Association between plasma leptin/adiponectin ratio and insulin resistance indexes in prepubertal children

ABSTRACT Objective: To assess the association between leptin/adiponectin ratio (LAR) and insulin resistance surrogates in prepubertal children. Subjects and methods: Study based on data from the Growth and Obesity Chilean Cohort Study (GOCS) involving 968 Chilean prepubertal children. Plasma insulin, leptin, and adiponectin were determined by immunoassays. Several common insulin resistance surrogates were calculated, including the homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride/HDL cholesterol index, triglyceride-glucose (TyG) index, and the TyG index corrected for body mass index (BMI; TyG-BMI) and waist circumference (WC; TyG-WC). Associations among variables were assessed using multiple linear and logistic regression analysis. Results: There was a significant direct association between plasma leptin and LAR with BMI z-score but no association between plasma adiponectin and adiposity. After adjustments for sex and age, LAR was significantly associated with all insulin resistance surrogates (which were categorized using the 75th percentile as the cutoff point), with the TyG-WC index emerging as the surrogate with the highest magnitude of association (odds ratio [OR] 2.44, 95% confidence interval [CI] 2.05-2.9). After additional adjustment for BMI z-score, only the association between LAR and TyG-WC remained significant (OR 1.64, 95% CI 1.27-2.12). Conclusion: Plasma leptin and LAR were strongly associated with several common insulin resistance surrogates in prepubertal children, most notably with the TyG-WC index. Associations between LAR and insulin resistance indexes were mainly driven by the effect of plasma leptin, which is also directly associated with increased adiposity.

Impact of the change of the Atalah standard cut-off point to classify underweight nutritional status during pregnancy

ABSTRACT Chile, and several Latin American countries, use the Atalah standard to assess nutritional status during pregnancy. However, this standard (underweight: pre-pregnancy body mass index (BMI)<20 kg/m2 and normal weight: pre-pregnancy BMI= 20-24.9 kg/m2) differ from those recommended by the US Institute of Medicine (IOM2009) (underweight: BMI<18.5 kg/m2 and normal weight: 18.5-24.9 kg/m2). Using a large population database from a Chilean public hospital, we compared the prevalence of underweight and normal weight at the beginning of pregnancy with Atalah and IOM2009 standards. Additionally, we evaluated the performance of both standards in detecting adverse neonatal outcomes and gestational weight gain. Methods: Data from clinical records of single birth pregnancies (n= 59,476) at the Sótero del Río Hospital, between 2003-2012 were collected. We compared 1. nutritional status, 2. proportion of excessive gestational weight gain, 3. association between nutritional status and neonatal outcomes (large/small for gestational age, low birth weight, preterm birth and macrosomia), using logistic regression models, and 4. Sensitivity, specificity, and predictive values to predict adverse neonatal outcomes per nutritional status. Results: Pre-pregnancy underweight decreased from 8.6% to 2.5% and women with BMI between 18.5-19.9kg/m2, who exceeded the recommended gestational weight gain increased from 32.7% to 49.2% when using IOM2009 instead of Atalah. Both standards showed low sensitivity, but the IOM2009 cut-off points showed better specificity for identifying healthy newborns. Conclusion: The cut-off points recommended by the IOM2009 better identify the prevalence of underweight and normal weight during pregnancy without increasing neonatal risk. This study supports the recent change of the Ministry of Health in adopting the WHO cut-off points during pregnancy.

RESUMEN Chile y diversos países Latinoaméricanos utilizan el estándar de Atalah para evaluar el estado nutricional (EN) durante el embarazo. Sin embargo, los puntos de corte de este estándar (bajo peso, BP: índice de masa corporal pre-gestacional (IMC)<20 kg/m2 y normal, NP: IMC pregestacional= 20-24,9 kg/m2) difieren de los recomendados por el Instituto de Medicina de EE.UU. (IOM2009) (BP: BMI<18.5kg/m2 and NP: 18,5-24,9 kg/m2). Con datos obtenidos desde el Hospital Sótero del Río, nosotros evaluamos la prevalencia de BP y NP al comienzo del embarazo con los estándares de Atalah e IOM2009. Adicionalmente, nosotros comparamos el comportamiento de ambos estándares en detectar resultados neonatales (RN) adversos y en la clasificación de la ganancia de peso gestacional (GPG). Métodos: Se obtuvieron datos de embarazos simples entre 2003-2012, (n= 59.476). Nosotros comparamos: 1. Prevalencia de EN, 2. Proporción de excesiva GPG, 3. Asociación entre EN y RN, usando modelos de regresión logística, y 4. Sensibilidad, especificidad y valores predictivos para predecir RN según EN. Resultados: La prevalencia de BP pregestacional disminuyó de 8,6% a 2,5% y las mujeres con IMC entre 18,5-19,9 kg/m2 que excedieron la GPG recomendada, incrementaron desde 33% a 50% cuando se utilizó el estándar IOM2009 en vez de Atalah. Ambos estándares mostraron baja sensibilidad, pero IOM2009 mostró mejor especificidad para identificar recién nacidos saludables. Conclusión: Estandar IOM2009 identifica con mayor precisión la prevalencia de BP y NP durante la gestación sin incrementar el riesgo neonatal. Este estudio respalda el reciente cambio del MINSAL al adoptar los puntos de corte de la OMS durante el embarazo.

