Calidad de medición en investigación científica en contexto de gran altitud: a nivel atómico análisis estudio de interlaboratorios, oxido de deuterio por FTIR ­ 2021 / Quality of measurement in scientific research in a high-altitude context: at the atomic level interlaboratory study analysis, deuterium oxide by FTIR ­ 2021

Se presenta conceptos del saber hacer investigación científica asociada a la calidad de las mediciones, y dentro de ella sobre la calidad intrínseca de la medición de variables, dirigida a dos condiciones de la misma: la precisión y exactitud. Se describe formas de evaluación de la precisión como ser el coeficiente de variación y el error técnico de las mediciones. Por otro lado se describe formas de evaluación de la exactitud como son la regresión linear y el puntaje Z. También se sugieren y se describen las acciones y las herramientas para mejorar tanto la precisión como la exactitud. El análisis de agua enriquecida con oxido de deuterio, es una temática que fue tomada en cuenta por la Agencia Internacional de Energía Atómica (IAEA), Viena, Austria, en la gestión 2021, y se organizó una actividad mediante el "Estudio de Interlaboratorios, Oxido de Deuterio por FTIR ­ 2021". El propósito fue asegurar la calidad integral en la capacidad construida en el uso de técnicas de isotopos estables para la evaluación del estado de salud y nutricional. Así mismo, evaluar la calidad de medición de la exactitud relativa sobre el enriquecimiento del agua con óxido de deuterio en 43 laboratorios a nivel internacional, grupo en cual se incluyó al Laboratorio de Biología Atómica (LABA) de la Unidad de Crecimiento y Desarrollo (UCREDE). Se utilizó la regresión linear y el puntaje Z para evaluar la exactitud. Se concluye que los resultados demostraron un muy buen rendimiento en exactitud relativa con los equipos FTIR que midieron el enriquecimiento de deuterio en muestras de agua.

Concepts of knowing how to do scientific research associated with the quality of measurements are presented, and within it on the intrinsic quality of the measurement of variables, aimed at two conditions of the same: precision and accuracy. Forms of precision evaluation are described, such as the coefficient of variation and the technical error of the measurements. On the other hand, forms of accuracy evaluation are described, such as linear regression and Z-score. Actions and tools to improve both precision and accuracy are also suggested and described. The analysis of water enriched with deuterium oxide is a topic that was taken into account by the International Atomic Energy Agency (IAEA), Vienna, Austria, in the 2021 management, and an activity was organized through the Interlaboratory Study, Deuterium Oxide by FTIR ­ 2021. The purpose was to ensure comprehensive quality in the capacity built in the use of stable isotope techniques for the evaluation of health and nutritional status. Likewise, to evaluate the quality of measurement of the relative accuracy of the enrichment of water with deuterium oxide in 43 laboratories at the international level, a group that included the Atomic Biology Laboratory (LABA) of the Growth and Development Unit (UCREDE ). Linear regression and Z-score were used to assess accuracy. It is concluded that the results demonstrated a very good performance in relative accuracy with the FTIR equipment that measured deuterium enrichment in water samples.

Nutritional status in children with cancer: comparison of deuterium oxide dilution with bioelectric impedance analysis and anthropometry / Estado nutricional em crianças com câncer: comparação entre diluição de deutério, impedância bioelétrica e antropometria

ABSTRACT Objective: To explore changes in the nutritional status of pediatric cancer patients before and after chemotherapy and evaluate the correlation between deuterium oxide dilution, bioelectric impedance analysis, and anthropometry for assessment of body composition. Methods: This study included 14 children (aged 5.6 to 13.6 years) and classified them as having hematologic or solid tumors. They had their body composition analyzed according to deuterium oxide, bioelectric impedance, and anthropometric measurements before the first chemotherapy cycle and after three and six months of therapy. Results: The patients in the hematologic tumor group had an increase in weight, height, body mass index, waist, hip, and arm circumference, subscapular skinfold thickness, and fat mass with the isotope dilution technique during chemotherapy. In the solid tumor group, the children showed a reduction in fat-free mass when assessed by bioimpedance analysis. We found a positive correlation between the triceps skinfold thickness and fat mass determined by bioimpedance analysis and deuterium oxide. The arm muscle circumference correlated with the fat-free mass estimated by bioimpedance analysis and deuterium oxide. Conclusions: Patients with hematologic tumors had an increase in body weight, height, and fat mass, which was not identified in the solid tumor group. The positive correlation between anthropometry (triceps skinfold thickness and arm muscle circumference), deuterium oxide dilution, and bioelectric impedance analysis shows the applicability of anthropometry in clinical practice.

