Usefulness of Peptide C during the oral glucose tolerance test to evaluate insulin resistance in pediatric patients

La Diabetes Mellitus tipo 2 es un trastorno metabólico, poligénico y multifactorial en el que se dan dos hechos fundamentales: la insulinoresistencia (IR) y la disfunción de la célula ß pancreática. Comofactor pre-coz en la historia natural de la diabetes, hasta 10 años antes de observarse laprimera hiperglucemia en ayunas, se han descripto fallas del pico precoz de insulina pos-tprandiala los 30 minutos de administrada la sobrecar-ga. El péptido C se libera en cantidades equimolecula-res con la insulina, por lo que la medición del mismo es una representación fidedigna de la función de la célula ß pancreática. Los inmunoensayos para la determinación de insulina presentan alta variabilidad, tanto que se ha considerado controvertida su utilidad. El péptido C tiene menor variabilidad metodológica, haciendo más repro-ducible y simple la interpretación de los resultados. Objetivos: evaluar la reproducibilidad de las determi-naciones de insulina y péptido C en dos plataformas comerciales, y establecer la utilidad de la medición de péptido C durante la prueba de tolerancia oral a la glu-cosa (PTOG) como una herramienta sencilla y confiable para la valoración de insulinorresistencia en pacientes pediátricos

Prevalence of abdominal obesity in Spanish children and adolescents. Do we need waist circumference measurements in pediatric practice?

BACKGROUND: Evidence indicates that central adiposity has increased to a higher degree than general adiposity in children and adolescents in recent decades. However, waist circumference is not a routine measurement in clinical practice. OBJECTIVE: This study aimed to determine the prevalence of abdominal obesity based on waist circumferences (WC) and waist to height ratio (WHtR) in Spanish children and adolescents aged 6 to 17 years. Further, the prevalence of abdominal obesity (AO) among normal and overweight individuals was analyzed. DESIGN: Data were obtained from a study conducted from 1998 to 2000 in a representative national sample of 1521 children and adolescents aged 6 to 17 years (50.0% female) in Spain. WC and WHtR measurements were obtained in addition to BMI. AO was defined as WHtR ≥0.50 (WHtR-AO), sex and age specific WC≥90(th) percentile (WC-AO1), and sex and age specific WC cut-off values associated with high trunk fat measured by by dual-energy X-ray absorptiometry (WC-AO2). RESULTS: IOTF- based overweight and obsity prevalence was 21.5% and 6.6% in children and 17.4% and 5.2% in adolescents, respectively. Abdominal obesity (AO) was defined as WHtR≥0.50 (WHtR-AO), sex- and age-specific WC≥90th percentile (WC-AO1), and sex- and age-specific WC cut-off values associated with high trunk fat measured by dual-energy X-ray absorptiometry (WC-AO2). The respective prevalence of WHtR-AO, WC-AO1, and WC-AO2 was 21.3% (24.6% boys; 17.9% girls), 9.4% (9.1% boys; 9.7% girls), and 26.8% (30.6% boys;22.9% girls) in children and 14.3% (20.0% boys; 8.7% girls), 9.6% (9.8% boys; 9.5% girls), and 21.1% (28.8% boys; 13.7% girls) in adolescents. CONCLUSION: The prevalence of AO in Spanish children and adolescents is of concern. The high proportion of AO observed in young patients who are normal weight or overweight indicates a need to include waist circumference measurements in routine clinical practice.This work was supported by grants from Instituto de Salud Carlos III-FEDER, (PI11/01900), the Spanish Ministry of Health [RED: Alimentación saludable en la prevención primaria de enfermedades crónicas: la Red Predimed, one of the Redes Temáticas de Investigación Cooperativa Sanitaria (RETICs)] Fundación Dieta Mediterránea, Spain; and Kellogg’s España SA and Kellogg’s Company, Battle Creek, USA via the Fundación Universitaria de Las Palmas de Gran Canaria and the Fundación para la Investigación Nutricional and by a joint contract (Miguel Servet CP03/00115) with the Instituto de Salud Carlos III and the Health Department of the Catalan Government (Generalitat de Catalunya). The CIBERESP and the CIBEROBN and the RETIC Predimed are initiatives of the Instituto de Salud Carlos III, Madrid, Spai