ABSTRACT
OBJECTIVES: To study differences in resting energy expenditure (REE) according to its determining factors (sex, weight, body fat mass, lean body mass) and in the oxidation of energy substrates in obese and non-obese children. PATIENTS AND METHODS: We studied 71 children (39 obese and 32 non-obese) aged from 4.1 to 13.6 years. The male/female ratio was 34/37. Energy expenditure (EE) was measured by using open circuit indirect calorimetry. The oxidation of energy substrates was calculated from oxygen consumption, carbon dioxide production, and urinary nitrogen excretion from urea. Body composition was determined by anthropometry. RESULTS: REE (kcal/day), adjusted for anthropometric parameters and body composition, was higher in boys than in girls. The absolute REE was significantly higher in obese than in non-obese children (1512.82 6 234.47 vs 1172.59 6 190.20) and was higher or the same when adjusted for its determinants. Compared with the non-obese group, the obese group presented a significantly higher percentage of fat oxidation (57.15 6 10.68 vs 51.08 6 13.61, p 5 0.04), a lower percentage of carbohydrate oxidation (30.10 6 9.85 vs 36.34 6 13.61, p 5 0.03) and a lower respiratory quotient (0.79 6 0.03 vs 0.82 6 0.04, p 5 0.02). No differences were found between male and female subjects in the percentages of carbohydrate, fat, and protein oxidation. CONCLUSIONS: We obtained the followings conclusions: a) When adjusted for anthropometric measurements and body composition, REE was significantly higher in boys than in girls; b) REE was higher in obese than in non-obese children, after adjustment for lean body mass; and c) Compared with the control group, obese children presented a higher percentage of fat oxidation, a lower percentage of carbohydrate oxidation, and a lower respiratory quotient.
Subject(s)
Energy Metabolism , Obesity/metabolism , Adolescent , Anthropometry , Basal Metabolism , Body Composition , Child , Child, Preschool , Female , Humans , MaleABSTRACT
Objetivos Estudiar las diferencias en el gasto energético en reposo (GER) en función de sus determinantes (sexo, peso, masa grasa, masa magra) y la oxidación de los sustratos energéticos entre niños obesos y no obesos. Pacientes y métodos Se ha estudiado una muestra de 71 niños, 39 obesos y 32 controles, con rango de edad entre 4,1 y 13,6 años, de los cuales 37 eran mujeres y 34 varones, a los que se realiza medida del gasto energético mediante calorimetría indirecta de circuito abierto. La oxidación de sustratos se calculó a partir del consumo de oxígeno, producción de anhídrido carbónico y excreción de nitrógeno ureico urinario. Se determinó la composición corporal por antropometría. Resultados El GER (kcal/día) ajustado en función de los parámetros antropométricos y de composición corporal es superior en niños que en niñas. El GER en valor absoluto es significativamente superior en los obesos (1.512,82 234,47 frente a 1.172,59 190,20), y al expresarlo en función de sus determinantes, sigue siendo mayor en los obesos o se iguala en ambos grupos. Los obesos presentan mayor porcentaje de oxidación de grasas (57,15 10,68 frente a 51,08 13,61; p 0,04), menor porcentaje de oxidación de hidratos de carbono (30,10 9,85 frente a 36,34 13,61; p 0,03) y menor cociente respiratorio (0,79 0,03 frente a 0,82 0,04; p 0,02). No existen diferencias en los porcentajes de oxidación de hidratos de carbono, grasas y proteínas según el sexo. Conclusiones Del estudio se han extraído las siguientes conclusiones: a) el GER ajustado en función de los parámetros antropométricos y de composición corporal es significativamente superior en el sexo masculino que en el femenino; b) el GER es superior en los obesos, y sigue siéndolo al estandarizarlo en función de la masa corporal magra, y c) los niños obesos presentan mayor porcentaje de oxidación de grasas, menor porcentaje de oxidación de hidratos de carbono y un cociente respiratorio menor que los niños no obesos. (AU)
Subject(s)
Child, Preschool , Child , Adolescent , Male , Female , Humans , Energy Metabolism , Obesity , Anthropometry , Body Composition , Basal MetabolismABSTRACT
UNLABELLED: Idiopathic short stature is a common pediatric problem that has a heterogeneous nature and an unknown outcome concerning adult height (AH). OBJECTIVE: The main objective of this study was to assess the spontaneous adult height and the influence of several pre and post pubertal predictors over AH. The secondary objective was to create an historical control group to compare these patients with others that had been treated with growth-promoting therapies. PATIENTS AND METHODS: A prospective observational study was made with prepubertal male patients who consulted for short stature before 1986 until they reached AH. They did not receive any treatment. The data are shown as mean and standard deviation. Student's paired t test was used for comparison of groups. Predictive and descriptive models over final height were performed with multivariant analysis. A "p" value of less than 0.05 was considered statistically significant. RESULTS: Data of 42 children was analyzed. Mean age was 10.8 (2.2) years. The standard deviation score (SDS) for adult height spontaneously increased in 0.37 +/- 0.24 (p < 0.05), but it was under target height by 0.59 +/- 0.26 (p = 0.05). Main predictors of AH were: initial height, prognosis of AH and initial age (R2 = 0.58). Final height was no different between children with familial or non-familial short stature. CONCLUSIONS: This group of children had a mean loss of 4 cms below their target height. These children may be considered as an historical control group to evaluate the treatment with growth-promoting therapies.
