ABSTRACT Objectives: To validate the homeostasis model assessment (HOMA) of insulin resistance (IR) as a surrogate to the hyperglycemic clamp to measure IR in both pubertal and postpubertal adolescents, and determine the HOMA-IR cutoff values for detecting IR in both pubertal stages. Subjects and methods: The study sample comprised 80 adolescents of both sexes (aged 10-18 years; 37 pubertal), in which IR was assessed with the HOMA-IR and the hyperglycemic clamp. Results: In the multivariable linear regression analysis, adjusted for sex, age, and waist circumference, the HOMA-IR was independently and negatively associated with the clamp-derived insulin sensitivity index in both pubertal (unstandardized coefficient – B = −0.087, 95% confidence interval [CI] = −0.135 to −0.040) and postpubertal (B = −0.101, 95% CI, −0.145 to −0.058) adolescents. Bland-Altman plots showed agreement between the predicted insulin sensitivity index and measured clamp-derived insulin sensitivity index in both pubertal stages (mean = −0.00 for pubertal and postpubertal); all P > 0.05. The HOMA-IR showed a good discriminatory power for detecting IR with an area under the receiver operator characteristic curve of 0.870 (95% CI, 0.718-0.957) in pubertal and 0.861 (95% CI, 0.721-0.947) in postpubertal adolescents; all P < 0.001. The optimal cutoff values of the HOMA-IR for detecting IR were > 3.22 (sensitivity, 85.7; 95% CI, 57.2-98.2; specificity, 82.6; 95% CI, 61.2-95.0) for pubertal and > 2.91 (sensitivity, 63.6; 95% CI, 30.8-89.1, specificity, 93.7; 95%CI, 79.2-99.2) for postpubertal adolescents. Conclusion: The threshold value of the HOMA-IR for identifying insulin resistance was > 3.22 for pubertal and > 2.91 for postpubertal adolescents.

SUMMARY OBJECTIVE: To analyze the use of a mobile physical activity application and its influence on body composition and sleep quality in overweight children. METHODS: Prospective study with 37 patients from the Child and Adolescent Obesity Clinic at Unicamp Hospital das Clínicas, between 2018 and 2019. Anamnesis and anthropometry were performed. We oriented the use of the application for six weeks, five days/week for ten minutes. RESULTS: Among 37 patients, 28 (mean age 10.7±2.0 years, 50% boys) used the application. The average use of the application ranged from 1.93±2.18 to 3.25±1.84 times/week, with a peak in the second week and a progressive decrease during follow-up. The paired t-test showed, on average, lean mass (t (27)=-2.91), weight (t (27)=-3.11) and height (t (27)=-3.79). After using the application, these were higher than before (all p<0.05). There was a significant difference in the proportion of children who presented difficulty sleeping (χ2 (1)=5.143) and insomnia (χ2 (1)=4.167). CONCLUSIONS: There was an improvement in sleep quality and an increase in lean mass, but no significant changes in BMI z-score, waist circumference, and body fat percentage.

OBJETIVO: Avaliar a correlação da circunferência do pescoço com resistência à insulina e com os componentes da síndrome metabólica em adolescentes com diferentes níveis de adiposidade e estadios puberais, bem como determinar a utilidade da circunferência do pescoço como um parâmetro na predição de resistência à insulina em adolescentes.MÉTODOS:Estudo transversal no qual se avaliaram 388 adolescentes de ambos os sexos, de dez a 19 anos. Os adolescentes foram submetidos à avaliação antropométrica e de composição corporal, incluindo circunferências do pescoço e da cintura, e a avaliação bioquímica. O estadio puberal foi obtido por meio de autoavaliação e a pressão arterial, pelo método auscultatório. Analisou-se a resistência à insulina pelo Homeostasis Model Assessment-Insulin Resistance. A correlação entre duas variáveis foi verificada com o coeficiente de correlação parcial ajustado para o percentual de gordura corporal e o estadio puberal. O desempenho da circunferência do pescoço para identificar resistência à insulina foi testado pela Receiver Operating Characteristic Curve.RESULTADOS: Após ajuste para o percentual de gordura corporal e estadio puberal, a circunferência do pescoço correlacionou-se com circunferência da cintura, pressão arterial, triglicérides e marcadores de resistência à insulina em ambos os sexos.CONCLUSÕES:Os resultados demonstraram que a circunferência do pescoço é uma ferramenta útil para detectar a resistência à insulina e a alteração nos indicadores de síndrome metabólica em adolescentes. A facilidade de aplicação e o baixo custo podem viabilizar sua utilização em serviços de Saúde Pública.

OBJECTIVE: To evaluate the correlation between neck circumference and insulin resistance and components of metabolic syndrome in adolescents with different adiposity levels and pubertal stages, as well as to determine the usefulness of neck circumference to predict insulin resistance in adolescents.METHODS:Cross-sectional study with 388 adolescents of both genders from ten to 19 years old. The adolescents underwent anthropometric and body composition assessment, including neck and waist circumferences, and biochemical evaluation. The pubertal stage was obtained by self-assessment, and the blood pressure, by auscultation. Insulin resistance was evaluated by the Homeostasis Model Assessment-Insulin Resistance. The correlation between two variables was evaluated by partial correlation coefficient adjusted for the percentage of body fat and pubertal stage. The performance of neck circumference to identify insulin resistance was tested by Receiver Operating Characteristic Curve.RESULTS: After the adjustment for percentage body fat and pubertal stage, neck circumference correlated with waist circumference, blood pressure, triglycerides and markers of insulin resistance in both genders.CONCLUSIONS: The results showed that the neck circumference is a useful tool for the detection of insulin resistance and changes in the indicators of metabolic syndrome in adolescents. The easiness of application and low cost of this measure may allow its use in Public Health services.

OBJETIVO:Evaluar la correlación de la circunferencia del cuello con resistencia a la insulina y con los componentes del síndrome metabólico en adolescentes con distintos niveles de adiposidad y estadios puberales, así como determinar la utilidad de la circunferencia del cuello como un parámetro en la predicción de resistencia a la insulina en adolescentes.MÉTODOS: Estudio transversal en el que se evaluó a 388 adolescentes de ambos sexos, de los 10 a los 19 años. Los adolescentes fueron sometidos a evaluación antropométrica y de composición corporal, incluyendo circunferencias del cuello y de la cintura, y la evaluación bioquímica. El estadio puberal se obtuvo mediante autoevaluación y la presión arterial, por el método de ausculta. Se evaluó la resistencia a la insulina por el Homeostasis Model Assessment-Insulin Resistence. La correlación entre dos variables fue evaluada con el coeficiente de corrrelación parcial ajustado para el porcentaje de grasa corporal y el estadio puberal. El desempeño de la circunferencia del cuello para identificar resistencia a la insulina fue evaluado por la Receiver Operating Characteristic Curve y se consideró p<0,05.RESULTADOS: Después del ajuste para el porcentaje de grasa corporal y estadio puberal, la circunferencia del cuello se correlacionó con la circunferencia de la cintura, presión arterial, triglicéridos y marcadores de resistencia a la insulina en ambos sexos.CONCLUSIONES: Los resultados demostraron que la circunferencia del cuello es una herramienta útil para detectar la resistencia a la insulina y la alteración en los indicadores de síndrome metabólico en adolescentes. La facilidad de aplicación y el bajo costo pueden hacer su uso viable en servicios de Salud Pública.