RESUMO Objetivo: Verificar mudanças no estado nutricional de crianças com câncer antes e após o tratamento quimioterápico e avaliar a correlação entre diluição de óxido de deutério, análise de impedância bioelétrica (BIA) e dados antropométricos. Métodos: Quatorze crianças (entre 5,6 e 13,6 anos de idade) foram incluídas e classificadas como tendo tumores hematológicos ou sólidos. A composição corporal foi medida pelo óxido de deutério, impedância bioelétrica e medidas antropométricas antes da primeira quimioterapia e após três e seis meses de terapia. Resultados: Os pacientes do grupo de tumores hematológicos aumentaram o peso, a estatura, o índice de massa corporal, a circunferência da cintura, quadril e braço, dobra cutânea subescapular e a massa gorda com a técnica de diluição isotópica durante o tratamento quimioterápico. No grupo de tumores sólidos, as crianças mostraram uma redução na massa magra quando avaliadas por análise de impedância. Houve uma correlação positiva entre a dobra cutânea tricipital e a massa gorda determinadas pela análise de impedância e pelo óxido de deutério. A circunferência muscular do braço correlacionou-se com a massa magra estimada pela análise de impedância e pelo óxido de deutério. Conclusões: Pacientes com tumores hematológicos tiveram aumento no peso corporal, estatura e massa gorda, o que não foi observado naqueles com tumores sólidos. A boa correlação entre a antropometria (dobra cutânea tricipital e circunferência muscular do braço), a diluição do óxido de deutério e a análise da impedância bioelétrica mostra a aplicabilidade da antropometria na prática clínica.

Validez del porcentaje de grasa corporal por pliegues cutáneos comparado con la dilución de óxido de deuterio en escolares costarricenses / Validity of percent body fat by skinfold thickness comparated with deuterium oxide dilution in Costa Rican school children

El objetivo del estudio fue determinar la validez del porcentaje de grasa corporal (% GC) estimado por la ecuación de Slaughter en escolares costarricenses. Participaron 54 niños y 49 niñas con una edad promedio 7.8 ± 1.0 años. El óxido de deuterio (D2O) fue el método de referencia para determinar la masa grasa (FM) expresada como % GC. Se utilizó un análisis de regresión lineal y prueba t para determinar la asociación y las diferencias entre el %GC por la ecuación de Slaughter y D2O. La concordancia entre métodos se determinó por el coeficiente de correlación de concordancia (CCC) de Lin. La medición de acuerdo entre los métodos se analizó mediante el procedimiento de Bland-Altman. El % GC entre métodos fue significativamente diferente en niños (26.3 ± 7.4% vs 22.4 ± 7.0%) y niñas (33.2 ± 5.7% vs 26.1 ± 5.7%). La asociación entre métodos no fue significativa en niños (R2 = 0.76, p <0.0001) y niñas (R2 = 0.24, p <0.0001). Los gráficos de Bland-Altman mostraron que la ecuación de Slaughter subestimó el % GC en 6,0% en niños y 3,5% en niñas, en comparación con D2O. El CCC de Lin identificó una fuerza de concordancia pobre entre métodos, niños ρc= 0.87 y niñas ρc= 0.56. Con los resultados se concluye que la ecuación de Slaughter registró baja concordancia del % GC en comparación con el D2O en escolares costarricenses(AU)

The aim of the study was to determine the validity of the body fat percentage (% GC) estimated by the Slaughter equation in Costa Rican school children. The sample consisted of 54 male and 49 female, mean age 7.8 ± 1.0 years. Deuterium oxide dilution (D2O) was the reference method to determine the fat mass (FM) expressed as BF%. Linear regression analyses and paired sample t-tests were used to test association and mean differences between Slaughter equation and D2O BF%. Concordance between Slaughter equation and D2O BF% was determined by Lin's concordance correlation coefficient (CCC). Measurement of agreement between the two methods was analyzed using the Bland-Altman procedure. Measurements of BF% by Slaughter equation and D2O were significantly different for boys (26.3 ± 7.4% vs 22.4 ± 7.0%) and for girls (33.2 ± 5.7% vs 26.1 ± 5.7%). Non-significant association between methods was found in males (R2 = 0.76, p <0.0001) and females (R2 = 0.24, p <0.0001). Bland-Altman plots showed that Slaughter equation underestimated the %BF in a 6.0% for boys and in a 3.5% for girls compared with D2O. Lin's CCC identified poor strength of concordance between the two methods, for boys ρc= 0.87 and for girls ρc= 0.56. With the results we conclude that the Slaughter equation registered low agreement of BF% compared against the one obtained by D2O in Costa Rican school children(AU)