Asociación entre el índice de masa corporal y la talla desde el nacimiento hasta los 5 años en preescolares chilenos / Association between body mass index (BMI) and height from birth to 5 years in Chilean preschool children

Background: It has been shown that excess weight gain during childhood is associated with a greater risk of obesity; this relationship may be mediated by growth in height. Aim: To quantify the associations between z scores for body mass index (BMIZ) and height for age (HAZ) from birth to 5 years of age and to assess how this association varies according to age and adiposity. Material and Methods: Weight and height were recorded at 11 occasions from birth on a cohort of1089 Chilean five year-old children with a birth weight > 2500 g. BMI, BMIZ, HAZ and prevalence of obesity were calculated. We determined the cross-sectional association between BMIZ and HAZ for the total sample and by 3 BMI Z categories, using Pearson correlation. We determined the probability of obesity according to four HAZ categories. Results: Obesity increased continuously reaching approximately 16 percent at 5 years. Stunting was virtually nonexistent. No association between BMIZ and HAZ was observed at birth, while at 1 and 2 months, leaner infants had lower stature. No association between theseparameters was observed between 6-24 months, while after 3 years, a clear relationship was observed. Conclusions: The probability of a preschool child of being obese is less than 10 percent with a HAZ is < 0. Nevertheless, children with heights above the median (even within the normal range) have an increased risk of obesity, especially after 3 y of age. Between 0-5 years, the relationship between weight and height varies by age and adiposity.

Evolución del estado nutricional de niños chilenos desde la etapa preescolar a la escolar: Resultados antropométricos según procedencia de las mediciones / Evolution of the nutritional status of Chilean children from preschool to school age: Anthropometric results according to the source of the data

Como los resultados del estado nutricional que entregan instituciones chilenas que recolectan datos antropométricos de su población bajo control, muestran diferentes magnitudes en el incremento del porcentaje de obesidad entre preescolares de 4 años y escolares de 1er grado, quisimos verificar la real magnitud de este aumento. Este estudio se basó en una investigación longitudinal que comenzó el 2006 con 1100 niños de 3 años, evaluados por el INTA a los 4, 5 y 6 años. Se determinó el estado nutricional a esas edades según Z IMC y referencias OMS 2006/2007. La información recogida sirvió además, para determinar la concordancia entre los datos antropométricos recogidos por profesores de escuelas públicas en escolares de 1er grado el 2009 (base JUNAEB) y los mismos niños evaluados paralelamente por el INTA (base INTA). La muestra incluyó a 474 niños de 6 años. No se observaron diferencias entre los promedios de Z IMC y Z talla/edad. El grado de concordancia entre los Z IMC fue bueno (rho= 0,73), sin embargo hubo diferencias en la clasificación nutricional, ya que el porcentaje de bajo peso fue significativamente mayor en la base JUNAEB (9,5% vs 3,6% ), mientras que el porcentaje de obesidad fue menor en la base INTA, 17,5% vs 19,2% (diferencia no significativo). A los 4 y 5 años los porcentajes de obesidad de estos niños fueron 13,3% y 15,7% respectivamente (datos INTA). Por la trayectoria observada, es más probable que el alza en el porcentaje de obesidad entre los 4 y 6 años fue de 4 puntos porcentuales y no de 6, tal como indican los datos INTA.

