Predictive Utility of Anthropometric Based Cut-offs in Assessing Excess Adiposity among Preschool Children in a Multiethnic Population

ABSTRACT Objective: Screening for childhood obesity is a necessary step in developing appropriate and effective interventions. We evaluated the diagnostic performance of various recommended international anthropometric cut-offs based on body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), triceps skinfold (TSF), and mid-upper arm circumference (MUAC) in predicting excess adiposity (body fat ≥ 25%) in a random sample of Trinidadian preschoolers. Methods: After obtaining written parental consent, weight, height, WC, TSF, and MUAC were measured in 596 children using standard procedures. These were used to calculate BMI for age, WHtR, TSF-for-age z-scores, and MUAC-for-age z-scores. Percentage body fat was measured using a Tanita-531 foot-to-foot bioelectrical impedance analyser (BIA). Sensitivities, specificities and area under the receiver-operating curve analysis and predictive values were then computed in reference to BIA estimates. Results: The prevalence of excess adiposity was 12.2% and 5.1% among males and females, respectively. Sensitivities for the various cut-offs ranged from 20.0% to 75.0% and 57.1% to 96.9% among males and females, respectively. WHO-BMI recommended cut-offs and those based on MUAC z-scores had significantly higher sensitivities in females than in males. TSF z-scores had significantly lower sensitivities compared to those based on BMI and WHtR among males. Similarly, specificities ranged from 81.3% to 99.9% and 79.8% to 99.9% among males and females, respectively. In girls, cut-offs based on TSF z-scores had a higher likelihood ratio than cut-offs from Centers for Disease Control, International Obesity Task Force and WHtR. Diagnostic performance was not associated with ethnicity. Conclusion: Our results suggest that diagnostic performance was associated with gender and the cut-offs used; however, it was not associated with ethnicity.

An evaluation of the diagnostic utility of anthropometric and body composition cut-off values in assessing elevated fasting blood sugar and blood pressure / Evaluación de la utilidad diagnóstica de los valores límites de composición corporal y antropométrica a la hora de evaluar la glucosa alta en ayunas y la presión sanguínea

OBJECTIVE: High blood pressure and diabetes mellitus account for over 50% of annual visits to health facilities in Trinidad and Tobago. This study investigates the ability of various absolute and relative body composition variables to predict elevated fasting blood sugar (FBS) and blood pressure (BP). SUBJECTS AND METHODS: Participants had overnight fasting finger-stick blood glucose analysed with a hand-held automated glucometer (Basic One-touch Ultra). Two blood pressure tests were taken on the right arm after ten minutes of rest in the sitting position using an automated blood pressure (Omron HEM 712C). Participation in the study was voluntary. Waist, height and weight circumferences were measured using standard procedure. Percentage body fat (%BF) was measured with a foot-to-foot bioelectric body fat analyser (Tanita UM026). RESULTS: One hundred and fifty-seven persons (90 females and 67 males) participated in the investigation. Approximately 23% of participants had BP, FBS and waist circumference levels that were above recommended cut-offs. In correlation, analyses controlling for ethnicity and age-adjusted FBS were significantly positively correlated with waist circumference, BMI, weight, fat mass and %BF. Receiver-operator curve analyses suggest that cut-offvalues based on BMI, waist circumference and waist-height ratio were significant predictors of elevated FBS among females while those based on waist circumference and %BF were significant predictors of elevated FBS among males. CONCLUSION: The findings suggest similar predictive ability among the various absolute and relative body composition measures in predicting FBS and BP.

OBJETIVO: La presión arterial alta y diabetes mellitus constituyen la causa de más de 50% de visitas anuales a los centros de salud en Trinidad y Tobago. Este estudio investiga la capacidad de varias variables de composición corporal absolutas y relativas para predecir la glucosa en sangre en ayunas (GSA) y la presión arterial (PA) altas. SUJETOS Y MÉTODOS: Se analizó la glucosa en sangre de los participantes tras una noche en ayunas mediante punción de la yema del dedo usando un glucómetro automático portable (Basic One Touch Ultra). Se hicieron dos tests de presión arterial en el brazo derecho luego de diez minutos de reposo en posición sentada, usando un monitor de presión arterial de inflado automático Omron HEM-712C. La participación en el estudio fue voluntaria. Las circunferencias de cintura, altura y peso fueron medidas usando procedimientos estándar. Se midió el índice de grasa corporal (IGC) mediante un monitor Tanita UM026 para el análisis bioeléctrico de grasa corporal de pie a pie. RESULTADOS: Ciento cincuenta y siete personas (90 hembras y 67 varones) participaron en la investigación. Aproximadamente 23% de los participantes tenían PA, GSA, y niveles de circunferencia de cintura por encima de los límites recomendados. En la correlación, los análisis que controlan la etnicidad, y la GSA ajustada por edad, guardaron una correlación significativamente positiva con la circunferencia de cintura, el IMC, el peso, la masa grasa y el IGC. Los análisis de la curva receptoroperador sugieren que los valores límites basados en el IMC, la circunferencia de cintura y el índice cintura/altura fueron predictores significativos de GSA elevada entre las hembras, en tanto que los basados en la circunferencia de cintura y el IGC fueron predictores significativos de GSA elevada entre los varones. CONCLUSIÓN: Los hallazgos sugieren una capacidad predictiva similar entre las diversas medidas de composición corporal absoluta y relativa a la hora de predecir la GSA y la PA.