Deuterium oxide dilution and body composition in overweight and obese schoolchildren aged 6-9 years / Diluição do óxido de deutério e composição corporal em escolares de seis a nove anos com sobrepeso e obesidade

ABSTRACT OBJECTIVE: To correlate different methods of body composition assessment in overweight or obese schoolchildren, using deuterium oxide (D2O) dilution as a reference. METHODS: Percentage of total body water (%TBW), fat free mass (%FFM), and body fat (%BF) were assessed by D2O and tetrapolar electrical bioimpedance analysis (BIA) in 54 obese and overweight students aged 6-9 years. Skinfold thickness (ST), body mass index (BMI), conicity index (CI), waist circumference (WC), waist-to-height ratio (WHtR), and waist-to-hip (WHR) ratio were also used. RESULTS: Mean values for body composition were 38.4% ± 8.4% BF, 44.9% ± 6.1% TBW and 61.6% ± 8.4% FFM. There was no significant difference in body weight, body fat mass (FM), TBW, and FFM between genders. Regarding D2O, ST underestimated %BF, and overestimated %FFM in both genders (p < 0.05). BIA overestimated %TBW in the group as a whole and in males (p < 0.05). The only positive and strong correlations occurred in females regarding the WC (s= 0.679), CI (r = 0.634), and WHtR (r = 0.666). CONCLUSIONS: In this sample of obese and overweight children, there were strong correlations between body composition measured by D2O and some indices and anthropometric indicators in females, but there was no positive and strong correlation of fat tissue with the indices/indicators at all ages and in both genders.

RESUMO OBJETIVO: Correlacionar diferentes métodos para avaliação de composição corporal em escolares diagnosticados com sobrepeso e obesos com o uso como referência da diluição de óxido de deutério (D2O). MÉTODOS: O percentual de água corporal total (%ACT), massa livre de gordura (%MLG) e gordura corporal (%GC) foi obtido pelo D2O e pela bioimpedância elétrica tetrapolar (BIA), em 54 estudantes com sobrepeso e obesos, entre seis-nove anos. O método das dobras cutâneas (DC) com o uso de triciptal e panturrilha, índice de massa corporal (IMC), índice de conicidade (IC), circunferência de cintura (CC), relação cintura/estatura (RCE) e relação cintura/quadril (RCQ) também foi usado. RESULTADOS: Os valores médios para composição corporal aferidos pelo D2O foram 38,4 ± 8,4%GC, 44,9 ± 6,1%ACT e 61,6 ± 8,4%MLG. Não houve diferença significativa entre peso corporal, massa corporal de gordura (MG), ACT e MLG entre os sexos. Considerando o D2O, DC subestimou o %GC e superestimou o %MLG em ambos os sexos (p < 0,05); BIA superestimou %ACT no grupo como um todo e no masculino (p < 0,05). As únicas correlações fortes e positivas ocorreram no grupo feminino nas variáveis CC (s = 0,679), IC (r = 0,634) e RCE (r = 0,666). CONCLUSÕES: Nessa amostra de crianças obesas e com sobrepeso, houve fortes correlações entre a composição corporal mensurada pelo D2O e alguns índices e indicadores antropométricos nas meninas, mas nenhuma correlação forte e positiva do tecido adiposo foi encontrada com os índices/indicadores em todas as idades e ambos os sexos.

Use and records of child health handbook focused on growth and development / Uso y llenado de la libreta de salud infantil con el foco en el crecimiento y el desarrollo / Uso e preenchimento da caderneta de saúde da criança com foco no crescimento e desenvolvimento

Objective To evaluate the use and records of the Child Health Handbook (CHH), especially growth and development. Method Cross-sectional study with 358 mother-child pairs registered in 12 Primary Health Centers (PHCs) of a small municipality. Mothers were interviewed at the PHC from February to April 2013 using a questionnaire. Data analysis was done using WHO Anthro software, Epi InfoTM and Stata. Results Fifty-three percent of the mothers were carrying the CHH at the time of the interview, similar to the proportion of mothers who were instructed to bring the CHH to health appointments. Annotations in the CHH during the visits were reported by 49%. The vaccination schedule was completed in 97% of the CHH, but only 9% and 8% of the CHH, respectively, contained growth charts and properly completed developmental milestones. Conclusion Low rates of use and unsatisfactory record-keeping in the CHH reinforce the need for investment in professional training and community awareness for the CHH to become an effective instrument of promotion of child health. .

