OBJECTIVE: To describe lung function findings in overweight children and adolescents without respiratory disease. METHODS: This was a cross-sectional study involving male and female overweight children and adolescents in the 8-18 year age bracket, without respiratory disease. All of the participants underwent anthropometric assessment, chest X-ray, pulse oximetry, spirometry, and lung volume measurements. Individuals with respiratory disease were excluded, as were those who were smokers, those with abnormal chest X-rays, and those with an SpO2 = 92%. Waist circumference was measured in centimeters. The body mass index-for-age Z score for boys and girls was used in order to classify the individuals as overweight, obese, or severely obese. Lung function variables were expressed in percentage of the predicted value and were correlated with the anthropometric indices.RESULTS: We included 59 individuals (30 males and 29 females). The mean age was 11.7 ± 2.7 years. Lung function was normal in 21 individuals (35.6%). Of the 38 remaining individuals, 19 (32.2%), 15 (25.4%), and 4 (6.7%) presented with obstructive, restrictive, and mixed ventilatory disorder, respectively. The bronchodilator response was positive in 15 individuals (25.4%), and TLC measurements revealed that all of the individuals with reduced VC had restrictive ventilatory disorder. There were significant negative correlations between the anthropometric indices and the Tiffeneau index in the individuals with mixed ventilatory disorder. CONCLUSIONS:Lung function was abnormal in approximately 65% of the individuals evaluated here, all of whom were overweight. Obstructive ventilatory disorder and positive bronchodilator response predominated.

Notably, this study found a high prevalence of glucose and insulin disorders in asymptomatic obese children and adolescents.

Key words:Non-alcoholic fatty liver disease. Fatty liver. Obesity. Palabras clave:Enfermedad del hígado graso no alcohólico. Hígado graso. Obesidad. ResumenObjetivo: aunque la enfermedad de hígado graso no alcohólico se identifi có por primera vez en 1980, presenta una fi siopatología multifactorial y mal defi nida. En esta revisión, tenemos la intención de actualizar los mecanismos fi siopatológicos de esta enfermedad con alta morbilidad y mortalidad asociadas que está afectando a niños obesos en todo el mundo. Fuentes de datos: las bases de datos PubMed y la Biblioteca Cochrane se utilizaron en la estrategia de búsqueda de los artículos relacionados con la enfermedad de hígado graso no alcohólico publicados en las últimas tres décadas. Resumen de datos: esta revisión describe el conocimiento actual acerca de los diferentes mecanismos relacionados con la fi siopatología de la enfermedad de hígado graso no alcohólico, con especial énfasis en aspectos histológicos, anatómicos y bioquímicos implicados en el desencadenamiento de la esteatohepatitis y conducentes a la cirrosis. Conclusiones: la investigación clínica y los recursos tecnológicos avanzados han demostrado diversos mecanismos fi siopatológicos determinantes de la enfermedad de hígado graso no alcohólico, tratando de ayudar en su tratamiento y cambiar su curso. AbstractObjective: Although the nonalcoholic fatty liver disease was fi rst identifi ed in 1980, it presents multifactorial and unclear pathophysiology. In this review, we intend to update the pathophysiological mechanisms of a high morbidity and mortality associated disease that is affecting obese children worldwide. Data sources: The PubMed and the Cochrane Library databases were used in the search strategy for articles related to nonalcoholic fatty liver disease and published in the last three decades. Data summary: This review describes the current knowledge on the different mechanisms related to the pathophysiology of nonalcoholic fatty liver disease focused on histological, anatomical and biochemical aspects involved in triggering steatohepatitis and leading to cirrhosis. Conclusions:The clinical research and advanced technological resources demonstrated several determinants pathophysiological mechanisms of nonalcoholic fatty liver disease trying to assist in their treatment and change its natural course.

Hepatic steatosis was prevalent in the group of children and adolescents studied, but was not related to obesity degrees.