Optimal Cut-off Points of Fasting and Post-Glucose Stimulus Surrogates of Insulin Resistance as Predictors of Metabolic Syndrome in Adolescents According to Several Definitions

OBJECTIVE: The aim of this study was to determine optimal cut-off points for fasting and post-glucose stimulus surrogates of insulin resistance to predict metabolic syndrome in adolescents according to several definitions. METHODS: One hundred fifty-five adolescents living in Mexico City were enrolled during 2011 and 2012. Waist circumference and blood pressure were recorded. Subjects received an oral glucose load of 1.75 g per kg up to a maximum dose of 75 g. Blood samples were drawn at baseline and 120 minutes. Concentrations of plasma glucose, triglycerides, high-density lipoprotein cholesterol and insulin were determined. RESULTS: The frequency of metabolic syndrome showed a large variability when using a variety of published definitions; in contrast, the optimal cut-off points for fasting insulin, homeostatic model assessment of insulin resistance and two-hour oral glucose tolerance test insulin were very similar in almost all the definitions considered and had adequate diagnostic performance: area under the curve >0.869, sensitivity >0.835 and specificity >0.755. Insulin resistance surrogates had substantial agreements with Ford, Cook and Salas definitions (Kappa~0.62; agreement~82%); moderate agreement was observed for International Diabetes Federation, Cruz and Ferranti definitions (Kappa~0.41­0.59; agreement~77%). CONCLUSION: Insulin resistance surrogates may be a better approach for metabolic syndrome assessment in an adolescent population because of reduced variability and a higher predictive value.

[Emerging and reemerging diseases]. / Enfermedades emergentes y reemergentes.

Emerging and reemerging diseases are the result of the interaction of multiple factors, such as social determinants of health, climate change, and conditions that prevail and are identifiable in some populations. As a consequence, there may be situations that by their nature are defined as a health emergency, impacting directly on the health of a population, either because they are not known or due to their rapid spread, resulting in a health security problem. Examples of these diseases are described in this article, starting with their origin, their impact on the population, and the response necessary in order to contain or prevent damage of a greater magnitude. The presence of these agents and their consequent damage to the population should lead efforts towards comprehensive prevention and appropriate containment strategies to ensure the protection of public health. Endeavors should be directed not only to a specific agent, but rather to factors that determine their reemergence, such as Ebola, or their permanence, such as the binomial infection of tuberculosis-AIDS. In order to correctly implement strategies, training and availability of supplies play a crucial role in facing the challenges that lie ahead.