Objetivo Evaluar el uso y llenado de la Libreta de Salud Infantil (LSI), especialmente el crecimiento y el desarrollo. Método Estudio transversal con 358 pares de madres e hijos matriculados en 12 Unidades Básicas de Salud (UBS) de una ciudad pequeña. Las madres fueron entrevistadas en el UBS desde febrero a abril 2013 mediante un cuestionario. Se utilizó Epi-info y software SPSS. Resultados 53% de las madres estaban llevando LSI durante la entrevista, proporción similar a las madres que recibieron instrucciones para llevar el LSI a la atención de la salud. Anotaciones en LSI durante las visitas se registraron en un 49%. Calendario de vacunas fue completa en el 97% de LSI, pero sólo el 9% y el 8% de LSI tenido, respectivamente, las curvas de crecimiento y desarrollos debidamente cumplimentados. Conclusión El uso y el relleno satisfactorio de LSI refuerzan la necesidad de inversión en la formación profesional y el acercamiento a la comunidad para la LSI se convierte efectivamente en un instrumento de promoción de la salud infantil.
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Objetivo Avaliar uso e preenchimento da Caderneta de Saúde da Criança (CSC), especialmente crescimento e desenvolvimento. Método Estudo transversal com 358 pares mãe-criança atendidos em 12 Unidades Básicas de Saúde (UBS) de município de pequeno porte. As mães foram entrevistadas nas UBS, de fevereiro a abril de 2013, com o uso de questionário. Utilizou-se softwares Epi-info e Stata. Resultados No momento da entrevista, 53% das mães portavam a CSC, proporção similar à de mães que referiram orientação para levar a CSC aos atendimentos de saúde. Anotações na CSC durante os atendimentos foram referidos por 49%. Esquema vacinal estava completo em 97% das CSC, mas apenas 9% e 8% das CSC tinham, respectivamente, gráficos de crescimento e desenvolvimento adequadamente preenchidos. Conclusão O uso e o preenchimento insatisfatório da CSC reforçam a necessidade de investimentos na capacitação dos profissionais e na sensibilização da comunidade para que a CSC se torne efetivamente um instrumento de promoção da saúde infantil. .

Body composition measures of obese adolescents by the deuterium oxide dilution method and by bioelectrical impedance

The objectives of the present study were to describe and compare the body composition variables determined by bioelectrical impedance (BIA) and the deuterium dilution method (DDM), to identify possible correlations and agreement between the two methods, and to construct a linear regression model including anthropometric measures. Obese adolescents were evaluated by anthropometric measures, and body composition was assessed by BIA and DDM. Forty obese adolescents were included in the study. Comparison of the mean values for the following variables: fat body mass (FM; kg), fat-free mass (FFM; kg), and total body water (TBW; percent) determined by DDM and by BIA revealed significant differences. BIA overestimated FFM and TBW and underestimated FM. When compared with data provided by DDM, the BIA data presented a significant correlation with FFM (r = 0.89; P < 0.001), FM (r = 0.93; P < 0.001) and TBW (r = 0.62; P < 0.001). The Bland-Altman plot showed no agreement for FFM, FM or TBW between data provided by BIA and DDM. The linear regression models proposed in our study with respect to FFM, FM, and TBW were well adjusted. FFM obtained by DDM = 0.842 x FFM obtained by BIA. FM obtained by DDM = 0.855 x FM obtained by BIA + 0.152 x weight (kg). TBW obtained by DDM = 0.813 x TBW obtained by BIA. The body composition results of obese adolescents determined by DDM can be predicted by using the measures provided by BIA through a regression equation.

Evaluación del consumo de leche humana por dilución con deuterio y detección por espectroscopia de infrarrojo / Assessment of human milk consumption by dilution with deuterium and detection by infrared spectroscopy

Objetivo. Adaptar la metodología de evaluación de ingestión de leche humana con isótopos estables utilizando un espectroscopio infrarrojo en lugar de un espectrómetro de masas. Material y métodos. Previo consentimiento informado, 12 mujeres que estaban amamantando recibieron 30 g de D2O por vía oral. a las 4 horas y 1, 3, 6, 9 y 14 días depués de la dosificación, se les tomó una muestra de saliva. Las muestras de saliva de los bebés se tomaron a los 1,2,5,6,13 y 14 días. Todas las muestras fueron preparadas por sublimación y centrifucación y la determinación de la concentración de D2O se determinó por espectroscopía de infrarrojo. Resultados. La recuperación del sistema de sublimación fue superior al 95 por ciento del volumen total tanto de agua sola como de saliva. Se encontró que con tres evaluaciones se alcanza la misma confiabilidad que con 5 evaluaciones. Los volúmenes de ingestión de leche humana fueron similares a los informados por otros autores