetal mortality (OR = 0.81; 95% CI: 0.77 to 0.86; P < 0.0001) but significantly higher risks of neonatal mortality (OR = 1.20; 95% CI: 1.16 to 1.25; P < 0.0001) and of infant mortality (OR = 1.38; 95% CI: 1.35 to 1.42; P < 0.0001). Among both the older teenage mothers and the mothers 2034 years old there was a significant downward trend in maternal, fetal, neonatal, and infant mortality rates in the period studied; in the younger adolescents only neonatal mortality and infant mortality declined significantly. There was a rising trend in the number of live births among the two groups of teenage mothers, but that trend was statistically significant only for the mothers under 15; among mothers 2034 years old there was a statistically significant downward trend. CONCLUSIONS: In the period studied, the Chilean teenage mothers faced greater reproductive risk than did the women 2034 years old. The number of live births among teenage mothers tended to rise during the 19901999 period, but the change was significant only for the mothers under age 15. These results point to the need to develop programs that improve both sex education and birth control practices starting in early adolescence.

OBJETIVOS: Evaluar en madres adolescentes chilenas menores de 15 años y de 15 a 19 años las tendencias de la natalidad y del riesgo reproductivo en el período de 19901999. MÉTODOS: Sobre la base de datos extraídos de los Anuarios de demografía publicados por el Instituto Nacional de Estadísticas de Chile para 19901999, se calcularon las tendencias mostradas por el número de nacidos vivos y las tasas de mortalidad materna, fetal tardía, neonatal e infantil entre madres adolescentes menores de 15 años y de 15 a 19 años de edad. Se calculó el riesgo (razón de posibilidades, RP) de ambos grupos en comparación con el de mujeres de 20 a 34 años de edad. La comparación entre grupos se efectuó mediante la prueba de Fisher o de ji2, según el caso, y el análisis de tendencias en el período estudiado se realizó mediante la correlación de Pearson con un nivel alfa de 0,05. RESULTADOS: En el período estudiado, las tasas de mortalidad materna, fetal tardía, neonatal e infantil en madres adolescentes menores de 15 años fueron, respectivamente, de 41,9 (por 100 000 nacidos vivos [NV]), 5,1 (por 1 000 NV), 15,2 (por 1 000 NV) y 27,4 (por 1 000 NV); en adolescentes de 15 a 19 años, de 19,3, 4,1, 8,1 por 1 000 y 16,6, respectivamente, mientras que en adultas de 20 a 34 años dichas tasas fueron de 26,8, 5,0, 6,7 y 12,1, respectivamente. En las adolescentes menores de 15 años el mayor riesgo de muerte materna (RP = 1,56; IC95%: 0,50 a 4,31; P = 0,372) y de muerte fetal (RP = 1,02; IC95%: 0,76 a 1,36; P = 0,890) no fue estadísticamente significativo; en cambio, sí se detectó un riesgo significativamente mayor de muerte neonatal (RP = 2,27; IC95%: 1,92 a 2,68; P <0,0001) y el de muerte infantil (RP = 2,39; IC95%: 2,04 a 2,62; P <0,0001). Entre las madres adolescentes de 15 a 19 años, el riesgo de muerte materna (RP = 0,72; IC95%: 0,56 a 0,92; P <0,008) y el de muerte fetal (RP = 0,81; IC95%: 0,77 a 0,86; P <0,0001) fueron inferiores en grado significativo en comparación con los del grupo testigo, mientras que el riesgo de muerte neonatal (RP = 1,20; IC95%: 1,16 a 1,25; P <0,0001) y el de muerte infantil (RP = 1,38; IC95%: 1,35 a 1,42; P <0,0001) fueron significativamente superiores. Tanto en las madres adolescentes mayores como en las del grupo testigo se observó una tendencia descendente significativa de la mortalidad materna, fetal, neonatal e infantil en el período estudiado; en las adolescentes menores solo la mortalidad neonatal y la mortalidad infantil descendieron significativamente. También se observó una tendencia ascendente del número de nacidos vivos entre los dos grupos de madres adolescentes, pero dicha tendencia fue significativa solamente entre las menores de 15 años, mientras que en el grupo testigo se observó una tendencia descendente estadísticamente significativa. CONCLUSIONES: Los resultados confirman que, en el período estudiado, las madres adolescentes chilenas tuvieron riesgos reproductivos elevados en comparación con las mujeres de 20 a 34 años y que el número de nacidos vivos de madres adolescentes mostró una tendencia ascendente durante el período, pero de un modo significativo solamente en las menores de 15 años. Los resultados apuntan a la necesidad de crear programas que permitan mejorar la educación sexual y la regulación de la fecundidad desde la adolescencia temprana.