Because the results of the nutritional status released by Chilean institutions which collect anthropometric data on their population under control, show different increments in the prevalence of obesity between preschoolers and children in 1st grade, we decided to verify the real magnitude of this increase. This study is based on a longitudinal investigation which began in 2006 and included 1100, three-year old children, which we evaluated when they were 4, 5 and 6 y. The nutritional status was determined according to BMI Z and WHO References 2006 / 2007. The information was also used to determine the concordance between the anthropometric data collected on first graders by teachers from public schools in 2009 (JUNAEB data set) and the same children assessed in parallel by INTA (INTA data set). The sample included 474, six-year olds. No differences were found between the average BMI Z and HAZ of the two data sets, and the degree of concordance between the BMI Z´s was good (rho = 0.73), however there were differences in the nutritional status, since the prevalence of low weight was significantly greater when assessed with JUNAEB´s data (9.5% vs 3.6% ), while that for obesity was lower with INTA´s data, 17.5% vs. 19.2% (not significantly different). At 4 and 5 y, obesity prevalence of the children was 13.3% and 15.7% respectively (INTA´s data). Considering the observed nutritional trajectory, it is likely that the rise in obesity between 4 and 6 y of age, was 4 percentage points and not 6, as was determined with INTA´s data.

Estado nutricional de preescolares asistentes a la junta nacional de jardines infantiles de Chile: evaluación de la concordancia entre indicadores antropométricos de obesidad y obesidad central / Nutritional status of preschool children attending the Chilean national nursery schools council programs (JUNJI): assessment of the agreement among anthropometric indicators of obesity and central obesity

Históricamente, el monitoreo nutricional de los programas de ayuda nutricional infantil ha utilizado indicadores de peso-edad y talla-edad para detectar deficiencias nutricionales. Recientemente, dado el aumento de la obesidad infantil se ha recomendado también incorporar mediciones de peso-talla y de circunferencia de cintura. Sin embargo, en preescolares no está claro cuál es el grado de concordancia existente entre estos indicadores. Los objetivos de este artículo son: reportar el estado nutricional de niños beneficiarios de la Junta Nacional de Jardines Infantiles de Chile y evaluar la concordancia entre medidas antropométricas de obesidad general y obesidad central en este grupo. En 574 niñas y 580 niños entre 3,0 y 5,9 años de edad se midió peso, talla, circunferencia de cintura y de cadera y 5 pliegues. Los puntajes Z se estimaron según los estándares de crecimiento OMS 2006. Se definió obesidad general como Z P/T ó Z IMC/E ≥+ 2DE y obesidad central como circunferencia de cintura ≥ percentil 90 para el sexo y la edad según NHANES III. La prevalencia de obesidad fue cercana al 16 por ciento con ambos indicadores, mientras que la de obesidad central fue 15 por ciento. La concordancia entre indicadores antropométricos de obesidad general y central fue buena (Kappa entre 0,6 y 0,7). En conclusión, en niños beneficiarios de un programa de ayuda social chileno se encontró una alta prevalencia de obesidad y obesidad central. En este grupo, existe una buena concordancia entre indicadores antropométricos de obesidad general y obesidad central, lo que sugiere que no se justificaría la incorporación de mediciones de circunferencia de cintura al monitoreo nutricional del programa.

Historically, the anthropometric assessment of nutritional welfare programs has been targeted to assess nutritional deficiencies based on weight-to-age and height-to-age indicators. Recently, given the increase on childhood obesity, it has been also recommended the measurement of indicators of obesity (i.e. weight-to-height) and central obesity (i.e. waist circumference). However, the agreement of these indicators in preschool children is unclear. The aims of this study were: 1) assess the nutritional status of children attending the Chilean National Nursery Schools Council Program (JUNJI); 2) assess the agreement between general and central obesity anthropometric measurements in these children. In 574 girls and 580 boys, 3.0 to 5.9 years old, we measured: weight, height, waist and hip circumference, and five skinfolds. We used the WHO 2006 growth standards to estimate Z-scores. We defined general obesity as WHZ or BAZ= 2, and central obesity as waist circumference ≥ 90 percentile of NHANES III. The participants were on average slightly shorter but considerably heavier and obese than the reference populations. Prevalence of general obesity was close to 16 percent with both indicators while prevalence of central obesity reached 15 percent. There was good agreement among general obesity indicators and central obesity indicators (Kappa = 0.6-0.7). In summary, we found a high prevalence of obesity and central obesity among Chilean preschool children beneficiaries of a welfare program. At this age, there was a good agreement among general obesity indicators and central obesity indicators. These results suggest that waist circumferences measurements should not be incorporated to the program.