Body image perception and the risk of unhealthy behaviours among University students / La percepción de la Imagen corporal y el riesgo de conductas malsanas entre los estudiantes Universitarios

BACKGROUND: In this study, we sought to determine whether dissatisfaction with one's body was associated with unhealthy behaviours among University students. SUBJECTIS AND MEHOTDS: A cross-section of 383 male and female students recruited from the general University population completed a questionnaire consisting of socio-demographic items, Eating Attitudes Test (EATS-26), Body Shape Questionnaire (BSQ-16), Body Silhouette Chart, Rosenberg Self-Esteem Scale (RSE) and the Centre for Epidemiologic Studies depression scale (CES-D). RESULTS: Overall, 4.2% of participants reported to have been diagnosed with an eating problem. Females had significantly higher EATS-26, BSQ-16 and RSE scores than males. They were significantly more likely than males to choose silhouettes that were underweight to represent their current or desired body sizes and to engage in dieting behaviours. Additionally, persons who reported being diagnosed with an eating disorder were significantly more likely than those not diagnosed to report binging, bulimic and other eating-related behaviours (p < 0.01). For both males and females, perceived body image was significantly and positively associated with BSQ-16, EATS-26, and CES-D and inversely associated with RSE scores. Females of African-descent were significantly more likely than those of East Indian descent and other ethnic groups to report higher weights and to select larger silhouettes to represent their current body figure. CONCLUSIONS: Among participants, body dissatisfaction was associated with increased risk for depression, lower self-esteem, disordered eating and other weight related behaviours.

ANTECEDENTES: En este estudio, buscamos determinar si la insatisfacción con el propio cuerpo se hallaba asociada con conductas malsanas entre los estudiantes universitarios. SUJETOS Y MÉTODOS: Una sección transversal de 383 estudiantes - hembras y varones - reclutados de la población universitaria general, respondieron un cuestionario sobre información socio-demográfica, el Test de Actitudes hacia la Comida (EATS-26), el Cuestionario sobre la Forma Corporal (BSQ-16), la Gráfica de Silueta Corporal, la Escala de Autoestima de Rosenberg (RSE), y la Escala de Depresión del Centro de Estudios Epidemiológicos (CES-D). RESULTADOS: En general, 4.2% de los participantes reportó que se le habían diagnosticado algún problema de hábito de ingestión. Las mujeres tenían puntuaciones de EATS-26, BSQ-16 y RSE significativamente más altas que los hombres. Asimismo presentaban una tendencia significativamente mayor que los hombres, a escoger figuras corporales de bajo peso, a la hora de representar las dimensiones corporales que tenían o deseaban, o establecer comportamientos dietéticos. Además, las personas que reportaron haber sido diagnosticadas con algún trastorno alimentario, presentaron una tendencia significativamente mayor que las no diagnosticadas de ese modo, a reportar hiperfagia, bulimia y otros comportamientos relacionados con la ingestión (p < 0.01). Tanto para los hombres como para las mujeres, la percepción de la imagen corporal estuvo significativamente y positivamente asociada con las puntuaciones de BSQ-16, EATS-26, y CES-D e inversamente asociada con las puntuaciones del RSE. Las mujeres de ascendencia africana presentaron una tendencia significativamente más alta que las de ascendencia indoriental y otras razas, a reportar pesos más altos y a elegir siluetas más grandes a la hora de presentar su figura corporal actual. CONCLUSIONES: Entre los participantes, la insatisfacción corporal estuvo asociada con el aumento del riesgo de depresión, baja autoestima, trastornos alimentarios y otras conductas relaciones con el peso.