Validation of anthropometric and bioelectrical impedance analysis (BIA) equations to predict total body water in a group of Cameroonian preschool children using deuterium dilution method

BACKGROUND: Little information is available on the validity of anthropometry or impedance-based equations for prediction of total body water (TBW) in African children. This study was designed to validate and develop equations to predict total body water in Cameroonian children. METHODS: TBW was measured by deuterium dilution in 102 children between 24 and 60 months of age and compared with the ones predicted by 5 anthropometric and 7 BIA equations. Multiple linear regression analysis was used to develop prediction equations for TBW from anthropometric parameters. RESULTS: Unacceptable discrepancies in the estimates of TBW at individual level were noted with all the equations tested. The following new anthropometry and BIA equations for the estimation of TBW were respectively developed: TBW = 6.488 + 0.434 × sex−0.039 × age + 0.670 × weight−0.081 × MUAC (cm)−0.372 × BMI (adjustedR2= 0.71,RMSE = 3.6), and TBW =−6.206 + 0.0037 × height2/Z−0.041 × age + 0.265 × weight + 0.1214 × height (adjustedR2=0.68, RMSE = 1.4). The cross-validation procedures revealed that the predicted values of TBW compared with measured values are accurate at a group level. CONCLUSION: The current published anthropometric and BIA equations are invalid for the estimation of TBW in Cameroonian preschool children. The newly developed anthropometry or BIA prediction equations are valid for use in Cameroonian children aged 24­60 months

Dilución isotópica con deuterio para determinar ingesta de leche humana y composición corporal materna / Deuterium-oxide turnover technique to assess breast milk intake and maternal body composition / Diluição isotópica com deutério para determinar a ingestão de leite humano e a composição corporal materna

El objetivo del trabajo fue describir la aplicación de la técnica de dilución isotópica con deuterio de dosis a la madre para determinar la ingesta de leche materna y la composición corporal de las madres, en distintos tipos de lactancia. El método analítico se aplicó en cuatro casos modelo de pares madre-lactante en los cuales las madres recibieron una dosis oral de agua deuterada, recolectándose 6 muestras de saliva de ambos durante 15 días. El enriquecimiento de deuterio se determinó en un espectrómetro FTIR-Shimadzu-Affinity obteniéndose la ingesta de leche materna (ILM) y de agua de otras fuentes (Fd). Se observó una variación del enriquecimiento de deuterio en la saliva del lactante, asociada al tipo de lactancia recibida, siendo mayor en el caso de lactancia materna exclusiva (LME). Asimismo, a medida que aumentó Fd, disminuyó ILM. Además, fueron determinadas el agua corporal, la masa libre de grasa y la masa grasa materna. La transferencia de las habilidades técnicas y del conocimiento a través de metodologías innovadoras para determinar la ingesta de leche materna es de utilidad como herramienta de evaluación de la alimentación del lactante y para investigar en qué medida la lactancia natural es reemplazada por la ingesta de otros alimentos. Mejorar la estimación de la LME contribuye al conocimiento de la recomendación de OMS y UNICEF de mantener la misma hasta el sexto mes de vida.

The aim of this study was to describe the application of the dose-to-the-mother deuterium-oxide turnover technique to determine the breast milk intake and body composition of mothers in different types of breastfeeding. This analytical method was performed in four mother-infant pairs at 4 months from birth. Mothers received an oral dose of deuterated water, collecting 6 samples of saliva from mother and baby during a period of 15 days. Deuterium enrichment was determined in a Shimadzu FTIR-spectrometer-Affinity to obtain the intake of breast milk and water from non-breast milk sources. In this study, a variation of the enrichment of deuterium in the saliva of the infant was observed, being higher when the infant was exclusively breastfed. As non-breast milk water increased, the intake of human milk decreased. Furthermore, maternal total body water, fat free mass and fat mass were determined. To improve technical skills and knowledge through innovative methods of breast milk measurement can be useful as an assessment tool for evaluating infant feeding and investigating the extent to which breast milk is being replaced by the consumption of other foods in order to estimate exclusive breastfeeding in the future. This would contribute to the knowledge of maintaining breastfeeding until the sixth month of life, as it is recommended by WHO and UNICEF.

O objetivo deste estudo foi descrever a aplicação da técnica de diluição isotópica com deutério de dose à mãe para determinar a ingestão de leite materno e a composição corporal das mães, em diferentes tipos de aleitamento. O método analítico foi aplicado em quatro casos modelo de pares mães-lactante nos quais as mães receberam uma dose oral de água deuterada, coletando-se 6 amostras de saliva de ambos (mães e lactantes) durante 15 días. O enriquecimento de deutério foi determinado em um espectrômetro FTIR-Shimadzu-Affinity, sendo obtida a ingestão de leite materno (ILM) e de água proveniente de outras fontes (Fd). Observou-se uma variação do enriquecimento de deutério na saliva do lactante, associada ao tipo de aleitamento recebido, sendo maior no caso de aleitamento materno exclusivo (AME). Também, na medida que aumentou Fd, diminuiu ILM. Além disso, a água corporal, a massa livre de gordura y a massa gorda materna foram determinadas. A transferência das habilidades técnicas e do conhecimento através de metodologias inovadoras para determinar a ingestão de leite materno é de utilidade como ferramenta de avaliação da alimentação do lactante e para investigar em que medida o aleitamento natural é substituído pela ingestão de outros alimentos. Melhorar a avaliação do AME contribui ao conhecimento da recomendação da OMS e UNICEF de manter a mesma até o sexto mês de vida.

Utilidad de las técnicas nucleares en nutrición: evaluación de la masa grasa corporal y de la ingesta de leche materna / Nuclear techniques in nutrition: assessment of body fat and intake of human milk in breast-fed infants

Las técnicas nucleares aplicables al área de nutrición son inocuas dado que utilizan isótopos estables. En particular, la dilución isotópica con deuterio evalúa la composición corporal y la ingesta de leche materna. Es un método de referencia para conocer grasa corporal y validar herramientas de bajo costo debido a su exactitud, facilidad de aplicación y por la base de antecedentes de su utilización en adultos y niños. Es no invasiva ya que utiliza saliva como muestra de análisis, lo que la hace aplicable a poblaciones pediátricas. Modificaciones en la grasa se asocian a enfermedades no transmisibles y existen individuos con peso normal pero mayor depósito de grasa. Por ello, es de utilidad analizar sus cambios como instrumento de evaluación en clínica y en programas de salud. Además, esta técnica es la forma exacta de determinar si los lactantes son amamantados exclusivamente mediante seno materno, establecer lactancia materna exclusiva y validar métodos convencionales basados en encuestas a las madres.

The application of nuclear techniques in the area of nutrition is safe because they use stable isotopes. The deuterium dilution method is used in body composition and human milk intake analysis. It is a reference method for body fat and validates inexpensive tools because of its accuracy, simplicity of application in individuals and population and the background of its usefulness in adults and children as an evaluation tool in clinical and health programs. It is a non-invasive technique as it uses saliva, which facilitates the assessment in pediatric populations. Changes in body fat are associated with non-communicable diseases; moreover, normal weight individuals with high fat deposition were reported. Furthermore, this technique is the only accurate way to determine whether infants are exclusively breast-fed and validate conventional methods based on surveys to mothers.